This blog is about an article I read in the New Scientist entitled ‘Europe may be blind to swine flu cases’. The article deals
with a point I raised in my previous blog posted on 1st May on H1N1 flu. Having flown back from a holiday in
Canada, I started suffering flu symptoms the week swine flu hit the news
headlines and I wasn’t tested for H1N1 because I didn’t fit the pattern of
suspect cases, which is having been to Mexico in the past 7 days, or being in
contact with a swine flu confirmed case. I mentioned then I thought this is a
simplistic way of deciding who is suitable for screening. As a scientist, I
would have included a control group, i.e. some of the people who don't fit the
pattern, so that we would have a better idea of the extent of the spreading of
the virus. My daughter who went to Canada with me also had flu a
couple of days after I had.
The article in the New
Scientist of 23rd May suggests Europe
might have more H1N1 flu than it knows simply because people are not being
tested. The article states that for the World Health Organisation to be able to
declare a pandemic, it needed evidence of sustained transmission of the H1N1 virus
outside the Americas,
where the virus originated. This meant finding cases in the general population
that have not had known contact with places or people confirmed to have the
virus. Japan
had reported over 100 cases, including many without known contact when the
article was published 5 days ago. However, European countries are using a case
definition from the European Centre for Disease Prevention and Control (ECDC)
in Stockholm, Sweden, that virtually precludes
discovering such cases. It recommends testing people with symptoms only if they
have been to affected countries or had contact with known or suspected case in
the past seven days. ‘We can’t test every mild case of flu symptoms,’ said
Johan Giesecke, chief scientist at ECDC. My flu symptoms were anything but mild
and even though I tried to convince my doctor’s surgery, I wasn’t tested.
Anyway, I thought the people who had H1N1 flu had only shown mild symptoms.
The article in the New
Scientist reported a similar case to mine of a reader and two family
members who had flu symptoms after one of them returned from New York around
the same time I had and were not tested for H1N1 either, for the same reasons I
wasn’t tested. The reason given by the British Medical Association was that not
many tests were available and if you can’t do many tests you save them for
people who meet the case definition. Any other cases would be picked up by
‘sentinel’ clinics that compile weekly statistics, says the Association’s
spokesman. However, such sentinel systems are designed to track ordinary flu,
and not a new infection that is initially highly localised, said the New Scientist. The International Society
for Infectious Diseases advises testing clusters of flu and all severe cases. Hong Kong is testing all hospitalised cases of flu and
pneumonia. Belgium,
departing from ECDC advice, is testing flu-like clusters and deaths. But
without more tests, Europe may be missing
epidemic, says the New Scientist
article.
Please visit the Cabi Swine Flu Dashboard for everything you want to know and the latest developments on H1N1 flu.
Source: New Scientist, 23 May 2009.