Concordance of Toxoplasma gondii Infection Markers Among Heterosexual Couples.

BACKGROUND: Very little is known about concordance of Toxoplasma gondii (T. gondii) infection markers among couples. Through a cross-sectional study, we sought to determine the correlation of T. gondii infection in a sample of 119 heterosexual couples in Durango State, Mexico. METHODS: Participants were examined for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. IgG and IgM seropositive couples were further analyzed for the presence of T. gondii DNA by using polymerase chain reaction (PCR). RESULTS: Anti-T. gondii IgG antibodies were found in 71 (59.7%) men and in 63 (52.9%) women (odds ratio (OR) = 1.31; 95% confidence interval (CI): 0.78 - 2.19; P = 0.29). Of the 71 seropositive men, 40 (56.3%) had a seropositive couple; in contrast, of the 63 seropositive women, 40 (63.5%) had a seropositive couple (OR = 0.74; 95% CI: 0.37 - 1.48; P = 0.39). In total, 65 (54.6%) couples had concordant results (both IgG positive or both IgG negative), and 54 (45.4%) had discordant results (a seropositive man with a seronegative woman, or a seropositive woman with a seronegative man) (kappa index = 0.08; 95% CI: -0.09 - 0.26). With respect to high (> 150 IU/mL) levels of anti-T. gondii IgG antibodies, 79 (66.4%) of the 119 couples had concordant results and 40 (33.6%) had discordant results (kappa index = -0.15; 95% CI: -0.03 - 0.33). Forty couples were positive for anti-T. gondii IgM antibodies. Of them, 21 (52.5%) had concordant results, and 19 (47.5%) had discordant results (kappa index = -0.01; 95% CI: -0.39 - 0.28). Concerning PCR, eight (50%) of 16 couples were positive for T. gondii DNA. Of them, 11 (68.8%) had concordant results, and five (31.2%) had discordant results (kappa index = 0.31; 95% CI: -0.17 - 0.79). CONCLUSIONS: Results suggest a poor concordance of serological and molecular markers of T. gondii infection among heterosexual couples. Further studies to confirm our results should be conducted.

High Prevalence of Toxoplasma gondii Infection in Miners: A Case-Control Study in Rural Durango, Mexico.

BACKGROUND: Very little is known about the seroepidemiology of infection with the parasite Toxoplasma gondii (T. gondii) in miners. We determine the association of T. gondii infection and the occupation of miner, and the association of seropositivity for T. gondii with the socio-demographic, clinical, work and behavioral characteristics of the miners. METHODS: Through a case-control study, 125 miners working in Durango State, Mexico and 250 age- and gender-matched non-miner subjects were examined for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. In addition, the presence of T. gondii DNA in miners was determined using polymerase chain reaction. Bivariate and multivariate analyses were used to determine the association of socio-demographic, work, clinical and behavioral characteristics of miners with T. gondii infection. RESULTS: Anti-T. gondii IgG antibodies were detected in 75 (60.0%) of 125 miners and in 55 (22.0%) of 250 controls (odds ratio (OR) = 5.31; 95% confidence interval (CI): 3.33 - 8.47; P < 0.001). Among IgG seropositive subjects, the frequency of anti-T. gondii IgM antibodies was significantly higher in miners (39/75, 52%) than in controls (8/55, 14.5%) (P < 0.001). All T. gondii seropositive miners referred themselves as healthy. Multivariate analysis of socio-demographic, housing, and behavioral characteristics of miners showed that T. gondii seropositivity was positively associated with being born in Durango State (OR = 3.44; 95% CI: 1.09 - 10.7; P = 0.03), consumption of boar meat (OR = 5.53; 95% CI: 1.49 - 20.3; P = 0.01), living in an overcrowded home (OR = 5.83; 95% CI: 1.49 - 22.8; P = 0.01), and was negatively associated with cleaning cat excrement (OR = 0.33; 95% CI: 0.11 - 0.90; P = 0.03) and consuming goat meat (OR = 0.16; 95% CI: 0.03 - 0.76; P = 0.02). CONCLUSIONS: Surprisingly, our results indicate that miners represent a risk group for T. gondii infection. This is the first age- and gender-matched case-control study on the association of T. gondii infection and the occupation of miner. Further studies to identify the exact cause of high seropositivity in miners in rural Durango are needed.

Toxoplasma gondii exposure in patients suffering from mental and behavioral disorders due to psychoactive substance use.

BACKGROUND: Toxoplasma gondii infection has been associated with psychiatric diseases. However, there is no information about the link between this infection and patients with mental and behavioral disorders due to psychoactive substance use. METHODS: We performed a case-control study with 149 psychiatric patients suffering from mental and behavioral disorders due to psychoactive substance use and 149 age- and gender-matched control subjects of the general population. We searched for anti-T. gondii IgG and IgM antibodies in the sera of participants by means of commercially available enzyme-linked immunoassays. Seroprevalence association with socio-demographic, clinical and behavioral characteristics in psychiatric patients was also investigated. RESULTS: Anti-T. gondii IgG antibodies were present in 15 (10.1%) of 149 cases and in 14 (9.4%) of 149 controls (P=1.0). Anti-T. gondii IgM antibodies were found in 11 (7.4%) of the 149 cases and in 16 (10.7%) of the 149 controls (P=0.31). No association of T. gondii exposure with socio-demographic characteristics of patients was found. Multivariate analysis of clinical and behavioral characteristics of cases showed that T. gondii seropositivity was positively associated with consumption of opossum meat (OR=10.78; 95% CI: 2.16-53.81; P=0.003) and soil flooring at home (OR=11.15; 95% CI: 1.58-78.92; P=0.01), and negatively associated with suicidal ideation (OR=0.17; 95% CI: 0.05-0.64; P=0.008). CONCLUSIONS: Mental and behavioral disorders due to psychoactive substance use do not appear to represent an increased risk for T. gondii exposure. This is the first report of a positive association of T. gondii exposure with consumption of opossum meat. Further studies to elucidate the role of T. gondii infection in suicidal ideation and behavior are needed to develop optimal strategies for the prevention of infection with T. gondii.

