2004 WHO Situation Updates - Avian Influenza Archive

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Avian influenza A(H5N1) in humans and poultry in Viet Nam


13 January 2004

Laboratory results received on Sunday have confirmed the presence of avian influenza virus strain A(H5N1) in samples taken from humans. The samples were taken from two children and one adult admitted to hospital with a severe respiratory illness in Hanoi.


Since the end of October, hospitals in Hanoi and surrounding provinces have admitted 14 persons with severe respiratory illness. The cases are in thirteen children and one adult, the mother of a deceased child. To date, eleven of the children and the adult have died.


It is not known whether all of these cases were caused by the same pathogen. At present, there is no evidence that human-to-human transmission has occurred. No reports indicate that health care workers have been infected.


The presence of avian influenza A(H5N1) in samples from three of these cases was confirmed by Hong Kong?s National Influenza Center, which is a member of the WHO Global Influenza Surveillance Network. Samples have also been sent for analysis to Japan?s National Institute for Infectious Diseases, another member of the WHO influenza network. Results are awaited shortly.


WHO is providing support to Vietnamese health authorities in their investigation of the cases and in the prevention of further spread to humans.


Avian influenza strains normally infect birds exclusively.


The first cases of human infection with avian influenza A(H5N1) were identified in 1997 in Hong Kong. The virus infected 18 persons and caused 6 deaths. Genetic studies subsequently linked the outbreak in humans to an outbreak of highly pathogenic avian influenza in poultry. The immediate culling of around 1.5 million poultry in Hong Kong is thought to have averted a larger outbreak in humans.


Other recent outbreaks of avian influenza in humans have caused limited disease. An outbreak of H5N1 in Hong Kong in February 2003 caused 2 cases and 1 death. An outbreak of H7N7 avian influenza in the Netherlands caused the death of one veterinarian in April 2003, and mild illness in 83 humans. Mild cases of avian influenza A(H9N2) in children occurred in Hong Kong in 1999 (two cases) and in mid-December 2003 (one case).


Highly pathogenic avian influenza in poultry

Last week, avian influenza virus A(H5N1) was identified as the cause of an outbreak of highly pathogenic avian influenza in two southern provinces of Viet Nam. To date, the virus, which spreads rapidly and has a mortality in chickens approaching 100%, has resulted in the deaths of 40,000 chickens and the culling of 30,000 more.


The relationship between the human and poultry outbreaks of avian influenza A(H5N1) in Viet Nam is not fully understood at present. WHO and Viet Nam?s Ministry of Health are undertaking investigations to determine the source of the human cases and whether human-to-human transmission has occurred. The situation is also being followed closely by the country?s Ministry of Agriculture and Rural Development.


An outbreak of avian influenza A(H5N1) occurred in South Korea in December 2003. On Monday, Japanese authorities announced the death of 6,000 chickens at a single farm as due to infection with the same strain of the virus. These outbreaks mark the first cases of avian influenza in South Korea, and the first cases in Japan since 1925.


No human cases of infection with the avian influenza virus have been reported in either of these outbreaks.


WHO regards every case of transmission of an avian influenza virus to humans as a cause for heightened vigilance and surveillance. The circulation of highly pathogenic avian influenza viruses in large numbers of poultry in a growing number of countries is of particular concern. Influenza viruses are highly unstable. The co-circulation of highly pathogenic animal viruses with human viruses could create opportunities for different species-specific viruses to exchange genetic material, giving rise to a new influenza virus to which humans would have little, if any, protective immunity.
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Avian influenza A(H5N1) in humans in Viet Nam and poultry in Asia - update


14 January 2004


Investigation of cases of acute respiratory illness are continuing in Viet Nam with support from WHO staff. The investigation has been undertaken in response to concerns over the laboratory confirmation, on Sunday, of the presence of avian influenza virus H5N1 in three patients who died of severe respiratory illness in late December and early January.


The H5N1 strain implicated in the outbreak has now been partially sequenced. All genes are of avian origin, indicating that the virus that caused death in the three confirmed cases had not yet acquired human genes. The acquisition of human genes increases the likelihood that a virus of avian origin can be readily transmitted from one human to another.


Investigations are focusing on the source of infection and possibilities of human-to-human transmission.


An outbreak of highly pathogenic H5N1 avian influenza was detected in southern Viet Nam in the beginning of January. The outbreak is now known to have spread to other provinces in the country. Reports indicate that pigs and ducks have also been infected.


Yesterday, officials in the Republic of Korea announced the spread of H5N1 avian influenza to an additional farm. Japan is also experiencing an outbreak in poultry caused by the H5N1 virus.


In response to these developments, WHO has initiated a series of activities. These include support to national authorities in investigating the outbreaks and enhanced surveillance activities in Asia. WHO has also initiated the development of candidates and reagents for vaccine production, and antigenic and genetic assessments of the H5N1 strain to provide up-to-date diagnostic tests to national influenza centres.


The WHO Global Influenza Network will receive virus and clinical specimens shortly. As a precautionary measure, network laboratories will immediately begin work on the development of a strain that can be used to produce a vaccine.



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Avian influenza A(H5N1) in humans in Viet Nam and in poultry in Asian countries - update 2


16 January 2004


As detailed in a fact sheetissued yesterday, epidemics of highly pathogenic avian influenza, recently reported in some Asian countries, need to be watched very closely because of their potential significance for human health. All reported bird epidemics, in the Republic of Korea, Viet Nam, and Japan, are now known to have been caused by an H5N1 strain of avian influenza viruses.


Earlier this week, laboratory tests confirmed the presence of the H5N1 variant in samples taken from three patients hospitalized with severe respiratory disease in Hanoi, Viet Nam. Today, laboratory tests have confirmed the presence of H5N1 in an additional Vietnamese patient. All four confirmed cases have been fatal.


Several other patients with respiratory illness are under investigation in Hanoi. A case definition of avian influenza in humans is being introduced to facilitate the detection of further cases in Viet Nam, and surveillance is improving as a result.


Apart from its severe impact on bird populations, this H5N1 variant has properties that make it a potential risk to human health of considerable significance. H5N1 virus recently isolated from Asian birds has been shown to mutate rapidly and has a known tendency to acquire genes from influenza viruses affecting other species.


Moreover, the simultaneous occurrence of large and highly fatal outbreaks of H5N1 in birds is considered unprecedented. WHO is concerned that these events may indicate that H5N1 is becoming established in birds in this part of the world. Because comprehensive surveillance to detect all cases in bird species is difficult, the true geographical occurrence of the avian epidemic may not be fully appreciated at present.


The outbreak in Viet Nam is of particular concern as it suggests the presence of many conditions that are known to have favoured the start of influenza pandemics in the past. Foremost among these is the co-circulation of human influenza viruses with an avian strain that is prone to mutate and has high pathogenicity. H5N1 has, on two occasions in the recent past, caused severe disease with high fatality in humans, and has done so again during the past three weeks.


