Descriptive ecology of bat flies (Diptera: Hippoboscoidea) associated with vampire bats (Chiroptera: Phyllostomidae) in the cerrado of Central Brazil

We studied the ectoparasitic bat flies of three phyllostomid vampire bat species. Bats were collected monthly from April 2004-March 2005 in caves within the Cafuringa Environmental Protection Area in the Federal District of Brazil. A total of 1,259 specimens from six species in the Streblidae family were collected from 332 bats. High host affinity from the sampled bat fly species and high prevalence of bat flies confirms the primary fly-host associations (Strebla wiedemanni, Trichobius parasiticus and Trichobius furmani with Desmodus, Trichobius diaemi and Strebla diaemi with Diaemus and T. furmani with Diphylla). Male flies outnumbered females in several associations. Some of the observed associations (e.g., Strebla mirabilis with Desmodus and S. mirabilis, Trichobius uniformis and S. wiedemanni with Diphylla) were inconclusive and the causes of the associations were unclear. There are several explanations for these associations, including (i) accidental contamination during sampling, (ii) simultaneous capture of several host species in the same net or (iii) genuine, but rare, ecological associations. Although various species of vampire bats share roosts, have similar feeding habits and are close phylogenetic relatives, they generally do not share ectoparasitic streblid bat flies. T. diaemi and S. diaemi associations with Diaemus youngi have not been previously reported in this region.

BAT-BORNE RABIES IN LATIN AMERICA

The situation of rabies in America is complex: rabies in dogs has decreased dramatically, but bats are increasingly recognized as natural reservoirs of other rabies variants. Here, bat species known to be rabies-positive with different antigenic variants, are summarized in relation to bat conservation status across Latin America. Rabies virus is widespread in Latin American bat species, 22.5%75 of bat species have been confirmed as rabies-positive. Most bat species found rabies positive are classified by the International Union for Conservation of Nature as “Least Concern”. According to diet type, insectivorous bats had the most species known as rabies reservoirs, while in proportion hematophagous bats were the most important. Research at coarse spatial scales must strive to understand rabies ecology; basic information on distribution and population dynamics of many Latin American and Caribbean bat species is needed; and detailed information on effects of landscape change in driving bat-borne rabies outbreaks remains unassessed. Finally, integrated approaches including public health, ecology, and conservation biology are needed to understand and prevent emergent diseases in bats.

Outbreak of vampire bat biting in a Venezuelan village

An outbreak of 154 cases of vampire bat biting in a four-month period in the gold mine of Payapal, a Venezuelan village, is reported. All patients were bitten during the night and the most bites were on their toes. No complication attributed to the bite was reported. Diagnoses of rabies virus made by means of immunofluorescence were negative. A possible reason for this outbreak may been the development of mining areas, with the inhabitants providing an alternative food source for the bats.

Rabies in the insectivorous bat Tadarida brasiliensis in Southeastern Brazil

This is the first recorded case of rabies in the insectivorous bat Tadarida brasiliensis in the State of S. Paulo, Southeastern Brazil. The infected bat was found in the afternoon while hanging on the internal wall of an urban building. This observation reinforces the notion as to the caution one must exercise regarding bats found in unusual situations.

Bat rabies in the north-northwestern regions of the state of São Paulo, Brazil: 1997-2002

OBJECTIVE: Reports on bat rabies in Brazil are sporadic and isolated. This study aimed at describing the detection of rabies virus in bats in the state of São Paulo. METHODS: A total of 7,393 bats from 235 municipalities of the north and northwestern areas of the state of São Paulo, Southeastern Brazil, were assessed according to their morphological and morphometric characteristics from 1997 to 2002. Fluorescent antibody test and mice inoculation were used for viral identification. RESULTS: Of all samples examined, 1.3% was rabies virus positive, ranging from 0.2% in 1997 to 1.6% in 2001. There were found 98 bats infected, 87 in the urban area. Fluorescent antibody test was detected in 77 positive samples, whereas 92 produced rabies signs in mice; incubation period ranging from 4 to 23 days. In 43 cities at least one rabid bat was observed. The highest proportion (33.7%) of rabies virus was found in Artibeus lituratus. Eptesicus and Myotis were the most frequent positive species (24.5%) of the Vespertilionidae family. The species Molossus molossus and Molossus rufus showed 14.3% positive bats. There were no differences in the distribution of positive rabies between females (33; 48.5%) and males (35; 51.5%). CONCLUSIONS: Rabies-infected bats were found in environments that pose a risk to both human and domestic animal population and there is a need for actions aiming at the control of these species and public education.

An outbreak of bat-transmitted human rabies in a village in the Brazilian Amazon

During 45 days without electrical power, 57 individuals (8.7% of the population) from the village of Antônio Dino (municipality of Turiaçu, Northeastern Brazil) were attacked by bats and 16 died from human rabies. The aim of the study was to analyze the factors associated with bat attacks and the development of human rabies. Of the 46 individuals, who suffered bat attacks, 36 (78.3%) were under 17 years of age. The risk factors associated with bat attacks were age under 17 years, having observed bats inside the bedroom and having been without electrical power in the house. Age under 17 years and having been without electrical power in the house were factors associated with human rabies.

The ecology of Triatoma sordida in natural environments in two different regions of the state of Minas Gerais, Brazil

A study was undertaken about T. sordida in the natural environment in two different regions of the state of Minas Gerais: Itapagipe (Triângulo), an area of cerrado modified by the formation of fields of pasture and agriculture, and Mato Verde (north) an area of transition between caatinga and cerrado with profound deforestation in the last years due to the expansion of cotton cultivation. In both regions the principal ecotopes identified were hollow trees and the bark of live or dead trees, where the occurrence of a food source is not frequent. In this environment, the triatomines utilize various food sources; opposums appear to represent an important source of infection. In the north of Minas, a greater concentration of reservoirs and vectors was observed than in the Triángulo which could explain the higher level of infection of the triatomines in the north. Close attention to the process of domiciliation of T. sordida in the north of Minas is recommended where an extensive intervention by man in the natural environment has occurred and where a rise in the population of triatomines in the peridomestic environment has been observed in recent years.

