Australia - Government statement: Human case of H5N1 avian influenza detected in returned traveller to Victoria from India - May 22, 2024

[Treyfish]

Human case of avian influenza (bird flu) detected in returned traveller to Victoria

Health advisory

Status: Active Advisory number: 240522 Date issued: 21 May 2024 Issued by: Dr Clare Looker, Chief Health Officer Issued to: Victorian public and health professionals

Key messages

• A human case of avian influenza A(H5N1) infection, also known as “bird flu”, has been reported in Victoria.
• There is a current global outbreak of avian influenza in birds and animals. Avian influenza does not usually infect people, but in rare cases human infection can occur.
• The recently reported case in Victoria was in a child who returned to Australia from overseas in March 2024. The child experienced a severe infection but is no longer unwell and has made a full recovery.
• There is no evidence of transmission in Victoria and the chance of additional human cases is very low as avian influenza does not easily spread between people.

What is the issue?


A case of avian influenza A (H5N1) infection, also known as “bird flu”, has been reported in Victoria. This is the first human case of H5N1 avian influenza in Australia. The case occurred in a child, who acquired the infection in India and was unwell in March 2024. The avian influenza virus was detected through further testing of positive influenza samples that takes place to detect novel or concerning flu virus strains, as part of Victoria’s enhanced surveillance system. Contact tracing has not identified any further cases of avian influenza connected to this case.

There are lots of different subtypes (strains) of avian influenza. Most of them don’t infect humans. Some subtypes, including H5N1, are more likely to cause disease and death in poultry. These are known as highly pathogenic avian influenza (HPAI) viruses. Significant outbreaks of HPAI viruses are being reported in poultry and non-poultry birds and mammals overseas. The United States of America is currently experiencing outbreaks of HPAI (H5N1) in dairy cows, with one recent human case in a dairy worker. Whilst the Victorian case is HPAI (H5N1), it is not the same as the strains that have caused these outbreaks in the United States of America.

The Department of Health is supporting Agriculture Victoria in responding to an outbreak of avian influenza among birds at a poultry farm in regional Victorian. Testing has confirmed this outbreak is not related to this human case.

Transmission to humans is very rare, with a small number of human cases of H5N1 reported globally, resulting in death in a number of cases. This is the first confirmed human case of highly pathogenic avian influenza in Australia, and the first time the H5N1 strain has been detected in a person or animal in Australia.

The seasonal flu vaccine doesn't protect against avian influenza. However, it can help prevent the mixing of highly pathogenic avian influenza with seasonal influenza, which can lead to new mutated viruses that could spread rapidly. This highlights the importance of seasonal influenza vaccination, particularly for poultry workers and those travelling to areas with outbreaks, to reduce the risk of new human pandemic viruses emerging.

Who is at risk?


The transmission of avian influenza from birds or animals to humans is very rare. Most people are not at risk, unless they have contact with infected birds or animals, or their secretions, while in affected areas of the world. Rarely, avian influenza infection in humans can pass to another person with prolonged contact. However, there is no evidence that the H5N1 strains of avian influenza circulating globally can be spread easily from human to human. In this case, contact tracing has identified that there is no evidence of onwards spread to people.

Symptoms and transmission


The symptoms of H5N1 infection may include fever, cough, headache, aching muscles and respiratory symptoms. Other early symptoms may include conjunctivitis and gastrointestinal symptoms. The infection may progress quickly to severe respiratory illness and neurological changes.

Avian influenza is spread by close contact with an infected bird (dead or alive), e.g. handling infected birds, touching droppings or bedding, or killing/preparing infected poultry for cooking. You can't catch avian influenza through eating fully cooked poultry or eggs, even in areas with an outbreak of avian influenza.

