sharon sanders
Editor-in-Chief & President
Influenza at the human-animal interface Summary and assessment as of 6 January 2015
Human infection with avian influenza A(H5N1) viruses
From 2003 through 6 January 2015, 694 laboratory-confirmed human cases of avian influenza A(H5N1)
virus infection have been officially reported to WHO from 16 countries. Of these cases, 402 have died.
Since the last WHO Influenza update on 4 December 2014, 18 new laboratory-confirmed human cases of
avian influenza A(H5N1) virus infection, including four fatal cases, were reported to WHO from Egypt.
Two cases had onset of disease in November 2014, the others had onset of disease in December 2014.
The cases were reported from eight different governorates of Egypt (see table 1). There was one cluster
reported which included two confirmed cases in siblings from Giza governorate and one probable case in
the siblings' mother who died from acute respiratory syndrome but was not tested for the avian
influenza A(H5N1) virus. The investigation of this cluster is ongoing. All cases had exposure to sick or
dead poultry. Identification of such sporadic human cases or small clusters are not unexpected as avian
influenza A(H5N1) viruses are known to be circulating in poultry in the country.
Currently, there are reports of an increased number of outbreaks and detections of influenza A(H5N1)
viruses in poultry in Egypt compared to previous months and compared to this month in previous years.
This is the highest number of laboratory-confirmed human cases of avian influenza A(H5N1) virus
infection reported by Egypt in a single month. Although all influenza viruses evolve over time,
preliminary laboratory investigation has not detected major genetic changes in the viruses isolated from
the patients or animals compared to previously circulating isolates. The increase in reported human
cases is likely a consequence of several factors. These includes increased circulation of influenza A(H5N1)
viruses in poultry, lower public health awareness of risks in middle and upper Egypt and seasonal factors
such as closer proximity to poultry and longer survival of the viruses in the environment because of cold.
Epidemiological and virological investigation in humans and animals is ongoing.
Overall public health risk assessment for avian influenza A(H5N1) viruses: Whenever avian influenza
viruses are circulating in poultry, sporadic infections or small clusters of human cases are possible in
people exposed to infected poultry or contaminated environments, especially in households. Human
infections remain rare and these influenza A(H5N1) viruses do not currently appear to transmit easily
among people. As such, the risk of community-level spread of these viruses remains low.
Human infection with other non-seasonal influenza viruses
Human infection with avian influenza A(H5N6) viruses
China reported a human infection with an influenza A(H5N6) virus in a 58-year-old man from Guangdong
province. He developed symptoms on 4 December 2014 and was admitted to hospital on 9 December
and is now in critical condition. The patient had a history of exposure to live poultry. No further cases
among contacts were reported.
This is the second time a human infection with influenza A(H5N6) has been detected. The first case was
detected in April 2014 in a patient in Sichuan province, China. The first case also likely acquired the
infection from exposure to infected poultry. Outbreaks of illness and deaths in poultry due to highly
pathogenic A(H5N6) avian influenza viruses have been reported to OIE from China, Lao People?s
Democratic Republic and Viet Nam in the last year.
Overall public health risk assessment for avian influenza A(H5N6) viruses: This human case appears also
to be an isolated case, but given that the virus seems to be circulating widely in poultry, further sporadic
human cases or small clusters of infection would not be unexpected. More information is sought and
close monitoring of the situation in humans and animals over the coming months is needed to better
understand the risks H5N6 viruses pose to public health.
Human infections with avian influenza A(H7N9) viruses in China
WHO is closely monitoring this event and separate risk assessments have been posted. Please find the
most updated information at
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/Risk_Assessment/en/index.ht
ml
http://www.who.int/csr/don/30-december-2014-avian-influenza/en/
Outbreaks in animals with avian influenza viruses with potential public health impact
The number of reported outbreaks of avian influenza in birds globally is currently at the level expected
during this period of the year, although novel strains of various subtypes have been detected for the first
time in birds in new geographic regions.
Owing in part to the emergence of avian influenza A(H7N9) virus, there is enhanced surveillance for nonseasonal
influenza viruses (those that are not currently circulating widely in human populations) in both
humans and animals. It is expected that influenza A(H5N1) and A(H7N9) virus infections in humans and
animals will continue to be reported over the coming months. In addition, various other subtypes, such
as influenza A(H5N8), A(H5N2), and A(H5N3) have recently been detected in poultry in Europe, North
America, and Asia, according to reports received by OIE. Although influenza A(H5N8) might have the
potential to cause disease in humans, so far no human cases of infection have been reported.
Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of
global surveillance to detect virological, epidemiological and clinical changes associated with circulating
influenza viruses that may affect human (or animal) health, especially over the coming winter months.
All human infections with non-seasonal influenza viruses are reportable to WHO under the IHR (2005). It
is critical that influenza viruses from animals and people are fully characterized in appropriate animal or
human health influenza reference laboratories and reported according to international standards.
Links:
WHO human-animal interface web page
http://www.who.int/influenza/human_animal_interface/en/
Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO
http://www.who.int/influenza/human_animal_interface/EN_GIP_LatestCumulativeNumberH5N1cases.pdf
Avian influenza A(H7N9) information
http://who.int/influenza/human_animal_interface/influenza_h7n9/en/index.html
World Organisation of Animal Health (OIE) web page: Web portal on Avian Influenza
http://www.oie.int/animal-health-in-the-world/web-portal-on-avian-influenza/
Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza
http://www.fao.org/avianflu/en/index.html
OFFLU
http://www.offlu.net/index.html
http://www.who.int/influenza/human_...ummary_IRA_HA_interface_6January2015.pdf?ua=1
Human infection with avian influenza A(H5N1) viruses
From 2003 through 6 January 2015, 694 laboratory-confirmed human cases of avian influenza A(H5N1)
virus infection have been officially reported to WHO from 16 countries. Of these cases, 402 have died.
