Stray dogs as indicators of <it>Toxoplasma gondii </it>distributed in the environment: the first report across an urban-rural gradient in China

• Main Authors: Yan Chao, Fu Lin-Lin, Yue Cai-Ling, Tang Ren-Xian, Liu Yi-Sheng, Lv Liang, Shi Na, Zeng Ping, Zhang Peng, Wang Dong-Hui, Zhou Dong-Hui, Zhu Xing-Quan, Zheng Kui-Yang
• Format: Article
• Language: English
• Published: BMC 2012-01-01
• Series: Parasites & Vectors
• Subjects: Prevalence; <it>Toxoplasma gondii</it>; Stray dog; Enzyme-linked immunosorbent assay (ELISA); Environment; Indicator
• Online Access: http://www.parasitesandvectors.com/content/5/1/5

<p>Abstract</p> <p>Background</p> <p>Toxoplasmosis is an important parasitic zoonosis caused by the protozoan <it>Toxoplasma gondii </it>that is distributed world-wide and infects a variety of hosts. However, the prevalence of <it>T. gondii </it>in the environment (such as soil, water and food) is largely unknown. Due to the technical difficulty in oocyst counting directly, an alternative assay using the serologic status of <it>T. gondii </it>in free-living animals, such as stray or free-living dogs, as an indicator, can be used to evaluate environmental contamination indirectly, as they are exposed to the same risk of infection as humans and other animals.</p> <p>Results</p> <p>In the present study, 231 stray or free-living dogs across an urban-rural gradient were examined to assess the frequency of <it>T. gondii </it>in the environment. Specific antibodies to <it>T. gondii </it>were found in 93 dogs (40.3%) by enzyme-linked immunosorbent assay (ELISA), and no statistically significant differences were observed in seroprevalences of <it>T. gondii </it>between urban dogs (38.7%) and rural dogs (41%) (<it>p </it>> 0.05).</p> <p>Conclusions</p> <p>A high seroprevalence of <it>T. gondii </it>in stray or free-living dogs in the present study indicates that there would be a wide distribution and a constant infection pressure of <it>T. gondii </it>across an urban-rural gradient, and the oocysts of <it>T. gondii </it>in the environment would be an important source of infection for humans and other animals both in urban and rural areas in China.</p>