Agriculture Minister Piyush Goyal.

That India is experiencing a new wave of livestock influenza, which has made it extremely difficult to trace and quantify the reported deaths or illnesses could have something to do with last week’s activity on the country’s coastline that, government officials say, may have been a continuation of a rapid trans-boundary transmission.

As of Thursday, India had reported 1,183 cases of H5N1, an unusually high number that evoked questions over the number of deaths, the number of laboratories equipped to process them and how highly contagious the new strain is.

On Tuesday, two Indians, both fishermen, had died from “swine” or “cattle flu”, which the government said was the result of skin-to-skin contact with pigs — something that is normally fatal.

Asked for more clarity on that, chief minister Yogi Adityanath said his government had not yet gotten any information, and added that if confirmation came in that such a figure was confirmed, it will be published.

On Thursday, India’s Defence Ministry said seven teams were conducting surveillance of the virus. “While this surveillance has gone on at four locations of the coastal regions, the army and air forces have not been asked to go into those locations,” the ministry said in a statement. “Though reported cases in Punjab have stopped since Monday, there is still lot of areas in this neck of the woods to be surveillanceed.”

The deaths in India are the latest in a string of cases of the disease that is threatening to spread and stir up a never-ending debate about its diagnosis, which has only just started to percolate in the country’s biggest newspaper, The Indian Express.

“The situation in places where H5N1 is prevalent has remained quite low,” said Radha Rane, head of H5N1 risk assessment for the WHO.

Seventeen deaths from swine influenza have been reported so far in India, with more than 7,000 people affected, most of them domestic workers.

Rane said several countries including the US and Canada are reporting high-spectrum cases of H5N1 in humans, which investigators suspect can be related to its infectious properties.

The H5N1 virus is much more virulent in pigs than humans. The recent spike in H5N1 deaths in India comes after the government failed to report a specific peak in cases for three years.

Last month, a delegation of USDA veterinarians, the US Centers for Disease Control and Prevention and the World Health Organization met India’s agriculture minister to discuss H5N1 risk.

US Agriculture Secretary Sonny Perdue said: “The science already provides very strong evidence of the spread of avian influenza to humans and Europe and specifically to India.”

A highly contagious bird flu that has been characterised by a broad and extensive transmission between poultry, pigs and humans, H5N1 is believed to have evolved through close contact with infected birds, though the researchers who conducted the study have raised the question over whether that included sharing of infected animals by friends.

“In the case of H5N1, we have now confirmed human-to-human transmission in persons in two different locations,” Patrick Kilpatrick, senior deputy director for disease control at the WHO, said in a statement.

The virulence of the new strain “is certainly something we would need to determine,” he said. “It certainly is very different from people I would hesitate to directly say that H5N1 is a trend of human-to-human transmission.”

The Indian government also suggested that its warning had been over-reacted, and that the country may have been over-estimated by reports of cases of the virus in Brazil and Argentina.

“There has been an increase in globally what has been called ‘swine flu’, but to my own mind, it has not been as severe as the Himalayan episode that happened several years ago,” said defence ministry spokesman V K Singh.

Doctors said animals should not start spreading viruses of this nature unless they are vaccinated.

“They need to be vaccinated by whichever contact they are with. If anyone is in a carriage carrying a carcass or guinea pig, they should be vaccinated too,” said Dr Jagannathan Keshav, a veterinary pathologist at New Delhi’s National Institute of Veterinary Sciences.

“We need to vaccinate our animals very broadly, and we should not forget that many have already started dying. It is best to stop the spread,” said Dr Fayan S. Qureshi, a senior scientist at India’s Institute of Tropical Medicine, who cautioned against applying