Seroprevalence of Toxoplasma gondii among School Children in Pyin Oo Lwin and Naung Cho, Upper Myanmar

A pre-existing Toxoplasma gondii infection exacerbates the pathophysiological response and extent of brain damage after traumatic brain injury in mice

Traumatic brain injury (TBI) is a key contributor to global morbidity that lacks effective treatments. Microbial infections are common in TBI patients, and their presence could modify the physiological response to TBI. It is estimated that one-third of the human population is incurably infected with the feline-borne parasite, Toxoplasma gondii, which can invade the central nervous system and result in chronic low-grade neuroinflammation, oxidative stress, and excitotoxicity-all of which are also important pathophysiological processes in TBI. Considering the large number of TBI patients that have a pre-existing T. gondii infection prior to injury, and the potential mechanistic synergies between the conditions, this study investigated how a pre-existing T. gondii infection modified TBI outcomes across acute, sub-acute and chronic recovery in male and female mice. Gene expression analysis of brain tissue found that neuroinflammation and immune cell markers were amplified in the combined T. gondii + TBI setting in both males and females as early as 2-h post-injury. Glutamatergic, neurotoxic, and oxidative stress markers were altered in a sex-specific manner in T. gondii + TBI mice. Structural MRI found that male, but not female, T. gondii + TBI mice had a significantly larger lesion size compared to their uninfected counterparts at 18-weeks post-injury. Similarly, diffusion MRI revealed that T. gondii + TBI mice had exacerbated white matter tract abnormalities, particularly in male mice. These novel findings indicate that a pre-existing T. gondii infection affects the pathophysiological aftermath of TBI in a sex-dependent manner, and may be an important modifier to consider in the care and prognostication of TBI patients.

Seroprevalence and associated risk factors of Toxoplasma gondii infection among slaughterhouse workers in Yangon Region, Myanmar: A cross-sectional study

BACKGROUND

Toxoplasmosis, having the significant consequences affecting mortality and quality of life, is still prevalent in various places throughout the world. The major gap in surveillance for Toxoplasma gondii infection among high-risk population, slaughterhouse workers, is an obstacle for the effective policies formulation to reduce the burden of toxoplasmosis in Myanmar. Therefore, this study aimed to assess the seroprevalence of toxoplasmosis and associated factors of seropositivity among slaughterhouse workers in Yangon Region, Myanmar.

METHODS

A cross-sectional study that was conducted from June to November 2020 included 139 slaughterhouse workers involving at five main slaughterhouses under Yangon City Development Committee, Myanmar. The presence of IgG and IgM anti-T. gondii antibodies in serum was detected using the OnSite Toxo IgG/IgM Combo Rapid Test. A face-to-face interview was also performed using pretested structured questionnaires to obtain the detail histories: sociodemographic characteristics, level of knowledge, occupational factors, and environmental factors related to T. gondii infection. Bivariate logistic regression was used to determine the factors associated with T. gondii infection.

RESULTS

Of all participants, the overall seroprevalence of anti-T. gondii was 43.9% (95% CI: 35.5-52.5%), of whom 98.4% (95% CI: 91.2-100.0%) were reactive only for IgG antibody and 1.6% (95% CI: 0.0-8.8%) were reactive for IgG and IgM antibodies. The significant factors associated with the seropositivity of T. gondii antibodies were blood transfusion history (OR: 5.74, 95% CI: 1.17-28.09), low level of knowledge (OR: 2.91, 95% CI: 1.46-5.83), contact with animal organs, muscles or blood (OR: 14.29, 95% CI: 1.83-111.51), and animals most frequently slaughtered (cattle) (OR: 3.22, 95% CI: 1.16-8.93).

CONCLUSIONS

A high seroprevalence of toxoplasmosis was detected among slaughterhouse workers in Yangon Region and it raises a significant public health concern. Therefore, providing health education regarding toxoplasmosis, enforcement of personal hygiene practices in workplaces, the establishment of training for occupational hygiene, and commencement of the risk assessment and serological screening for toxoplasmosis are crucial to curtail the prevalence of T. gondii infection among slaughterhouse workers.

