Mexico - WHO: Fatal H5N2 Infection In Mexico City + Mexican MOH Statement - June 5, 2024 - Mexico denies - WHO update June 14, 2024

[Michael Coston]

WHO: Fatal H5N2 Infection In Mexico City



Credit Wikipedia


#18,103


We've a late afternoon announcement from the WHO regarding a fatal H5N2 infection (onset began in April) of a 59 year-old resident with several preexisting conditions. This is the first confirmed human infections with this subtype, although seroconversion has been observed in poultry workers (see Taiwan: Three Poultry Workers Show H5N2 Antibodies).

Unfortunately, two of the main details we'd like to see in a case like this are not provided in today's report.

• Is this an HPAI H5N2 virus, or is it LPAI? Both have been reported in Mexico recently (see last March Mexico Reports HPAI H5N2 For the 1st Time in Nearly 30 Years)

• What clade of H5 is this virus? Is it clade 2.3.4.4b, like the H5N1 viruses that have dominated recently? Or is it a different lineage?

It may be that the full genome of the virus was not recoverable, or that those tests are still pending. Hopefully we'll be getting more details sooner rather than later.


But either way, this is another milestone for H5 influenza, in a year where they seem to be happening with increasing regularity.

Avian Influenza A (H5N2) - Mexico
5 June 2024

Situation at a glance

On 23 May 2024, the Mexico International Health Regulations (IHR) National Focal Point (NFP) reported to PAHO/WHO a confirmed fatal case of human infection with avian influenza A(H5N2) virus detected in a resident of the State of Mexico who was hospitalized in Mexico City.

This is the first laboratory-confirmed human case of infection with an influenza A(H5N2) virus reported globally and the first avian H5 virus infection in a person reported in Mexico.

Although the source of exposure to the virus in this case is currently unknown, A(H5N2) viruses have been reported in poultry in Mexico. According to the IHR (2005), a human infection caused by a novel influenza A virus subtype is an event that has the potential for high public health impact and must be notified to the WHO. Based on available information, WHO assesses the current risk to the general population posed by this virus as low.
Description of the situation

On 23 May 2024, the Mexico IHR NFP reported to PAHO/WHO a confirmed case of human infection with avian influenza A(H5N2) virus detected in a 59-year-old resident of the State of Mexico who was hospitalized in Mexico City and had no history of exposure to poultry or other animals. The case had multiple underlying medical conditions. The case’s relatives reported that the case had already been bedridden for three weeks, for other reasons, prior to the onset of acute symptoms.

On 17 April, the case developed fever, shortness of breath, diarrhoea, nausea and general malaise. On 24 April, the case sought medical attention, was hospitalized at the National Institute of Respiratory Diseases “Ismael Cosio Villegas” (INER per its acronym in Spanish) and died the same day due to complications of his condition.

Results from Real-Time Polymerase Chain Reaction (RT-PCR) of a respiratory sample collected and tested at INER on 24 April indicated a non-subtypeable influenza A virus. On 8 May, the sample was sent for sequencing to the Laboratory of Molecular Biology of Emerging Diseases Center for Research in Infectious Diseases (CIENI per its acronym in Spanish) of INER, which indicated that the sample was positive for influenza A(H5N2). On 20 May, the sample was received at the Institute of Epidemiological Diagnosis and Reference (InDRE per its acronym in Spanish) of the Mexico National Influenza Centre, for analysis by RT-PCR, obtaining a positive result for influenza A. On 22 May, sequencing of the sample confirmed the influenza subtype was A(H5N2).

No further cases were reported during the epidemiological investigation. Of the 17 contacts

Public health response

Local and national health authorities implemented the following public health measures:

• Epidemiological investigation of case and contacts.
• Monitoring of health care workers with a history of contact with the patient.
• Monitoring and surveillance of influenza-like respiratory illness (ILI) and severe acute respiratory illness (SARI) in neighbouring municipalities (within the same health region), in order to analyze the behaviour and trends of respiratory syndromes and viruses in the region.
• Analysis of the trends of pneumonia and bronchopneumonia, acute respiratory infections, and conjunctivitis by the health services of Mexico City and the State of Mexico.
• Identification of transmission chains and risk factors in the municipality where the case resided, the State of Mexico and surrounding areas.
• Training on the National Guide for preparedness, prevention and response to an outbreak or zoonotic influenza event at the animal-human interface.
• Communicated with animal and environmental health authorities to strengthen surveillance activities in poultry and wild birds near the case's residence and areas with a history of low pathogenic avian influenza A(H5N2) outbreaks.

PAHO/WHO implemented the following measures:

• Strengthening routine and event surveillance on the human-animal interface with WHO Collaborating Centers and strategic partners.
• Improvement of molecular diagnostic capacity for detection of zoonotic diseases through knowledge transfer, training and technical support with recent emphasis in avian influenza A(H5N1)
• Strengthening national capacity for the prompt shipment of human and animal samples to WHO collaborating centers for additional characterization and/or vaccine composition analysis.
• Regular risk assessment for transmissibility and severity for zoonotic viruses.
• Update of guidelines on influenza surveillance and response at the human-animal interface.
• Revision of experiences in response and lessons learned from countries that experienced zoonotic influenza outbreaks.
• Technical strengthening of risk communication capacities for events at the human-animal interface.
• Clinical management training on zoonotic influenza treatment, infection prevention and control (IPC), and reorganization of health services.
• Animal carcass handling training, including IPC technical aspects.
• PAHO published recommendation

WHO risk assessment

This is the first laboratory-confirmed human case of infection with an influenza A(H5N2) virus reported globally, and the first A(H5) virus infection in a person reported in Mexico. The case had multiple underlying conditions, and the investigation by the health authorities in Mexico is ongoing to determine the likely source of exposure to the virus. Influenza A(H5N2) viruses have been detected in poultry in Mexico recently.

