First record of mass wild waterfowl mortality due to Clostridium botulinum in Brazilian semiarid.

In 2008, 270 wild birds from aquatic environments were found dead or debilitated on the banks of smaller lakes that had been formed due to the decrease in the level of the holding lake of the Sobradinho Dam located on the São Francisco River in the Caatinga of Bahia, Brazil. The outbreak occurred months after the dam's partial drainage, with the formation of puddles that accumulated decomposing organic material. Amongst the 270 individuals examined and/or found dead, the majority (50%) of the birds found belonged to the Anatidae family. The debilitated birds presented neurological clinical signs including lack of motor coordination, weakness, grave flaccid paralysis in the legs, wings, neck and eyelids, diarrhea, and dyspnea. Tissue samples of the birds were collected, as were water samples and samples of the substrate of the lakes. Zoonotic arboviroses or heavy metals were not detected. Analyses of liver and digestive tract content samples through bioassay and serum neutralization in mice revealed the presence of type C botulinic toxin in the viscerae samples, and type D in sediment samples. According to our knowledge, this is the first record of an outbreak of botulism in wild birds in natural conditions in Brazil.

TRYPANOSOMA CRUZI AND LEISHMANIA SP. INFECTION IN WILDLIFE FROM URBAN RAINFOREST FRAGMENTS IN NORTHEAST BRAZIL.

: Trypanosoma cruzi and Leishmania sp. are important protozoan parasites for humans and animals in the Americas, causing Chagas disease and cutaneous or visceral leishmaniasis, respectively. These vector-borne diseases affect permanent and transient populations in developing tropical countries that exhibit favorable conditions for the perpetuation of the parasite cycle. Our objective was to investigate the occurrence of infection with these parasites in wild animals from urban rainforest fragments in the city of Salvador, the largest city in the northeast region of Brazil. Sixty-five wild animals were captured, clinically examined, and sampled for parasite detection by PCR and culture. Ten different mammalian genera were identified, being 58% (38/65) marsupials. The prevalence of T. cruzi and Leishmania sp. infections was 13% and 43%, respectively. Both parasites were detected by PCR in 11% (7/65), three of which were also double infected as determined by culture. Among the 28 animals found infected with at least one parasite (43%, 28/65), 68% (19/28) were marsupials, two specimens were Callithrix sp. (7%), and one was Trinomys sp. (3%). Most infected animals (89%) had no clinical signs of disease. We found that healthy free-living animals from urban rainforest fragments harbored pathogenic trypanosomatids and should be included in epidemiology studies of diseases in big cities in tropical countries, as these cities grow and engulf rainforest remnants.

Avaliação da infectividade parasitária a Lutzomyia longipalpis por xenodiagnóstico em cães tratados para leishmaniose visceral naturalmente adquirida / Evaluation of parasite infectivity for Lutzomyia longipalpis by xenodiagnosis in dogs treated for natural visceral leishmaniasis

O efeito de um protocolo quimioterápico multidrogas contra a leishmaniose visceral (LV) canina, sobre a capacidade de transmissão de Leishmania infantum ao vetor, foi analisado por meio de xenodiagnóstico. Trinta e cinco cães naturalmente infectados foram avaliados antes e durante o tratamento com a combinação de metronidazol, cetoconazol e alopurinol a cada três meses por até um ano. Em cada avaliação, os cães foram individualmente submetidos ao xenodiagnóstico e quantificação da carga parasitária por PCR quantitativa. O tratamento foi eficaz em bloquear a transmissibilidade parasitária do cão para o flebotomíneo (p= 0,011) nos cães avaliados. Houve significante correlação entre recuperação clínica e infectividade: cães com melhora clínica mais evidente apresentaram menores chances de transferir L. infantum ao Lutzomyia longipalpis via xenodiagnóstico (r=0,528, p= 0,002). Esses resultados demonstram que o tratamento canino com o protocolo proposto pode representar uma alternativa ao sacrifício de cães no Brasil como medida de controle da doença, uma vez que as drogas utilizadas não são aplicadas ao tratamento da LV humana em áreas endêmicas.(AU)

