Cell mediated immunity after measles in Guinea-Bissau: historical cohort studyBMJ 1996; 313 doi: https://doi.org/10.1136/bmj.313.7063.969 (Published 19 October 1996) Cite this as: BMJ 1996;313:969
- S O Shaheen, Wellcome Trust training fellow in clinical epidemiologya,
- P Aaby, senior researcherb,
- A J Hall, reader in epidemiologyc,
- D J P Barker, directora,
- C B Heyes, research assistanta,
- A W Shiell, statisticiana,
- A Goudiaby, paediatriciand
- a MRC Environmental Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton SO16 6YD,
- b Epidemiology Research Unit, Danish Epidemiology Science Centre, Statens Seruminstitut, Copenhagen, Denmark,
- c Communicable Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, London WC1E 7HT,
- d Ministry of Public Health, Bissau, Guinea-Bissau
- Correspondence to: Dr S O Shaheen, Department of Public Health Medicine, United Medical and Dental Schools of Guy's and St Thomas's Hospitals, St Thomas's Hospital, London SE1 7EH.
- Accepted 20 August 1996
Objective: To investigate whether children who have had measles have reduced general cell mediated immunity three years later compared with vaccinated children who have not had measles.
Design: Historical cohort study.
Setting: Bissau, Guinea-Bissau.
Subjects: 391 children aged 3–13 years who were living in Bissau during a measles epidemic in 1991 and still lived there. These included 131 primary cases and 139 secondary cases from the epidemic and 121 vaccinated controls with no history of measles.
Main outcome measures: General cell mediated immunity assessed by measurement of delayed type hypersensitivity skin responses to seven recall antigens. Anergy was defined as a lack of response to all antigens.
Results: 82 out of 268 cases of measles (31%) were anergic compared with 20 of the 121 vaccinated controls (17%) (odds ratio adjusted for potential confounding variables 2.2 (95% confidence interval 1.2 to 4.0); P = 0.009). The prevalence of anergy was higher in secondary cases (33% (46/138)) than in primary cases (28% (36/130)), although this difference was not significant. Anergy was more common in the rainy season (unadjusted prevalence 31% (91/291)) than in the dry season (11% (11/98)) (adjusted odds ratio 4.8 (2.2 to 10.3)). This seasonal increase occurred predominantly in the cases of measles.
Conclusions: Reduced general cell mediated immunity may contribute to the higher long term mortality in children who have had measles compared with recipients of standard measles vaccine and to the higher child mortality in the rainy season in west Africa.
The mechanisms underlying delayed mortality are not understood
In Guinea-Bissau children who were tested three years after having had measles had lower general cell mediated immunity than vaccinated children
Reduced cell mediated immunity was more common in the rainy season than in the dry season, particularly in cases of measles
A reduction in cell mediated immunity may, by increasing susceptibility to other infections, contribute to delayed mortality after measles and to the higher death rates during the rainy season in west African children
Funding Funding: The Ministry of Health of Guinea-Bissau supported this study. The Danish Council for Development Research, the Danish Medical Research Council, the Danish Social Science Research Council, and the Science and Technology for Development Programme of the European Community (TS3*CT91*0002) have supported research on measles in Bandim. CBH and the study were funded by the Wellcome Trust.
Conflict of interest None.
- Accepted 20 August 1996