Recommendations

For the public

• People travelling to areas affected by avian influenza should:
  • avoid poultry farms and live bird “wet” markets
  • avoid contact with wild or domesticated birds
  • wash their hands thoroughly after handling birds and uncooked poultry products such as meat or eggs
  • ensure that poultry or poultry products are cooked thoroughly before eating
• Immunisation against seasonal influenza is recommended for everyone aged ≥6 months and over. Speak to your immunisation provider to see if you are eligible for a free flu vaccine. Otherwise, you can purchase the flu vaccine from your immunisation provider. In Victoria the most common way people access the flu vaccine is from their doctor (GP) or a pharmacist immuniser (a service fee may apply). Some local council immunisation services also provide the flu vaccine as do some hospitals, maternity services and community health services.
• As a reminder, poultry workers, people who handle poultry, and people involved in culling during an outbreak of avian influenza are recommended to receive annual seasonal influenza vaccine.
• If you have returned from a country affected by avian influenza and feel unwell, it is important to seek medical advice. Although the risk of becoming infected with avian influenza is very low, it is important when making an appointment with your healthcare provider to tell them about any possible exposures to avian influenza.

For health professionals

• Consider the possibility of avian influenza infection in people presenting with compatible symptoms and epidemiological risk factors, such as travel to an area where avian influenza is transmitting, and recent contact with poultry.
• Ensure diagnostic samples (e.g., nasopharyngeal swabs or aspirates) are taken for influenza PCR and sent for further typing in returned travellers presenting with influenza-like-illnesses who have epidemiological risk factors for avian influenza.
• Provide education and advice about the risk of avian influenza in travellers (including people returning to their country of birth, or visiting friends and family), and advise precautionary measures, such as avoiding contact with wild or domesticated birds to prevent the risk of infection and avoid consuming uncooked poultry.
• Annual influenza vaccination is the most important way to prevent influenza and its complications. Influenza vaccination is recommended for all people aged ≥6 months. Influenza vaccination can be given on the same day as COVID-19 vaccines and other vaccines.
• Encourage annual seasonal influenza vaccination in people who are at risk of being exposed to avian influenza, including poultry workers and those in regular contact with poultry.

Reviewed 22 May 2024

https://www.health.vic.gov.au/health-advisories/human-case-of-avian-influenza-bird-flu-detected-in-returned-traveller-to-victoria?utm_source=social&utm_medium=twitter&utm_ campaign=CHO_Advisory&utm_content=Bird_Flu

[sharon sanders]

Please see:

FluTrackers 2016+ Global H5N1 Human Cases List

[sharon sanders]

Please see:

India: Andhra Pradesh - Bird flu in poultry 2024

India: Bird flu in poultry in Kerala: 2022-2024

Jharkhand, India: 2024 Avian flu in poultry

Maharashtra, India: Bird flu in poultry 2024

Maharashtra - Bird flu in wild birds - 2024

Rare Himalayan Griffon vulture falls ill, dies in West Bengal of avian flu - strain not mentioned - January 20, 2024

[sharon sanders]

It would have been nice if the government notice had mentioned the location(s) in India where the patient had traveled. As seen in the above post there are active H5N1 outbreaks in poultry in India.

[Commonground]

Published Date: 2024-05-22 21:08:04 EDT
Subject: PRO/AH/EDR> Avian influenza, human - Australia: ex India, H5N1
Archive Number: 20240523.8716662

AVIAN INFLUENZA, HUMAN - AUSTRALIA: ex INDIA, H5N1
**************************************************
A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org

Date: Wed 22 May 2024
From: Dr Finn Romanes <finn.romanes@wh.org.au> [edited]

snip

The child who became unwell whilst in India was hospitalised upon return to Australia in March 2024. Influenza A was detected by PCR during admission, and the child was treated with oseltamivir during a prolonged stay in intensive care with severe lower respiratory tract infection and hypoxia with respiratory failure. The child has since been discharged home and has made a complete recovery.

Genome sequencing conducted at the WHO Collaborating Centre for Reference and Research on Influenza (Melbourne, Victoria, Australia) identified the virus as A(H5N1) with a multibasic cleavage site, confirming highly pathogenic avian influenza.

Blast analysis of the hemagglutinin (HA) sequence revealed the closest sequence match to be an A/duck/Bangladesh/46162/2020 with 98% homology. The HA clade has been identified as 2.3.2.1a, a clade which has previously been detected in Southeast Asia and is distinct from the HA 2.3.4.4b clade currently circulating in birds and dairy cows globally.

Blast analysis of the neuraminidase (NA) sequence revealed the closest sequence match to be an A/chicken/Bangladesh/18-B-569/2022 with 98% homology. Sequence analysis of the N1 gene indicated sensitivity to oseltamivir.