Whenever avian influenza viruses are circulating in poultry, there is a risk for infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. Human cases of infection with other H5 subtypes including A(H5N1), A(H5N6) and A(H5N8) viruses have been reported previously. Available epidemiological and virological evidence suggests that A(H5) viruses from previous events have not acquired the ability to sustain transmission between humans, thus the current likelihood of sustained human-to-human spread is low. According to the information available thus far, no further human cases of infection with A(H5N2) associated with this case have been detected.

There are no specific vaccines for preventing influenza A(H5) virus infection in humans. Candidate vaccines to prevent A(H5) infection in humans have been developed for pandemic preparedness purposes. Close analysis of the epidemiological situation, further characterization of the most recent viruses (in human and birds) and serological investigations are critical to assess associated risks and to adjust risk management measures in a timely manner.

Based on the available information, WHO assesses the current risk to the general population posed by this virus to be low. If needed, the risk assessment will be reviewed should further epidemiological or virological information, including information on A(H5N2) viruses detected in local animal populations, become available.

(Continue . . . )

https://afludiary.blogspot.com/2024/...xico-city.html

[Michael Coston]

Mexico: MOH Statement on Fatal H5N2 Infection In Mexico City




#18,105

Overnight the Mexican Ministry of Health published a lengthy report on the world's first confirmed H5N2 case announced yesterday afternoon by the World Health Organization (see WHO: Fatal H5N2 Infection In Mexico City).

While the bulk of this statement revolves around the steps being taken by government and its agencies to protect the public, and reassurances that this single case poses a very low risk to the public, there are a couple of new pieces of information provided.

• First, we learn that the patient was male, with a history of `chronic kidney disease, type 2 diabetes, and long-standing systemic arterial hypertension'.

• Second, they describe the virus as a `low pathogenicity avian influenza A (H5N2)', although no other characterization of the virus is provided.

While their statement emphasizes that "It is important to note that, during a thorough epidemiological investigation, all samples from identified contacts have tested negative.", the timeline provided yesterday by the WHO indicates there were substantial delays in identifying the virus, and in conducting contact tracing and testing.

• The patient died in the hospital on April 24th, but H5N2 wasn't identified until two weeks later (May 8th)
• Notification of WHO/PAHO occurred on May 23rd, two weeks after the H5N2 test results were obtained
• Samples were collected from contacts at the hospital on May 27 & 28, 3 weeks after H5N2 had been identified, and 5 weeks after the index patient died. While some were reportedly mildly symptomatic post exposure - all tested negative - although serological tests are still pending

This timeline illustrates (again) how difficult picking up novel flu infections can be - even in a big city hospital, and during a time of increased awareness. As to the delays following the initial identification of the virus, no details are provided.

A little over a year ago, a study from the UK HSA (see UK Novel Flu Surveillance: Quantifying TTD) estimated the TTD (Time To Detect) a novel H5N1 virus in the community via passive surveillance could take weeks, and the virus might only be picked up after hundreds or possibly even thousands of infections.

We are left with more questions than answers at this point, since the source of this infection remains unknown. While poultry workers have shown antibodies to H5N2, this is the first time human illness has been linked to this particular subtype.

We'll need to learn good deal more about this particular subtype, and how it may differ from past H5N2 viruses, before we can make any reasonable guesses about the threat it may (or may not) pose.

For now, it is fair to say that H5 influenza continues to surprise, and that we should expect more twists and turns in the days, weeks, and months ahead.

(translated)

Ministry of Health reports that there is no risk for the population following the detection of the first human case of avian influenza A (H5N2)

To date, no further cases have been identified in humans.

Ministry of Health | June 5, 2024 | National

It is a viral disease that affects wild and domestic birds.

• WHO considers that the public health risk of this virus for the general population is low.
• Health, Semarnat and Agriculture implement immediate actions in the context of One Health
• All tests from contacts identified with the case study are negative
• In the context of international epidemiological surveillance, WHO/PAHO was notified

The Ministry of Health reports that there is no risk of contagion for the population with the detection of the first human case of low pathogenicity avian influenza A (H5N2) in Mexico. Since there is no identified source of infection, the investigation continues.

The case was recorded in a 59-year-old man, with a history of chronic kidney disease, type 2 diabetes, and long-standing systemic arterial hypertension, residing in the State of Mexico. After several days of symptoms, on April 24 he was hospitalized and the same day he died at the “Ismael Cosío Villegas” National Institute of Respiratory Diseases (INER).

The patient's sample tested positive for influenza type A and the type of influenza he was suffering from was not identified in the first instance.

This sample, initially studied in the Laboratory of Molecular Biology of Emerging Diseases of the Center for Research in Infectious Diseases (Cieni) of the INER, was sent to the Institute of Epidemiological Diagnosis and Reference (InDRE), confirming the positivity to low pathogenicity influenza type A (H5N2).

