|
S Afr Med J 1994 Mar;84(3):145-149 |
The 1992 measles epidemic in Cape Town--a changing
epidemiological pattern.
Coetzee N, Hussey GD, Visser G, Barron P, Keen A.
Department of Community Health, University of Cape Town.
Over the last 6 years there has been a decline in the incidence of measles in
Cape Town. However, during August 1992 an outbreak occurred, with cases
reported at many schools in children presumably immunised. The objectives of
this study were to characterise the epidemic in Cape Town and to determine
possible reasons for the outbreak. The investigation consisted of two
components--a description of the epidemic and an investigation of an outbreak
at one primary school. Results indicate that during the last 4 months of the
year, 757 cases were notified in Cape Town, compared with 144 in the first 8
months. The epidemic affected mainly white and coloured children over 5 years
of age (P < 0.001). In contrast, during the period before the epidemic most
cases occurred in black children and in those aged less than 1 year (P <
0.001). There was no significant increase in hospitalised cases. Investigation
of the outbreak at one school revealed that the attack rate was 7.6% (25/329
children). Immunisation coverage (at least one dose of any measles vaccine) was
91% and vaccine efficacy was estimated to be 79% (95% CI 55-90); it was highest
for monovalent measles (100%) and lowest for measles-mumps-rubella (74%). The
epidemiology of measles in Cape Town has thus changed as evinced in this
epidemic, with an increase in the number of cases occurring in older,
previously vaccinated children. The possible reasons for this include both
primary and secondary vaccine failure.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 7740350 [PubMed - indexed for MEDLINE]
ALL
INFORMATION, DATA, AND MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR
GENERAL INFORMATION PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE
KNOWLEDGE OR OPINIONS OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED
AS PROVIDING MEDICAL OR LEGAL ADVICE. THE DECISION WHETHER OR NOT TO
VACCINATE IS AN IMPORTANT AND COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU
ALONE, IN CONSULTATION WITH YOUR HEALTH CARE PROVIDER.