Dr. Shyam P Lohani

Sporadic outbreaks of avian influenza, also known as bird flu, are reported from many parts of the world every year. Nepal experienced the first-ever outbreak of bird flu in 2009 in the eastern part of the country. The first human death in Nepal following respiratory complications while undergoing treatment was reported in 2019.
There are several types of bird flu, and H5N1 was the first avian influenza virus reported to have infected humans. H5N1 was first discovered in humans in 1997. The first infection in humans occurred in Hong Kong during that year. The outbreak was linked to the human handling of infected poultry. Since 2003, a total of 860 human cases have been reported with more than 50 per cent mortality rate (WHO, 2019).

Transmission
Bird flu is a viral infection that can infect birds but has the potential to infect also humans and other animals. However, most forms of the bird flu virus affect birds. Although avian influenza viruses usually do not infect people, rare cases of human infection with these viruses have been reported. Infected birds discharge the avian influenza virus in their saliva, mucous, and faeces. Human infections with bird flu viruses can occur after enough viruses enter into a person’s eyes, nose or mouth, or are inhaled. The infection in humans occurs when the virus is in the form of droplets or possibly dusts is inhaled by a person, or when a person touches surfaces that contain the virus on it and then touches his/her mouth, eyes, or nose.
Though rare, human infections with avian influenza viruses may have occurred most often after unprotected contact with infected birds or surfaces contaminated with avian influenza viruses. The direct contact with nasal secretions, feces, or secretions from the mouth or eyes of the infected birds is responsible for the disease transmission to humans.
Consuming properly cooked poultry or eggs from infected birds does not transmit the bird flu, however, eggs should never be served raw and meat is safe only when cooked to an internal temperature of 165OF or 74OC. However, some infections have been reported without direct contact. Illness in people may range from mild to severe. There are few reports of human-to-human transmission among people with exceptionally close contact, such as a mother who caught the virus while caring for their sick infant.
The spread of avian influenza viruses from one infected person to another has been reported very rarely, and when it has been reported it has been limited and without substantial evidence. But unlike the human flu virus, H5N1 bird flu does not spread easily from one person to another. The virus has the potential to mutate and gain the ability to spread easily between people. Therefore, monitoring human infection and human to human transmission is particularly important from a public health perspective.
Since H5N1 is the most common form of bird flu, it is often deadly to birds and can affect humans and other animals that come in contact with a carrier. Symptoms range from typical flu-like ones such as cough, diarrhea, respiratory difficulties, fever (over 100.4°F or 38°C), headache, muscle aches, malaise, runny nose, to a sore throat.
There are several preventive measures that would reduce the risk of Influenza A (H5N1). Washing hands frequently and properly, taking due care of personal hygiene such as washing hands with disinfectants like soaps after touching the poultry can reduce the chance of transfer of deadly virus in human, maintaining the cleanliness of surroundings, and using gloves and masks during handling domestic poultry and other birds.
Avoiding preparing or eating raw or undercooked poultry products, handling raw poultry hygienically and cooking all poultry and poultry products (including eggs) thoroughly before eating, keeping children away from the dead or sick birds, and avoiding contact with domestic birds (poultry) that appear ill or have died are other preventive measures.
It is advised to avoid contact with high-risk environments such as live wet poultry, animal markets, and poultry farms, and any free-ranging or caged poultry, and avoid direct contact with surfaces contaminated with feces of wild or domestic birds. It is also wise to avoid close contact with people with respiratory symptoms such as cough, sneezing and cold, and travelers returning from areas affected by avian flu outbreak in domestic or wild birds should report to local health services if respiratory symptoms such as cough, sneezing and cold suspecting avian influenza.

Prevention
Persons experiencing flu-like symptoms (fever, cough, malaise, muscle pain, diarrhea) should wash their hands regularly with proper drying of the hands, cover mouth and nose when coughing or sneezing. Used tissues should be disposed of safely. Like in most cases of viral infection, a person with symptoms should self-isolate early if feeling unwell, feverish, and having other symptoms.
People working in poultry and with direct contact with sick poultry to be vigilant to notice the occurrence of the illness early and seek treatment early and it is advised to use masks, goggles, gloves, gown, and cap when near infected patients and always wash hands with soap and water or use hand sanitizer. People who are at most risks of contracting H5N1 are a poultry farmer, a traveller visiting affected areas, exposed to infected birds, someone who eats undercooked poultry or eggs, a healthcare worker in contact with infected patients, and a family member of an infected person. Thus, it is advised that people who are at most risks should be more cautious and adopt preventive measures strictly.

(A Professor, Lohani is the founder and academic director at Nobel Academy. lohanis@gmail.com)