Resistant strain of swine flu feared; virus killing thousands in India


A surge in swine flu infections has killed more than 800 people in India and is challenging health workers, who say the virus is harder to treat than the type that caused a global pandemic in 2009.

High-risk patients with the infection now need an average of 10 days of treatment with the anti-viral medicine oseltamivir, according to Om Shrivastav, director of the infectious diseases department at Jaslok Hospital in Mumbai. That is double the length of treatment in previous outbreaks, he estimates.

The H1N1 type of the influenza virus that is spreading in India is similar to the virus that caused the 2009 outbreak, which killed more than 18,000 people worldwide. India, whose public spending on health as a percentage of gross domestic product is among the lowest in the world, is racing to procure more antiviral drugs for its emergency stocks. The government is also launching an education campaign for prevention that includes promoting hand hygiene.

Compared to the 2009 outbreak, “this time, we see that it’s become more aggressive,” said Ritesh Gupta, a senior consultant at Fortis Hospital’s diabetes center in New Delhi. “The virus is responding less to therapy. Even the so-called uncomplicated cases are taking a long time for symptomatic improvement.”

The virus is transmitted by droplets from coughs and sneezes that are inhaled or picked up from contaminated hands or surfaces. Symptoms include high fever, sore throat, fatigue and chills. People in the affected pockets of India may lack immunity against the virus and have no vaccination history, said Masato Tashiro, director of Japan’s National Institute of Infectious Diseases.

It is also possible that the virus circulating in India has developed resistance to oseltamivir, he said.

“As far as we recognize, significant antigenic changes have not occurred with H1N1 viruses circulating in the world, but my concern is that such changes have occurred in India,” said Tashiro. Analysis of the gene sequence of the virus is needed to determine whether changes have occurred.

Pockets of oseltamivir-resistant H1N1 occurred last year in Hokkaido, northern China and the U.S., as well as in Australia in 2011. The past outbreaks of resistant flu have been in pockets and haven’t spread far, Tashiro said.

The WHO in June 2009 issued a pandemic alert after the discovery of the new H1N1 virus in Mexico and the U.S. two months earlier. Most countries around the world reported infections. By August 2010, the virus had killed at least 18,449 people, the agency said.

The WHO says the H1N1 virus that caused the pandemic in 2009 is now a regular human flu virus and continues to circulate seasonally worldwide. The oseltamivir treatment still works, Jaslok Hospital’s Shrivastav said. “The difference is that you might have to use a bigger dose over a longer period of time.”

India’s Cipla Ltd. and Strides Arcolab Ltd. make oseltamivir — versions of Roche Holding AG’s anti-viral Tamiflu. Roche in 2005 granted a voluntary license to another Indian company, Hetero Drugs, to manufacture an authorized copy.

High-risk patients are those who also have diabetes, hypertension, tuberculosis and other respiratory diseases. They include patients with immune systems compromised due to cancer or HIV, patients on steroid treatment and pregnant women.

“As of now, the numbers are only increasing — there’s no hint of it going down,” Fortis Hospital’s Gupta said. “But I believe that once the weather changes in northern India, once the temperatures rise a little, we will see a reduction in the cases.”

The current outbreak has killed 841 people in the last two months, compared to 981 deaths spanning eight months in 2009, according to health ministry data from Feb. 24.

The Indian government includes oseltamivir on a list of prescription drugs known as Schedule X, which pharmacies have to apply for special permits to sell, making the drug harder to buy.

“We cannot afford a situation where due to irrational use of the drug, resistance is developed, rendering the drug incapable of fighting the virus,” the health ministry said in a statement. The ministry has recommended influenza vaccination for all health workers, and not the public.