Endemicity of Toxoplasma infection and its associated risk factors in Cebu, Philippines.
ABSTRACT: Toxoplasma gondii is a single-celled intracellular apicomplexan parasite that causes toxoplasmosis. It is capable of infecting humans and nearly all warm-blooded animals including pigs, but cats are the only known definitive host. This ubiquitous zoonotic pathogen can cause abortion, stillbirth and fetal abnormalities, and has been associated with mental and behavioral changes in humans. Acute infection is potentially fatal in immunocompromised individuals. The present study aimed to assess the Toxoplasma seroprevalence in pigs, humans and cats after its initial reported detection in pigs about three decades ago in Cebu, Philippines. A total of 924 humans, 104 cats and 514 slaughter pigs were tested for antibodies against T. gondii using a commercial latex agglutination test. The results revealed positive detection rates of 26.3% (244/924) for humans, 42.3% (44/104) for cats and 13.4% (69/514) for slaughter pigs. Statistical analyses revealed that the area (P = 0.004), cat ownership (P = 0.020), the frequency of contact with cats (P < 0.0001) and consumption of street foods (P = 0.043) were significantly associated with seropositivity for T. gondii in humans. Meanwhile, the use of litter trays (P = 0.001) and contact with other animals (P = 0.007) were significantly associated with seropositivity in cats. The odds ratio for selected significant factors revealed that living in suburban areas (OR 1.66, 95% CI: 1.20-2.31), owning a cat (OR 1.482, 95% CI: 1.07-2.07) and eating street foods (OR 1.585, 95% CI: 1.01-2.48) were associated with an increased risk of T. gondii exposure in humans. In cats, the use of a litter tray (OR 4.5, 95% CI: 1.73-11.71) was associated with an increased risk of exposure. None of the profile parameters were found to be significantly associated with seropositivity in slaughter pigs (P > 0.05). This study is the first report of the serological detection of T. gondii in humans and cats in Cebu, Philippines, and the first assessment of the prevalence of the parasite in pigs in the area since its initial detection in 1982. This is also the first report documenting the seropositivity of T. gondii in pregnant women in the country. The confirmed seropositivity of T. gondii in Cebu, Philippines, in the present study implies the endemicity of toxoplasmosis in this area and highlights the need for routine testing and increased public awareness.
Project description:A seroepizootiological study of Toxoplasma gondii infection involving a total of 488 slaughter pigs (468 market-weight pigs and 20 sows) in the Belgrade area, also included examination of the presence of T. gondii in the blood. Blood sampled at the slaughter line was examined for specific antibodies by modified direct agglutination, and blood clots of those seropositive at titres of 1:50-1:12800 were bioassayed in mice. The overall seroprevalence was 9.2%, significantly higher (p = 0.0063) in sows (30.0%) than in market-weight pigs (8.3%). Amongst the 22 bioassays performed, a total of 16 (72.7%) were positive, by observation of T. gondii cysts (12), seropositivity (7, including 3 in which cysts were not detected), and/or detection of T. gondii DNA by real-time PCR (12, including one otherwise negative). The positive bioassays originated from the blood of 12 market-weight pigs and 4 sows. Despite a general increase in the rate of demonstration of T. gondii with the increase in the specific antibody level, the association was not significant (p = 0.101). The risk of infection was 41-fold increased in sows vs market-weight pigs, and 15-fold in pigs from smallholders' finishing type farms vs those from large farrow-to-finish farms. The presence of viable T. gondii in a proportion of the samples indicates that some of the pigs had an active parasitaemia at the time of slaughter, which, along with the seroprevalence established, points to a potential source of human infection in Serbia. This is the first report on parasitaemia in naturally infected swine.