Two human cases of A(H5N1) from the same HA clade as this new Australian case have previously been detected, one in Nepal in 2019 and one in India in 2021. Interview with the child's family has been unable to identify a clear acquisition source, with the child having no interaction with birds, animals or sick human contacts either in India or Australia, and no geographic or epidemiological links to any of the previously isolated homologous cases. There was also no known consumption of undercooked poultry or meat products during the acquisition period.

Contact tracing did not identify any contact with animals whilst ill on return to Australia, and there were no ill human contacts identified and no evidence of any onwards transmission to humans or animals.

...https://promedmail.org

[Pathfinder]

Avian Influenza A (H5N1) - Australia

7 June 2024

Situation at a glance

On 22 May 2024, the World Health Organization (WHO) was notified of a laboratory-confirmed case of human infection with avian influenza A(H5N1) virus (clade 2.3.2.1a) by the International Health Regulations (IHR) National Focal Point (NFP) of Australia. This is the first confirmed human infection caused by avian influenza A(H5N1) virus detected and reported by Australia. Although the source of exposure to the virus in this case is currently unknown, the exposure likely occurred in India, where the case had travelled, and where this clade of A(H5N1) viruses has been detected in birds in the past. 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 17 May 2024, the WHO Collaborating Centre (WHO CC) for Reference and Research on Influenza in Australia notified the NFP of Australia of a suspected case of human A(H5N1) avian influenza (HPAI) in Melbourne, Victoria.

The state Victorian Department of Health confirmed this case on 18 May 2024. Under Article 44, the NFP of Australia advised the NFP of India of the confirmed case on 21 May 2024. Under Article 8, the IHR NFP of Australia notified WHO of the case on 22 May 2024.

The case is a 2.5-year-old-female child with no underlying conditions. She had a history of travel to Kolkata, India from 12 to 29 February 2024. She returned to Australia on 1 March 2024.

Upon returning to Australia, the child presented at a hospital in Victoria on 2 March 2024, where she received medical care and was admitted on the same day. On 4 March, the patient was transferred to the intensive care unit at a referral hospital in Melbourne, Victoria, due to worsening symptoms, for a period of one week. The patient was discharged from hospital after a 2.5-week admission. The case is now reported to be clinically well.

The Victorian Department of Health reported on 23 May 2024 that the family advised that the child started to feel unwell on 25 February 2024, with loss of appetite, irritability and fever, and was taken to a doctor on the evening of 28 February 2024 in India. She was febrile, coughing and vomiting and was given paracetamol. It was not reported to an Australian airport biosecurity officer that the child was unwell when she arrived in Australia on 1 March 2024.

Additional information provided by the family indicates that the case did not travel outside of Kolkata, India, and did not have any known exposure to sick persons or animals while in India. It is understood that no close family contacts of the case in Australia or India developed symptoms, as of 22 May 2024.

A nasopharyngeal swab and endotracheal aspirate taken on 6 and 7 March respectively tested positive for influenza A at the referral hospital. The samples were sent to the WHO CC for further characterisation on 3 April as part of a batch, as there was insufficient knowledge from the referring practitioners at the hospital to connect the case to the H5N1 virus. Virus genetic sequence obtained from the samples confirmed the subtype A(H5N1) and indicated that the haemagglutinin (HA) gene belonged to clade 2.3.2.1a, which circulates in South-East Asia and has been detected in previous human infections and in poultry.

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 disease ranging from mild upper respiratory tract infection to more severe disease and can be fatal. Conjunctivitis, gastrointestinal symptoms, encephalitis and encephalopathy have also been reported. There have also been several detections of A(H5N1) virus in asymptomatic persons who had exposure to infected birds.

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 prospects of survival in some cases.

From 2003 to 22 May 2024, 891 cases of human infections with avian influenza A(H5N1), including 463 deaths, have been reported to WHO from 24 countries. Almost all of these cases have been linked to close contact with infected live or dead birds, or contaminated environments.

