Socio-demographic determinants of Toxoplasma gondii seroprevalence in migrant workers of Peninsular Malaysia

Background The number of migrants working in Malaysia has increased sharply since the 1970’s and there is concern that infectious diseases endemic in other (e.g. neighbouring) countries may be inadvertently imported. Compulsory medical screening prior to entering the workforce does not include parasitic infections such as toxoplasmosis. Therefore, this study aimed to evaluate the seroprevalence of T. gondii infection among migrant workers in Peninsular Malaysia by means of serosurveys conducted on a voluntary basis among low-skilled and semi-skilled workers from five working sectors, namely, manufacturing, food service, agriculture and plantation, construction and domestic work. Methods A total of 484 migrant workers originating from rural locations in neighbouring countries, namely, Indonesia (n = 247, 51.0%), Nepal (n = 99, 20.5%), Bangladesh (n = 72, 14.9%), India (n = 52, 10.7%) and Myanmar (n = 14, 2.9%) were included in this study. Results The overall seroprevalence of T. gondii was 57.4% (n = 278; 95% CI: 52.7–61.8%) with 52.9% (n = 256; 95% CI: 48.4–57.2%) seropositive for anti-Toxoplasma IgG only, 0.8% (n = 4; 95% CI: 0.2–1.7%) seropositive for anti-Toxoplasma IgM only and 3.7% (n = 18; 95% CI: 2.1–5.4%) seropositive with both IgG and IgM antibodies. All positive samples with both IgG and IgM antibodies showed high avidity (> 40%), suggesting latent infection. Age (being older than 45 years), Nepalese nationality, manufacturing occupation, and being a newcomer in Malaysia (excepting domestic work) were positively and statistically significantly associated with seroprevalence (P < 0.05). Conclusions The results of this study suggest that better promotion of knowledge about parasite transmission is required for both migrant workers and permanent residents in Malaysia. Efforts should be made to encourage improved personal hygiene before consumption of food and fluids, thorough cooking of meat and better disposal of feline excreta from domestic pets

Toxoplasma, Toxocara and Tuberculosis co-infection in a four year old child

<p>Abstract</p> <p>Background</p> <p>Tuberculosis. toxocariasis and toxoplasmosis are among the common infectious causes of lymphadenitis in children. Cases of <it>Toxoplasma gondii </it>and <it>Toxocara spp </it>co-infection have been reported.</p> <p>Case Presentation</p> <p>This case report describes a co-infection of <it>Toxoplasma gondii</it>, <it>Toxocara </it>spp and tuberculosis in a child with chronic lymphadenopathy and eosinophilia.</p> <p>Conclusion</p> <p>The case report highlights two important points. First is the diagnostic challenges that are encountered by clinicians in tropical countries such as Sri Lanka, where lymphadenopathy and eosinophilia with a positive serology commonly point towards a parasitic infection. Secondly the importance of proper history taking and performing the Mantoux test as a first line investigation in a country where the incidence of tuberculosis is low, even in the absence of a positive contact history.</p

Longer pregnancy and slower fetal development in women with latent "asymptomatic" toxoplasmosis

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to confirm that women with latent toxoplasmosis have developmentally younger fetuses at estimated pregnancy week 16 and to test four exclusive hypotheses that could explain the observed data.</p> <p>Methods</p> <p>In the present retrospective cohort study we analysed by the GLM (general linear model) method data from 730 <it>Toxoplasma</it>-free and 185 <it>Toxoplasma</it>-infected pregnant women.</p> <p>Results</p> <p>At pregnancy week 16 estimated from the date of the last menstruation, the mothers with latent toxoplasmosis had developmentally younger fetuses based on ultrasound scan (<it>P </it>= 0.014). Pregnancy of <it>Toxoplasma</it>-positive compared to <it>Toxoplasma</it>-negative women was by about 1.3 days longer, as estimated both from the date of the last menstruation (<it>P </it>= 0.015) and by ultrasonography (<it>P </it>= 0.025).</p> <p>Conclusion</p> <p>The most parsimonious explanation for the observed data is retarded fetal growth during the first weeks of pregnancy in <it>Toxoplasma</it>-positive women. The phenomenon was only detectable in multiparous women, suggesting that the immune system may play some role in it.</p

Toxoplasma seroprevalence in a rural population in France: detection of a household effect