Project description:Toxoplasma gondii is the causative agent of the parasitic disease toxoplasmosis, which is an important foodborne zoonosis. Eating undercooked meat of infected animals, including pigs, has been considered the major transmission route of T. gondii to humans. Therefore, it is urgent to develop and implement intervention measures in the pork meat chain to reduce risks of acquiring a T. gondii infection. Proposed measures for control of T. gondii in pigs include serological testing of pigs and audits of pig farms on risk factors for T. gondii infection. So far, these ideas have not been tested in practice. In order to generate knowledge about the epidemiology and seroprevalence of T. gondii, as a basis for developing a surveillance system, we studied the long term seroprevalence over years, farming systems and regions, and seasonal patterns of T. gondii seroprevalence in Dutch slaughter pigs. During a five year study period from 2012 to 2016, serum samples were routinely collected in five Dutch pig slaughterhouses. The sera were tested in an ELISA for the presence of antibodies against Toxoplasma. In total 226,340 serum samples were collected and tested during the study period. The observed seroprevalence varied over years, with the highest overall seroprevalence in 2014 (2.8%) and the lowest in 2016 (1.4%). A higher seroprevalence was observed in pigs from organic farms compared to pigs from conventional farms. The overall risk of infection was on average 2.63 times significantly (p?<?0.001) higher for organically raised pigs than for conventionally raised pigs. A seasonal pattern in seroprevalence was observed: the results showed a dominant annual periodicity with a seroprevalence peak in winter around week 1 and a minimum seroprevalence in summer around week 27. To our knowledge, this is the first large scale study on the seroprevalence of T. gondii in slaughter pigs. In comparison to other European serological studies, the observed seroprevalence seems to be relatively low. However, care is needed when comparing the results with other studies because of differences in test setup, the number of samples and time period of sampling. The results can be used as a starting point for developing a surveillance system for T. gondii, and for implementation of intervention measures.
Project description:Toxoplasma gondii is a widespread zoonotic parasite that is relevant for veterinary and public health. The domestic cat, the definitive host species with the largest worldwide population, has become evolutionarily and epidemiologically the most important host of T. gondii. The outcome of T. gondii infection is influenced by congenital and acquired host characteristics. We detected differences in T. gondii seroprevalence by cat breed in our previous studies. The aims of this study were to estimate T. gondii seroprevalence in selected domestic cat breeds, and to evaluate whether being of a certain breed is associated with T. gondii seropositivity, when the age and lifestyle of the cat are taken into account. The studied breeds were the Birman, British Shorthair, Burmese, Korat, Norwegian Forest Cat, Ocicat, Persian, and Siamese. Plasma samples were analyzed for the presence of immunoglobulin G antibodies against T. gondii with a commercial direct agglutination test at dilution 1:40. The samples were accompanied by owner-completed questionnaires that provided background data on the cats. Overall, 41.12% of the 1121 cats tested seropositive, and the seroprevalence increased with age. The Burmese had the lowest seroprevalence (18.82%) and the Persian had the highest (60.00%). According to the final multivariable logistic regression model, the odds to test seropositive were four to seven times higher in Birmans, Ocicats, Norwegian Forest Cats, and Persians when compared with the Burmese, while older age and receiving raw meat were also risk factors for T. gondii seropositivity. This study showed that T. gondii seroprevalence varies by cat breed and identified being of certain breeds, older age, and receiving raw meat as risk factors for seropositivity.
Project description:BACKGROUND:Toxoplasma gondii, an important food borne zoonotic parasite, infects almost all warm-blooded animals including pigs. People primarily become infected with T. gondii via consuming meat of infected animals. Status of T. gondii is largely unknown in pigs in India including northern regions. We, therefore, determined the prevalence of T. gondii infection in pigs from North India. RESULTS:DNA of T. gondii was detected in 6.7% (54/810) of the tested slaughter pigs. Highest prevalence was observed in pigs from Punjab (8.2%) followed by Chandigarh (5.3%) and Uttarakhand (4.8%). Phylogenetic analysis revealed that the isolates from pigs had 96-100% nucleotide identity with Type I RH strain (AF179871), 96-99.7% with VEG type III strain (LN714499) and 67-72% with type II ME 49 strain (XM002370240). However, low level of polymorphism in the targeted B1 gene did not allow the determination of the clonal lineages of the isolates. Antibodies against T. gondii was reported in 48.3% (73/151) of the sera obtained from pigs slaughtered at Chandigarh abattoir, and scavenging by pigs was a significant risk factor. CONCLUSION:Prevalence of T. gondii DNA was low in pigs in North India, however, presence of the parasite warrants food safety concerns. Further studies are required to identify the clonal lineage of T. gondii circulating in pigs reared in North India. Pig farmers should be educated about the hygienic management practices.