It is important to note that, during a thorough epidemiological investigation, all samples from identified contacts have tested negative.

Once the reference case was identified, the following actions were immediately implemented in the context of the One Health strategy promoted by the WHO:

The One Health group includes, on behalf of the Ministry of Health, holders or representatives of the National Committee for Epidemiological Surveillance (Conave), the National Center for Preventive Programs and Disease Control (Cenaprece), and the Operational Center for Contingency Care. (Copac), General Directorate of Health Promotion (DGPS), National Center for Child and Adolescent Health (Censia), General Directorate of Health Information (DGIS), General Directorate of Epidemiology (DGE-InDRE) , and the Regulatory Center for Medical Emergencies (CRUM).

On the part of Agriculture, the National Service for Agri-Food Health, Safety and Quality (Senasica) participates, and the National Commission of Protected Natural Areas (Conanp) collaborates with the Ministry of Environment and Natural Resources (Semarnat).

In addition, the representation in Mexico of the Pan American Health Organization (PAHO) is incorporated.

Health

• An intentional search for cases with suspected viral respiratory disease was carried out.
• The analysis of information is carried out to identify changes in the behavioral trends of viral respiratory diseases in Mexico City and the State of Mexico.
• International communication and operation of international agreements such as the North American Plan for Animal and Pandemic Influenza (NAPAHPI).
• Health personnel from the Health Services of Mexico City, State of Mexico and Cenaprece and INER brigades were trained in relation to the National Guide for preparation, prevention and response to an outbreak or event due to zoonotic influenza in the animal-human interface .

Semarnat - Conanp

• Tours and biological sampling of wild and synanthropic birds were carried out in the wetlands of Tláhuac-Xico and the area of influence surrounding the home of the positive case for avian influenza A(H5N2), in coordination with Senasica, and a permanent monitoring system was established to the timely detection of other similar cases in wildlife that lives in the area.

Agriculture - Senasica

• The Directorate of the United States-Mexico Commission for the Prevention of Foot and Mouth Disease and other Exotic Animal Diseases (CPA) implemented active epidemiological surveillance in backyards in the area, in order to identify any possible case in birds, and that this could be related to the human case.
• Farms near the home were monitored and wild and synanthropic birds were captured in wetlands and urban areas of the population to identify a possible case.
• To date, no affected birds have been identified and biosecurity measures on farms are being reinforced.

• Collaboration and intersectoral communication between environmental health, human health and animal health is maintained.
  
  The Ministry of Health informs the population:
  
  The WHO considers that the public health risk of this virus for the general population is low, which is why the consumption of well-cooked chicken or eggs does not represent a danger to human health.
  
  Avian influenza is a viral disease that affects wild and domestic birds; It is found naturally in waterfowl; Low temperatures and environmental humidity favor the survival of the virus, which is related to climatic conditions, that is, ambient temperature.
  
  Exhaustive epidemiological surveillance was carried out in the area of residence of the infected person to detect any possible case of contagion in another person or persons. Zoonotic influenza is a disease that can be transmitted from birds or other animals to humans. So far there is no evidence of human-to-human transmission.
  
  Currently, these viruses are being monitored to detect changes in their transmission. The incubation period of avian influenza in humans is usually longer than that of seasonal influenza. The WHO recommends a follow-up period of 14 days in suspected cases.

• Whenever avian influenza viruses circulate in poultry, there is a risk of sporadic infection and small clusters of human cases due to exposure to infected poultry.

• It is recommended to the population:

• • Wash your hands frequently with soap and water or 70 percent alcohol-based solutions.
  • Use face masks in case of respiratory symptoms and ventilate spaces.
  • Cover your mouth and nose when coughing or sneezing.
  • Wash hands before handling cooked foods and after handling raw foods.
  • Properly cook chicken meat and egg (greater than 70°C).
  • Do not use the same utensils to handle raw and cooked foods.
  • Avoid touching or approaching wild animals.
  • Do not handle or collect dead animals.
  • Do not touch birds or poultry that are sick or dead from unknown causes.
  • Use gloves, face masks and protective clothing if you work on farms or slaughterhouses and have contact with birds or other animals, their products and waste.
  • Monitor possible signs of illness or abnormal death in farm or backyard animals and immediately notify the authorities.

The Ministry of Health recommends seeking medical attention in case of fever, conjunctivitis (burning, itching, red eyes), cough, burning throat, runny nose, difficulty breathing, headache, vomiting, diarrhea, bleeding or changes in vision. consciousness, after contact with sick or dead birds or other animals and call 55 53 37 18 45 or 55 53 37 16 00 ext. 41845, 41844 and 41843.

Senasica reminds that any person who produces, processes, handles, moves or markets birds must immediately report to the health authority any abnormal behavior in their flocks, unusual mortality or any other suspicion of this disease to the telephone number 800 751 2100, or from their telephone. mobile through the “AVISE” app, available for Android devices.

https://afludiary.blogspot.com/2024/06/mexico-moh-statement-on-fatal-h5n2.html

[Pathfinder]

Translation Google

"Bad and erroneous" WHO statement regarding H5N2 avian flu in Mexico: Ssa

The Secretary of Health indicated that there is no case or evidence of human-to-human transmission so far.

