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| EPI-NEWS |
National
surveillance of communicable diseases
Dept. of Epidemiology
Editor: Susanne Samuelsson |
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| Tel.: +45 3268 3038 - Fax: +45 3268
3874 |
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epinews@ssi.dk - ISSN: 1396-4796 |
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| HEPATITIS A 2000 |
In the year
2000, 81 patients were notified with hepatitis A, 49 men and 32
women. This represents the same low level as in previous years,
EPI-NEWS 9/99 and 18/00. The age distribution is shown in
Table 1.
As before, the incidence was highest in the
under-10-year age group. Of the 34 children aged 0-9 years, 22
were 5 or under 5 years old, comprising 10 Danes and 12
immigrants. The incidence per 100,000 was 1.1 for Danes and 6.9
for immigrants. 37 patients (40%) were admitted to hospital in
connection with hepatitis A infection; 25 were Danes, seven of
whom were aged 15 years or less. Of the 12 immigrants admitted
to hospital 11 were under 15 years. The incidence was highest in
the Municipality of Copenhagen and Roskilde County,
Table 2.
Mode of infection
In 41 cases (51%) the infection was aquired in Denmark; the mode
of infection was unknown in 18 of these,
Table 3. Of the 55 Danish patients, 22 were infected
abroad, in 15 different countries. Of the 26 immigrant patients,
18 were infected abroad, in seven different countries, six in
Morocco and five in Turkey. In the 0-19-year age group, three of
19 Danes and 17 of 23 immigrants were infected abroad. Eight
persons were notified with presumed occupational infection in
2000; three were employed at day-care and two at special care
institutions, one worked at an asylum centre, one as a tour
leader and one as a plummer.
Vaccination status was reported for 27 patients, comprising 22
Danes (nine children below nine years of age) and five immigrant
children, all under nine years. None had been vaccinated, but
one had been given gammaglobulin in connection with a sister's
infection.
Case clusters
Six family and seven institutional outbreaks were recorded, each
category affecting a total of 14 persons. Three of the family
outbreaks and two of the institutional outbreaks could be
attributed with certainty to primary infection abroad.
Comments
The number of notified hepatitis A cases remains low. The
proportion of immigrants was 32% in 2000, nearly half that in
1999 (56%). Hepatitis A in immigrants is still most frequent in
children and adolescents. Vaccination or passive immunization of
immigrant children is therefore still relevant before visits to
their home country or other countries in which the risk of
hepatitis A viral infection is high.
(A. H. Christiansen, M. S. Nielsen, Dept. of Epidemiology)
THIMEROSAL IN VACCINES
The presence of thimerosal (also called thiomersal or
merthiolate) in
influenza vaccines has been mentioned in the press. Thimerosal
is an organic mercury compound used as a preservative or may
occur in trace amounts as a residue from the production process
for some inactivated vaccines. In Denmark, thimerosal has not
been used in vaccines for children since 1992. Overseas vaccine
manufacturers are working on eliminating the compound, which is
still used in certain vaccines, including influenza vaccines.
Thimerosal may produce allergic reactions, usually in the form
of contact dermatitis. Such reactions can be avoided by giving
the vaccine intramuscularly, EPI-NEWS 39/01. Mercury is regarded
as neurotoxic to the developing brain. Children could previously
get a cumulative dose due to the thimerosal content of many
children's vaccines. Statens Serum Institut has issued two
influenza vaccines containing thimerosal this year. Both have
been approved by the Danish Medicines Agency for the vaccination
of both children and adults. However, it has also been possible
to obtain a small amount of thimerosal-free vaccine, principally
intended for children belonging to risk groups, EPI-NEWS 39/01.
Some fish may contain mercury compounds in greater amounts than
those found in vaccines.
(A.-M. Plesner, Dept. of Medicine)
PILGRIMAGES TO MECCA
Saudi-Arabian health authorities have previously required
vaccination against meningococcal disease due to groups A+C
before entry during the pilgrimage season. In spring 2000 an
epidemic of group W135 infection broke out, repeated this
spring, when there was also a Danish case, EPI-NEWS 17/00 +
18/01. The authorities are therefore now requiring vaccination
with the tetravalent polysaccharide vaccine against groups
A+C+W135+Y.
All travellers over two years of age, including those vaccinated
against groups A+C within the last three years, must be
vaccinated once with the tetravalent vaccine at least 10 days
before entry. Children aged 3-24 months must have two doses at
an interval of three months, although only protection against
group A is to be expected.
(S. Samuelsson, Dept. of Epidemiology)
7 November 2001 |
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