Leishmania infantum infection rate in dogs housed in open-admission shelters is higher than of domiciled dogs in an endemic area of canine visceral leishmaniasis. Epidemiological implications.

Canine visceral leishmaniasis (CVL) is caused by Leishmania infantum and is endemic in many areas of southeastern Brazil. We have hypothesized that the prevalence of infection by L. infantum in dogs housed in open-admission animal shelters is beyond the range of 3.4 - 9.6% reported among dogs domiciled in similar CVL-endemic areas. Hence, this study aimed to determine the rate of L. infantum infection among dogs maintained in shelters and to investigate the epidemiology of CVL in such environments by analyzing hematological and biochemical parameters. A total of 627 dogs from 17 different shelters across the State of Minas Gerais were screened using the Dual-Path Platform test and enzyme-linked immunosorbent assay and 211 (33.6%) were found to be seropositive in both tests. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed on skin, bone marrow and lymphoid tissues of 118 seropositive dogs with inconclusive CVL clinical diagnosis and, of these, 78 (66.1%) were PCR+ for L. infantum and 7 (5.9%) were PCR+ for L. amazonensis. One dog presented a PCR-RFLP profile that was consistent with co-infection by both parasites. Leishmania amazonensis DNA was detected in skin samples of six single-infected dogs and this constitutes a novel finding. Dogs infected only with L. amazonensis were less debilitated than those infected by L. infantum, which showed typical clinical manifestations of CVL. The co-infected dog showed only mild clinical signs. The results presented herein not only support our original hypothesis but also suggest that dogs are potential reservoirs of L. amazonensis. Public health authorities should acknowledge their responsibility towards animals in collective shelters, recognize that they are potential foci of zoonotic diseases, and establish proper functioning directives to minimize transmission to humans and to other dogs.

Important frequency of Anaplasma phagocytophilum infection in a population of domiciled dogs in an urbanized area in south-eastern Brazil / Importante frequência da infecção por Anaplasma phagocytophilum em uma população de cães domiciliados em área urbanizada no sudeste do Brasil

Anaplasma phagocytophilum is responsible for granulocytic anaplasmosis in humans and various animal species. The aim of the present study was to determine the prevalence of A. phagocytophilum-infected dogs in a residential area of Belo Horizonte, Minas Gerais state, Brazil. A total of 62 dogs were submitted to serological (indirect fluorescent-antibody -IFI) and molecular (PCR) tests. Anti-A. phagocytophilum antibodies were detected in 43.8% of the dogs. Seven dogs (10.9%) were PCR-positive for the msp4 gene, six and four of these were positive for the for the msp2/p44 gene of A. phagocytophilum and 16S rRNA region of granulocytic Anaplasmataceae respectively. This study confirms a relatively high frequency of A. phagocytophilum infection in a population of domiciled dogs in an urbanized area in south-eastern Brazil and highlights the need for further studies on the role of Rhipicephalus sanguineus sensu lato ticks in the transmission of this bacterium to dogs in urban Brazilian areas.(AU)

Anaplasma phagocytophilum é responsável pela anaplasmose granulocítica, doença que acomete seres-humanos e várias espécies de animais. O objetivo do presente estudo foi determinar a prevalência de cães acometidos por A. phagocytophlium em uma área residencial de Belo Horizonte, MG, Brasil. Sessenta e dois cães foram submetidos a testes sorológicos (reação de imunofluorescência indireta - IFAT) e moleculares (PCR). Anticorpos anti-A. phagocytophilum foram detectados em 43,8% dos cães. Sete cães (10,9%) foram positivos no PCR para o gene msp4 de A. phagocytophilum, seis para o gene msp2/p44 A. phagocytophilum e quatro para a região 16S rRNA de Anaplasmataceae granulocíticas. Esse estudo confirma a frequência relativamente alta da infecção por A. phagocytophilum em uma população de cães domiciliados em área urbanizada no sudeste do Brasil e destaca a necessidade de pesquisas para determinar o papel do carrapato Rhipicephalus sanguineus sensu lato na transmissão desse microrganismo para cães de áreas urbanas brasileiras.(AU)