BY: SIPSE.COM
|THURSDAY, JUNE 6, 2024

The Secretary of Health, Jorge Alcocer , explained that the WHO statement on the H5N2 avian flu was "quite bad" , as he considered that it offers erroneous information.

"Since from the outset it talks about a fatal case, which was not the case, he died from another cause and without a ruling and only marginally does it say that the risk in this case is low ," Alcocer said.

This is a 59-year-old man, from the State of Mexico , who was treated at the National Institute of Respiratory Diseases (INER) for respiratory problems.

"This diabetic patient, with kidney problems, was treated, but basically what was taken were samples and in one of the samples the H5 N2 virus was found, which is linked to avian flu , " explained the Secretary.

Alcocer emphasized that "it regularly affects birds and that the infections in humans that have been detected, especially in workers on poultry farms, are very mild, they do not lead to these manifestations . "

In addition, he stressed that "until now there is no evidence of human-to-human transmission " and that "the patient, who I repeat, comes from the State of Mexico, has no history of family contact or knowledge of where he lived."

Regarding the cause of the patient's death, the Secretary of Health indicated that "it has not been specified, but basically it was kidney failure and of course the respiratory failure that he had in a matter of hours . "

Alcocer pointed out that there is no reason to avoid eating chicken or its derivatives, or to be worried about this.

https://sipse.com/mexico/ssa-cuestiona-a-la-oms-muerte-en-mexico-no-fue-causada-por-gripe-aviar-h5n2-470803.html

-----------------------------

Mexico denies the WHO report on a death from bird flu in that country

The Mexican Secretary of Health acknowledged that the AH5N2 virus was found in the deceased person, aged 59, but stated that “he died from another cause.”

June 6, 2024
15:24
THE NATION

MEXICO CITY.- After the World Health Organization (WHO) reported the first death in Mexico of a man from AH5N2 bird flu, the Mexican Secretary of Health, Jorge Alcocer, rejected that the 59-year-old person had died from this cause.

In the “morning” conference led by President Andrés Manuel López Obrador (AMLO) this Thursday at the National Palace, the Secretary of Health asked to take the information “with caution” because “it is not accurate.”

“The statement made by the World Health Organization is quite bad , since from the outset it talks about a fatal case, which was not the case, he died from another cause and without a ruling ,” he said.

“There is no reason to avoid eating chicken or its derivatives, or to be concerned about this ,” said the Secretary of Health.

He indicated that the man with diabetes and kidney problems was treated at the Institute of Respiratory Diseases , from whom several samples were taken and in one of them the AH5N2 virus was found, which is linked to avian flu : “And that, in This case can of course be an epidemiological warning in the case of the actions that are taken for workers who care for birds and who work on them.

"This patient did not have any of this, he came from the State of Mexico, due to these other types of manifestations, and we know that the virus regularly affects birds and that the infections in humans that have been detected, especially in workers on poultry farms, are very mild, they do not reach these manifestations,” he pointed out.

Jorge Alcocer added that so far “there is no evidence of human-human transmission.” He noted that the patient had no history of family contact, nor around where he lived.

The WHO statement noted that this was the first human case in the world confirmed in a laboratory of an infection with subtype A(H5N2) of bird flu. Cases of avian influenza subtype A(H5N2) in poultry have been reported in Mexico.

“This is the first laboratory-confirmed human case of infection with an influenza A (H5N2) virus reported in the world, and the first infection with the avian H5 virus reported in a person in Mexico,” declared the health agency of the UN in a statement on its website.

The Mexican authorities had informed the WHO on May 23 of a confirmed case of H5N2 avian flu infection in a 59-year-old person, who had been hospitalized in the capital.

The patient had “multiple underlying pathologies” and on April 17 developed fever, respiratory problems, diarrhea and nausea, before dying on April 24, the WHO said.

The UN agency stated that the origin of the infection is “currently unknown” and stressed that the victim had “no history of exposure to birds or other animals.”

The organization pointed out that in March an epidemiological focus of avian flu of the H5N2 type was detected in a poultry farm in the state of Michoacán, bordering the State of Mexico. Other cases in poultry were also identified in March in Texcoco and in April in Temascalapa, both municipalities in the State of Mexico.

Based on the information available, the organization estimates that the current risk that this virus represents for the population is “weak.”

AFP Agency

THE NATION

https://www.lanacion.com.ar/el-mundo/mexico-desmiente-el-reporte-de-la-oms-sobre-un-muerto-por-gripe-aviar-en-ese-pais-nid06062024/

[Treyfish]

Mexico denies bird flu death in the country following a 'pretty lousy' WHO report

Health Minister Jorge Alcocer said the person died of kidney failure and complications resulting from diabetes
Demian Bio @bio_demian /Published Jun 06 2024, 3:32 PM EDT
…..

It discusses a fatality, which didn't happen. He died of something else and without determining (it was bird flu), and only marginally highlights that risks are low in these cases," said Alcocer.

He went on to say that Mexican authorities will meet with WHO counterparts to "clarify" the release announcing the "first human death confirmed in a lab of bird flu AH5N2 reported at a global level."
…

https://www.latintimes.com/mexico-denies-bird-flu-death-country-following-pretty-lousy-who-report-554925

[Pathfinder]

Translation Google
219. Person related to influenza A (H5N2) died due to chronic diseases: Health sector

He suffered from kidney disease, type 2 diabetes and systemic arterial hypertension of more than 14 years' duration.

