Cutaneous leishmaniasis in the Peruvian Andes: an epidemiological study of infection and immunity.
A prospective longitudinal survey of cutaneous leishmaniasis (Leishmania peruviana) was carried out in Peru on a study population of 4716 persons living in 38 villages (Departments of Lima, Ancash and Piura). Demographic and clinical data were collected from all individuals, and a Montenegro skin test (MST) was carried out on 72% (3418) of the study population. Each household was revisited at 3-monthly intervals for up to 2 years to detect new leishmaniasis cases; 497 people received a second MST at the end of the study. Analysis of the epidemiological data indicated that (i) 17% (16/94) of all infections were subclinical, (ii) this percentage increased significantly with age, (iii) clinical infections led to 73.9% protective immunity (95% C.I. 53.0-85.5%) and relatively permanent MST responsiveness (recovery rate = 0.0098/year; 95% C.I. 0.000-0.020/year), (iv) sub-clinical infections led to protective immunity, which was positively correlated with their MST induration size (increasing by 17.9% per mm; P < 0.0001), and a mean MST recovery rate of 0.114/year (4/421 man-months), and (v) recurrent leishmaniasis was dominated by reactivations, not by reinfections.
Davies
C R
CR
Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK.
Llanos-Cuentas
E A
EA
Pyke
S D
SD
Dye
C
C
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000953:Antigens, Protozoan; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007110:Immunity, Active; D015994:Incidence; D007223:Infant; D007892:Leishmania braziliensis / Q000276:immunology; D016773:Leishmaniasis, Cutaneous / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission; D008297:Male; D008875:Middle Aged; D010568:Peru / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012008:Recurrence; D012882:Skin Tests
D000953:Antigens, Protozoan; C032127:leishmanin