India has reported detections of avian influenza A(H5N1) in domestic birds in 2024 to the World Organisation for Animal Health (WOAH). As the virus continues to circulate in poultry, the potential for further sporadic human cases remains. This is the first human infection with avian influenza A(H5N1) reported in Australia. In this case, the exposure likely occurred in India where this clade of A(H5N1) viruses has been detected in birds in the past, although the likely source of exposure to the virus is currently unknown.

Public health response


Australia

• The Australian Government Department of Health and Aged Care convened a Monitoring and Investigation Team (MIT), with the first meeting held on 20 May 2024. Currently the MIT is meeting weekly, to assess any ongoing risk of the overall highly pathogenic avian influenza situation in Australia associated with the confirmed case of H5N1 in Victoria and the current international HPAI outbreaks. The frequency of the MIT meetings will be reassessed, as required.
• The National Incident Centre of the Australian Government, Department of Health and Aged Care, has been activated to coordinate the response to the event.
• The IHR NFP of India was notified on 21 May 2024.
• On 22 May 2024, the Chief Health Officer of Victoria issued a health advisory on their website, informing of a recently reported human case of avian influenza in Victoria.
• On 23 May 2024, the Head of the interim Australian Centre for Disease Control issued a media release about Australia’s first human case of avian influenza A(H5N1) in Victoria. The interim CDC’s website was updated and included public health advice about avian influenza. This included the importance for people who work on a poultry farm or factory, or travelling overseas to countries with avian influenza outbreaks, to get a seasonal influenza vaccination each year which can help prevent avian influenza from mixing with other influenza viruses which may lead to new mutated viruses thus becoming a greater threat to people.

India

• On receipt of information from IHR NFP Australia, the Ministry of Health and Family Welfare, Government of India, initiated an epidemiological investigation with participation of all relevant sectors.

WHO risk assessment


This is the first human infection with an avian influenza A(H5N1) virus reported by Australia. Most human cases of infection with avian influenza viruses reported to date have been due to exposure to infected poultry or contaminated environments. Currently, the likely source of exposure to the virus in the case remains unknown but likely occurred in India where the patient travelled before onset of illness.

Human infection can cause severe disease and has a high mortality rate. These A(H5N1) influenza viruses, belonging to different genetic groups, do not easily infect humans, and human-to-human transmission thus far appears unusual. As the virus continues to circulate in poultry, particularly in rural areas, the potential for further sporadic human cases remains.

Currently, available epidemiological and virological evidence suggests that A(H5) viruses have not acquired the ability of sustained transmission among humans, thus, the likelihood of human-to-human spread is low.

Based on available information, WHO assesses the current risk to the general population posed by this virus as low. The risk assessment will be reviewed if additional virological and epidemiological information becomes available.

WHO advice


This event does not change the current WHO recommendations on public health measures and influenza surveillance.

The public should avoid contact with high-risk environments such as live animal markets/farms and live poultry, or surfaces that might be contaminated by poultry droppings. Additionally, it is recommended to maintain good hand hygiene with frequent washing or the use of alcohol-based hand sanitizer.

The general public and at-risk individuals should immediately report instances of sick or unexpected animal deaths to veterinary authorities. Consumption of poultry that are sick or have died unexpectedly should be avoided.

Any person who has had exposure to potentially infected animals or contaminated environments and who feels unwell should seek health care promptly, inform their healthcare provider of their possible exposure, wear a face mask and limit contact with others. For more information, please visit the updated guidance here.

Close analysis of the epidemiological situation, further characterization of the most recent influenza A(H5N1) viruses in both human and animal populations, and serological investigations are critical to assess associated risks to public health and promptly adjust risk management measures.

There are no specific vaccines for influenza A(H5N1) in humans. However, candidate vaccines have been developed for pandemic preparedness in some countries. WHO continues to update the list of zoonotic influenza candidate vaccine viruses (CVV), which are reviewed and updated twice a year at the WHO consultation on influenza virus vaccine composition.

WHO advises against implementing travel or trade restrictions based on the current information available on this event. WHO does not advise special traveller screening at points of entry or other restrictions due to the current situation of influenza viruses at the human-animal interface.

State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed case of a recent human infection caused by a new subtype of influenza virus. Evidence of illness is not required for this notification.

...

https://www.who.int/emergencies/disease-outbreak-news/item/2024-DON519