Ministry of Health | June 7, 2024 | National


Specialists in epidemiology, infectious disease, pulmonology, microbiology, critical medicine and other specialties make up the team that made the opinion.

• Ministry of Health reaffirms that there are no risks for the population; So far, all tests from contacts related to the case study are negative.

A team of experts from the Health sector ruled that the person identified with influenza A (H5N2) did not die because of this virus, but as a result of chronic conditions that generated septic shock.

The diseases he suffered were long-term and caused conditions that favored the failure of several organs, specialists concluded.

The case was recorded in a 59-year-old man, with chronic kidney disease, type 2 diabetes and systemic arterial hypertension of more than 14 years of evolution; He was a resident of the State of Mexico. As part of the medical care protocol, samples were taken for respiratory viruses; After analysis in specialized laboratories of the Ministry of Health, the influenza A (H5N2) virus was identified.

The multidisciplinary group that carried out the investigation and analysis of the death is made up of experts from the Coordinating Commission of National Institutes of Health and High Specialty Hospitals (CCINSHAE); National Center for Preventive Programs and Disease Control (Cenaprece); General Directorate of Health Information; General Directorate of Epidemiology and General Directorate of Health Promotion of the Ministry of Health, with specialties in epidemiology, infectology, pulmonology, microbiology and critical medicine, among others.

Specialists from the Secretariats of the National Defense (Sedena) and the Mexican Navy (Semar), the Mexican Social Security Institute (IMSS), the IMSS-Wellbeing Health Services and the Mexican Petróleos (Pemex) also collaborated.

Likewise, the Secretariat of Agriculture and Rural Development (Sader), through the National Service of Health, Safety and Agri-Food Quality (Senasica); the Ministry of Environment and Natural Resources (Semarnat), through the National Commission of Protected Natural Areas (Conanp); the Colegio de la Frontera Sur, the National Autonomous University of Mexico (UNAM) and the Spanish Hospital of Mexico.

After reaffirming that there are no risks for the population, the Ministry of Health reports that, to this date, all the tests of the contacts related to the case study are negative and, because the source of infection has not been identified, the Research continues and intersectoral collaboration and communication between environmental health, human health and animal health is maintained, within the framework of One Health.

https://www.gob.mx/salud/prensa/219-...s-sector-salud

[Mary Wilson]

Mexico says bird flu patient died of chronic disease, not virus

June 7, 202410:55 AM CDT
Updated 35 min ago
By Reuters

MEXICO CITY, June 7 (Reuters) - A man who contracted bird flu in Mexico died due to chronic diseases and not the virus, Mexico's health ministry said on Friday. ...

Mexico's health ministry on Friday stressed that the 59-year-old man's death was due to chronic conditions that led to septic shock, and was not attributed to the virus.
"The diseases were long-term and caused conditions that led to the failure of several organs," the ministry said, citing the findings by a team of experts. ...

https://www.reuters.com/world/americas/mexico-health-ministry-bird-flu-patient-died-chronic-disease-not-virus-2024-06-07/

[Pathfinder]

The other bird flu: H5N2

Texas Public Radio | By Bonnie Petrie
Published June 10, 2024 at 4:00 PM CD
...
TPR's Bonnie Petrie asked Texas Biomedical Research Institute virus expert and vaccine researcher Luis Martinez-Sobrido about H5N2.
...
Martinez-Sobrido: H5N2 is a subtype of influenza A virus that has been circulating in farms in Mexico for years...However, no human cases of H5N2 has been reported until this recent case of avian H5N2 influenza virus in April 2024; it is unclear if there is a link between this human case and cases of high or low pathogenic avian H5N2 in farms.
...
This lethal human case of avian H5N2 corresponds to a person with no history of exposure to poultry or other animals. It will be important to know how this person was infected with the H5N2 avian influenza virus.
...
This is the first laboratory-confirmed human case of infection with an avian H5N2 influenza virus reported and the first case of an avian H5 virus infection in a person in Mexico.
...

https://www.tpr.org/bioscience-medicine/2024-06-10/the-other-bird-flu-h5n2

[Pathfinder]

Avian Influenza A(H5N2) - Mexico

14 June 2024

Situation at a glance

Following further investigation and information sharing by national authorities in Mexico, this is an update to the Disease Outbreak News (DON) on human infection caused by avian influenza A(H5N2) published on 5 June 2024. As was previously reported, on 23 May 2024, the Mexico International Health Regulations (IHR) National Focal Point (NFP) reported to PAHO/WHO a confirmed case of human infection with avian influenza A(H5N2) virus in a patient with underlying co-morbidities who subsequently died. This is the first laboratory-confirmed human case of infection with an influenza A(H5N2) virus reported globally and the first avian A(H5) virus infection in a person reported in Mexico. Although the source of exposure to the virus in this case is currently unknown, A(H5N2) viruses have been reported in poultry in Mexico. In their update, Mexican authorities informed WHO that a national group of experts determined on 6 June that the patient died due to complications related to his co-morbidities and that genetic analysis performed by the national authorities identified that this virus has a 99% similarity with the strain obtained during 2024 in birds in Texcoco State of Mexico. Based on available information, WHO’s risk assessment is unchanged: the current risk to the general population posed by this virus is low. The risk assessment will be reviewed should further epidemiological or virological information become available.

