Further evidences on a new diagnostic approach for monitoring human Leishmania (L.) infantum chagasi infection in Amazonian Brazil.
This was a prospective study carried out during a period over 2 years (May/2006-September/2008) with a cohort of 1,099 individuals of both genders, aged 1 year old and older, from an endemic area of American visceral leishmaniasis (AVL) in Pará state, Brazil. The object was to analyze the prevalence and incidence of human Leishmania (L.) infantum chagasi infection as well as the dynamics evolution of its clinical-immunological profiles prior identified: (1) asymptomatic infection (AI); (2) symptomatic infection (SI = AVL); (3) sub-clinical oligosymptomatic infection (SOI); (4) sub-clinical resistant infection (SRI) and; (5) indeterminate initial infection (III). The infection diagnosis was performed by using both the indirect fluorescent antibody test and leishmanin skin test with amastigotes and promastigotes antigens of L. (L.) i. chagasi, respectively. A total of 187 cases of infection were recorded in the prevalence (17%), 117 in the final incidence (6.9%), and 304 in the accumulated prevalence (26.7%), which provided the following distribution into the clinical-immunological profiles: AI, 51.6%; III, 22.4%; SRI, 20.1%; SOI, 4.3%; and SI (=AVL), 1.6%. The major finding regarding the dynamics evolution of infection was concerned to III profile, from which the cases of infection evolved to either the resistant profiles, SRI (21 cases, 30.8%) and AI (30 cases, 44.1%), or the susceptible SI (=AVL; 1 case, 1.5%); the latter 16 cases remained as III till the end of the study. These results provided the conclusion that this diagnostic approach may be useful for monitoring human L. (L.) i. chagasi infection in endemic area and preventing the high morbidity of severe AVL cases.
Silveira
Fernando Tobias
FT
Parasitology Department, Evandro Chagas Institute (Surveillance Secretary of Health, Ministry of Health), Belém, Pará, Brazil. fernandotobias@iec.pa.gov.br
Lainson
Ralph
R
De Souza
Adelson Alcimar Almeida
AA
Campos
Marliane Batista
MB
Carneiro
Liliane Almeida
LA
Lima
Luciana Vieira Rego
LV
Ramos
Patrícia Karla Santos
PK
de Castro Gomes
Cláudia Maria
CM
Laurenti
Marcia Dalastra
MD
Corbett
Carlos Eduardo Pereira
CE
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006801:Humans; D015994:Incidence; D007223:Infant; D018314:Leishmania infantum / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012882:Skin Tests / Q000379:methods; D055815:Young Adult