Widespread epidemics in birds increase opportunities for human exposure. Increases in the number of infections in humans increase opportunities for the avian and human strains to exchange genetic material. If a new virus subtype emerges as a result, and if that virus proves capable of spreading easily and sustainably from person to person, then the conditions for the start of an influenza pandemic will have been met.


The H5N1 variant isolated from fatal human cases in Viet Nam was partially sequenced earlier this week. All genes are of avian origin, indicating that the virus had not yet acquired genes from the human influenza virus. The acquisition of such genes increases the likelihood that a virus of avian origin can be readily transmitted from person to person.


In response to these concerns, WHO and its partners have intensified activities needed to reach three main objectives: to reduce death and disease among humans due to H5N1, to reduce opportunities for a new influenza pandemic to emerge, and to initiate urgently needed international and national research. Specific lines of research will allow a better scientific assessment of the significance of ongoing epidemics in birds for human health in affected countries, and possibly elsewhere.


Laboratories in the WHO global influenza network are now conducting studies, at the molecular level, of viruses isolated from infected birds in the different countries, and from the human cases. Such molecular ?detective work? can help identify the origins of currently circulating viruses, determine how they might be related, and thus shed considerable light on how the viruses are evolving.


Despite the seriousness of the current outbreak in humans, WHO believes that it can be controlled, provided decisive measures are taken to eliminate the animal reservoir for human infections. Surveillance for human respiratory disease in this part of the world has been intensified. WHO has alerted countries regarding the need to intensify surveillance for animal infections. Culling of infected or potentially exposed poultry flocks is a standard control measure that has proved effective in halting past epidemics of avian influenza in several countries.


H5N1 is the only one of the 15 subtypes of avian influenza that has, to date, caused severe outbreaks in humans. In Hong Kong in 1997, H5N1 caused disease in 18 persons, of whom 6 died. In February, 2003, H5N1 infected two persons, causing the death of one.


Three incidents of human infection with other avian subtypes, namely H7N7 and H9N2, were documented in 1999 and 2003, but caused only mild illness and altogether only 1 death.


During the 1997 outbreak of H5N1 influenza in humans, the culling ? within three days ? of Hong Kong?s entire poultry population is thought, by many experts, to have averted an influenza pandemic.



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Avian influenza A(H5N1) in humans in Viet Nam - update 3


19 January 2004


Laboratory tests have confirmed a fifth case of H5N1 avian influenza in humans in Viet Nam. The case occurred in an 8-year-old girl who died on 17 January in Hanoi, where she had been hospitalized since 15 January.


All five confirmed cases have been fatal. The first death occurred on 30 December 2003.



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Development of a vaccine effective against avian influenza H5N1 infection in humans - update 4


20 January 2004


The WHO influenza pandemic preparedness plan, issued in 1999, sets out a series of steps to be taken following confirmation of human infection with a new influenza virus subtype not yet spreading from person to person. One of these steps concerns the initiation of research needed for vaccine production.


As a precautionary measure, WHO is moving forward with the procedures needed to rapidly produce a new influenza vaccine capable of protecting humans against the H5N1 strain of avian influenza recently detected in Viet Nam. These procedures have been initiated following mounting concern over 5 laboratory confirmed human cases of H5N1 avian influenza in Hanoi, Viet Nam in recent weeks. All 5 cases were fatal.


The human deaths in Viet Nam coincide with historically unprecedented epidemics, in bird populations, of highly pathogenic H5N1 avian influenza in Viet Nam, the Republic of Korea, and Japan. The epidemic in birds is the first in Japan since 1925, and the first ever documented in Viet Nam and the Republic of Korea.


Prototype viruses for vaccine production are being prepared by laboratories in the WHO Global Influenza Network. Several laboratories in this network have the high-security (biosafety level 3) facilities needed to safely conduct work on a highly pathogenic virus such as H5N1. Prototype viruses are then supplied to manufacturers as the ?seed stock? for vaccine production.


Laboratories in Hong Kong and Japan have isolated the virus from specimens obtained from two of the laboratory confirmed fatal cases in Viet Nam. The virus is now being analysed at the molecular level to obtain information about its origin and its relationship to viruses currently circulating in birds and possibly other animals. These studies will also determine the antigenic and genetic characteristics of the virus that are needed to produce a candidate vaccine.


Using laboratories in the WHO influenza network, and following procedures established by WHO to detect and respond to a new influenza virus subtype, a prototype virus could be made available to vaccine manufacturing companies within about four weeks.


Candidate vaccines were developed last year, by network laboratories in London, UK and Memphis, Tennessee, for protection against the H5N1 virus strain which caused two cases and one death in Hong Kong last February.
If the virus isolated from the fatal cases in Viet Nam proves sufficiently similar to the 2003 H5N1 strain in Hong Kong, the existing candidate vaccines could expedite the availability of a new vaccine. The candidate prototype vaccines have already undergone basic tests to ensure safety and effectiveness, genetic stability, and antigenic homogeneity.


Several steps are needed before a new influenza vaccine can be ready for use in humans. Virus for use in influenza vaccines is grown in chicken eggs. However, because H5N1 is so deadly in chicken embryos, a new technique, known as ?reverse genetics?, is required to prepare the prototype H5N1 virus for vaccine production.


Reverse genetics merges selected genetic information of the virus taken from actual cases with a laboratory virus. The resulting virus is recognized by the human immune system, and causes a protective immune response, but no disease. The virus can also be genetically modified so that it is no longer lethal to chicken embryos. As a further advantage, use of the reverse genetics technique produces a prototype virus with predictable growth during vaccine production.


The prototype virus is then used by manufacturers to produce sample vaccines for clinical testing. WHO will offer support in the coordination of these clinical trials, which are needed to determine the amount of vaccine and number of doses required to confer protection, also in different age groups.


As part of its influenza pandemic preparedness plans, WHO also has in place procedures for making specific recommendations to vaccine manufacturing companies and licensing agencies for the composition and approval of a vaccine during an influenza pandemic.


The WHO Global Influenza Laboratory Network was established in 1947 to guide the yearly composition of influenza vaccines. The oldest disease surveillance network at WHO, it also operates as an early warning system for detecting conditions, including novel viruses, that could give rise to another influenza pandemic. Historically, influenza pandemics have spread rapidly around the world, causing high mortality and affecting all age groups, including young and healthy adults. The most severe pandemic in the previous century, in 1918?1919, killed an estimated 50 million persons.



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Human influenza A/H3N2 activity increases in many countries in central and eastern Europe - update 8


21 January 2004
Summary of global influenza surveillance (to 10 January 2004)

Influenza activity associated with A/Fujian/411/2002-like viruses continued to increase and/or remained widespread in many central and eastern European countries (Austria, Croatia, Latvia, Norway, Russia Federation, Slovenia, Switzerland and Ukraine). Influenza activity also increased in Italy and Japan and remained widespread in some parts of Canada and USA.
Most reported influenza infections this season have been attributed to influenza A(H3N2) viruses. The majority of A(H3N2) viruses antigenically characterized so far have been shown to be A/Fujian/411/2002-like; the others have been A/Panama/2007/99-like.


