Epidemiological evidence for immunity following Trypanosoma brucei gambiense sleeping sickness.
In order to investigate whether protective immunity appears after Trypanosoma brucei gambiense sleeping sickness, we undertook a retrospective cohort study of 3 remote villages in central Zaire (total population 1431), in which 38% of all adults had a past history of human African trypanosomiasis. Among adults previously diagnosed with trypanosomiasis and treated, the risk of a second episode of trypanosomiasis during the 10 years period of observation was only 15% (with a 24 months refractory period) and 30% (without a refractory period) of the risk of a first episode in adults never previously diagnosed. We could not demonstrate a similar difference among children, to some extent because only a few of them were diagnosed for a first time with trypanosomiasis. Our findings suggest that very significant immunity appears after Gambian sleeping sickness, and that developing a vaccine against this subspecies of trypanosomes is biologically plausible.
Khonde
N
N
Department of Medicine, Université de Sherbrooke, Canada.
Pépin
J
J
Niyonsenga
T
T
Milord
F
F
De Wals
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015023:Democratic Republic of the Congo / Q000453:epidemiology; D005260:Female; D006801:Humans; D007109:Immunity; D007156:Immunologic Memory; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014347:Trypanosoma brucei gambiense; D014353:Trypanosomiasis, African / Q000453:epidemiology / Q000276:immunology*