Description of the situation


As summarized in the previous DON (link), on 23 May 2024, the Mexico IHR NFP reported to PAHO/WHO a confirmed case of infection with avian influenza A(H5N2) virus detected in a 59-year-old resident of the State of Mexico who was hospitalized on 24 April 2024 in Mexico City. The case had no known history of exposure to poultry or other animals. He had multiple underlying medical conditions. His relatives reported that he had been bedridden for three weeks, for other reasons, prior to the onset of acute symptoms. On 22 May, sequencing of the sample by the national authorities confirmed the influenza subtype was A(H5N2). The genetic analysis by the national authorities identified that this virus has a 99% similarity with the low pathogenicity (in birds) avian influenza A/chicken/Texcoco, México/CPA-01654/2024 (H5N2) strain, obtained during 2024 from birds in Texcoco State of Mexico. The detailed H5N2 virus genetic sequence from the patient specimen has been uploaded to GISAID.

A national multidisciplinary group of experts was formed to investigate the cause of death. It included infectious disease specialists, pneumonologists, microbiologists and intensive care professionals. Upon review of the patient’s clinical history and records, the national multidisciplinary team concluded on 6 June that, although the patient had a laboratory-confirmed infection with avian influenza A(H5N2) virus, he died due to complications of his co-morbidities.

No further cases were reported during the epidemiological investigation. The 17 contacts identified and monitored at the hospital where the man died and 12 additional contacts near his residence, were tested and the results were negative for influenza viruses. Samples from these persons were taken a month after the acute disease onset in the patient with confirmed influenza A(H5N2) infection. The results of the serological samples are pending.

In March 2024, an outbreak of low pathogenicity avian influenza (LPAI) A(H5N2) was identified in poultry in Texcoco, State of Mexico, and a second outbreak of LPAI A(H5N2) in April in the municipality of Temascalapa in the same state (1).

Additionally, in March 2024, a high pathogenicity avian influenza A(H5N2) outbreak was detected in a backyard poultry farm in the state of Michoacán. A study describing the continuous circulation of low pathogenicity avian influenza H5N2 viruses in Mexico and spread to several other countries was published in 2022 (2), indicating that both LPAI and HPAI A(H5) subtypes were reported in avian species in Mexico recently and in past years. Epidemiology


Animal influenza viruses normally circulate in animals but can also infect humans. Infections in humans have primarily been acquired through direct contact with infected animals or contaminated environments. Depending on the original host, influenza A viruses can be classified as avian influenza, swine influenza, or other types of animal influenza viruses.

Avian influenza virus infections in humans may cause mild to severe upper respiratory tract infections and influenza-associated deaths have been reported in persons with or without comorbidities. Conjunctivitis, gastrointestinal symptoms, encephalitis and encephalopathy have also been reported.

Laboratory tests are required to diagnose human infection with influenza. WHO periodically updates technical guidance protocols for the detection of zoonotic influenza using molecular methods, e.g. RT-PCR. Evidence suggests that some antiviral drugs, notably neuraminidase inhibitors (oseltamivir, zanamivir), can reduce the duration of viral replication and improve survival prospects for some cases.

Public health response


Local and national health authorities report implementing the following public health measures:

• Conducting an ongoing investigation into the source of infection.
• Formed a multi-disciplinary group experts to determine the cause of death. It comprised of professionals from Secretaría de Salud: Comisión Coordinadora de Institutos Nacionales de Salud y Hospitales de Alta Especialidad (CCINSHAE) of the Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE); Dirección General de Información en Salud (DGIS), Dirección General de Epidemiología (DGE-InDRE) and Dirección General de Promoción de la Salud (DGPS); Secretarías de la Defensa Nacional (SEDENA); Secretaría de Marina Armada de México (SEMAR); and Instituto Mexicano del Seguro Social.
• Issued official press releases including updates of national investigations and actions with a multisectoral approach, as well as general information and recommendations for the population.

The below actions were previously reported

• Epidemiological investigation of case and contacts.
• Monitoring of health care workers with a history of contact with the patient.
• Monitoring and surveillance of influenza-like respiratory illness (ILI) and severe acute respiratory illness (SARI) in neighbouring municipalities (within the same health region), in order to analyze the behaviour and trends of respiratory syndromes and viruses in the region.
• Analysis of the trends of pneumonia and bronchopneumonia, acute respiratory infections, and conjunctivitis by the health services of Mexico City and the State of Mexico.
• Identification of transmission chains and risk factors in the municipality where the case resided, the State of Mexico and surrounding areas.
• Training on the National Guide for preparedness, prevention and response to an outbreak or zoonotic influenza event at the animal-human interface.
• Communicated with animal and environmental health authorities to strengthen surveillance activities in poultry and wild birds near the case's residence and areas with a history of low pathogenic avian influenza A(H5N2) outbreaks.

