Thiruvananthapuram: People exposed to H5NI virus-infected birds should remain in home quarantine for 10 days from the last day of exposure, according to the new guidelines and Standard Operating Procedure (SoP) issued by the Kerala Health Department in the wake of repeated bird flu outbreaks in the state.

The Kerala government has issued new guidelines as most human infections reported globally occurred after unprotected exposure to sick or dead, infected poultry.
Home quarantine has been recommended even to exposed people even if they were wearing personal protective equipment (PPE) while handling the birds. 

Post-exposure, people should monitor themselves for new respiratory illness symptoms, including conjunctivitis, beginning after their first exposure and for 10 days after their last exposure. Symptomatic persons should isolate from others including household members until it is determined that they do not have H5N1 virus infection.
The health department has recommended treating post-exposure influenza with antiviral Oseltamivir to prevent infection, especially in those who had unprotected exposure to virus-infected birds.

Those who develop symptoms shall seek medical evaluation, testing and antiviral treatment. Poultry farmers and workers, veterinarians have been directed to avoid unprotected direct physical contact with sick birds in a 10 km radius around the epicentre, carcasses of birds within a 10 km radius, faeces, raw milk, surfaces and water that might be contaminated with bird/ animal secretions.

The document notes that sporadic human infections with highly pathogenic Avian Influenza A(H5N1) virus, with a wide spectrum of clinical severity and a cumulative case fatality of more than 50 per cent, have been reported in 23 countries over more than 20 years. Three cases of H5N1 virus infection in dairy farm workers were recently reported from the USA. Spillover of H5N1 to mammals has not been reported in Kerala. 

Influenza A viruses infect the respiratory and gastrointestinal tracts of birds causing birds to shed the virus in their saliva, mucous, and faeces. The viruses can also infect the respiratory tract of mammals and cause systemic infection in other organ tissues. Human infections with avian influenza A viruses can happen when enough virus gets into a person’s eyes, nose, or mouth or is inhaled. People with close or prolonged unprotected contact with infected birds or animals or their contaminated environments are at greater risk of infection. Recent preliminary findings from pathogenicity and transmissibility studies indicate that the reassortant influenza A(H5N1) strains cause more severe illness in ferrets, increasing concerns about the potential for transmission to humans, according to the document.

Individuals can be exposed to the virus through contact with infected birds, dead birds, or birds' secretions (mucus, saliva), blood and faeces (as birds shed the virus in their secretions and faeces). Transmission of the virus occurs via inhalation or contact with mucus membranes (e.g., eyes, nose, mouth).