In Viet Nam there have been 5 laboratory-confirmed cases of infection with A(H5N1) virus . All have died. On Tuesday 6 January, WHO announced influenza pandemic preparedness Phase 0 Level 2


Several countries have reported outbreaks of highly pathogenic influenza A(H5N1) in poultry. This is of great concern as frequent transmission of avian influenza viruses to humans increases the possibility for genetic reassortment with circulating human influenza strains and the possibility of a new influenza pandemic caused by such reassortant viruses. A WHO team has been sent to Viet Nam to investigate the outbreaks and WHO Collaborating Centres for Reference and Research on Influenza and some national reference laboratories are conducting antigenic and genetic analysis of the H5N1 viruses isolated from human and birds during the recent outbreaks in Asia. Results will guide WHO in preparing prototype viruses for pandemic vaccine production and providing diagnostic test kits for H5N1 viruses to national influenza centres.


Reports from individual countries
Austria. An increase in influenza activity was observed in week 2 (4?10 January), although the acute respiratory illness (ARI) consultation rate was still below the epidemic threshold.


Belgium. Influenza A(H3N2) activity continued to decline in week 2, with a fall in both the number of viruses identified and the influenza-like illness (ILI) consultation rate. Regional influenza activity was reported for week 2.


Canada. In week 2, widespread influenza activity continued in Newfoundland, Quebec and Ontario. The overall ILI consultation rate was 40 cases per 1000 consultations, which was within the expected range for the time of year. Of the 490 influenza viruses antigenically characterized by the National Microbiology Laboratory to date, 456 (93%) were A/Fujian/411/2002-like, 25 (5%) were A/Panama/2007/99-like, one was an A/New Caledonia/20/99 (H1N1)-like virus, one was A(H1N2) and 7 (1.4%) were influenza B viruses (1 B/Hong Kong/330/2001-like and 6 B/Sichuan/379/99-like).


Croatia. Influenza A(H3N2) activity continued to increase significantly and was reported as widespread for week 2, with 10 influenza A(H3N2) and 11 A non-subtyped viruses identified.


Denmark. Influenza activity declined in week 2, with the ILI consultation rate dropping below the epidemic threshold.


France. Influenza activity continued to decline throughout France. Widespread influenza A(H3N2) activity was reported in one region for week 2.


Germany. Localized influenza activity was reported for week 2, with 9 influenza A(H3N2) and 9 A non-subtyped viruses identified.


Israel. Influenza activity remained at a low level in week 2, with 7 influenza viruses detected.


Italy. Influenza activity was reported as sporadic, with a slight increase in influenza A(H3N2) activity in week 2.


Japan. Influenza activity increased in week 2, with 37 influenza A(H3N2) viruses detected (compared with 6 in week 1).


Latvia. Influenza A(H3N2) activity increased significantly in week 2, with localized activity reported.


Norway. Influenza activity has been declining gradually since week 51, although significant activity still remained in large parts of the country in week 2. Of 919 influenza A virus detected so far this season, 237 were subtyped as A(H3) and 27 as A(H1). All A(H3) strains antigenically characterized were A/Fujian/411/2002-like and all A(H1) strains were A/New Caledonia/20/99-like. The neuraminidase of recent A(H1N2) viruses was N2.


Romania. Regional influenza activity was reported for week 2, with medium ARI morbidity.


Russia Federation. Widespread influenza activity persisted. In 21 of 34 cities, ILI morbidity exceeded the epidemic threshold by 16.6?127.8% in week 2.


Slovenia. Influenza activity increased significantly in week 2 and was reported as regional.


Sweden. The ILI consultation rate decreased in week 2, with 138 influenza viruses detected. Influenza activity was reported as regional.


Switzerland. In week 2, the ILI consultation rate and the number of influenza viruses detected declined for the first time since the beginning of the recent epidemic phase, although activity remained widespread. All strains antigenically characterized were closely related to influenza A/Fujian/411/2002-like virus.


Ukraine. In week 2, widespread influenza activity was reported in the north and east the country; an increase in activity was observed in the west.


United Kingdom. During week 2 the ILI consultation rate changed little in England, Scotland and Wales but increased slightly in Northern Ireland. The number of specimens decreased following the overall decline in influenza activity. No influenza virus was detected during week 2. Of the viruses antigenically characterized, 172 (97%) have been confirmed as A/Fujian/411/2002-like, 3 as A/Panama/2007/99-like and 2 as B/Hong Kong/330/2001-like.


United States. The overall ILI consultation rate, the number of states reporting widespread influenza activity and the percentage of specimens testing positive for influenza continued to decrease in week 2. However, pneumonia and influenza mortality (10.2%) continued to increase and exceeded the epidemic threshold (8.1%) for the time of year. Widespread influenza activity was reported in 20 states and in New York City, and regional activity was reported in 24 states during week 2. Of the specimens tested, 11.9% were positive for influenza, with 313 influenza A viruses and 6 B viruses identified. Since week 40, the Centers for Disease Control and Prevention in Atlanta have antigenically characterized 2 influenza A(H1) viruses, 511 A(H3N2) viruses and 5 B viruses from the USA. Of the 511 A(H3N2) viruses characterized, 98 (19.2%) were A/Panama/2007/99-like and 413 (80.8%) were A/Fujian/411/2002-like.


Other reports. Low influenza activity was reported in Greece, Guyana, Hong Kong Special Administrative Region of China, Hungary, Morocco and Portugal. Argentina, Australia, Madagascar, Poland and Spain reported no influenza activity.



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Avian influenza H5N1 infection in humans: urgent need to eliminate the animal reservoir - update 5


22 January 2004


Epidemics of highly pathogenic avian influenza, caused by various H5N1 strains, have been reported in parts of Asia since mid-December 2003. Millions of domestic poultry have either died or been destroyed as a result. Thousands of workers have been involved in the culling operations.


The current situation is of serious concern for human health as well as for agriculture and the poultry industry. Rapid elimination of the H5N1 virus in bird populations should be given high priority as a matter of international public health importance.


WHO is collaborating closely, at high levels, with FAO and the World Organisation for Animal Health (OIE) to ensure that appropriate measures in the agricultural sector are introduced as a matter of urgency, and in the interest of protecting public health at the international level. Joint investigations are currently under way in Viet Nam.


Of all the avian influenza viruses, which normally cause infection in birds and pigs only, the H5N1 strain may have a unique capacity to cause severe disease, with high mortality, in humans.


The simultaneous occurrence in several countries of large epidemics of highly pathogenic H5N1 influenza in domestic poultry is historically unprecedented. The present situation may grow worse. In bird populations, the disease is highly contagious and rapidly fatal, and spreads easily from farm to farm. Wild migratory waterfowl can spread infection to domestic flocks. The potential for further spread of ongoing poultry epidemics, both within affected countries and to other countries, is therefore great.


For all these reasons, the H5N1 strain may be more widely established in bird populations and in the environment in this part of the world than presently appreciated. Studies have shown that infected birds can shed large amounts of the virus in their faeces. The virus can survive for long periods in the tissues and faeces of diseased birds and in water, especially when temperatures are low. In water, the virus can survive for up to four days at 22oC and more than 30 days at 0oC. The virus survives in frozen material indefinitely.


