Background: Vampire bats are important rabies virus vectors, causing critical problems in both the livestock industry and public health sector in Latin America. In order to assess the epidemiological characteristics of vampire bat-transmitted rabies, the authors conducted phylogenetic and geographical analyses using sequence data of a large number of cattle rabies isolates collected from a wide geographical area in Brazil.

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. KEYWORDS

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Introduction:Rabies is an important zoonosis that causes thousands of deaths worldwide each year. Although the terrestrial cycle, mainly transmitted by dogs, is controlled in Brazil, the aerial cycle remains a serious public health issue, besides the economic problem. In the aerial cycle, the haematophagous bat Desmodus rotundus is the main source of infection, where several different species of non-haematophagous bats can be infected and can transmit the virus. Methods: The aim of this work was to study the epidemiological pattern of rabies using antigenic characterization with monoclonal antibodies and genetic characterization by reversetranscriptase polymerase chain reaction followed by sequencing and phylogenetic analysis of non-haematophagous bats' and herbivorous animals' central nervous system samples from the western region of the State of São Paulo, Brazil. Results: From 27 samples, 3 antigenic variants were identified: AgV-3, AgV-4, and AgV-6; and from 29 samples, 5 different clusters were identified, all belonging to the rabies virus species. Conclusions: Although only nonhaematophagous bats were evaluated in the studied region, the majority of samples were from antigenic and genetic variants related to haematophagous bats Desmodus rotundus. Samples from the same antigenic variant were segregated in more than one genetic cluster. This study demonstrated the diversity of rabies virus genetic lineages presented and circulating in nonhaematophagous bats in the studied region.

OBJECTIVE:To identify the species of bats involved in maintaining the rabies cycle; to investigate the distribution of the rabies virus in the tissues and organs of bats and the time taken for mortality among inoculated mice. METHODS:From April 2002 to November 2003, bats from municipalities in the State of São Paulo were screened for the presence of the rabies virus, by means of direct immunofl uorescence. The virus distribution in the bats was evaluated by inoculating mice and N2A cells with 20% suspensions prepared from fragments of different organs and tissues, plus the brain and salivary glands. The time taken for mortality among the mice was monitored daily, following intracerebral inoculation. RESULTS:Out of the 4,395 bats received, 1.9% were found positive for the rabies virus. They belonged to ten genera, with predominance of insectivores. The maximum mean times taken for mortality among the mice following inoculation with brain and salivary gland material were 15.33±2.08 days and 11.33±2.30 days for vampire bats, 16.45±4.48 days and 18.91±6.12 days for insectivorous bats, and 12.60±2.13 days and 15.67±4.82 days for frugivorous bats, respectively. CONCLUSIONS:The species infected with the rabies virus were: Artibeus lituratus, Artibeus sp., Myotis nigricans, Myotis sp., Eptesicus sp., Lasiurus ega, Lasiurus cinereus, Nyctinomops laticaudatus, Tadarida brasiliensis, Histiotus velatus, Molossus rufus, Eumops sp. and Desmodus rotundus. Virus investigation in the different tissues and organs showed that the brain and salivary glands were the most suitable sites for virus isolation.

Efeito de uma dose de reforço da vacina anti-rábica sobre a duração de títulos de anticorpos neutralizantes do vírus, em bovinos

Introduction:Rabies is an important zoonosis that occurs in mammals, with bats acting as Lyssavirus reservoirs in urban, rural and natural areas. Rabies cases in bats have been recorded primarily in urban areas in Northwestern State of São Paulo since 1998. This study investigated the circulation of rabies virus by seeking to identify the virus in the brain in several species of bats in this region and by measuring rabies-virus neutralizing antibody levels in the hematophagous bat Desmodus rotundus. Methods: From 2008 to 2012, 1,490 bat brain samples were sent to the Universidade Estadual Paulista (UNESP) Rabies Laboratory in Araçatuba, and 125 serum samples from vampire bats that were captured in this geographical region were analyzed. Results: Rabies virus was detected in the brains of 26 (2%) of 1,314 non-hematophagous bats using the fl uorescent antibody test (FAT) and the mouse inoculation test (MIT). None of the 176 hematophagous bat samples were positive for rabies virus when a virus detection test was utilized. Out of 125 vampire bat serum samples, 9 (7%) had levels of rabies virus neutralization antibodies (RVNAs) that were higher than 0.5IU/mL; 65% (81/125) had titers between 0.10IU/mL and 0.5IU/mL; and 28% (35/125) were negative for RVNAs using the simplifi ed fl uorescent inhibition microtest (SFIMT) in BHK21 cells. The observed positivity rate (1.7%) was higher than the average positivity rate of 1.3% that was previously found in this region. Conclusions: The high percentage of vampire bats with neutralizing antibodies suggests that recent rabies virus exposure has occurred, indicating the necessity of surveillance measures in nearby regions that are at risk to avoid diffusion of the rabies virus and possible rabies occurrences.

INTRODUÇÃO: O laboratório do Pólo da Alta Sorocabana de Presidente Prudente, SP, em parceria com outras instituições de pesquisa, realizou estudos pertinentes aos morcegos da região oeste do Estado de São Paulo, Brasil. Para tal, foram pesquisadas algumas situações, tais como: a) isolamento do vírus rábico, no período 2006 a 2008; b) as respectivas variantes antigênicas; c) abrigos diurnos do morcego hematófago Desmodus rotundus. MÉTODOS: As amostras para exame foram provenientes de morcegos não hematófagos encaminhadas ao laboratório sendo submetidas aos testes de imunofluorescência direta e prova biológica. As amostras positivas foram caracterizadas antigenicamente por meio do teste de anticorpos monoclonais. Quanto aos morcegos, foram identificados e classificados, e também foi realizado mapeamento de abrigos dos mesmos. RESULTADOS: O laboratório recebeu 1.113 morcegos não hematófagos para diagnóstico laboratorial, sendo 11 (1%) deles positivos, e dentre as amostras positivas, 5 (45,5%) delas tiveram variante antigênica 3 associada ao morcego D. rotundus e 4 (36,5%) foram compatíveis com amostras de morcegos insetívoros. Foram pesquisados 16 abrigos de morcegos hematófagos e observou-se a presença de outras 3 espécies de morcegos não hematófagos convivendo com eles. CONCLUSÕES: Os experimentos mostraram que o vírus rábico continua circulando na região com pelo menos 3 variantes antigênicas, e que, a coabitação de morcegos hematófagos com não hematófagos pode ter alguma relação com a disseminação do vírus rábico.