At the end of the second week of September a secondary
school in Dublin reported that several students were ill with an influenza-like
illness. The school has more than 300 pupils, the majority of whom are boarding
pupils. The first case had onset of illness on 7 September. The patient had
returned from the United Kingdom four days previously*
Over the next 10 days, other pupils developed a similar illness. The symptoms
were mainly high fever (39°C), headache and sore throat. One pupil was
admitted to hospital with fever and abdominal pain. In total, 81 pupils and
one staff member were ill. The student attack rate was 26%.
Nine throat swabs were sent for bacteriological and viral culture. Influenza
A (H3N2) has been identified by the National Virus Reference Laboratory
in four of the specimens. Investigations are ongoing to determine if the
virus strain identified is similar to that in the 2003/2004 influenza vaccine.
These are the first confirmed cases of influenza in Ireland this season.
Until now, only isolated cases of influenza, in two countries, have been
reported to the European Influenza Surveillance Scheme (EISS, http://www.eiss.org).
The report from Ireland is the first report of an influenza outbreak (that
is, the occurrence of a localized cluster of cases) in Europe this season.
EISS will begin publishing its seasonal Weekly Electronic Bulletin on 17
*Correction from the authors, 3 October 2003: The index
case was in the United Kingdom (UK) prior to returning to school and not in
Asia as previously reported. As the onset of illness was reported to be four
days after returning to school it is more likely that the flu was picked up
locally. The three other laboratory confirmed cases were also based either
in Ireland or the UK over the summer.