IE 11 is not supported. For an optimal experience visit our site on another browser.

H1N1 mutation found in some flu fatalities

Norwegian health authorities said Friday they have discovered a potentially significant mutation in the H1N1 influenza strain that could be responsible for causing the severest symptoms among those infected.
H1N1 flu vaccine bottle is seen at George Washington University in Washington
Authorities said there is no reason to believe any mutation of the H1N1 virus had any implication for the effectiveness of the vaccine.Hyungwon Kang / REUTERS
/ Source: Reuters

Norwegian health authorities said Friday they have discovered a potentially significant mutation in the H1N1 influenza strain that could be responsible for causing the severest symptoms among those infected.

"The mutation could be affecting the virus' ability to go deeper into the respiratory system, thus causing more serious illness," the Norwegian Institute of Public Health said in a statement.

The concern over mutation of the H1N1 virus came as health officials said the H1N1 virus is moving eastwards across Europe and Asia after appearing to peak in parts of western Europe and the United States, the World Health Organization (WHO) said on Friday.

There are "early signs of a peak in disease activity in some areas of the northern hemisphere," the WHO said in a statement Friday.

At least 6,770 deaths have been recorded worldwide since the swine flu virus emerged in April, according to the latest WHO update which showed 520 known fatalities in the past week.

Authorities added they had no reason to believe the mutation had any implication for the effect of flu vaccines or antiviral drugs made by groups such as Roche, GlaxoSmithKline, Novartis or AstraZeneca.

In Norway the mutation was found in the bodies of two people killed by the virus and of one person made seriously ill.

The two people infected by the mutated virus were among the first fatalities from the H1N1 pandemic in Norway, the institute said. The WHO is investigating samples of the virus in those two people.

It was unclear whether the mutated virus was transmitted among humans, the health authorities said.

"Based on what we know so far, it doesn't seem like the mutated virus is circulating in the population, but rather that spontaneous changes have happened in the three patients," director Geir Stene Larsen at the public health institute said in the statement.

In some later fatalities linked to H1N1 that were studied, the same mutation was not found. It had found other mutations in some other cases, but the mutations found in two of the first fatalities and one seriously ill patient had been of "particular interest," it said.

Norway has seen relatively more fatalities in the flu pandemic compared to the size of the population versus other European countries, with 23 confirmed deaths and 680,000 estimated to have been infected.

Public health authorities have said this could be due to the country being hit early in the pandemic's northern hemisphere winter wave, before a mass vaccination program got underway.

"Nevertheless, it is important to study if there's still something about the Norwegian fatalities that separate us from other countries, and that make us learn something that strengthens our treatment of the seriously ill," director Bjorn-Inge Larsen at the Norwegian Directorate of Health said.

Still widespread in U.S.
H1N1 flu is still widespread across the United States although it appears to have recently peaked in most areas except the northeast. But transmission continues to intensify in Canada, with the highest number of doctor visits by children.

Spread of the flu appears to have peaked in western European countries including Belgium, Britain, Iceland and Ireland after a period of intense outbreaks, the United Nations agency said.

Norway and countries further east including Georgia, Lithuania, Moldova and Serbia are reporting sharp increases in influenza-like illness or acute respiratory infection, it said.

Kazakhstan, Uzbekistan and parts of Afghanistan — particularly Kabul — are reporting higher numbers of flu cases. Israel is also reporting sharp increases.

"Essentially what is happening is that it is spreading eastwards," Anthony Mounts, medical epidemiologist on WHO's influenza team, told Reuters. "Typically seasonal influenza always starts west and moves eastwards. It seems to be following that pattern except it is coming very early this year."

Flu transmission remains active in east Asia, the WHO said. "In Japan, influenza activity remains elevated but stable nationally and may be decreasing slightly in populated urban areas," it said.

Most countries in tropical areas of central and South America continue to report declining numbers of flu cases, with the exception of Peru and Colombia, it said.