A prospective study on the dynamics of the clinical and immunological evolution of human Leishmania (L.) infantum chagasi infection in the Brazilian Amazon region.
This prospective study was carried out from October 2003 to December 2005 and involved a cohort of 946 individuals of both genders, aged 1-89 years, from an endemic area for American visceral leishmaniasis (AVL), in Pará State, Brazil. The aim of the study was to analyze the dynamics of the clinical and immunological evolution of human Leishmania (L.) infantum chagasi infection represented by the following clinical-immunological profiles: asymptomatic infection (AI); symptomatic infection (SI=AVL); subclinical oligosymptomatic infection (SOI); subclinical resistant infection (SRI); and indeterminate initial infection (III). Infection diagnosis was determined by the indirect fluorescent antibody test and leishmanin skin test. In total, 231 cases of infection were diagnosed: the AI profile was the most frequent (73.2%), followed by SRI (12.1%), III (9.9%), SI (2.6%) and SOI (2.2%). The major conclusion regarding evolution dynamics was that the III profile plays a pivotal role from which the cases evolve to either the resistant, SRI and AI, or susceptible, SOI and SI, profiles; only one of the 23 III cases evolved to SI, while most evolved to either SRI (nine cases) or SOI (five cases) and eight cases remained as III.
Silveira
Fernando T
FT
Parasitology Department, Evandro Chagas Institute (Surveillance Secretary of Health, Ministry of Health), Avenida Almirante Barroso, 492, 66090-000, Belém, PA, Brazil. silveiraft@lim50.fm.usp.br
Lainson
Ralph
R
Crescente
José Angelo
JA
de Souza
Adelson A A
AA
Campos
Marliane B
MB
Gomes
Claudia M C
CM
Laurenti
Márcia D
MD
Corbett
Carlos E P
CE
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006801:Humans; D007223:Infant; D018314:Leishmania infantum / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000453:epidemiology / Q000276:immunology* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012882:Skin Tests; D055815:Young Adult
D000913:Antibodies, Protozoan