Britain’s Health Protection Agency (HPA) said five cases have been confirmed in Wales of patients infected with H1N1 resistant to oseltamivir — the generic name of Roche and Gilead Sciences Inc’s antiviral drug Tamiflu.The World Health Organization is looking into reports in Britain and the United States that the H1N1 flu may have developed resistance to Tamiflu in people with severely suppressed immune systems, a spokesman said Tuesday.
“We have seen the reports, we need to look into them,” WHO spokesman Thomas Abraham said in Geneva.The patients had serious conditions that suppressed their immune systems, which can give the virus a better than usual opportunity to develop resistance, the HPA said. It said the drug-resistant strain had probably spread person to person.
The U.S. Centers for Disease Control and Prevention last week also reported four cases of H1N1 resistant to Tamiflu at Duke University Hospital in North Carolina. All were said to be very ill with underlying severely compromised immune systems and multiple other complex medical conditions.”We’ll see if we need to put any additional measures in place to protect this vulnerable group of patients. It might mean that they are at more serious risk than others,” Abraham said.
The WHO spokesman said both the reports involved Tamiflu resistance in people with severely compromised immune systems.People with suppressed immune systems, such as those undergoing chemotherapy or suffering from HIV are more likely to fall ill from infections.The WHO has previously reported cases of the pandemic virus being resistant to oseltamivir but says these are rare.
The Norwegian Institute of Public Health said last Friday the mutation could affect the virus’ ability to go deeper into the respiratory system, causing more serious illness.”It is a major issue we are looking at,” Abraham said.”If the mutation in fact is associated with severe cases then we really need to know about it. This might be a signal. We need to investigate,” he said. “As of now there is no evidence of a particular association with severe cases.”
H1N1, a mixture of swine, bird and human viruses, has killed at least 6,770 people globally, according to the WHO. Most people suffer mild symptoms such as aches or fever, but recover without special treatment, it says.
There have now been four cases of mutated virus in patients in Norway, following a similar mutation in H1N1 viruses circulating in several other countries since April, he said. The other countries are Brazil, China, Japan, Mexico, Ukraine and the United States.”What we’ve seen has been pretty much equal in terms of severe and non-severe cases,” Abraham said.
(re-edited by admin)