PETA, the People for the Ethical Treatment of Animals have linked the filth of factory farms in India to the recent bird flu outbreak in Darjeeling in their latest claims.

The animal rights group says that in the midst of avian flu outbreak in Darjeeling, they released undercover video footage of crowded and filthy conditions on chicken and egg factory farms, which leading health experts believe causes the spread of the deadly H5N1 strain of bird flu.

The findings were sent to the West Bengal government last year, and the government was warned about how unsanitary conditions on factory farms could lead to an outbreak of the deadly H5N1 virus.

Because of the conditions that many chickens raised for meat and eggs are forced to endure, disease is rampant. On its website, the Environmental Defense Fund explains that "[a]ntibiotics are routinely fed to healthy livestock and poultry to make them gain weight faster and to compensate for unsanitary living conditions", reports PETA.

According to researcher Malati Puranik, who conducted a study of chickens sold in Mumbai, "[W]e realised that poultry sold under such unhygienic conditions is a serious health hazard. Pathogens such as campylobacter and salmonella proliferate, causing severe bacterial contamination". During the evisceration process, chicken carcasses easily become contaminated with faecal material when the intestines are cut or torn and the contents leak out during extraction.

According to a PETA report, unhygienic conditions on factory farms lead to outbreaks of bird flu. In 2007, Indian health officials confirmed a bird flu outbreak among poultry in the north-eastern state of Manipur. According to the World Health Organisation, out of the 342 registered cases of the H5N1 strain of bird flu, 211 people have died in 13 countries. Factory farms provide the perfect environment for the virus to strike. Because of the intense confinement of the animals, the deadly virus could spread like wildfire. Bird flu can be caught by humans who handle infected birds, and experts fear that the virus will eventually mutate into a form that is transmissible from human to human, setting off a catastrophic worldwide pandemic. Five people have been found to have bird flu symptoms in India. Recurrent outbreak of bird flu is a waste of public money. According to Health Minister Anbumani Ramadoss, the Indian government paid more than $19, 47,619 as compensation for poultry and feed in 2006, and more than $2, 23,810 was paid for birds culled in the 2007 outbreak.

In its report, PETA suggests that the welfare standards recommended by the UK's Royal Society for Prevention of Cruelty to Animals (RSPCA) should be used as the basic guidelines for the treatment of chickens in the poultry industry. Chickens die to provide the industry with huge profits, and PETA suggests that the industry owes the animals at least basic humane treatment in return.