The large epidemics of highly pathogenic avian influenza currently seen in poultry, and possible widespread presence of the virus in the environment, increase opportunities for human exposure and infection. They also increase opportunities for human and avian influenza viruses to exchange genes This can occur when humans are simultaneously infected by human and avian influenza viruses. The frequency of such co-infections increases the likelihood that a completely new influenza virus subtype might emerge, carrying sufficient human genes to allow efficient and sustainable person-to-person transmission.


Research has shown that the risk of direct transmission of H5N1 infection from birds to humans is greatest in persons having close contact with live infected poultry. Contact with poultry kept in live markets is considered the source of infection for 17 of the 18 human cases of H5N1 infection that occurred in Hong Kong in 1997. The additional case ? the first in the outbreak ? has been linked to contact with poultry at farms experiencing epidemics of highly pathogenic avian H5N1 influenza. Six of the 18 cases were fatal.


Occupational exposure can occur among poultry workers, and among workers involved in culling operations.


Rapid elimination of the H5N1 virus in animal populations is an essential measure to prevent the emergence of a new influenza virus subtype with pandemic potential. This measure not only helps prevent further spread in bird populations, but also reduces opportunities for human infection. However, in the present situation, the problem of controlling all human exposures is compounded by the large number of ?back yard? farms where chickens are kept in rural areas.


While rapid culling of infected or exposed flocks is strongly recommended, prevention of infection during culling operations must also be given high priority. Culling operations can place large numbers of workers at risk of brief but intensive exposure to the virus.


In 1997, Hong Kong authorities culled the entire poultry population, an estimated 1.5 million birds, within three days. This rapid and comprehensive action is thought by many experts to have averted an influenza pandemic.


Culling operations were performed by trained government workers, most of whom wore protective masks, gloves, and gowns. Although subsequent investigation detected H5 antibodies, indicating exposure to the virus, in around 3% of persons involved in the culling of infected poultry, no case of severe respiratory disease was detected as a result of this exposure.


In the Netherlands in 2003, an outbreak of highly pathogenic H7N7 avian influenza in poultry caused infection, with mild illness, in 89 persons, and fatal illness in a veterinarian. An estimated 30 million poultry were culled within a week.


Further information about highly pathogenic avian influenza is available in a WHO fact sheet, at the FAO web site , and the OIE web site. Information on safety precautions during culling operations will be issued soon by the WHO Regional Office for the Western Pacific.


Laboratory characterization of the 2004 H5N1 viruses
Laboratories in the WHO Global Influenza Surveillance Network have today discussed results from the sequencing and antigenic characterization of H5N1 strains isolated from humans and poultry in Viet Nam. Initial results show significant differences between these viruses and strains obtained during outbreaks of H5N1 avian influenza in Hong Kong, in 1997 and 2003, indicating that the virus has mutated.


Work continues on the updating of WHO diagnostic kits for the rapid detection of H5N1 infection in humans, and on the development of a prototype virus for use in vaccine manufacturing. Viruses from birds in other currently affected countries are urgently needed in order to conduct additional laboratory investigations. Such investigations are part of the information needed by WHO to recommend and develop a vaccine strain that can protect humans against circulating H5N1 strains.
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Avian influenza A(H5N1) in humans in Thailand - update 6


23 January 2004



The Ministry of Public Health in Thailand has today informed WHO of two cases of H5N1 avian influenza in humans. Both cases, which are in children, are laboratory confirmed.


A WHO influenza reference centre in Thailand has been involved in the testing.


The first case is a 7-year-old boy from Suphanburi province who developed fever and cough on 3 January, and progressed to acute respiratory distress syndrome on 13 January. Test results received today have detected the H5N1 avian influenza virus strain in specimens taken from this patient.


The second case is a 6-year-old boy from Kanchanaburi province. He developed fever on 6 January, followed a week later by severe pneumonia with acute respiratory distress syndrome. Test results, made available to the Ministry of Public Health this morning, have detected the H5N1 avian influenza virus strain in specimens taken from this patient.


Both patients are alive.


WHO has also received official information that a 49-year-old man in Nakornsawan province, hospitalized with severe pneumonia, has been treated with antibiotics. His condition is now improving, suggesting that his illness has a bacterial, and not a viral cause.


WHO will be collaborating closely with health authorities in Thailand in responding to this situation.



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Avian influenza A(H5N1)- update 7: Two further cases confirmed in Viet Nam, Overview of the current situation, Implications for food safety


24 January 2004


Two further cases confirmed in Viet Nam
Laboratory tests have confirmed two additional human cases of H5N1 avian influenza in Viet Nam. The cases, both in Ho Chi Minh City, are two children, an 8-year-old girl and a 13-year-old boy. The boy died on 22 January. The girl is hospitalized in stable, but critical condition.


The two cases are the first to be confirmed in the south of the country. They bring the total number of confirmed H5N1 cases in Viet Nam to seven, including five in Hanoi. Of the seven cases in Viet Nam, six (five children and one 30-year old woman) have died since 30 December 2003.


A WHO team is in Viet Nam working closely with health authorities to assess the current situation, conduct epidemiological investigations, and identify the most appropriate control measures.


Overview of the current situation
Yesterday, health authorities in Thailand announced laboratory confirmed H5N1 infection in two boys. Additional patients with respiratory symptoms that might signal H5N1 infection are being tested, and results are expected next week.


At present, Viet Nam and Thailand are the only two countries in which human cases of H5N1 avian influenza are known to have occurred in the current outbreak. The first recorded outbreak of H5N1 infection in humans occurred in Hong Kong in 1997, when 18 persons developed serious disease and six died.


The present human cases in Viet Nam and Thailand coincide with an historically unprecedented spread of highly pathogenic H5N1 avian influenza in the poultry populations of Asian countries. Since mid-December 2003, outbreaks of H5N1 disease in poultry have been confirmed in the Republic of Korea, Viet Nam, Japan, Thailand, and Cambodia. Additional countries have detected deaths in poultry flocks, and the cause is currently under investigation.


In Viet Nam, H5N1 infection in poultry has now been detected in 23 of the country?s 64 provinces. Since 23 December 2003, about 2.9 million poultry stock have either died or been destroyed because of the disease.


WHO has identified the rapid culling of H5N1 infected or exposed poultry as the major line of defence for preventing further human cases and possibly averting the emergence of a new influenza virus capable of causing an influenza pandemic.


At present, WHO has no evidence that person-to-person transmission is occurring.


Laboratories in the WHO Global Influenza Surveillance Network are characterizing avian and human viruses obtained from the current outbreaks. Preliminary results indicate that these viruses are significantly different from other H5N1 strains isolated in Asia in the recent past, thus necessitating the development of a new prototype strain for use in vaccine manufacturing.


Viruses are needed from all areas currently experiencing outbreaks in either infected birds or humans. Information from these viruses will then be used by WHO network laboratories to develop H5N1 prototype strains for vaccine manufacturers. Information about viruses from all outbreak sites is needed to ensure that the vaccine composition recommended by WHO will protect humans against all currently circulating H5N1 strains.


