ABSTRACT
Between December 2007 and March 2009, small mammals were captured in 6 Atlantic Forest patches in Brazil. We assessed tick-host associations and whether they differ among forest strata, sites, seasons, and host age classes or between sexes. Moreover, we assessed the exposure of animals to Rickettsia spp. In total, 432 animals were captured and 808 ticks were found on 32·9% of them. Significant differences were found among host species, collection sites, and forest strata; microhabitat preference was a strong risk factor for tick infestation. The highest tick density rates were recorded in forest fragments settled in rural areas; 91·3% of the ticks were collected from animals trapped in these forest fragments. A high prevalence (68·8%) of antibodies to Rickettsia spp. was detected among animals. This study suggests that disturbed Atlantic Forest fragments provide an environment for ticks and small mammals, which are highly exposed to rickettsiae. It also indicates that forest patches settled in rural areas are usually associated with higher small mammal diversity as well as with higher tick density rates.
Subject(s)
Host-Pathogen Interactions , Mammals/microbiology , Tick Infestations/epidemiology , Trees , Animals , Antibodies, Bacterial/blood , Brazil , Ecosystem , Humans , Marsupialia/microbiology , Population Density , Prevalence , Risk Factors , Rodentia/microbiology , SeasonsABSTRACT
Blood serum samples were collected from 451 bats captured within the São Paulo city from April 2007 to November 2008, and individually tested by indirect immunofluorescence assay against antigens derived from five Rickettsia species reported to occur in Brazil: the spotted fever group (SFG) species R. rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, and the ancestral group species R. bellii. For this purpose, an anti-bat immunoglobulin G was produced and used in the present study. Overall, 8.6% (39/451), 9.5% (34/358), 7.8% (28/358), 1.1% (4/358), and 0% (0/358) serum samples were reactive to R. rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, and R. bellii, respectively. Endpoint titers of reactive sera ranged from 64 to 256. From 20 bat species of 3 different families (Molossidae, Vespertilionidae, and Phyllostomidae), 46 animals were shown to be reactive to at least one rickettsial antigen. Seropositivity per bat species ranged from 0% to 33.3%. Most of the serologically positive sera reacted with two or more rickettsial antigens. Seropositivity for SFG rickettsial antigens in the absence of reactivity against R. bellii (ancestral group species) suggests that bats from São Paulo city can be infected by SFG rickettsiae. The possible role of soft ticks in serving as vectors of SFG rickettsiae to bats within the São Paulo city, associated to its public health risks, is discussed.
Subject(s)
Animals , Chiroptera , Serology , Rickettsia InfectionsABSTRACT
Blood serum samples were collected from 451 bats captured within the São Paulo city from April 2007 to November 2008, and individually tested by indirect immunofluorescence assay against antigens derived from five Rickettsia species reported to occur in Brazil: the spotted fever group (SFG) species R. rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, and the ancestral group species R. bellii. For this purpose, an anti-bat immunoglobulin G was produced and used in the present study. Overall, 8.6% (39/451), 9.5% (34/358), 7.8% (28/358), 1.1% (4/358), and 0% (0/358) serum samples were reactive to R. rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, and R. bellii, respectively. Endpoint titers of reactive sera ranged from 64 to 256. From 20 bat species of 3 different families (Molossidae, Vespertilionidae, and Phyllostomidae), 46 animals were shown to be reactive to at least one rickettsial antigen. Seropositivity per bat species ranged from 0% to 33.3%. Most of the serologically positive sera reacted with two or more rickettsial antigens. Seropositivity for SFG rickettsial antigens in the absence of reactivity against R. bellii (ancestral group species) suggests that bats from São Paulo city can be infected by SFG rickettsiae. The possible role of soft ticks in serving as vectors of SFG rickettsiae to bats within the São Paulo city, associated to its public health risks, is discussed.
Subject(s)
Chiroptera , Rickettsia Infections/veterinary , Animals , Antigens, Bacterial , Brazil/epidemiology , Rickettsia/classification , Rickettsia/immunology , Rickettsia Infections/blood , Rickettsia Infections/epidemiology , Seroepidemiologic StudiesABSTRACT
Inquérito sorológico para leishmaniose tegumentar americana em 973 cäes errantes, capturados próximos a áreas verdes do Município de Säo Paulo, por meio da reaçäo de imunofluorescência indireta, näo demonstrou soros reagentes. No entanto, casos humanos autóctones dessa zoonose ocorridos no município indicam a circulaçäo do parasita no ambiente. A existência de vetores e a aparente ausência de cäes infectados nas áreas pesquisadas sugerem que o cäo errante desempenhe papel irrelevante na disseminaçäo do protozoário
