The epidemiology of measles has been investigated in Niakhar, a rural area of Senegal, during two periods, 1983-1986 and 1987-1990.
Following a major increase in immunization coverage beginning in 1987, the case fatality ratio for all ages declined fourfold from the first to the second period (relative risk (RR)=0.24,95% confidence interval (CI) 0.13-0.46).
The measles incidence for children under 10 years of age declined by 69% (95% CI 65-72) and the risk of dying of measles by 91% (95% CI 82-95).
Vaccinated children who contracted measles had significantly lower case fatality ratio than unvaccinated children with measles (p=0.038).
Children infected by an immunized case tended to have lower case fatality ratio than those infected by an unimmunized index case (p=0.104) and immunized index cases generated fewer secondary cases than unimmunized index cases (p<0.001).
Respiratory complications were more common in secondary cases infected by an index case with respiratory complications than by an index case without such complications (RR=1.60,95% CI 1.08-2.37), which suggests that severe cases give rise to further severe cases.
As expected, there was a significant increase in the proportion of vaccinated cases in the second period (RR=1.41,95% CI 1.00-1.98).
Mean age at infection increased from 4 to 7 years between the two periods and the change in age structure accounted for 20% of the decline in case fatality ratio. (...)
Mots-clés Pascal : Rougeole, Virose, Infection, Vaccination, Mortalité, Epidémiologie, Evaluation, Incidence, Evolution, Enfant, Homme, Programme sanitaire, Sénégal, Afrique, Zone rurale
Mots-clés Pascal anglais : Measles, Viral disease, Infection, Vaccination, Mortality, Epidemiology, Evaluation, Incidence, Evolution, Child, Human, Sanitary program, Senegal, Africa, Rural area
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0133244
Code Inist : 002B30A03B. Création : 21/05/1997.