Implications for food safety
Since 1997, when the H5N1 avian influenza virus strain is first known to have caused infections in humans, fewer than 30 laboratory-confirmed cases have been documented worldwide. The 1997 outbreak in Hong Kong has been extensively studied. However, data about this disease in humans and its modes of transmission are limited by the small number of cases.


Investigations of the Hong Kong outbreak determined that close contact with live infected poultry was the source of human infection in all 18 cases. For this reason, the practice of marketing live poultry directly to consumers should be discouraged in areas currently experiencing outbreaks of highly pathogenic H5N1 avian influenza among poultry.


While trade restrictions have been put in place by some countries to protect animal health, on the basis of presently available data, WHO does not conclude that any processed poultry products (whole refrigerated or frozen carcasses and products derived from them) and eggs in or arriving from areas currently experiencing outbreaks of avian influenza H5N1 in poultry flocks pose a risk to public health.


It is well known that influenza viruses are killed by adequate heat. WHO continuously emphasizes, and in this particular situation reiterates, the importance of good hygiene practices during handling of poultry products, including hand washing, prevention of cross-contamination and thorough cooking (70?C).



http://www.who.int/csr/don/2004_01_24/en/print.html

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Avian influenza A(H5N1)- update 8: Situation in Thailand, Advice to international travellers


26 January 2004

Situation in Thailand

The Ministry of Public Health in Thailand has today announced laboratory confirmation of the country?s third human case of H5N1 avian influenza infection. The patient, who remains alive, is a 6-year-old child from Sukhothai province.


Health officials in Thailand have also confirmed the death of a 6-year-old boy from Kanchanaburi province. The boy, whose infection with the H5N1 strain was announced on Friday, died Sunday night. He had been hospitalized in Bangkok with severe pneumonia and acute respiratory distress syndrome.


The other case previously announced in Thailand is a 7-year-old boy from Suphanburi province.


Advice to international travellers
WHO does not at present recommend any restrictions on travel to any country currently experiencing outbreaks of H5N1 avian infection in poultry flocks, including countries which have also reported cases in humans.
At this time, WHO recommends that travellers to areas experiencing outbreaks of this disease in poultry should avoid contact with live animal markets and poultry farms. Large amounts of the virus are known to be excreted in the droppings from infected birds.


Since mid-December, outbreaks of H5N1 infection have been detected in the poultry populations of the Republic of Korea, Japan, Viet Nam, Thailand and Cambodia. Additional countries have detected deaths in poultry flocks, and the cause is currently under investigation.


The outbreak in Japan was limited to a single farm in Yamaguchi Prefecture. The outbreak was reported on 12 January, and no further spread to other farms has been detected. All 34,600 chickens at the infected farm had either died or been destroyed by 20 January.


Some human cases and deaths caused by the same H5N1 virus strain have been reported in two of these countries, Viet Nam and Thailand. Most of these cases have been linked to direct contact with diseased birds. At present, WHO has no information that the disease is spreading from person to person.


Influenza viruses are destroyed by heat. As a precaution, consumers should ensure that all foods from poultry, including eggs, have been thoroughly cooked.



http://www.who.int/csr/don/2004_01_26/en/print.html

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Avian influenza A(H5N1) in humans - update 9: Situation in Thailand, Overview of the current situation


27 January 2004
Situation in Thailand
The Ministry of Public Health in Thailand has today confirmed a second death caused by human infection with the H5N1 strain of avian influenza virus.


The fatal case is a 6-year-old boy from Sukhothai province, whose infection with H5N1 was confirmed yesterday. He died today. He was Thailand?s third confirmed case of H5N1 avian influenza and the country?s second death from this disease.


The other fatal case in Thailand was another 6-year-old boy from Kanchanaburi province. He died on 25 January.


Overview of the current situation
To date, only two countries, Viet Nam and Thailand, have reported laboratory confirmed cases of H5N1 infection in humans. Viet Nam has reported 7 cases, 6 of them fatal. Thailand has reported 3 cases, 2 of them fatal.


The cases and deaths in humans coincide with outbreaks of highly pathogenic H5N1 avian influenza in poultry populations in these two countries and several others in Asia. The disease in poultry is widespread in both Viet Nam and Thailand. WHO teams, drawn from the Global Outbreak Alert and Response Network, are in both countries to support national authorities. Laboratories in the WHO Global Influenza Surveillance Network have been providing diagnostic and investigative support. WHO is collaborating closely with FAO and the World Organisation for Animal Health (OIE).


Over the past few days, several countries in Asia have detected deaths in poultry flocks, and testing to determine the causative agent is under way.
The possible transmission of highly pathogenic H5N1 avian influenza from animals to humans is of great concern. Testing for the presence of this particular strain takes several days and must be performed in specially equipped laboratories.



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Avian influenza A(H5N1) in China - update 10


27 January 2004

The Ministry of Health in China has today confirmed the presence of highly pathogenic H5N1 avian influenza in poultry in the southern province of Guangxi. The H5N1 strain was detected in samples taken from a duck farm.


Testing is under way of samples from poultry outbreaks in the adjacent Hunan and Hubei provinces. Ducks are involved in the outbreak in Hunan, and chickens are involved in Hubei.


Strict measures to control all outbreaks, including culling and quarantine, have been undertaken.


No cases of human illness linked to these outbreaks have been detected to date.



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Avian influenza A(H5N1) in humans - update 11: Note to national authorities, Situation in Viet Nam, Rapid - and safe - culling of infected poultry: the first line of defence for protecting international public health


28 January 2004


Note to national authorities
WHO is concurrently reporting on the outbreaks of H5N1 avian influenza in poultry and human in Asian countries, and normal human influenza activity involving currently circulating H3N2 strains. These two events are separate. Reports on normal influenza activity during seasonal epidemics are regularly and routinely issued by WHO and published in the Weekly Epidemiological Record.

Situation in Viet Nam
Laboratory testing has confirmed an eighth case of human infection with H5N1 avian influenza in Viet Nam. The case is a 4-year-old boy, who fell ill on 22 December 2003 and was hospitalized in Hanoi on 29 December. He has fully recovered and been discharged from hospital.


Altogether, Viet Nam has reported 8 laboratory-confirmed cases, 6 of which have been fatal. An 8-year-old girl, whose infection was reported earlier, remains hospitalized in Ho Chi Minh City.


Two deaths in Viet Nam currently under investigation have been prematurely reported as laboratory confirmed. Test results are inconclusive. Further testing is under way at WHO influenza reference laboratories in Hong Kong. Information from these tests should allow conclusive identification of the causative agent.


To date, highly pathogenic H5N1 avian influenza has been detected in poultry in 28 of the country’s 64 provinces. Around 3.7 million poultry are reported to have died or been slaughtered as a result.