Antigenic and genetic characterization of the first rabies virus isolated from the bat Eumops perotis in Brazil

Although the main transmitters of rabies in Brazil are dogs and vampire bats, the role of other species such as insectivorous and frugivorous bats deserves special attention, as the rabies virus has been isolated from 36 bat species. This study describes the first isolation of the rabies virus from the insectivorous bat Eumops perotis. The infected animal was found in the city of Ribeirão Preto, São Paulo. The virus was identified by immunofluorescence antibody test (FAT) in central nervous system (CNS) samples, and the isolation was carried out in N2A cell culture and adult mice. The sample was submitted to antigenic typing using a panel of monoclonal antibodies (CDC/Atlanta/USA). The DNA sequence of the nucleoprotein gene located between nucleotides 102 and 1385 was aligned with homologous sequences from GenBank using the CLUSTAL/W method, and the alignment was used to build a neighbor-joining distance-based phylogenetic tree with the K-2-P model. CNS was negative by FAT, and only one mouse died after inoculation with a suspension from the bat's CNS. Antigenic typing gave a result that was not compatible with the patterns defined by the panel. Phylogenetic analysis showed that the virus isolated segregated into the same cluster related to other viruses isolated from insectivorous bats belonging to genus Nyctinomops ssp. (98.8% nucleotide identity with each other).

Updated list of bat species positive for rabies in Brazil

This paper presents an updated list of bat species positive for rabies in Brazil. It was developed based on database research via the internet, of international and national literature and annals of the most important technical and scientific meetings related to rabies and chiroptera in Brazil from 1996 to 2009. The new list of rabies positive bats consists of 41 species, belonging to 25 genera and three families: Phyllostomidae 43.9%, Vespertilionidae 29.3% and Molossidae 26.8%. In addition, questions were raised regarding the lack of data, including sex, age, circumstances and location of bat capture and incomplete and outdated species identification. Results of genetic and antigenic studies performed on Brazilian rabies positive bats were shown.

ASPECTS OF THE ECOLOGY OF PHLEBOTOMINES (Diptera: Psychodidae: Phlebotominae) IN AN AREA OF CUTANEOUS LEISHMANIASIS OCCURRENCE, MUNICIPALITY OF ANGRA DOS REIS, COAST OF RIO DE JANEIRO STATE, BRAZIL

Over a complete two-year period, phlebotomine specimens were caught in an area of cutaneous leishmaniasis occurrence in the municipality of Angra dos Reis. A manual suction tube was used to catch phlebotomines on house walls, and also light traps in domestic and peridomestic settings and in the forest. This yielded 14,170 specimens of 13 species: two in the genus Brumptomyia and eleven in the genus Lutzomyia. L. intermedia predominantly in domestic and peridomestic settings, with little presence in the forest, with the same trend being found in relation to L. migonei, thus proving that these species have adapted to the human environment. L. fischeri appeared to be eclectic regarding location, but was seen to be proportionally more endophilic. L. intermedia and L. migonei were more numerous in peridomestic settings, throughout the year, while L. fischeri was more numerous in domestic settings except in March, April, May and September. From the prevalence of L. intermedia, its proven anthropophily and findings of this species naturally infected with Leishmania(Viannia) braziliensis, it can be incriminated as the main vector for this agent of cutaneous leishmaniasis in the study area, especially in the peridomestic environment. L. fischeri may be a coadjuvant in carrying the parasite.

Growth and differentiation on a trypanosome of the subgenus Schizotrypanum from the bat Phyllostomus hastatus

The effects of temperature, pH, osmolarity and aeration on the growth and differentiation of a trypanosome ofthe subgenus Schizotrypanum isolatedfrom the bat Phyllostomus hastatus were studied. In general, the growth characteristics ofthe flagellate were similar to those of Trypanosoma (Schizotrypanum) cruzi. However, the parasite did not growth at 33 or 37C. Increase in the osmolarity and aeration promoted growth at 33C. Significant metacyclogenesis was detected only in the growth condition where maximal growth occured (28C, pH 7.3, 380m0s/kg, in tissue cullure flasks), at the end ofthe exponential growth phase. The begining of the metacyclogenesis process was coincident with most glucose utilization and lowest pH. During metacyclogenesis both culture medium pH and osmolarity increased steadly.

Ecology of Phlebotomine sandflies (Diptera, Psychodidae) in Brazilian Atlantic Forest

The phlebotomine sandfly fauna of a primary forest reserve at Morretes (eastern Paraná State) was studied, using CDC-like light traps, one night per month, at canopy and ground level, between April 1995 and March 1996. A total of 3,106 insects were collected, identified as belonging to nine species. Lutzomyia ayrozai and Lu.geniculata were predominant, seven other species also being present. Monthly mean temperature, rainfall and the temperature of the collection night significantly influenced the numbers of Lu. ayrozai while the two first factors influenced the numbers of Lu. geniculata, besides the collected quantities of females of the two species. The influence of the factors on Lu. ayrozai numbers was more immediate than in those of Lu. geniculata. Numbers of both species and of the females of Lu. geniculata collected in different seasons, but not at the different heights, varied significantly. Differences between the behaviour of Lu. ayrozai in Morretes and in other regions could be attributed to environmental differences and/or to regional variations in the species, which could constitute species complexes. Hourly variations of collections were different in the species and seasons.