Seroprevalence and risk factors for Neospora caninum infection in cattle from the eastern Antioquia, Colombia.

Bovine neosporosis is a parasitic disease with worldwide distribution that causes important economic losses. Because of the limited information on the occurrence of Neospora caninum infection in Colombia, this study aimed to determine the seroprevalence and identify the risk factors associated with this infection in cattle in Antioquia, which is the largest milk-producing state in the country. We collected 1,038 blood samples from Holstein, Jersey and crossbred cows from 31 farms. An epidemiologic questionnaire was given to all the owners. A commercial ELISA kit was used as the diagnostic technique. The occurrence of anti-N. caninum antibodies was determined to be 28.3% (294/1038), and 100% of the screened farms were positive, indicating that all the properties had at least one positive animal. The seropositivity within each farm ranged from 5.5% to 50%. A multivariable logistic regression model identified the following as significant risk factors: history of abortion (OR = 5.33, p < 0.001), replacement with cattle purchased outside the farm (OR = 1.54, p < 0.05), age (OR = 1.7, p < 0.01) and poor hygienic practices associated with manual milking (OR = 1.69, p < 0.01). The latter two factors suggest that horizontal transmission is an important route of infection. This study is the first to report the seroprevalence of and risk factors for N. caninum infection in Antioquia and allows us to conclude that N. caninum is widely distributed in this region.

Genetic characterisation of Neospora caninum strains from clinical samples of zebuine foetuses obtained in abattoirs in Goiás, Brazil.

The Neospora caninum microsatellite markers were applied to clinical samples. Genotyping technology involving fluorescently labelled DNA fragment analysis was used in combination with DNA sequencing for markers with complex repetitive sequences. Nineteen DNA samples from 15 brains and four hearts of naturally infected non-aborted zebuine foetuses from abattoirs in Goiás, Brazil. N. caninum had been detected in these foetuses by nested-PCR of the internal transcribed spacer-1 rRNA region, and the samples were analysed using these microsatellites. Seven complete or nearly complete allele profiles were obtained from six foetuses. Three distinct profiles of N. caninum were identified in a unique microregion (Meia Ponte) of Goiás. Two alleles for the same marker were detected in a unique foetus that was probably infected with two different strains. A new allele for one of the microsatellites is described. The multilocus analysis performed here revealed a preliminary means of discriminating between individual strains according to their geographical origins. These are the first results that have been obtained regarding the molecular characterisation of strains of N. caninum from infected zebuine foetuses in South America and reveal for the first time that there are genotypic differences in the strains that are responsible for foetal transmission in zebuine foetuses.

Differences in the behavior of Rhipicephalus sanguineus tested against resistant and susceptible dogs.

To ascertain whether brown dog tick Rhipicephalus sp. infests resistant (beagle) and susceptible (English cocker spaniel) dogs differently, five animals of each breed were maintained in a kennel whose walls were infested with 7,000 larvae, 320 nymphs, 80 males and 80 females, in 3 infestations, at 10-day intervals. Five times more ticks were found on cocker spaniels (498) than on beagles (96). Substances were collected by rubbing pieces of clean flannel on the dogs for 15 min and these were tested for arrestment and attractiveness of ticks. Three choices were offered: cocker extract vs. control; beagle extract vs. control, and cocker extract vs. beagle extract. When allowed to choose between substances rubbed from dogs and a control, more ticks were arrested by extracts from the cockers than from beagles. In the arrestment tests with only a choice between substances from dogs of each breed, more ticks were arrested by cocker substances. To test for attraction, capsules containing adsorbent were used and the tests were carried out in a Y-olfactometer. Fifteen males and 15 females were tested, for each treatment. In the olfactometer, the ticks were not attracted to the odor of either breed, however the odor of the Beagle was apparently repellent. These results indicate that R. sanguineus can use substances from the dogs to differentiate susceptible English Cocker Spaniels from resistant Beagles.

Ocorrência de helmintos gastrintestinais em cães errantes na cidade de Goiânia- Goiás / Occurrence of intestinal parasites in stray dogs from Goiânia, Goiás, Brazil

O crescente número de animais de companhia em áreas urbanas, principalmente cães (Canis familiaris) e gatos (Felis catus) tem como consequência o estreitamento do contato desses animais com o homem, aumentando sua exposição às zoonoses. Com o objetivo de verificar a ocorrência de helmintos gastrintestinais em cães errantes em Goiânia e suas possíveis implicações em saúde pública, foram analisadas 201 amostras fecais de cães de rua recolhidos pelo Centro de Controle de Zoonoses. As amostras foram colhidas no período de fevereiro a maio de 2007 e examinadas segundo as técnicas convencionais para pequenos animais. Foram encontrados ovos das seguintes espécies de helmintos: Ancylostoma sp. (45,3por cento), Toxocara canis (8por cento), Trichuris vulpis (1por cento) e Dipylidium caninum (1por cento). A infecção isolada causada por Ancylostoma sp. foi observada em maior porcentagem, demonstrando o risco potencial da transmissão de zoonoses causadas por helmintos gastrintestinais de cães. Tal fato reforça a necessidade de medidas efetivas de saúde pública para que seja reduzida a ocorrência desses parasitos e sua possível transmissão ao homem.