Project description:BACKGROUND: Recent studies of Toxoplasma gondii isolates from animals in different regions of China have shown a limited genetic diversity and type China 1 was the dominant genotype of T. gondii prevalent in Chinese animals. However, little has been known concerning the isolation and genotyping of T. gondii circulating in chickens, pigs and rodents in China. The aim of the study was to characterize samples of T. gondii isolates obtained from naturally infected cats, pigs and free-range chickens slaughtered for human consumption in China. METHODS: In the present study, brain tissues of 77 animals collected from different areas of China, including 24 free-range chickens (Gallus domesticus) , 13 voles (Rattus flavipectus), 23 pigs and 17 cats, were bioassayed in mice and viable T. gondii were isolated from the brains of eleven. These eleven T. gondii isolates were maintained in Kunming (KM) outbred mice and DNA isolated from tissues of infected mice was characterized using 11 PCR-restriction fragment length polymorphism (PCR-RFLP) markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3. Moreover, to determine mouse virulence of China 1 lineage of parasites, a TgCtgy5 genotype isolate was selected randomly and assessed in KM mice with different inoculation doses. RESULTS: Results of genotyping revealed that ten isolates were type China 1 (ToxoDB PCR-RFLP genotype #9), and TgCksz1 was a new genotype that was reported for the first time designated here as ToxoDB PCR-RFLP #225. No clonal types I, II and III lineages were found. DNA sequencing of four introns (EF1, HP2, UPRT1 and UPRT7) and two genes (GRA6 and GRA7) from representative isolates confirmed the results of PCR-RFLP genotyping. The TgCtgy5 isolate was highly virulent in KM mice; all infected mice died of acute toxoplasmosis, irrespective of the inoculation dose. The results indicate that mouse virulent isolates of T. gondii are predominantly circulating in cats in China. CONCLUSIONS: T. gondii isolated from chickens, pigs, cats and rodents in different locations in China were genotyped and the results reconfirmed the limited diversity of T. gondii in China and showed that type China 1 lineage was dominant in this country.
Project description:Toxoplasmosis is a major zoonosis, and its prevention requires multiple approaches due to the complex life-cycle of its causative agent, Toxoplasma gondii. Environmental contamination by oocysts is a key factor in the transmission of T. gondii to both humans and meat-producing animals; however, its spatial and temporal variations are poorly understood. We analysed the distribution of T. gondii seropositivity in a sample of 210 cats, including the European wildcat (Felis silvestris silvestris), the domestic cat (Felis silvestris catus) and their hybrids that were collected in Central and Eastern France between 1996 and 2006. We searched for spatial variability among communes and temporal variations among years to relate this variability to landscape and meteorological conditions, which can affect the population dynamics of rodent hosts and the survival of oocysts. The overall seroprevalence was 65.2% (95% CI: 58.6-71.4). As expected, adults were more often infected than young individuals, while the occurrence of infection was not related to cat genotypes. Seroprevalence correlated significantly with farm density and the North-Atlantic Oscillation index, which describes temporal variations of meteorological conditions at the continental scale. The highest seroprevalence values were obtained in areas with high farm densities and during years with cool and moist winters. These results suggest that both farming areas and years with cool and wet winters are associated with increased T. gondii seroprevalence in cats. As cat infection determines the environmental contamination by oocysts, climate and landscape characteristics should be taken into account to improve the risk analysis and prevention of T. gondii.