<p>Abstract</p> <p>Background</p> <p><it>Toxoplasma gondii</it>, the agent of toxoplasmosis, has a complex life cycle. In humans, the parasite may be acquired either through ingestion of contaminated meat or through oocysts present in the environment. The importance of each source of contamination varies locally according to the environment characteristics and to differences concerning human eating habits and the presence of cats; thus, the risk factors may be determined through fine-scale studies. Here, we searched for factors associated with seropositivity in the population of two adjacent villages in Lorraine region, France.</p> <p>Methods</p> <p>All voluntary inhabitants filled out a questionnaire and gave a blood sample. The seroprevalence was estimated globally and according to the inhabitants' ages using a cubic spline regression. A mixed logistic regression model was used to quantify the effect of individual and household factors on the probability of seropositivity.</p> <p>Results</p> <p>Based on serological results from 273 persons, we estimated seroprevalence to be 47% (95% confidence interval: 41 to 53%). That seroprevalence increased with age: the slope was the steepest up to the age of 40 years (OR = 2.48 per 10-year increment, 95% credibility interval: [1.29 to 5.09]), but that increase was not significant afterwards. The probability of seropositivity tended to be higher in men than in women (OR = 2.01, 95% credibility interval: [0.92 to 4.72]) and in subjects eating raw vegetables at least once a week than in the others (OR = 8.4, 95% credibility interval: [0.93 to 72.1]). These effects were close to statistical significance. The multivariable analysis highlighted a significant seroprevalence heterogeneity among households. That seroprevalence varied between 6 and 91% (5^thand 95^thpercentile of the household seropositivity distribution).</p> <p>Conclusion</p> <p>The major finding is the household effect, with a strong heterogeneity of seroprevalence among households. This effect may be explained by common exposures of household members to local risk factors. Future work will quantify the link between the presence of oocysts in the soil and the seroprevalence of exposed households using a spatial analysis.</p

Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Latent toxoplasmosis, protozoan parasitosis with prevalence rates from 20 to 60% in most populations, is known to impair reaction times in infected subjects, which results, for example, in a higher risk of traffic accidents in subjects with this life-long infection. Two recent studies have reported that RhD-positive subjects, especially RhD heterozygotes, are protected against latent toxoplasmosis-induced impairment of reaction times. In the present study we searched for increased incidence of traffic accidents and for protective effect of RhD positivity in 3890 military drivers.</p> <p>Methods</p> <p>Male draftees who attended the Central Military Hospital in Prague for regular entrance psychological examinations between 2000 and 2003 were tested for <it>Toxoplasma </it>infection and RhD phenotype at the beginning of their 1 to1.5-year compulsory military service. Subsequently, the data on <it>Toxoplasma </it>infection and RhD phenotype were matched with those on traffic accidents from military police records and the effects of RhD phenotype and <it>Toxoplasma </it>infection on probability of traffic accident was estimated with logistic regression.</p> <p>Results</p> <p>We confirmed, using for the first time a prospective cohort study design, increased risk of traffic accidents in <it>Toxoplasma</it>-infected subjects and demonstrated a strong protective effect of RhD positivity against the risk of traffic accidents posed by latent toxoplasmosis. Our results show that RhD-negative subjects with high titers of anti-<it>Toxoplasma </it>antibodies had a probability of a traffic accident of about 16.7%, i.e. a more than six times higher rate than <it>Toxoplasma</it>-free or RhD-positive subjects.</p> <p>Conclusion</p> <p>Our results showed that a common infection by <it>Toxoplasma gondii </it>could have strong impact on the probability of traffic accident in RhD negative subjects. The observed effects could provide not only a clue to the long-standing evolutionary enigma of the origin of RhD polymorphism in humans (the effect of balancing selection), but might also be the missing piece in the puzzle of the physiological function of the RhD molecule.</p

Seroprevalence and risk factors for toxoplasma infection among pregnant women in Aydin province, Turkey

BACKGROUND: The aims of the present study were to determine the prevalence of toxoplasmosis in pregnant women at first trimester of their pregnancy and to follow up the seroconversion for next two trimesters, and to identify the risk factors and possible contamination routes in Aydin province, Turkey. METHOD: The sample size was calculated as 423 on a prevalence of 50%, d=0.05 at a confidence level of 95% with 10% addition. It was a cross-sectional study with multistage sampling. After a questionnaire applied to the pregnant women, anti-Toxoplasma IgG antibodies were studied with ELISA and IFA, values in conflict with DA test, where IgM antibodies were studied with ELISA and for borderline or positive values of IgM avidity test was used. RESULTS: The mean age of 389 (92.9%) of pregnant women in the study was 24.28+/-4.56 years, the seroprevalence of anti-Toxoplasma IgG antibodies for toxoplasmosis was 30.1%. Seroprevalence was increased with age (p=0.001) and with drinking water consumption other than bottled water (p=0.042). No significant relations were observed between anti-Toxoplasma IgG antibodies and education level, being native or migrant, abortion history, consumption of meat, vegetable and milk/milk products, personal or kitchen hygiene habits, cat owning at home of the pregnant women. No IgM antibody was detected. CONCLUSION: One of every three pregnant women in Aydin was at risk of toxoplasmosis at the first trimester of their pregnancy. Increased seroprevalance with age was a predictable result because of increasing time of exposure. Increased seroprevalence with consumption of municipal and uncontrolled water (well/spring water) supplies was similar with latest epidemiological findings