Could bird u turn into the next pandemic?
Since 2006 India has experienced annual outbreaks of HPAI in dierent regions, leading to substantial economic losses.
Several states across the country including Kerala, Maharashtra, Chhattisgarh, and Jharkhand among others have been directed to stay vigilant after the emergence of a highly pathogenic avian in uenza that has spread to cattle was detected in eight U.S. states. While the Centre has asked for vigilance, the World Health Organization (WHO) expressed deep concern regarding the increasing transmission of H5N1 bird
u to other species, including humans. ”The current bird u outbreak, which originated in 2020, has aected not only ducks and chickens but also cows and goats, which is why the u has been described as “a global zoonotic animal pandemic,” it said.
WHO is warning about the risk of the virus evolving to infect humans and gaining the ability to transmit from human-to-human. Although there is no evidence of human-to-human spread yet, the mortality rate among those infected through contact with animals remains high. Over the past 15 months, WHO has documented 889 human cases across 23 countries, resulting in 463 deaths, a mortality rate of 52%
The Central government in India maintains that Highly Pathogenic Avian In uenza (HPAI), commonly known as bird u, was rst detected in the state of Maharashtra in February 2006. Since then, the country has experienced annual outbreaks of HPAI in dierent regions, leading to substantial economic losses.
WHO is warning about the potential risk of the virus evolving to infect humans and gaining the ability to transmit from human-to-human
The disease has been reported in 24 states, resulting in the culling of over 9 million birds to control its spread. It’s important to note that vaccination against HPAI is not permitted in India. The Centre has maintained that with the long-term use of vaccination either the disease has become endemic and therefore widespread, or the infection in aected animals is too dicult to detect. Accordingly, the Government of India does not permit use of any vaccine against avian in uenza in the country.
An article titled, ‘Bird u in US cows where will it end’ in Nature on May 8, 2024, notes that various forms of the
H5N1 virus have been circulating since the 1990s. A particularly deadly variant that was rst detected in 1996 killed millions of birds and has been found in numerous mammalian species, including seals and mink. But until now, cows were not among the virus’s known hosts. US ocials rst announced on 25 March that H5N1 had been found in cattle. Cows from 36 herds in 9 states have tested positive as of 7 May. Tests of pasteurized milk have found no living virus. But the virus’s increasing ubiquity has made scientists uneasy. It adds further that from a human perspective, cows might be one of the worst possible animal reservoirs for in uenza because of their sheer number and the degree to which humans interact with them. Culling poultry has curbed previous bird u outbreaks, that isn’t a viable option for cattle. The animals are too valuable and, unlike birds, don’t seem to die from the infection.
(bindu.p@thehindu.co.in)