Toxoplasma gondii infection in interstate truck drivers: a case-control seroprevalence study.

BACKGROUND: Infection with Toxoplasma gondii can be acquired via the ingestion of undercooked or raw meat containing tissue cysts, or via ingestion of water contaminated with oocysts. Professional long distance truck driving may have epidemiological importance for food-borne infections since drivers eat out of home and in places where hygiene and cooking practices are uncertain. We aimed to determine whether interstate truck drivers in Durango, Mexico have an increased risk of infection with T. gondii as indicated by seropositivity; and to determine the socio-demographic, work, clinical, and behavioral characteristics associated with T. gondii seropositivity in interstate truck drivers. METHODS: Through a case-control study design, 192 truck drivers and 192 controls from the general population of the same region matched by gender and age were examined with enzyme-linked immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies. Socio-demographic, work, clinical and behavioral characteristics from the truck drivers were obtained. RESULTS: Anti-T. gondii IgG antibodies were found in 23 (12.0%) of 192 truck drivers and in 13 (6.8%) of 192 controls (OR = 21.0; 95% CI: 1.23-358.38; P = 0.002). Anti-T. gondii IgM antibodies were found in 7 (3.6%) cases and in 7 (3.6%) controls (P = 1.00). The seroprevalence of T. gondii infection was higher in drivers with reflex impairment than in those without this impairment (4/13, 30.8% vs 19/179, 10.6%, respectively; P = 0.05), and in drivers with hearing impairment than in those without this impairment (3/7, 42.9% vs 20/185, 10.8%, respectively; P = 0.03). Multivariate analysis of work and behavioral characteristics of truck drives showed positive associations of T. gondii exposure with trips to the south of Mexico (OR = 3.11; 95% CI: 1.02-9.44; P = 0.04) and consumption of horse meat (OR = 5.18; 95% CI: 1.62-16.55; P = 0.005). CONCLUSIONS: Results suggest that interstate truck drivers may have an increased risk for T. gondii infection, and that T. gondii exposure may be impacting neurological functions in truck drivers. Contributing factors for T. gondii exposure should be taken into account for the design of optimal prevention measures against T. gondii infection.

Lack of association between Toxoplasma gondii infection and occupational exposure to animals.

The association of infection with Toxoplasma gondii and occupational exposure to animals has been scantly determined. We performed a case-control study with 200 subjects from Durango Province, Mexico, occupationally exposed to animals and 200 age- and gender-matched subjects without this occupation. Sera from all participants were analyzed for anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. The association of seroprevalence with sociodemographic, work, clinical, and behavioral characteristics in cases was determined. Cases and controls had similar frequencies of anti-T. gondii IgG antibodies (12/200: 6.0% and 11/200: 5.5%, respectively) (OR = 3.0; 95% CI: 0.12-73.64; P = 1.0). The frequency of sera with high (>150 IU/ml) levels of anti-T. gondii IgG antibodies was comparable among cases and controls (P = 0.61). Seroprevalence of anti-T. gondii IgM antibodies was similar in cases (4, 2.0%) than in controls (4, 2.0%) (P = 1.0). Multivariate analysis showed that seropositivity was associated with eating while working (OR = 7.14; 95% CI: 1.91-26.72; P = 0.003) and consumption of duck meat (OR = 5.43; 95% CI: 1.43-20.54; P = 0.01). No association between seropositivity to T. gondii and occupational exposure to animals was found. However, risk factors for infection found should be taken into account to reduce the exposure to T. gondii.

Seroprevalence of Toxoplasma gondii infection and associated risk factors in Huicholes in Mexico.

BACKGROUND: Very little is known about the seroepidemiology of Toxoplasma gondii infection in ethnic groups in Mexico. Huicholes are an indigenous ethnic group living in a remote mountainous region in Mexico. We sought to determine the prevalence of anti-Toxoplasma IgG and IgM antibodies in Huicholes; and to determine the association of Toxoplasma seropositivity with socio-demographic, behavioral, and clinical characteristics of Huicholes. METHODS: We performed a cross sectional survey in Huicholes from September 2013 to January 2014. A convenience sampling method was used. We investigated the prevalence of anti-Toxoplasma IgG and IgM antibodies in 214 Huicholes using enzyme-linked immunoassays. A standardized questionnaire was used to obtain the characteristics of the Huicholes. Bivariate and multivariate analyses were used to assess the association of Toxoplasma exposure and Huicholes' characteristics. RESULTS: Of the 214 Huicholes studied (mean age: 37.98 ± 15.80 years), 71 (33.2%) were positive for anti-T. gondii IgG antibodies and 47 (66.2%) of them were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection did not vary with age, sex, or occupation. However, seroprevalence of anti-T. gondii IgM antibodies was significantly higher in female than in male Huicholes. Multivariate analysis of socio-demographic and behavioral characteristics showed that T. gondii exposure was associated with consumption of turkey meat (OR = 2.28; 95% CI: 1.16-4.46; P = 0.01). In addition, seroprevalence of T. gondii infection was significantly higher in Huicholes suffering from dizziness and memory impairment than those without such clinical characteristics. CONCLUSIONS: Our results demonstrate serological evidence of T. gondii exposure among Huicholes which may be impacting their health. Results of this first study of T. gondii infection in Huicholes may be useful for the design of optimal preventive measures against infection with T. gondii.