The outcome of a multidrug chemotherapeutic protocol against canine visceral leishmaniasis (VL) has been evaluated for its effect on dogs' capacity of transferring Leishmania infantum to sand flies by xenodiagnosis. Thirty-five naturally infected dogs were examined before and during treatment with a combination of metronidazole, ketoconazole, and allopurinol, at every three months up to one year. For each evaluation, treated dogs were individually submitted to xenodiagnosis and quantitative PCR to quantify parasite load in sand flies. The treatment was effective in blocking parasite transmission from host to sand flies (p=0.011) in the assessed dogs. There was a significant correlation between clinical improvement and sand fly infectivity: dogs that achieved better clinical conditions showed a lower chance of L. infantum transference to vector by xenodiagnosis (r=0.528, p=0.002). These results demonstrate that the treatment of dogs with the proposed protocol may represent an alternative to dog culling in Brazil for disease control, since these drugs are not used for treating human VL in endemic areas.(AU)

Association between Leishmania infantum DNA in the hair of dogs and their infectiousness to Lutzomyia longipalpis.

Diagnosis of infection with Leishmania infantum by DNA detection in the hair has been recently demonstrated in dogs and wild animals. Our objective was to investigate if polymerase chain reaction (PCR) in hair might be used to identify infectious dogs. Thus, we assessed the infectiousness to Lutzomyia longipalpis by xenodiagnosis in comparison with the detection of L. infantum DNA by PCR in the hair, and with serology for anti-Leishmania IgG by ELISA in 15 positive dogs for L. infantum infection. Eight healthy dogs were included as negative controls. Among the 15 infected dogs, 13 were found positive in the ELISA (87%), 12 were PCR positive in the hair (80%), and 10 were positive in xenodiagnosis (67%). Positivity in the hair was associated with positivity in spleen (p=0.0003), seropositivity for antibodies (p=0.0006) and parasite transmission to L. longipalpis (p=0.0028). Considering the benefits to animal welfare and feasibility of hair sampling method, studies in larger and more diverse populations of naturally infected dogs from endemic areas should be conducted to evaluate the sensitivity, specificity, and predictive values of PCR using hair as a possible biomarker of infectiousness in dogs.

Evaluation of PCR and multiplex PCR in relation to nested PCR for diagnosing Theileria equi / Avaliação da PCR e PCR multiplex com relação a nested PCR no diagnóstico de Theileria equi

Conventional PCR (PCRTeq) for diagnosing Theileria equi and multiplex PCR (M/PCRTeq-Bc) for diagnosing T. equi and Babesia caballi were comparatively evaluated with nested PCR (N/PCR-Teq) for diagnosing equine piroplasmosis. In DNA sensitivity determinations, in multiple dilutions of equine blood that had tested positive for T. equi, PCR-Teq and N/PCR-Teq detected hemoparasite DNA in the larger dilutions (1:128), but did not differ significantly from the M/PCRTeq-Bc (1:64). In analyses on equine serum tested by ELISA, there was high agreement between this serological test and PCR-Teq (k = 0.780) and moderate agreement with N/PCR-Teq (k = 0.562) and M/PCRTeq-Bc (k = 0.488). PCR-Teq found a higher frequency of T. equi both in extensively and intensively reared horses, but this was not significant in relation to N/PCR-Teq (P>0.05), and both PCRs indicated that there was an endemic situation regarding T. equi in the population of horses of this sample. PCR-Teq was only significantly different from M/PCR-Teq-Bc (P<0.05). PCR-Teq presented high sensitivity and specificity, comparable to N/PCR-Teq, but with the advantage of higher speed in obtaining results and lower costs and risks of laboratory contamination. This accredits PCR-Teq for epidemiological studies and for determinations on affected horses.

