Elsevier

Veterinary Parasitology

Volume 106, Issue 4, 2 July 2002, Pages 307-313
Veterinary Parasitology

Serological survey of Neospora caninum and Leishmania infantum co-infection in dogs

https://doi.org/10.1016/S0304-4017(02)00114-0Get rights and content

Abstract

A seroprevalence survey and risk analysis of Neospora caninum and Leishmania infantum was conducted in dogs from an area of the Campania region of southern Italy, in order to investigate the co-infection of these two protozoa.

Blood samples were collected from 1058 asymptomatic dogs over a 18 months period. Serum samples were tested for antibodies to N. caninum and to L. infantum using the indirect fluorescent antibody test.

Epidemiological data (breed, age, sex, and utilization) were collected and statistically analysed in relation to N. caninum and to L. infantum seropositivity and antibody titres.

Out of the 1058 sera samples tested, 68 (6.4%) were found to have antibodies to N. caninum, and 222 (21.0%) to have antibodies to L. infantum. The co-presence of antibodies to N. caninum and to L. infantum was found in 46 (4.3%) dogs. Thus, 67.6% of the dogs positive for N. caninum also had antibodies to L. infantum.

The major risk factor for N. caninum seropositivity was the presence of antibodies to L. infantum, and the major risk factor for L. infantum seropositivity was the presence of antibodies to N. caninum. In addition, high N. caninum seroprevalence was closely correlated to Boxer breed, and high L. infantum seroprevalence was correlated to masculine gender and Setter and Pit bull breeds. Low L. infantum seroprevalence was closely correlated to Yorkshire breed.

The findings of this survey indicate that in the Campania region of southern Italy the co-presence of antibodies to N. caninum and to L. infantum is very common in dogs, and that infection by one protozoan seems to enhance the susceptibility to the other one. This is probably due to the immunological status of the tested dogs.

Introduction

Neospora caninum is a recently recognized protozoan of dogs, cattle and other mammals (Dubey and Lindsay, 1996, Dubey, 1999). The dog has been identified as a definitive host, releasing oocysts in faeces following experimental oral infection with tissue cysts (McAllister et al., 1998, Lindsay et al., 1999). Under natural conditions, a dog has also been reported to shed oocysts in La Plata, Argentina (Basso et al., 2001).

In Italy, this protozoan was first isolated in dogs in 1998 (Pasquali et al., 1998, Poli et al., 1998), however, serological evidence of its presence had been observed earlier both in cattle (Ferrari et al., 1995) and in dogs (Cringoli et al., 1996a).

Leishmania infantum is the agent of canine leishmaniosis throughout the entire Mediterranean basin. It has been continuously reported in Italy since the beginning of the 1900s, and is widespread in many central and southern Italian regions (Pozio et al., 1985, Zaffaroni et al., 1999).

N. caninum and L. infantum skin co-infection has recently been reported in a young dog in Italy (Tarantino et al., 2001). A previous sero-epidemiological survey of N. caninum in a small number of dogs from the Campania region of southern Italy, also observed high levels of N. caninum and L. infantum co-infection (Cringoli et al., 1996b).

The present serological survey investigates a large sample of clinically asymptomatic dogs living in an area of southern Italy endemic for canine leishmaniosis, in order to further study N. caninum and L. infantum co-infection and risk factors.

Section snippets

Study area

The study was conducted in the Campania region of southern Italy within an 2446 km2 area (40°45′–41°03′N and 14°15′–14°45′E), that includes 60 non-contiguous municipalities of four different provinces (Avellino, Napoli, Caserta, and Salerno).

Animals and blood samples

The sample size was calculated using the formula proposed by Thrusfield (1995) for a large (theoretically “infinite”) population using the following values: expected prevalence 29% (based on our previous studies on N. caninum, Cringoli et al., 1996a);

Seroprevalence and antibody titres

The epidemiological data and the seroprevalence results of tested dogs are shown in Table 1.

Out of the 1058 dog sera samples, 68 (6.4%) were found to have antibodies to N. caninum, and 222 (21.0%) were found to have antibodies to L. infantum. The co-presence of antibodies to N. caninum and L. infantum was found in 46 (4.3%) dogs. Thus, 67.6% of the dogs positive for N. caninum also had antibodies to L. infantum, and 20.7% of the dogs positive for L. infantum also had antibodies to N. caninum.

Discussion

In the Campania region of southern Italy, the occurrence of antibodies to N. caninum has been reported in dogs (Cringoli et al., 1996a, Cringoli et al., 1996b), cattle (Guarino et al., 1998) and water buffaloes (Guarino et al., 2000).

The seroprevalence of N. caninum reported for dogs in the present survey (6.4%) confirms the wide diffusion of this protozoan in this region.

The seroprevalence of L. infantum reported in the present survey (21.0%) is higher than that reported in previous studies

References (22)

  • W Basso et al.

    First isolation of Neospora caninum from the faeces of a naturally infected dog

    J. Parasitol.

    (2001)
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