Investigation of canine visceral leishmaniasis in a non-endemic area in Brazil and the comparison of serological and molecular diagnostic tests

Abstract INTRODUCTION: Visceral leishmaniasis (VL) is an important zoonosis in Brazil. Previous identification of parasitized dogs can also help prevent the disease in humans, even in non-endemic areas of the country. The Brazilian Ministry of Health recommends diagnosis in dogs using a DPP® (rapid test) as a screening test and an immunoenzymatic assay (ELISA) as a confirmatory test (DPP®+ELISA), and culling infected dogs as a legal control measure. However, the accuracy of these serological tests has been questioned. METHODS: VL in dogs was investigated in a non-endemic area of the São Paulo state for three consecutive years, and the performances of different diagnostic tests were compared. RESULTS: A total of 331 dog samples were collected in 2015, 373 in 2016, and 347 in 2017. The seroprevalence by DPP®+ELISA was 3.3, 3.2, and 0.3%, respectively, and by indirect immunofluorescence assay (IFA), it was 3.0, 5.6, and 5.5%, respectively. ELISA confirmed 18.4% of DPP® positive samples. The concordance between the IFA and DPP® was 83.9%. The concordance between IFA and DPP®+ELISA was 92.9%. A molecular diagnostic test (PCR) was performed in 63.2% of the seropositive samples, all of which were negative. CONCLUSIONS: In non-endemic areas, diagnostic tests in dogs should be carefully evaluated to avoid false results.

Seroprevalence and incidence of Toxoplasma gondii and Neospora caninum infection in naturally exposed domestic dogs from a rural area of São Paulo state, Brazil / Soroprevalência e incidência de infecção por Toxoplasma gondii e Neospora caninum em cães domésticos naturalmente expostos em uma área rural no estado de São Paulo, Brasil

Abstract Dogs are hosts of the protozoans Toxoplasma gondii, which causes an important public health disease, and Neospora caninum. Studies that have evaluated toxoplasmosis and neosporosis for prolonged periods in dog populations are rare. We analyzed infection by both parasites in a domestic dog population over three consecutive years in São Paulo state, Brazil. In the 1st, 2nd and 3rd years of collection, 181, 193 and 172 domiciles were visited, and blood samples of 331, 371 and 348 dogs were collected for antibody serology, respectively. The seroprevalence of T. gondii in each year was 27.2%, 22.5% and 43.9%, respectively, and that of N. caninum was 7.8%, 4.8% and 6.8%, respectively. The incidence rates for T. gondii in the 2nd and 3rd collections were 13.2% and 30.0%, and those for N. caninum were 3.3% and 4.4%, respectively. Positive and negative serological conversions for both agents occurred at high frequencies during the study period. This study reveals the canine population's serological profile and demonstrates the constant exposure of dogs to the investigated pathogens, indicating the need for prevention and control measures in the region.

Resumo Os cães são hospedeiros dos protozoários Toxoplasma gondii, que causam uma importante doença para a saúde pública, e Neospora caninum. Estudos que avaliam a toxoplasmose e a neosporose por períodos prolongados em populações caninas são raros. Foi analisada a infecção por esses dois parasitas em uma população de cães domésticos e domiciliados por três anos consecutivos, no Estado de São Paulo, Brasil. Nos 1º, 2º e 3º anos de coletas, 181, 193 e 172 domicílios foram visitados, nos quais foram coletadas amostras de sangue de 331, 371 e 348 cães para sorologia, respectivamente. A soroprevalência de T. gondii em cada ano foi de 27,2%, 22,5% e 43,9%, respectivamente; e a de N. caninum foi de 7,8%, 4,8% e 6,8%, respectivamente. As taxas de incidência para T. gondii, nas 2ª e 3ª coletas, foram de 13,2% e 30,0%, respectivamente; e para N. caninum, 3,3% e 4,4%, respectivamente. As conversões sorológicas positivas e negativas para ambos os agentes ocorreram em alta frequência durante o período analisado. Este estudo revela o perfil sorológico da população canina e demonstra sua constante exposição aos patógenos investigados, o que requer medidas de prevenção e controle na região.

Detection of Mycobacterium avium in pet birds / Detecção de Mycobacterium avium em aves de companhia

The present study is a report on the presence of Mycobacterium avium in four birds of the psittaciform order kept as pets. Anatomopathological diagnosis showed lesions suggestive of the agent and presence of alcohol-acid resistant bacilli (AARB) shown by the Ziehl-Neelsen staining. The identification of Mycobacterium avium was performed by means of PRA (PCR Restriction Analysis). DNA was directly extracted from tissue of the lesions and blocked in paraffin. The role of this agent in pet bird infection is discussed, as well as its zoonotic potential.

Este estudo relata a presença de Mycobacterium avium em quatro aves da ordem Psitaciformes, mantidos como animais de estimação. O exame anatomopatológico revelou a presença de bacilos álcool ácido resistentes na coloração de Ziehl-Neelsen, e o diagnostico definitivo foi feito pelo método PRA (PCR Restriction Analysis) a partir de tecidos emblocados em parafina. Este estudo visa alertar o possível potencial zoonótico deste agente em aves mantidas domiciliadas.

Principais processos neoplásicos encontrados em psitacídeos mantidos em cativeiro / Main neoplasic processes in psittacines birds kept in captivity

Um estudo anatomopatológico envolvendo 130 psitacídeos oriundos de centros de triagens, zoológicos e criadouros, visando a determinação da causa de morte destes animais, revelou a presença de neoplasias em sete animais, totalizando 5,4 por cento dos casos. Os processos neoplasicos foram caracterizados como colangiocarcinoma, colangioma, linfoma, hemangiossarcoma e carcinoma renal primário, sendo o colangiocarcinoma o mais freqüentemente encontrado, presente em três animais. Este trabalho descreve estas neoplasias, levando em consideração os aspectos macro e microscópicos, meios de diagnósticos e espécies acometidas.

An anatomopathologic study of 130 captivy psittacines from zoos, breeders and rehabilitation centers showed the presence of neoplastic disease in seven birds, totalizing 5.4 percent of the cases. The neoplasms were identified like cholangiocarcinoma, cholangioma, lymphoma, haemangiosarcoma and renal cell carcinoma. The cholangiocarcinoma was the tumor most commonly observed. it was present in birds. This study describes the macro and microscopic findings of these tumors; also reports diagnostic methods employed to identify these neoplasms.