WHO: Fatal H5N2 Infection In Mexico City - Mexican MOH Statement

[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 . . . )​

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https://afludiary.blogspot.com/2024/06/who-fatal-h5n2-infection-in-mexico-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.​

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