Molecular Characterization of Toxoplasma gondii in Cats and Its Zoonotic Potential for Public Health Significance

Toxoplasmosis is a globally distributed disease of warm-blooded animals. It is caused by the opportunistic parasite Toxoplasma gondii (T. gondii). One-third of the global human population is believed to be infected with T. gondii. Cats serve as final host of T. gondii and are the main source of contamination of soil and water. This study aimed to detect genotypes of T. gondii in cats. Fecal samples (n = 400) were collected from districts of South Punjab (Khanewal and Sahiwal), and were processed by polymerase chain reaction (PCR) followed by sequencing and phylogenetic analysis. The obtained oligonucleotide sequences (T. gondii) were submitted to the GenBank database, and the evolutionary tree was constructed using MEGA-X software. Seven fecal samples (3.5%) from cats were positive. Five out of thirteen fecal samples (38.46%) found to be positive for T. gondii with microscopy were confirmed by PCR. After phylogenetic analysis with 3 clonal types and atypical strains, isolates of T. gondii in current study were more closely linked to a typical strain (AF249696). Besides genotyping from cats, seroprevalence from humans and ruminants is still considered to be the best and easiest way to identify the Toxoplasma. Blood samples were collected from sheep and goats (n = 2000 each), and human blood samples (n = 400) were collected from the same vicinity. Seroprevalence was determined using a commercial enzyme-linked immunosorbent assay (ELISA) kit. In Khanewal, the blood samples of 292 goats (29.2%) and 265 sheep (26.5%), and 6 fecal samples from cats (3%) were positive. Out of 200 human blood samples, 52 were positive, with a seroprevalence of 26%. In the Sahiwal district, the blood samples from 49 humans, 235 sheep and 348 goats were positive, with seroprevalence of 24.5%, 23.5% and 34.8%, respectively. The present study revealed the current circulating genotype of T. gondii from cats in the districts Khanewal and Sahiwal and the seroprevalence of the organism in small ruminants and humans living in the same vicinity. Further genotype analyses of the organism from ruminants and humans are needed.

Toxoplasma oocysts in the soil of public places worldwide: a systematic review and meta-analysis

Toxoplasmosis is a zoonotic and cosmopolitan infection. Although a few studies have evaluated the prevalence of Toxoplasma oocysts in the soil of public places, the present study was conducted to provide insights into environmental contamination levels and its potential transmission to humans on a global scale. A systematic search was conducted using bibliographic databases through 30 August 2020. A random effects model was utilized to estimate pooled prevalence with 95% confidence intervals (CIs). Subgroup analysis and meta-regressions were also performed on the geographical and environmental parameters. Finally, 22 articles, wherein 15 420 soil samples were examined, met the systematic review and meta-analysis requirements. The mean pooled prevalence of Toxoplasma oocysts was estimated at 16% (95% CI 10 to 26) in public places. The estimated prevalences in Europe, South America, Asia and North America were 23% (95% CI 4 to 65), 22% (95% CI 18 to 26), 15% (95% CI 0.06 to 33) and 8% (95% CI 0.00 to 97), respectively. An increasing trend was observed in the prevalence of Toxoplasma oocysts with increasing latitude (41-56°), decreasing longitude (0-40°) and increasing relative humidity (≥76%). Loop-mediated isothermal amplification and polymerase chain reaction methods revealed the highest and lowest prevalence rates, respectively, in the detection of Toxoplasma oocysts. Awareness of the health authorities and people about Toxoplasma prevalence in the soil of public places and its risk factors is of great importance to developing effective strategies to prevent infection.

Potential linkage between Toxoplasma gondii infection and physical education scores of college students

Objective

Toxoplasma gondii is a worldwide protozoan parasite that could infect virtually all warm-blooded animals, including humans. Our study aimed to investigate the prevalence of T. gondii infection in college students at Anhui province, China and to assess risk factors for T. gondii infection in college students. Moreover, growing studies demonstrated the association between T. gondii infection and host behavioral changes. We also studied the linkage between T. gondii and physical education (PE) scores of college students.

