H5N1

WHO: Avian influenza A(H5N1) – Viet Nam

A WHO Disease Outbreak News report: Avian Influenza A(H5N1) – Viet Nam. Excerpt:

Situation at a Glance

The World Health Organization (WHO) was notified about a case of human infection with an influenza A(H5N1) virus on 25 March 2024 by the national authorities of Viet Nam. The patient, who had no underlying medical conditions, developed symptoms on 11 March and died on 23 March. Exposure to birds was ascertained to have taken place in the third week of February. Samples collected from close contacts tested negative for influenza A(H5N1) virus.  

This is the first human infection with an avian influenza A (H5N1) virus reported in Viet Nam since 2022. According to the International Health Regulations (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 risk to the general population posed by this virus as low.  

Description of the Situation  

On 25 March 2024, Viet Nam National Focal Point (NFP) for International Health Regulations (IHR) notified the World Health Organization (WHO) of one case of human infection with an influenza A(H5N1) virus in a 21-year-old male with no underlying conditions from Khanh Hoa Province, Viet Nam.  

The case developed a fever and cough on 11 March 2024 and was admitted on 15 March to a local hospital due to persistent symptoms, including abdominal pain and diarrhoea. On 17 March, his condition worsened, and he was transferred to the Intensive Care Unit (ICU) of a provincial hospital. On 20 March, the patient was transferred to another provincial hospital with a diagnosis of severe pneumonia, severe sepsis, and acute respiratory distress syndrome. The case died on 23 March.  

On 19 March, samples were taken for real-time polymerase chain reaction (RT-PCR) testing by the Pasteur Institut in Nha Trang, which resulted in a positive result for the influenza (H5) virus. On 22 March, genomic sequencing conducted by the Pasteur Institut of Nha Trang revealed the presence of the avian influenza A (H5N1) virus.  

Initial results from the case investigation revealed that during the second and third weeks of February 2024, the case went bird hunting. Between that time and the onset of illness, no contact with dead or sick poultry nor contact with anyone exhibiting similar symptoms was reported. Among close contacts traced, no further cases of influenza A(H5N1) were detected.

US: Bird flu reported in person exposed to presumably infected cattle

Via STAT, a report by Helen Branswell, who has been tracking H5N1 longer than anyone else: Bird flu reported in person exposed to presumably infected cattle. Excerpt:

Texas health officials reported Monday that an individual who had been in contact with cattle has contracted H5N1 avian flu, only the second case ever recorded in the U.S.  

The person had contact with dairy cattle that are believed to have been infected with the virus, the Texas Department of State Health Services said in a statement. It went on to say that the individual’s only symptom is eye inflammation — infection of the conjunctiva, the tissue surrounding the eye.  

Nirav Shah, principal deputy director of the Centers for Disease Control and Prevention, said the infected individual is doing well and is being treated with the influenza antiviral oseltamivir, sold as Tamiflu. The individual was instructed to isolate to reduce the risk of infecting others, and to date there’s no indication of onward spread, Shah said.

“We are not aware of reports that any of this individual’s close contacts have developed any symptoms,” he told STAT.  

The person was tested late last week, with confirmatory testing taking place at the CDC over the weekend. The CDC is not currently running any other confirmatory H5 tests, Shah said. “The fact that there are not other samples cooking right now is reassuring, insofar as that we’re not aware of other individuals who are symptomatic following an exposure to livestock,” he added.  

“We are still out there looking, to be very clear,” he said. “Our antennae are up and we have been working with state public health officials in a number of jurisdictions to look for individuals who report signs and symptoms of illness, to make sure they know how to get tested.”