Project description:BACKGROUND:Felids (domestic and wild cats) are important in the epidemiology of the parasite Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts. We conducted a systematic review and meta-analysis to estimate the global prevalence of T. gondii in species of the family Felidae. METHODS:We searched seven databases (PubMed, Embase, Google Scholar, ScienceDirect, Scopus, Proquest and Web of Science) for studies reporting seroprevalence of T. gondii in felids from 1967 to 31 December 2017. A total of 217 published papers, containing 223 datasets were eligible for inclusion in the meta-analysis, comprised 59,517 domestic and 2733 wild cats from 1967 to 2017. RESULTS:The pooled global T. gondii seroprevalence was estimated to be 35% (95% CI: 32-38%) and 59% (95% CI: 56-63%) in domestic cats and wild felids, respectively, using random effects model. The seroprevalence was higher in Australia and Africa where the T. gondii seropositivity in domestic cats was 52% (95% CI: 15-89%) and 51% (95% CI: 20-81%), respectively. The lowest seroprevalence was estimated in Asia 27% (95% CI: 24-30%). The seroprevalence values for T. gondii in wild felids were 74% (95% CI: 62-83%) in Africa, 67% (95% CI: 23-111%) in Asia, 67% (95% CI: 58-75%) in Europe and 66% (95% CI: 41-91%) in South America. CONCLUSIONS:Our study provides the global prevalence of T. gondii in species of the family Felidae and is a source of information to aid public health workers in developing prevention plans.
Project description:The close contact between cats and humans poses a threat to public health because of the potential zoonotic transmission of influenza viruses to humans. Therefore, we examined the seroprevalence of pandemic H1N1/09, canine H3N2, and human H3N2 viruses in pet cats in northern China from 2010 to 2014.Of 1794 serum samples, the seropositivity rates for H1N1/09, canine H3N2, and human H3N2 were 5.7%, 0.7%, and 0.4%, respectively. The seropositivity rate for H1N1/09 in cats was highest in 2010 (8.3%), and then declined continuously thereafter. Cats older than 10 years were most commonly seropositive for the H1N1/09 virus.Our findings emphasize the need for continuous surveillance of influenza viruses in cats in China.
Project description:Cats (Felis catus) are reservoirs of several pathogens that affect humans, including Toxoplasma gondii. Infection of pregnant women with T. gondii can cause ocular and neurological lesions in newborns, and congenital toxoplasmosis has been associated with schizophrenia, epilepsy, movement disorders, and Alzheimer's disease. We compared seroprevalence of T. gondii and risk factors in people on seven islands in Mexico with and without introduced cats to determine the effect of cat eradication and cat density on exposure to T. gondii. Seroprevalence was zero on an island that never had cats and 1.8% on an island where cats were eradicated in 2000. Seroprevalence was significantly higher (12-26%) on the five islands with cats, yet it did not increase across a five-fold range of cat density. Having cats near households, being male and spending time on the mainland were significant risk factors for T. gondii seroprevalence among individuals, whereas eating shellfish was protective. Our results suggest that cats are an important source of T. gondii on islands, and eradicating, but not controlling, introduced cats from islands could benefit human health.
Project description:The increasing prevalence of Toxoplasma gondii infection in the human population in the Republic of Korea (= Korea) is due to various reasons such as an increase in meat consumption. However, the importance of cats in transmitting T. gondii infection through oocysts to humans has seldom been assessed. A total of 300 fecal samples of stray cats captured around Seoul from June to August 2013 were examined for T. gondii B1 gene (indicating the presence of oocysts) using nested-PCR. Fourteen (4.7%) of 300 cats examined were positive for B1 gene. Female cats (7.5%) showed a higher prevalence than male cats (1.4%). Cats younger than 3 months (5.5%) showed a higher prevalence than cats (1.5%) older than 3 months. For laboratory passage of the positive samples, the fecal suspension (0.2 ml) of B1 gene positive cats was orally inoculated into experimental mice. Brain tissues of the mice were obtained after 40 days and examined for the presence of tissue cysts. Two isolates were successfully passaged (designated KNIH-1 and KNIH-2) and were molecularly analyzed using the SAG5D and SAG5E gene sequences. The SAG5D and SAG5E gene sequences showed high homologies with the ME49 strain (less virulent strain). The results indicated the importance of stray cats in transmitting T. gondii to humans in Korea, as revealed by detection of B1 gene in fecal samples. T. gondii isolates from cats were successfully passaged in the laboratory for the first time in Korea.