Leishmania infantum chagasi in northeastern Brazil: asymptomatic infection at the urban perimeter.
Visceral leishmaniasis (VL) is endemic in large cities in Brazil, including Natal. We determined the prevalence of asymptomatic human infection with Leishmania infantum chagasi and associated environmental risks around Natal. Infection was detected by Leishmania skin test (LST) and anti-leishmanial antibodies in humans and anti-leishmanial antibodies in dogs. Amongst 345 humans, 24.6% were seropositive, and 38.6% were LST-positive. Prevalence of positive serology was similar in both sexes and across all ages. However, positive LST responses increased with age, suggesting that LST is long-lasting and cumulative. Multinomial logistic analysis showed that LST response varied with location (P = 0.007) and that males were more frequently LST-positive (P = 0.027). Indicators of lower socioeconomic status associated significantly with human infection. Furthermore, there was geographic coincidence of seropositive humans and dogs (r = 0.7926, P = 0.011). These data suggest that dog and human L. i. chagasi infection are intimately interrelated in environmental conditions associated with low income.
Health Post-Graduate Program, Department of Infectious Diseases, Health Sciences Center, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
Iraci D
ID
Lima
Jose W
JW
Queiroz
Henio G
HG
Lacerda
Paula V S
PV
Queiroz
Nubia N
NN
Pontes
James D A
JD
Barbosa
Daniella R
DR
Martins
Jason L
JL
Weirather
Richard D
RD
Pearson
Mary E
ME
Wilson
Selma M B
SM
Jeronimo
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D058345:Asymptomatic Infections / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004197:Disease Reservoirs; D004283:Dog Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology; D004285:Dogs; D005260:Female; D006801:Humans; D018314:Leishmania infantum / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology / Q000662:veterinary; D008297:Male; D015995:Prevalence; D012424:Rural Population; D012882:Skin Tests; D014505:Urban Population
D000913:Antibodies, Protozoan