Mutation of pandemic H1N1 in Norway
The Norwegian Institute of Public Health announced today to have found a mutated version of the influenza A (H1N1) virus in three patients in Norway who had tested positive for the new flu
The Norwegian Institute of Public Health has analyzed virus from a number of patients as part of the surveillance of the pandemic flu virus. The viruses have many similarities, but some mutations have been observed. This is normal and most of these mutations will probably have little or no importance.
However, one mutation has caught special interest. It has been found in two patients who died from the new influenza A (H1N1) and in one patient with severe influenza disease. These were the two first patients who died from the new influenza in Norway. Some of those who died later have been examined without finding the same mutated virus.
The mutation could possibly make the virus more prone to infect deeper in the airways and thus cause more severe disease.
“We have analyzed approximately 70 viruses from confirmed Norwegian cases and found the mutation in only these three patients,” says Director General Geir Stene-Larsen at the Norwegian Institute of Public Health. “Based on what we know so far, it seems that the mutated virus does not circulate in the population, but might be a result of spontaneous changes which have occurred in these three patients.”
“There is no indication that this change in the virus is of any importance for the effect of the vaccine or the effect of antiviral treatment,” concludes Stene-Larsen.