Rapid - and safe - culling of infected poultry: the first line of defence for protecting international public health
As a follow-up to yesterday's joint FAO/WHO press release, WHO has issued a document explaining why the unprecedented recent outbreaks of avian influenza in Asian countries represent a serious threat to international public health. The document also outlines specific measures that should be taken on an urgent basis to prevent further human cases and reduce opportunities for a new pandemic virus to emerge. Foremost among these measures is the rapid - and safe - culling of all infected or exposed poultry in countries experiencing outbreaks of highly pathogenic H5N1 avian influenza.
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Confirmed Human Cases of Avian Influenza A(H5N1)


28 January 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">3</td> <td align="center" width="32%">2</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">8</td> <td align="center" width="32%">6</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">11</td> <td align="center" width="32%">8</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

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Avian influenza A(H5N1) in humans - update 12: Prevention of further cases of H5N1 disease in humans,Investigation of the origins of the current outbreaks in poultry


29 January 2004


Prevention of further cases of H5N1 disease in humans

In response to outbreaks of highly pathogenic H5N1 avian influenza in poultry, several countries are currently conducting the mass slaughter of millions of chickens. Such action is the major line of defence for preventing further human cases of H5N1 infection and possibly averting the emergence of a new influenza virus with pandemic potential.


WHO continues to stress the need for personal protection of these workers, who are at high risk of exposure to a virus that has demonstrated its capacity to cause severe disease and deaths in humans.


Recommendations about safety measures that should be in place before the mass destruction of poultry begins have been issued. Adherence to these recommendations will reduce the likelihood that measures aimed at preventing the further spread of H5N1 infection in poultry might lead to increased transmission of the virus to humans.


Those organizing culling operations in affected countries need to ensure that WHO recommendations are followed as strictly as possible. The recommendations spell out the appropriate personal protective equipment, which includes goggles and preferably N95 respirator masks, as well as specific types of protective clothing that can be either disinfected or discarded after use. Frequent handwashing is strongly recommended.


WHO also recommends that effective antiviral drugs be readily available for the treatment of suspected H5N1 respiratory infections in cullers and farm workers.


N95 masks and prophylactic treatment with antiviral drugs were used to protect thousands of poultry workers and cullers during an outbreak of highly pathogenic H7N7 avian influenza in the Netherlands in 2003. During that outbreak, nearly 30 million poultry were destroyed. Although avian influenza virus caused mild illness in 89 poultry workers and members of their families, the single death in that outbreak occurred in a veterinarian who was not adequately protected.


Investigation of the origins of the current outbreaks in poultry

Countries currently experiencing outbreaks of highly pathogenic H5N1 avian influenza in poultry have provided numerous samples and viruses to laboratories in the WHO Global Influenza Surveillance Network. WHO is grateful for the high level of international collaboration of all affected countries and influenza experts around the world.


Laboratory characterization of several viruses from humans and different species of birds has helped to compare, retrospectively, H5N1 viruses taken from infected birds and humans in January 2004 with viruses obtained from birds several months ago. Results indicate that the virus now causing severe disease in poultry and some humans has been circulating in parts of Asia for longer than initially presumed.


Presently available evidence from these studies is not sufficient to support any speculations about the geographical origins of the current outbreaks of highly pathogenic H5N1 avian influenza.


Up to now, laboratories in the WHO network have analyzed viruses from the current outbreaks made available by authorities in Cambodia, Japan, South Korea, and Viet Nam. Viruses from the outbreaks in Indonesia, Laos, and Thailand are expected to be available for analysis soon.



http://www.who.int/csr/don/2004_01_29/en/print.html




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Confirmed Human Cases of Avian Influenza A(H5N1)


29 January 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">3</td> <td align="center" width="32%">2</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">8</td> <td align="center" width="32%">6</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">11</td> <td align="center" width="32%">8</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2004_01_29/en/print.html


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Avian influenza A(H5N1) - update 13: China confirms spread of infection in poultry, Development of an H5N1 vaccine for humans: need for samples and viruses, Protection of workers involved in culling operations


30 January 2004


China confirms spread of infection in poultry

Health and agricultural authorities in China have today informed WHO of further outbreaks of highly pathogenic H5N1 avian influenza in poultry. The outbreaks, which are laboratory confirmed, have been detected in Hunan and Hubei provinces.


A confirmed outbreak of highly pathogenic H5N1 avian influenza at a duck farm in Guangxi province was announced on 27 January.


As announced today, outbreaks of disease in poultry have also been detected at farms in Anhui, Shanghai, and Guangdong provinces. According to the authorities, highly pathogenic H5N1 avian influenza is the suspected cause. Samples from birds in these outbreaks are being tested, in China, to confirm the causative agent.


Local authorities in the affected provinces have undertaken immediate culling operations and quarantining of farms. Compulsory vaccination of poultry is being introduced.


At present, no human cases of H5N1 infection have been detected in China.


Development of an H5N1 vaccine for humans: need for samples and viruses

With the confirmed spread of H5N1 infection in poultry in China, WHO is again stressing the need for access to samples and viruses from all countries currently experiencing H5N1 outbreaks. Such materials are needed to support laboratory studies being conducted by the WHO Global Influenza Surveillance Network.


Up to now, laboratories in the WHO network have analyzed viruses from the current outbreaks made available by authorities in Cambodia, Japan, the Republic of Korea, and Viet Nam. Viruses from the outbreaks in Indonesia, Laos, and Thailand are expected to be available for analysis soon.


Network laboratories are now working to develop a prototype virus that can be recommended by WHO for use by companies in the production of a human vaccine effective against H5N1 influenza strains. Both human and avian viruses are needed. Information from these viruses will help WHO and its partners ensure that a fully tested and licensed vaccine for humans is available as soon as possible.


Protection of workers involved in culling operations

As more countries announce plans for the mass slaughter of poultry, WHO continues to stress the need for personal protection of these workers. Targeted administration of seasonal influenza vaccine to high-risk groups, such as cullers and poultry workers, is being recommended as one of several measures that reduce opportunities for the emergence of a new influenza virus subtype with pandemic potential. Guidelines for the use of seasonal influenza vaccine in humans at risk of H5N1 infection have been issued today.



http://www.who.int/csr/don/2004_01_30/en/print.html




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Confirmed Human Cases of Avian Influenza A(H5N1)


30 January 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">3</td> <td align="center" width="32%">2</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">8</td> <td align="center" width="32%">6</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">11</td> <td align="center" width="32%">8</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2004_01_30/en/print.html


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Avian influenza A(H5N1) - update 14: Two additional human cases of H5N1 infection laboratory confirmed in Viet Nam,
Investigation of a family cluster


1 February 2004
Two additional human cases of H5N1 infection laboratory confirmed in Viet Nam

Laboratory tests have confirmed an additional 2 cases of human infection with H5N1 avian influenza in Viet Nam. Both have died.


The two deaths announced today were in sisters, aged 23 and 30 years. Both women fell ill on 10 January, were admitted to hospital on 13 January, and died on 23 January. The results from initial local testing of these two cases were inconclusive. Today’s official confirmation follows more extensive testing at a WHO influenza reference laboratory in Hong Kong.
Altogether, 10 cases of human infection with H5N1 avian influenza have been confirmed in Viet Nam. Of these 10 cases, 8 have died, one has recovered and one remains in hospital.


