Factsheets

H5N1 in wild birds in Thailand

About H5N1 Virus

H5N1 is an Influenza A virus subtype that belongs to the genus Alphainfluenzavirus and the family Orthomyxoviridae. The H5N1 virus is a negative-sense, single-stranded RNA virus, and its genome contains eight RNA segments.

H5N1 in Thailand

In Thailand, the H5N1 outbreak first occurred on poultry farms in December 2003, and the first case of human H5N1 infection was reported on January 23, 2004. The first wild bird that tested positive for H5N1 was found in February 2004. However, it is apparent that the H5N1 virus has been detected at a low level (approximately 1%) in wild bird populations. At least 50% of H5N1-infected wild birds appear to be healthy, while more than 30% have died. Outbreaks in wild birds were only found in areas where domestic poultry outbreaks were reported.

There have been no reported cases of H5N1 in both animals and humans since 2008 in Thailand.

Types of wild birds that can be infected with H5N1

In Thailand, numerous wild bird species have tested positive for antibodies, including rock pigeons (Columba livia), Asian pied starlings (Gracupica contra), spotted doves (Streptopelia chinensis), oriental magpie robins (Copsychus saularis), blue-tailed bee-eaters (Merops philippinus), mynas (Acridotheres spp.), and pond herons (Ardeola spp.). Some of wild bird species have been found to carry the H5N1 genome, including Asian pied starlings, white-vented mynas (Acridotheres grandis), rock pigeons, tree sparrows (Passer montanus), common mynas (Acridotheres tristis), common koels (Eudynamys scolopacea), black drongos (Dicrurus macrocercus), scaly-breasted munias (Lonchura punctulata), plain-backed sparrows (Passer flaveolus), unidentified pond heron species, unidentified heron species, and unidentified dove species (all residential species). Additionally, this includes the Kentish plover (Charadrius alexandrinus), brown-headed gull (Larus brunnicephalus), Asian openbilled stork (Anastomus oscitans) (all winter visitors), and various duck species.

Transmission from birds to humans

Between 2004 and 2006, only 25 cases of H5N1 virus infection in humans were reported in Thailand. The outbreaks in humans and poultry shared similar timeframes and geographical distributions, suggesting that poultry was the source of infection in humans. Infected birds can spread the virus through their mucous, saliva, or feces. Transmission could occur through prolonged and direct contact with sick birds and/or contaminated materials. There have been no reported cases of H5N1 infection in humans resulting from exposure to wild birds in Thailand. Although transmission from birds to humans is relatively rare, it is recommended to practice good hygiene, such as handwashing and avoiding contact with your face, when handling wild birds.

When you encounter a dead bird that appears abnormal, you should follow these steps:

  1. Avoid Touching the Bird: Do not touch the dead bird with your bare hands, as it may be infected or carry contagious diseases (not only H5N1). Use gloves or thick plastic bags when handling or picking up the bird.
  2. Notify Authorities: Inform local authorities and providing detailed information about the location and condition of the bird.
    • In Bangkok
      • Department of Livestock Development.
        Tel. 02 653 4444
        Line official account: @dldthailand
        Facebook page:  https://www.facebook.com/DLDthailand
      • The Monitoring and surveillance center for zoonotic diseases in wildlife and exotic animals.
        Tel. 02 441 5242-4 Ext. 1201, 1202.
        Facebook page:  https://www.facebook.com/MoZWE
        Email: mozwe.muvs@gmail.com
    • For other provinces, notify the District Livestock Office or the Provincial/Community Health Volunteers (CHVs), Health Station Officers, Village Chiefs, Municipality, or Tambon Administrative Organization.
  3. Do Not Consume the Bird: Do not consume birds that have died abnormally or exhibit signs of illness, as they may pose health risks.
  4. Maintain Cleanliness: After handling the bird, thoroughly wash your hands with soap and water, or use hand sanitizer or disinfectant gel.
  5. Wait for Assessment: Wait for local authorities or relevant offices to assess the situation. Further examination or investigation of the cause of the bird’s death may be necessary.
Thailand-NWHC admin
Ladawan Sariya

The Monitoring and Surveillance Center
for Zoonotic Diseases in Wildlife and Exotic Animals (MoZWE)
Faculty of Veterinary Science, Mahidol University