Uma PCR convencional (PCRTeq) para diagnóstico de Theileria equi e PCR multiplex (M/PCRTeq-Bc) para diagnóstico T. equi e Babesia caballi foram avaliadas comparativamente a nested PCR (N/PCR-Teq) no diagnóstico de piroplasmose equina. Na determinação da sensibilidade com DNA em diluições múltiplas de sangue de equino positivo para T. equi, as PCR-Teq e N/PCR-Teq detectaram DNA do hemoparasito nas diluições maiores (1:128), mas não diferiu significativamente da M/PCRTeq-Bc (1:64). Na análise com soros de equinos testados por ELISA houve uma concordância elevada entre esse teste sorológico e a PCR-Teq (k =0,780) e moderada com N/PCR-Teq (k = 0.562) e M/PCRTeq-Bc (k = 0.488). A PCR-Teq determinou freqüência maior de T. equi tanto nos equinos de criação extensiva como na intensiva, entretanto essa não foi significativa com relação N/PCR-Teq (P>0.05), e ambas PCRs indicaram que há uma situação endêmica para T. equi na população de equinos que constaram da amostragem. A PCR-Teq diferiu significativamente apenas para a M/PCRTeq-Bc (P<0.05). A PCR-Teq apresentou alta sensibilidade e especificidade comparável a N/PCR-Teq, mas com a vantagem de maior rapidez na obtenção dos resultados e menor custo e risco de contaminação no laboratório. Isso credencia a PCR-Teq para estudos epidemiológicos e para determinação de equinos portadores.

Spatial analysis of migrating Apis mellifera colonies in Salvador, Bahia, Brazil.

Beekeeping in Brazil is growing but also associated with an increase in the number of human and animal accidents involved. In particular, bees of the Apis mellifera species (Africanized bees) are known for their aggressive behaviour and frequent swarming activity due to their poor adaptation to the human environment. This study analyzed the spatial distribution of occurrences of migratory swarms of A. mellifera and recorded apicultural accidents in the city of Salvador, Bahia, Brazil. The association of demographic and climatic variations on places where the swarms occurred was also evaluated. The study is based on data collected within the frame of the "SOS Bees", a project initiated for the protection of the environment and enforced by a special unit of the military police in Bahia. In the 3-year period from 2000 to 2003, 590 swarms were registered in 75 of the 98 zones of information of Salvador. Three cluster areas, representing 25.4% of all events, were identified. In that period, 316 apicultural accidents were registered involving humans and one involving dogs. The seasonal rise of the monthly average temperature showed an association with the increase of the number of swarming events.

Headspace solid phase microextraction/gas chromatography-mass spectrometry combined to chemometric analysis for volatile organic compounds determination in canine hair: a new tool to detect dog contamination by visceral leishmaniasis.

A new analytical methodology using HS-SPME/GC-MS was optimized in order to attain maximum sensitivity, using multivariate strategies. The proposed method was employed to evaluate the VOC profile exhaled from canine hair samples collected from 8 healthy dogs and from 16 dogs infected by Leishmania infantum. 274 VOCs were detected, which could be identified as aldehydes, ketones and hydrocarbons. After application of the Soft Independent Modeling of Class Analogy (SIMCA) and Principal Component Analysis (PCA) healthy and infected dogs, with similar VOCs profiles, could be separately grouped, based on compounds such as 2-hexanone, benzaldehyde, and 2,4-nonadienal. The proposed method is non-invasive, painless, readily accepted by dog owners and could be useful to identify several biomarkers with applications in the diagnosis of diseases.

Investigação de áreas de risco como metodologia complementar ao controle da leishmaniose visceral canina / Investigation of risk areas as complemental methodology for the control of canine visceral leishmaniasis

Foram investigadas áreas de risco de leishmaniose visceral canina no município de Camaçari, Bahia. Um total de 278 cães distribuídos em 141 residências, pertencentes a 20 áreas de risco investigadas, foi examinado sorologicamente (ELISA). A soroprevalência geral foi 21,7 por cento (56/258) depois da exclusão dos 20 cães usados no início do estudo para delimitar a área. Os resultados respectivos das análises univariada e multivariada dos fatores relacionados à infecção do cão por Leishmania chagasi, a captura e distribuição do vetor na área e a metodologia usada para localizar os focos caninos são discutidos.

Risk areas of canine visceral leishmaniasis in the city of Camaçari, Bahia, Brazil, were investigated. A total of 278 dogs from 141 homes pertaining to 20 investigated risk areas was serologically screened (ELISA). The general seroprevalence was 21.7 percent (56/258) after exclusion of 20 dogs used at the beginning of the survey to limit the study area. The respective results of the univariated and multivariated analysis of factors related to infection of dogs by Leishmania chagasi, to vector distribu-tion pattern in the area and to the methodology used to localize the canine focuses are discussed.