Investigation of a family cluster

The two sisters who died are part of a cluster of four cases of severe respiratory illness in a family from Thai Binh province. The cluster includes the two sisters, their brother, and his wife, who has fully recovered. The brother was hospitalized in Hanoi with a severe respiratory illness on 7 January and died on 12 January. No samples were available for testing.


A detailed investigation of this cluster has been undertaken by WHO, Viet Nam’s National Institute of Hygiene and Epidemiology, and local health officials.


To date, the investigation has not been able to conclusively identify the source of infection for the two sisters. With the exception of this family cluster, all human cases in the Viet Nam outbreak have been linked to contact with infected poultry.


In Hong Kong in 1997, extensive studies, using both molecular and epidemiological data, eventually linked all 18 cases of human H5N1 infection to contact with live infected poultry.


In addition to these 18 cases, WHO notes that laboratory evidence indicated very limited human-to-human transmission during the H5N1 outbreak in Hong Kong, and during a 2003 outbreak of highly pathogenic H7N7 avian influenza in the Netherlands. However, no cases of severe disease in humans occurred as a result of this very limited secondary transmission.


In the current family cluster of cases in Viet Nam, WHO considers that limited human-to-human transmission, from the brother to his sisters, is one possible explanation. The investigation failed to reveal a specific event, such as contact with infected poultry or an environmental source, that might explain the source of infection in these cases. However, as H5N1 infection in poultry is widespread in Viet Nam, direct transmission from poultry to humans cannot be entirely ruled out on the basis of available evidence.


At present, no evidence indicates that efficient human-to-human transmission is occurring in Viet Nam or elsewhere. WHO and health authorities in Viet Nam and globally are continuing to assess the outbreak in terms of its epidemiological evolution. Human cases are being investigated to identify the source of infection, and evidence to date is reassuring.


WHO teams are supporting national investigations in Viet Nam and Thailand, and will arrive soon in other countries that have requested such support.
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Confirmed Human Cases of Avian Influenza A(H5N1)


1 February 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">3</td> <td align="center" width="32%">2</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">10</td> <td align="center" width="32%">8</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">13</td> <td align="center" width="32%">10</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

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Avian influenza A(H5N1) - update 15: Additional confirmed human case in Thailand; China announces suspected spread of infection in poultry; investigation of possible human-to-human transmission


2 February 2004


New human case confirmed in Thailand

Health authorities in Thailand have today announced a new laboratory-confirmed case of human infection with H5N1 avian influenza. The case, a 58-year-old woman, fell ill on 19 January and died on 27 January.


This latest case brings the total of human cases in Thailand to 4, of whom 3 have died.


To date, human cases of H5N1 have been reported only in Thailand and Viet Nam. Both countries have widespread outbreaks of the disease in poultry. The new case in Thailand brings the total number of cases in these two countries to 14, of whom 11 have died.


China announces spread of suspected H5N1 infection in poultry to additional areas

WHO has been informed by Chinese authorities that outbreaks in poultry of highly pathogenic H5N1 avian influenza are suspected in additional parts of the country.


The new suspected poultry outbreaks have been detected at farms in the eastern province of Zhejiang (geese), in the southwestern province of Yunnan (chickens), in the central province of Henan (chickens), and in Xinjiang Uygar Autonomous Region (chickens) in northwestern China.


In addition, further suspected outbreaks have been reported in Hubei (chickens and ducks) and Guangdong (geese) provinces. Both provinces had previously reported outbreaks.


Samples taken from diseased birds at all these sites are now being tested in China for the presence of the H5N1 strain.


Altogether, confirmed or suspected outbreaks of highly pathogenic H5N1 avian influenza have been reported on poultry farms in 10 of China’s 31 provinces, autonomous regions, and municipalities.


The additional areas with outbreaks in poultry, announced last week, are Guangxi, Hunan, Hubei, Shanghai, Guangdong, and Anhui provinces. Of these, highly pathogenic H5N1 avian influenza has been confirmed in Guangxi, Hunan, and Hubei.


No cases of human H5N1 infection have been reported in China to date.


Investigation of possible human-to-human transmission

WHO has investigated a cluster of respiratory illness in members of a family from Thai Binh province, Viet Nam. The cluster involves a 31-year-old man, his two sisters, aged 23 and 30 years, and his 28-year-old wife. Both the man and his two sisters have died. The wife has fully recovered. Laboratory tests received over the weekend have confirmed H5N1 infection in the sisters. Neither the man nor his wife was tested.


The family members gathered in late December to prepare for the man’s wedding on 3 January. Both the man and one sister are reported to have handled ducks while preparing a meal on 4 January. However, the investigation failed to reveal any direct contact with poultry for the man’s other sister and his wife.


In the absence of evidence of direct exposure to poultry in these two cases, WHO epidemiologists are considering various alternative explanations. Both sisters are known to have provided health care for their brother, prior to his hospitalization, and would thus have had opportunities for close exposure. Direct human-to-human transmission following this close exposure is thus one possible explanation.


However, contact with an infected bird, or some other environmental source of the virus, is another possible route of infection that has not been ruled out. Outbreaks of H5N1 in poultry are widespread in Viet Nam. Large amounts of the virus are excreted in bird droppings, and can survive for some time in the environment.


Limited human-to-human transmission of a highly pathogenic avian influenza virus is not entirely unexpected, as this has been documented to have occurred on two occasions in the recent past (in Hong Kong in 1997 and in the Netherlands in 2003).


Local authorities report that no other family members or wedding guests developed an illness. No illness has been detected in members of the community where the wedding was held, or in health staff involved in care of these cases.


WHO stresses the need to continue to investigate each human case of H5N1 in order to identify the source of infection.



http://www.who.int/csr/don/2004_02_02/en/print.html




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Confirmed Human Cases of Avian Influenza A(H5N1)


2 February 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">4</td> <td align="center" width="32%">3</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">10</td> <td align="center" width="32%">8</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">14</td> <td align="center" width="32%">11</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2004_02_02/en/print.html


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Avian influenza A(H5N1) - update 16: Situation in Viet Nam


3 February 2004

The Ministry of Health in Viet Nam has today officially confirmed three additional cases, including one fatality, of avian influenza H5N1 infection in humans.


Two of the newly reported cases, a 19-year-old man and a 20-year-old woman, have been under treatment at a hospital in Hanoi. The 19-year-old man has recovered and the 20-year-old woman remains hospitalized.


The third case, which was fatal, was in an 18-year-old man who died on 2 February at a hospital in Ho Chi Minh City. He is the country’s first confirmed case from the Central Highlands area.


These newly reported cases bring the number of laboratory confirmed H5N1 cases in Viet Nam to 13. Of these, nine have died, two remain hospitalized, and two have recovered.


