title: Natural Plasmodium infections in Brazilian wild monkeys: reservoirs for human infections?
abstract: 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.
authors.affiliation: 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
authors.forename: Ana Maria Ribeiro de Castro
authors.initials: AM
authors.lastname: Duarte
authors.forename: Rosely dos Santos
authors.initials: Rdos S
authors.lastname: Malafronte
authors.forename: Crispim
authors.initials: C
authors.lastname: Cerutti
authors.forename: Izilda
authors.initials: I
authors.lastname: Curado
authors.forename: Byanca Regina
authors.initials: BR
authors.lastname: de Paiva
authors.forename: Adriana Yurika
authors.initials: AY
authors.lastname: Maeda
authors.forename: Tasciane
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Maria Eugênia Laurito
authors.initials: ME
authors.lastname: Summa
authors.forename: Dafne do Valle Dutra de Andrade
authors.initials: Ddo V
authors.lastname: Neves
authors.forename: Salma Gomes
authors.initials: SG
authors.lastname: de Oliveira
authors.forename: Almério de Castro
authors.initials: Ade C
authors.lastname: Gomes
mesh_terms: 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