PAHO/WHO implemented the following measures:

• Strengthening routine and event surveillance on the human-animal interface with WHO Collaborating Centers and strategic partners.
• Improvement of molecular diagnostic capacity for detection of zoonotic diseases through knowledge transfer, training and technical support with recent emphasis in avian influenza A(H5N1).
• Strengthening national capacity for the prompt shipment of human and animal samples to WHO collaborating centers for additional characterization and/or vaccine composition analysis.
• Regular risk assessment for transmissibility and severity for zoonotic viruses.
• Update of guidelines on influenza surveillance and response at the human-animal interface.
• Revision of experiences in response and lessons learned from countries that experienced zoonotic influenza outbreaks.
• Technical strengthening of risk communication capacities for events at the human-animal interface.
• Clinical management training on zoonotic influenza treatment, infection prevention and control (IPC), and reorganization of health services.
• Animal carcass handling training, including IPC technical aspects.
• PAHO published recommendations to strengthen intersectoral work in surveillance, early detection, and research at the human animal interface.

WHO risk assessment


This new information does not change WHO’s risk assessment. This is the first laboratory-confirmed human case of infection with an influenza A(H5N2) virus reported globally, and the first A(H5) virus infection in a person reported in Mexico. The case had multiple underlying conditions, and although the source of exposure has not been definitively determined, genetic analysis by authorities in Mexico identified that the virus from the patient has a 99% similarity with the strain obtained during 2024 in birds in Texcoco State of Mexico.

Whenever avian influenza viruses are circulating in poultry, there is a risk for infection and small clusters of human cases due to exposure to infected poultry or contaminated environments. Therefore, sporadic human cases are not unexpected. Human cases of infection with other A(H5) subtypes including A(H5N1), A(H5N6) and A(H5N8) viruses have been reported previously. Epidemiological and virological evidence available so far suggests that A(H5) viruses from previous events have not acquired the ability to sustain transmission between humans, thus the risk of sustained human-to-human spread remains assessed as low. According to the information available thus far, no further human cases of infection with A(H5N2) associated with this case have been detected.

There are no specific vaccines for preventing influenza A(H5) virus infection in humans. Candidate vaccines to prevent A(H5) infection in humans have been developed for pandemic preparedness purposes. Close analysis of the epidemiological situation, further characterization of the most recent viruses (in human and birds) and serological investigations are critical to assess associated risks and to adjust risk management measures in a timely manner.

Based on the available information, WHO assesses the current risk to the general population posed by this virus to be low. If needed, the risk assessment will be reviewed should further epidemiological or virological information, including information on A(H5N2) viruses detected in local animal populations, become available.

WHO advice


This case and this update do not change the current WHO recommendations on public health measures and surveillance of influenza.

Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of thorough and timely epidemiologic investigation and global surveillance to detect and monitor virological, epidemiological and clinical changes associated with emerging or circulating influenza viruses that may affect human and animal health and timely virus-sharing for risk assessment.

When there has been human exposure to a known outbreak of an influenza A virus in domestic poultry, wild birds or other animals or when there has been an identified human case of infection with such a virus, enhanced surveillance in potentially exposed human populations becomes necessary. Enhanced surveillance should consider the healthcare-seeking behaviour of the population. It could include a range of active and passive healthcare and/or community-based approaches, including enhanced surveillance in local ARI/ILI/ SARI systems, active screening in hospitals and of groups that may be at higher occupational risk of exposure, and inclusion of other sources such as traditional healers, private practitioners and private diagnostic laboratories.

In the case of a confirmed or suspected human infection caused by a novel influenza A virus with pandemic potential, including avian influenza virus, a thorough epidemiologic investigation (even while awaiting the confirmatory laboratory results) of a history of exposure to animals and/or travel should be undertaken along with contact tracing. The epidemiologic investigation should include early identification of unusual events that could signal person-to-person transmission of the novel virus. Clinical samples collected from suspected human cases should be tested and sent to a WHO Collaboration Centre for further characterization.

Travellers to countries with known outbreaks of animal influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that may have been contaminated with animal faeces. Travellers should also wash their hands often with soap and water. Travelers should follow good food safety and good food hygiene practices. Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this occurs, further community-level spread is considered unlikely as this virus has not acquired the ability to transmit easily among humans.

All human infections caused by a novel influenza A virus subtype are notifiable under the IHR, and State Parties to the regulations are required to immediately notify WHO of any laboratory-confirmed case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic. Evidence of illness is not required for this report.

WHO does not advise special traveller screening at points of entry or restrictions regarding the current situation of influenza viruses at the human-animal interface.

Further information

...

https://www.who.int/emergencies/dise...em/2024-DON524

[Pathfinder]

First laboratory-confirmed human case of infection with influenza A(H5N2) virus reported in Mexico

View ORCID ProfileJoel A Vazquez-Perez, Claudia Wong-Arambula, Mario Solis-Hernandez, Eduardo Becerril-Vargas, Gisela Barrera-Badillo, Victor Hugo Ahumada-Topete, Santiago Avila-Rios, Rogelio Perez-Padilla, Fidencio Mejia-Nepomuceno, Enrique Mendoza-Ramirez, Marisol Karina Rocha-Martinez, Carlos Javier Alcazar-Ramiro, Alfredo Cruz, Joaquin Zuniga, Karolina Bozena-Piekarska, Dayanira Sarith Arellano-Suarez, Maria Natividad Cruz-Ortiz, Tatiana Ernestina Nunez-Garcia, Erendira Molina-Gomez, Laura Adriana Flores-Cisneros, Rodrigo Aparicio-Antonio, Abril Rodriguez-Maldonado, Magaly Landa-Flores, Armando Garcia-Lopez, Jorge Membrillo-Hernandez, Gabriel Garcia-Rodriguez, Herlinda Garcia-Lozano, Irma Lopez-Martinez, Ruth P Gonzalez-Sanchez, Gustavo Reyes-Teran, Carmen M Hernandez-Cardenas
doi: https://doi.org/10.1101/2024.08.15.24311897

This article is a preprint and has not been certified by peer review [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

Posted August 17, 2024.