Since the last WHO Influenza update on 4 December 2014, 18 new laboratory-confirmed human cases of
avian influenza A(H5N1) virus infection, including four fatal cases, were reported to WHO from Egypt.
Two cases had onset of disease in November 2014, the others had onset of disease in December 2014.
The cases were reported from eight different governorates of Egypt (see table 1). There was one cluster
reported which included two confirmed cases in siblings from Giza governorate and one probable case in
the siblings' mother who died from acute respiratory syndrome but was not tested for the avian
influenza A(H5N1) virus. The investigation of this cluster is ongoing. All cases had exposure to sick or
dead poultry. Identification of such sporadic human cases or small clusters are not unexpected as avian
influenza A(H5N1) viruses are known to be circulating in poultry in the country.
Currently, there are reports of an increased number of outbreaks and detections of influenza A(H5N1)
viruses in poultry in Egypt compared to previous months and compared to this month in previous years.
This is the highest number of laboratory-confirmed human cases of avian influenza A(H5N1) virus
infection reported by Egypt in a single month. Although all influenza viruses evolve over time,
preliminary laboratory investigation has not detected major genetic changes in the viruses isolated from
the patients or animals compared to previously circulating isolates. The increase in reported human
cases is likely a consequence of several factors. These includes increased circulation of influenza A(H5N1)
viruses in poultry, lower public health awareness of risks in middle and upper Egypt and seasonal factors
such as closer proximity to poultry and longer survival of the viruses in the environment because of cold.
Epidemiological and virological investigation in humans and animals is ongoing.
Overall public health risk assessment for avian influenza A(H5N1) viruses: Whenever avian influenza
viruses are circulating in poultry, sporadic infections or small clusters of human cases are possible in
people exposed to infected poultry or contaminated environments, especially in households. Human
infections remain rare and these influenza A(H5N1) viruses do not currently appear to transmit easily
among people. As such, the risk of community-level spread of these viruses remains low.
Human infection with other non-seasonal influenza viruses
Human infection with avian influenza A(H5N6) viruses
China reported a human infection with an influenza A(H5N6) virus in a 58-year-old man from Guangdong
province. He developed symptoms on 4 December 2014 and was admitted to hospital on 9 December
and is now in critical condition. The patient had a history of exposure to live poultry. No further cases
among contacts were reported.
This is the second time a human infection with influenza A(H5N6) has been detected. The first case was
detected in April 2014 in a patient in Sichuan province, China. The first case also likely acquired the
infection from exposure to infected poultry. Outbreaks of illness and deaths in poultry due to highly
pathogenic A(H5N6) avian influenza viruses have been reported to OIE from China, Lao People?s
Democratic Republic and Viet Nam in the last year.
Overall public health risk assessment for avian influenza A(H5N6) viruses: This human case appears also
to be an isolated case, but given that the virus seems to be circulating widely in poultry, further sporadic
human cases or small clusters of infection would not be unexpected. More information is sought and
close monitoring of the situation in humans and animals over the coming months is needed to better
understand the risks H5N6 viruses pose to public health.
Human infections with avian influenza A(H7N9) viruses in China
WHO is closely monitoring this event and separate risk assessments have been posted. Please find the
most updated information at
http://www.who.int/influenza/human_animal_interface/influenza_h7n9/Risk_Assessment/en/index.ht
ml
http://www.who.int/csr/don/30-december-2014-avian-influenza/en/
Outbreaks in animals with avian influenza viruses with potential public health impact
The number of reported outbreaks of avian influenza in birds globally is currently at the level expected
during this period of the year, although novel strains of various subtypes have been detected for the first
time in birds in new geographic regions.
Owing in part to the emergence of avian influenza A(H7N9) virus, there is enhanced surveillance for nonseasonal
influenza viruses (those that are not currently circulating widely in human populations) in both
humans and animals. It is expected that influenza A(H5N1) and A(H7N9) virus infections in humans and
animals will continue to be reported over the coming months. In addition, various other subtypes, such
as influenza A(H5N8), A(H5N2), and A(H5N3) have recently been detected in poultry in Europe, North
America, and Asia, according to reports received by OIE. Although influenza A(H5N8) might have the
potential to cause disease in humans, so far no human cases of infection have been reported.
Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of
global surveillance to detect virological, epidemiological and clinical changes associated with circulating
influenza viruses that may affect human (or animal) health, especially over the coming winter months.
All human infections with non-seasonal influenza viruses are reportable to WHO under the IHR (2005). It
is critical that influenza viruses from animals and people are fully characterized in appropriate animal or
human health influenza reference laboratories and reported according to international standards.
Links:
WHO human-animal interface web page
http://www.who.int/influenza/human_animal_interface/en/
Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO
http://www.who.int/influenza/human_animal_interface/EN_GIP_LatestCumulativeNumberH5N1cases.pdf
Avian influenza A(H7N9) information
http://who.int/influenza/human_animal_interface/influenza_h7n9/en/index.html
World Organisation of Animal Health (OIE) web page: Web portal on Avian Influenza
http://www.oie.int/animal-health-in-the-world/web-portal-on-avian-influenza/
Food and Agriculture Organization of the UN (FAO) webpage: Avian Influenza
http://www.fao.org/avianflu/en/index.html
OFFLU
http://www.offlu.net/index.html
http://www.who.int/influenza/human_...ummary_IRA_HA_interface_6January2015.pdf?ua=1