http://www.elsevier.com/gej-ng/10/42/35/80/25/41/abstract.html
Please note! As of 2002 online access to
full-text articles is available to all readers whose library
|
Vaccine, Vol. 21 (1-2) (2002) pp. 120-126
© 2002 Elsevier Science Ltd. All rights reserved.
PII: S0264-410X(02)00430-9
a Unité de Recherche sur les Maladies Infectieuses
et Parasitaires, IRD, Dakar, Senegal
b Department of Epidemiology Research, Danish
Epidemiology Science Centre, Statens Serum Institut, Artillerivej 5, DK-2300
Copenhagen S, Denmark
c IRD, Montpellier, France
d Université Cheikh Anta Diop, Dakar, Senegal
e MRC Laboratories, Banjul, Gambia
Received 20 November 2001; received in revised form 2 August 2002; accepted 4 August 2002
Background: It has been assumed that measles infection may be associated with persistent immune suppression and long-term excess mortality. However, few community studies of mortality after measles infection have been carried out. We examined long-term mortality for measles cases, sub-clinical measles cases, and uninfected contacts after an epidemic in rural Senegal.
Methods: The study was carried out in Niakhar, a rural area of Senegal. Index cases of measles were identified and children less than 7 years of age exposed to measles in the same compound had acute and convalescent blood samples collected. Clinically diagnosed measles cases were serologically confirmed. Children without clinical symptoms were classified as sub-clinical cases if they had a four-fold or greater change in antibody levels between samples collected at exposure and 1 month later and as uninfected if there was no or a two-fold change in antibody levels.
Results: There were 31 index cases, and among 184 exposed contacts, 35 (19%) children developed clinical measles. Among contacts that did not develop clinical measles, 45% had sub-clinical infection. Measles cases, sub-clinical cases, and uninfected contacts did not differ with respect to nutritional status. However, uninfected children without clinical symptoms and change in antibody level had higher initial measles specific IgG antibody levels and less intensive exposure to the index case. No index or secondary case of measles died in the acute phase of infection nor did any of the children exposed to measles die in the first 2 months after exposure. Exposed children developing clinical measles had lower age-adjusted mortality over the next 4 years than exposed children who did not develop clinical measles (P<0.05). Sub-clinical measles cases tended to have low mortality and compared with uninfected children, exposed children with clinical or sub-clinical measles had lower age-adjusted mortality (mortality ratio (MR)=0.20 (0.06-0.74)). Controlling for background factors had no impact of the estimates.
Conclusions: When measles infection is mild, clinical measles has no long-term excess mortality and may be associated with better overall survival than no clinical measles infection. Sub-clinical measles is common among immunised children and is not associated with excess mortality.
Keywords: Beneficial immune stimulation; Long-term excess mortality; Mortality; Measles infection; Measles immunisation; Sub-clinical measles
*Corresponding author. Fax: +45-3268-3165.
Full text supplied by [ScienceDirect]
© Copyright 2002, Elsevier Science, All rights reserved.
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.