Authorities in Viet Nam have reported that 52 of the country’s 64 provinces have now detected outbreaks of highly pathogenic H5N1 avian influenza in poultry.



http://www.who.int/csr/don/2004_02_03/en/print.html




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Confirmed Human Cases of Avian Influenza A(H5N1)


3 February 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">4</td> <td align="center" width="32%">3</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">13</td> <td align="center" width="32%">9</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">17</td> <td align="center" width="32%">12</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2004_02_03/en/print.html

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Avian influenza A(H5N1) - update 17:
Situation (human) in Thailand and (poultry) in China, Indonesia and Worldwide


4 February 2004
Situation (human) in Thailand

The Ministry of Public Health in Thailand has announced the death, on 3 February, of a previously confirmed case of H5N1 infection. This latest death was in a 6-year-old boy from Suphanburi province
To date, Thailand has reported 4 laboratory confirmed cases of H5N1 in humans. All have died.


Situation (poultry) in China

Authorities in China have confirmed suspected outbreaks of H5N1 avian inflenza in poultry at farms in an additional two provinces, Gansu and Shaanxi. To date, confirmed or suspected outbreaks of highly pathogenic H5N1 avian influenza have been reported at poultry farms in 12 of the country’s 31 provinces, autonomous regions, and municipalities.


Situation (poultry) in Indonesia

The outbreak of suspected avian influenza in poultry, previously announced by Indonesian authorities, has now been confirmed as caused by the H5N1 strain.


Situation (poultry) worldwide

Full details on poultry outbreaks are available at the OIE website.
To date, outbreaks in poultry caused by the H5N1 strain have been confirmed in the following countries (listed in order of reporting):

• Republic of Korea (12 December 2003 – first outbreak of this disease ever reported)
• Viet Nam (8 January 2004 – first outbreak of this disease ever reported)
• Japan (12 January 2004 – first outbreak of this disease since 1925)
• Thailand (23 January 2004 – first outbreak of this disease ever reported)
• Cambodia (24 January 2004)
• China (27 January 2004)
• Laos (27 January 2004 – H5 confirmed, testing for H5N1 under way)
• Indonesia (2 February 2004 – first outbreak of this disease ever reported)

Two other areas (Taiwan, China and Pakistan) have reported outbreaks of avian influenza in poultry. However, tests have confirmed that these outbreaks are not caused by the H5N1 strain.


In addition, authorities in Hong Kong SAR have reported H5N1 in a single peregrine falcon found dead on 19 January. In Hong Kong, monitoring of diseases in both wild and domestic birds is systematic and efficient. No other cases of H5N1 infection have been detected.



http://www.who.int/csr/don/2004_02_04/en/print.html




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Confirmed Human Cases of Avian Influenza A(H5N1)


4 February 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">4</td> <td align="center" width="32%">4</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">13</td> <td align="center" width="32%">9</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">17</td> <td align="center" width="32%">13</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2004_02_04/en/print.html


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[MHSC]

Re: WHO Situation Updates - Avian Influenza Archive

Re: WHO Situation Updates - Avian Influenza Archive

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Avian influenza A(H5N1) - update 18:
FAO/OIE/WHO Technical Consultation on the Control of Avian Influenza, Situation (human) in Thailand and Viet Nam


5 February 2004


Situation (human) in Viet Nam

The Ministry of Health in Viet Nam has informed WHO that two additional cases of H5N1 infection in humans have been confirmed. Both cases were fatal.


The two cases were in young women, aged 16 and 17 years, from the southern part of the country. Both were treated at hospitals in Ho Chi Minh City. The 16-year-old woman died on 3 February. The 17-year-old woman died on 27 January.


These cases bring the number of laboratory confirmed H5N1 infections in Viet Nam to 15. Of these, 11 have died, two remain hospitalized, and two have recovered.


Situation (human) in Thailand

The Ministry of Public Health in Thailand has confirmed the country’s fifth human case of H5N1 infection. The case, a six-year-old boy from Kanchanaburi Province, developed illness on 24 January and died on 2 February.


All five laboratory-confirmed cases in Thailand have been fatal.


FAO/OIE/WHO Technical Consultation on the Control of Avian Influenza

(Rome, 3–4 February 2004)
Several conclusions and recommendations made during this consultation strengthen WHO recommendations for protecting humans from the consequences of widespread outbreaks of highly pathogenic H5N1 avian influenza in poultry in several Asian countries.


Experts at the consultation recognized the need for immediate application of measures to prevent human infection in groups, notably poultry workers and cullers, at high risk of exposure to the H5N1 avian influenza virus. Personal protective equipment should be available for persons in these groups, who also need training in the proper use of this equipment. WHO has issued guidelines for the protection of cullers.


The experts further recognized the need to reduce opportunities for the simultaneous infection of humans with H5N1 and human strains of influenza virus. Such dual infections give the avian and human viruses opportunities to exchange genes, possibly resulting in the emergence of a new influenza virus subtype. The consultation recommended that poultry workers, who can experience intensive exposures, be given the existing seasonal influenza vaccine. (The vaccine protects against infection with currently circulating human influenza viruses, but does not protect against H5N1 infection). WHO has issued guidelines for the targeted administration of seasonal vaccines.


WHO priorities for responding to the current situation include rapid control of the animal reservoir of H5N1, as doing so reduces the risk of both more cases and deaths in humans and more opportunities for a new subtype of the influenza virus to emerge. Recommendations from the consultation also support this priority.


The consultation concluded that culling, or “stamping out”, of infected flocks remains the preferred option for controlling H5N1 outbreaks in poultry. However, the present outbreaks in poultry are historically unprecedented in their scale, geographical spread, and devastating economic consequences for both the poultry industry and rural farmers.


While culling remains the preferred option for infected flocks, targeted vaccination of healthy poultry can be used as a complementary tool for achieving the rapid reduction of the risk posed by the H5N1 virus in its avian host – an objective which supports both elimination of the disease in poultry and prevention of further human cases and deaths.


Vaccination alone will not be sufficient to bring the present outbreaks in poultry under control.


Experts at the consultation stressed that, where vaccination is being considered as a complementary control tool, it must be used in conjunction with a comprehensive strategy that includes culling of all diseased or exposed poultry, strict biosecurity, quarantine, and other measures aimed at preventing further spread of the disease.



http://www.who.int/csr/don/2004_02_05/en/print.html




<hr style="border: 1px none ; height: 1px; background-color: rgb(0, 0, 0); width: 759px;" align="left">
Confirmed Human Cases of Avian Influenza A(H5N1)


5 February 2004

<table border="1" cellspacing="0" width="79%"> <tbody><tr> <td width="31%">

Country/Territory​

</td> <td width="37%">

Total cases​

</td> <td width="32%">

Deaths​

</td> </tr> <tr> <td width="31%">Thailand</td> <td align="center" width="37%">5</td> <td align="center" width="32%">5</td> </tr> <tr> <td width="31%">Viet Nam</td> <td align="center" width="37%">15</td> <td align="center" width="32%">11</td> </tr> <tr> <td width="31%">Total</td> <td align="center" width="37%">20</td> <td align="center" width="32%">16</td> </tr> </tbody></table> Notes

Total number of cases includes number of deaths.
WHO reports only laboratory-confirmed cases.

http://www.who.int/csr/disease/avian_influenza/country/cases_table_2004_02_05/en/print.html

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