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...
Abstract

In late April, 2024, we detected a non-subtypeable influenza virus in a hospitalized patient, resident of the Metropolitan area of Mexico City. Our results using 5 complete viral segments M, NS, NA, NP and HA, showed identity of 99% with avian influenza A(H5N2) from Texcoco, Mexico of 2024. This case is the first with direct evidence of human infection caused by the H5N2 influenza virus, relationship with severity remain unknow.
...

Introduction:

Avian influenza viruses have been implicated in several infections in humans since the
90´s(1). The main subtypes that have been causing occasionally respiratory diseases in
humans are H5N1, H7N9, H5N6 (2). Additionally, avian influenza viruses like H5N1 or H7N3
have also been implicated in human infections causing conjunctivitis but not respiratory
disease (3)(4). Moreover, H5N2 has been associated mostly with migratory birds and
commercial and backyard poultry infections (5).

The first avian influenza H5N2 strain isolated was the A/Chick/Penn/83 (H5N2) influenza
virus was originally described infecting chickens in Pennsylvania in April 1983 and
subsequently this strain became virulent in 1983 (6). To date, different viral clades of H5N2
have been described in several countries including Mexico, infecting chickens and other
bird species (5).

In Mexico, government records show that low pathogenic H5N2 influenza viruses were
detected in 1994 in poultry in different areas of Mexico, possibly linked to migratory bird
species. At the end of 1994 highly pathogenic H5N2 strains were detected in several
poultry farms causing serious economic damage amongst poultry farmers (6).
In March 2024, a high pathogenicity H5N2 outbreak was identified in a poultry farm in
Michoacán state. During the same month, two low pathogenicity H5N2 outbreaks were
reported in backyard poultry in the State of Mexico, in the municipalities of Texcoco and
Temascalapa (7).

Some reports indicated that human cases could have occurred showing serology evidence
of H5N2 infection (8)(9). However, to our knowledge no evidence of human infection
caused by influenza virus H5N2 has been reported until now. Here, we described the first
case of respiratory disease associated with avian influenza H5N2 in humans in Mexico.
...
Discussion

Detection and molecular characterization of influenza virus H5N2 in a respiratory sample,
confirmed the first report of human infection due of this subtype in Mexico.

Molecular evidence suggests that the human isolate of this study (INER_INF645_24) and
the avian isolates from 2022, 2023 y 2024, possibly derive from a common avian H5N2
ancestor from 2019 of Central Mexico (Influenza A virus (A/chicken/Queretaro/CPA-04673-
1/2019(H5N2)). The observation of the highest homology (99%) of the study virus and an
avian H5N2 isolate from Texcoco, State of Mexico (2024), suggests a direct relationship
between these isolates. Although a direct contact of the patient in this study with poultry
or other domestic animals could not be confirmed, it is plausible that this avian virus,
causing high disease burden in chickens in this geographical area in 2024 could be the
source of the human case described here, as human to human transmission seems
unplausible.

This is the first report of a human case of influenza H5N2 infection in Mexico. Further
studies are required to determine the predicted pathogenicity of the virus and to predict
its capability for human-to-human transmission and potential threat to human health.
Unfortunately, several comorbidities in the case described here led to a fatal outcome, but
the pathogenicity of the isolate needs to be further studied.

Since no cases of H5N2 influenza in humans have been reported so far, we are unaware of
the clinical outcomes that this influenza virus subtype may have in humans. Referring to
the clinical manifestations associated with other currently circulating avian influenza
viruses, such as H5N1, which has documented transmission to humans causing acute
respiratory infections as well as mild symptoms where conjunctivitis has notably been the
main manifestation in documented cases. At admission the patient was severely ill, with
uremia, renal failure and important metabolic acidosis and shock state, that deteriorated
progressively, and a bacteremic infection originating likely from peritonitis. It is uncertain
what was the contribution of the influenza virus H5N2 to the final clinical status of the
patient and also unknown how the patient acquired the influenza virus very similar to bird
viruses identified in the valley of Mexico in 2022.

Dr. Vazquez-Perez is a head of Molecular Biology and Emerging Diseases Laboratory at
Instituto Nacional de Enfermedades Respiratorias (INER). His research interests are the
molecular epidemiology and pathogenesis of respiratory viruses, and Dr. HernandezCardenas
is a General Director of Instituto Nacional de Enfermedades Respiratorias (INER).
Her research interests are pulmonary chronic and acute diseases. Is a qualified critical care
physician, a registered internist and anesthesiologist.
...

https://www.medrxiv.org/content/10.1101/2024.08.15.24311897v1.full.pdf

https://www.medrxiv.org/content/10.1101/2024.08.15.24311897v1.full