In Uganda, Bissonet al. the disease toxoplasmosis in humans and animals and its antibodies are known to be present in about a third of the global human population, although local and regional prevalences vary widely.Toxoplasma gondiiis very successful as a pathogen owing to its ability to infect almost all mammals and birds (Dubey2002). Toxoplasmosis is found worldwide, but is usually more common at lower altitudes and in warm and humid climates. Members of the family Felidae are the only known definitive hosts forT. gondii. Cats can become infected by feeding on prey already infected with dormantT. gondiicysts or tachyzoites and also by drinking oocyst-contaminated water. Infected cats are known to shed infective oocysts in their faeces 512 days post ingestion of oocysts (Al Kappanyet al.2010; N106 Dubey1995; Elmoreet al.2010), thereby contaminating the environment and posing a risk of transmission to other species. Toxoplasmosis causes substantial economic losses in sheep Rabbit polyclonal to CREB1 farming globally and was first described in ovines in 1954 (Buxtonet al.2007; Jones & Dubey2012). PrimaryT. gondiiinfections in livestock, in particular sheep and goats, pose a health risk to these animals, as infection is known to cause abortions, stillbirths and neonatal mortalities. In the United Kingdom, for example, ovine toxoplasmosis causes up to 2% of foetal losses per annum (Buxtonet al.2007; Inneset al.2009). In humans and animals,T. gondiiinfections are acquired post natally by the ingestion of tissue cysts in partially cooked meat, infective oocysts in food or water contaminated with infected felid faeces, or handling of tissues of animals infected with tissue cysts. Contamination can also occur by vertical transmission from mother to foetus in humans, sheep, goats and small rodents (Hill & Dubey2002; Jones & Dubey2012; Smith1993). In humans, contamination can also occur via blood transfusions and organ N106 transplantation, although this is rare. Infection has been known to occur via inhalation of aerosols made up of infective oocysts or from contact with contaminated soils in both humans and animals. In sheep,T. gondiiinfection is mainly acquired post natally, as congenital infections usually lead to abortions. Rarely, congenitally affected lambs are given birth to, which can be N106 a possible route for contamination in humans (Dubey & Welcome1988; Williamset al.2005). There are various risk N106 factors reported to be associated withT. gondiiinfection in sheep. Seroprevalence in sheep is known to increase with age and is therefore higher in ewes or rams than in lambs (Dubey2009). Other risk factors forT. gondiiinfection in sheep include the presence of cats on farms, the nature of farming and management practices (commercial vs noncommercial; intensive, semiintensive, free range or open), climatic conditions and geographic location, presence of surface drinking water sources and size of the farm (Abu Samraet al.2007; Andradeet al.2013; Mainaret al.1996). Although infected ewes do not usually show symptoms of clinical toxoplasmosis,T. gondiiinfection has been noted as an important cause of ovine abortions in the United States and Europe (Dubey2009), with seroprevalence in sheep ranging from 20.8% (Huffmanet al.1981) to 73.8% (Dubey & Welcome1988) in the United States. It has also been suggested that some breeds of sheep may be more susceptible toT. gondiiinfection than others (Dubey & Welcome1988; Williamset al.2005). In South Africa, seroprevalence studies have been reported in human populations (both asymptomatic and HIV and/or AIDS cohorts) as well as in animal populations, as reviewed by Hammond-Aryee, Esser and Van Helden (2014a). However, these studies are limited and few of them are from the post-HIV era. There have been even fewer studies in animal populations and only one focused on sheep, reporting seroprevalence as 4.3% via enzyme-linked immunosorbent assay (ELISA).