Natural Plasmodium infections in Brazilian wild monkeys: reservoirs for human infections?
Four hundred and forty-eight samples of total blood from wild monkeys living in areas where human autochthonous malaria cases have been reported were screened for the presence of Plasmodium using microscopy and PCR analysis. Samples came from the following distinct ecological areas of Brazil: Atlantic forest (N=140), semideciduous Atlantic forest (N=257) and Cerrado (a savannah-like habitat) (N=51). Thick and thin blood smears of each specimen were examined and Plasmodium infection was screened by multiplex polymerase chain reaction (multiplex PCR). The frequency of Plasmodium infections detected by PCR in Alouatta guariba clamitans in the São Paulo Atlantic forest was 11.3% or 8/71 (5.6% for Plasmodium malariae and 5.6% for Plasmodium vivax) and one specimen was positive for Plasmodium falciparum (1.4%); Callithrix sp. (N=30) and Cebus apella (N=39) specimens were negative by PCR tests. Microscopy analysis was negative for all specimens from the Atlantic forest. The positivity rate for Alouatta caraya from semideciduous Atlantic forest was 6.8% (16/235) in the PCR tests (5.5, 0.8 and 0.4% for P. malariae, P. falciparum and P. vivax, respectively), while C. apella specimens were negative. Parasitological examination of the samples using thick smears revealed Plasmodium sp. infections in only seven specimens, which had few parasites (3.0%). Monkeys from the Cerrado (a savannah-like habitat) (42 specimens of A. caraya, 5 of Callithrix jacchus and 4 of C. apella) were negative in both tests. The parasitological prevalence of P. vivax and P. malariae in wild monkeys from Atlantic forest and semideciduous Atlantic forest and the finding of a positive result for P. falciparum in Alouatta from both types of forest support the hypothesis that monkeys belonging to this genus could be a potential reservoir. Furthermore, these findings raise the question of the relationship between simian and autochthonous human malaria in extra-Amazonian regions.
Duarte
Ana Maria Ribeiro de Castro
AM
Laboratório de Bioquímica e Biologia Molecular, Superintendência de Controle de Endemias (SUCEN), Secretaria de Estado da Saúde, Rua Paula Souza 166, São Paulo, Brazil. amrcd@usp.br
Malafronte
Rosely dos Santos
Rdos S
Cerutti
Crispim
C
Curado
Izilda
I
de Paiva
Byanca Regina
BR
Maeda
Adriana Yurika
AY
Yamasaki
Tasciane
T
Summa
Maria Eugênia Laurito
ME
Neves
Dafne do Valle Dutra de Andrade
Ddo V
de Oliveira
Salma Gomes
SG
Gomes
Almério de Castro
Ade C
D000508:Alouatta / Q000469:parasitology*; D000818:Animals; D000835:Animals, Wild / Q000469:parasitology*; D001938:Brazil / Q000453:epidemiology; D004197:Disease Reservoirs; D017753:Ecosystem; D006801:Humans; D008288:Malaria / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D008992:Monkey Diseases / Q000453:epidemiology / Q000469:parasitology; D010961:Plasmodium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006109:Poaceae; D016133:Polymerase Chain Reaction; D014197:Trees