Abstract: A cross-sectional study was conducted to identify the seroprevalence of Toxoplasma gondii infection in cats, dogs, sheep, goats, cattle and camels in Al-Ahsa area, Saudi Arabia. Serum samples were collected from cats, dogs and slaughtered ruminant animals and analysed for Toxoplasma gondii antibodies using ELIZA. The seroprevalence was 90, 20, 19, 10, 22, 12, 4 and 8% in stray and household cats, stray and household dogs, sheep, goats, cattle and camels, respectively. Significantly higher value of prevalence was seen in stray cats compared to other animals. The presence of Toxoplasma gondii in slaughtered animals indicates that toxoplasmosis in this area poses an occupational risk to workers in the slaughter house and that toxoplasmosis could be a veterinary public health that necessitates integrated control measures.

INTRODUCTION

Several cross-sectional studies carried out in Saudi Arabia have revealed a relatively high seroprevalence of Toxoplasma gondii infection in pregnant women (Al-Harthi et al., 2006; Mohammad et al., 2010), blood donors (Al-Amari, 1994) and among Saudi population (Al-Qurashi et al., 2001). Ingestion of food or water contaminated with oocysts shed by cats or consumption of under cooked or raw meat containing tissue cysts are implicated as possible risk to infection (Dubey and Streitel, 1976; Dubey and Beattie, 1988). People living in rural areas with animals exposure are at higher risk for infection (Al-Harthi et al., 2006; Al-Qurashi et al., 2001). Animals by virtue of being the intermediate host could serve as potential risk to human public health. This study, therefore was designed to determine the seroprevalence of T. gondii in cats and ruminant animals in Al-Ahsa area, Saudi Arabia where high toxoplasmosis was reported in humans (Mohammad et al., 2010).

MATERIALS AND METHODS

Blood samples were obtained from stray and house hold cats and dogs. For other animals, samples were obtained from slaughter houses in Al-Ahsa in summer 2010. Samples (2 mL) were collected from cats (156), dogs (42), sheep (400), goats (196), camels (210) and cattle (130) into plain tubes. Serum was separated and stored at -30°C until analysis.

Toxoplasma assay: The CIV-test T. gondii ELISA kit for animals (Shenzhen, China) was performed to determine antibodies to T. gondii according to the manufacturer’s instructions. In brief, after incubation of antigen-coated microplates with the test sera diluted 1:100, T. gondii specific antibodies were detected through binding the antigen/antibody complex with a peroxidase-labelled anti-ruminant IgG monoclonal antibody conjugate for 90 min. Both the positive and negative controls were provided in the kit. A chromogenic enzyme substrate was added and the optical density at wave length of 450 nm was read using a photometer (Bio-RAD, Hercules, CA, USA). A relative rate percent value was calculated and sera considered positive to T. gondii if the value exceeds 2.1 as recommended by manufacturer.

Statistical analysis: Chi-square and Fisher’s exact tests were used to compare seroprevalence values relative to animal species. Analysis shall be performed with SPSS software for windows with a (p<0.05) as statistically significant.

RESULTS

The seroprevalence rate of antibodies against T. gondii for 156 cats, 92 dogs, 400 sheep, 196 goats, 30 cattle and 210 camels are shown in Table 1. The seroprevalence for stray and household cats and dogs, sheep, goats, cattle and camels was 90, 20, 19, 10, 22, 12, 4 and 8%, respectively. The overall prevalence for cats and dogs were 63 and 15%, respectively.

Table 1:	Prevalence of antibodies to Toxoplasma gondii in animals

Significantly (p<0.05) higher value of prevalence was seen in stray cats compared to other animals. Similar value of prevalence was seen in household cats, dogs and sheep. Significantly (p<0.05) lower values of prevalence were observed in goats, camels and cattle. The cattle have the lowest prevalence rate among animals.

DISCUSSION

The overall seroprevalence of anti T. gondii in cats was 63% which was similar (Miro et al., 2004) or higher than in other countries (Zhang et al., 2009). The prevalence of antibodies T. gondii infection in stray cats was significantly higher than in household cats. Comparable results were reported in Iran (Haddadzadeh et al., 2006), Spain (Gauss et al., 2003) and China (Zhang et al., 2009) which could be due to hunting habbit of stray cats that their diet includes rodents, placenta, stillborn foeti and wild birds. Stray dogs too have access to similar diets (Lindsay et al., 1990; Mineo et al., 2001).

CONCLUSION

In this study the high seroprevalence of T. gondii in sheep, goats, cattle and camels may be attributed to the fact that stray infected cats (90%) were found almost every where in Al-Ahsa and to the viability of T. gondii oocysts in the environment (Fleck, 1972; Hilali et al., 1995). Similar values of prevalence rate of toxoplasmosis in sheep and goats was reported elsewhere (Hashemi-Fesharki, 1996; Van Der Puije et al., 2000; Daryani et al., 2006). Likewise, toxoplasmosis was reported in cattle (Bekele and Kasali, 1989; Matsuo and Husin, 1996) and camels. The lower value of seroprevalence in these two later species may be due to differences in management methods (Pita Gondim et al., 1999). The prevalence of Toxoplasma in slaughtered sheep, goats, cattle and camels indicates that toxoplasmosis in this area poses an occupational risk to veterinarians, animal owners, slaughter house workers who handle infected material (Radostitis et al., 2000) and that toxoplasmosis could be a veterinary public health hazard that necessitates integrated control strategies.

ACKNOWLEDGEMENT

The researcher would like to thank the Deanship of Scientific Research for financial support.