Methods

A total of 2704 serum samples of medical school students attending physical education lessons were collected from September 2017 to September 2019 and evaluated for T. gondii IgG antibodies using an enzyme-linked immunosorbent assay (ELISA). Questionnaires and statistical analysis were used to determine the risk factors for T. gondii infection. We also analysed PE scores of T. gondii -infected students and T. gondii-uninfected students.

Results

The overall seroprevalence of T. gondii was 11.5%. The main risk factors related to T. gondii infection in college students were cat in the household and gardening or agriculture activity. Furthermore, in the basketball group and the soccer group, scores of T. gondii seropositive students were significantly higher than those of seronegative students, while in other sports there was no difference between scores of T. gondii-infected students and T. gondii uninfected students.

Conclusion

This is the first report of T. gondii seroprevalence in college students in Anhui province, China.

Seroprevalence of toxoplasmosis among reproductive-aged women in Myanmar and evaluation of luciferase immunoprecipitation system assay

BACKGROUNDS

Primary infection with Toxoplasma gondii during pregnancy can pose serious health problems for the fetus. However, the epidemiological status of toxoplasmosis among reproductive-aged population in Myanmar is largely unknown. Although luciferase immunoprecipitation system (LIPS) assays for serodiagnosis of toxoplasmosis was developed mostly using mouse infection model, had not been tested by using field-derived human samples.

METHODS

A total of 251 serum samples were collected from reproductive-aged women, residing in Shwegyin township, Bago region, Myanmar and analyzed with a commercial ELISA kit, as well as in-house LIPS assays.

RESULTS

The overall seroprevalence for Toxoplasma gondii infection by the commercial ELISA was 11.5%. No clear risk factor was identified except for being in the younger age group (15-30 years old). Overall, LIPS assays showed low sensitivity when the commercial ELSA was used as a reference test.

CONCLUSION

We identified the epidemiological situation of toxoplasmosis in some rural communities in Myanmar. The data obtained here will serve as a primary information for the effort to reduce toxoplasmosis in this region. Although looked promising in the previous experiments with mouse infection model, we found that the reported LIPS procedures need further improvements to increase the sensitivities.

Seroprevalence of Toxoplasma gondii in household cats in Myanmar and molecular identification of parasites using feline faecal oocysts

Felids play an important role in the transmission of Toxoplasma gondii to humans and other animals since they can excrete millions of oocysts into the environment as definitive hosts. In the present study, seroprevalence and risk factors of feline Toxoplasma infection were investigated, and molecular identification was conducted for T. gondii oocysts isolated from faecal samples of seropositive cats. A total of 276 cat serum samples collected from the Yangon, Myanmar were tested for T. gondii antibodies by ELISA. The overall seroprevalence of T. gondii infection was 41.30% (114 seropositive cats). Age between 1 and 6 years (OR = 3.284; 95% CI = 1.462–7.375), age > 6 years (OR = 4.560; 95% CI = 1.588–13.100) and sex (OR = 1.725; 95% CI = 1.026–2.899) were found to be significant (P < 0.05) factors associated with T. gondii infection. DNA samples extracted from a single oocyst of seropositive cats were employed in three PCR assays amplifying parasite TOX-element and mitochondrial COI, and SAG2 locus. The obtained sequences of TOX-elements (n = 6) and COI (n = 5) were identical to those of T. gondii previously deposited in Genbank. SAG2 PCR yielded three different sequences, all of which were clustered with Type I T. gondii isolates in a phylogenetic tree. This study reported the seroprevalence and risk factors for T. gondii infection in cats and provided the molecular information on the parasite in Myanmar.

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Seroprevalence of Toxoplasma gondii in cats was investigated for the first time in Myanmar.

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The overall seroprevalence of T. gondii infection in cats was 41.30% (out of 114 seropositive individuals).

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Age, sex, and type of feed were associated with T. gondii infection.

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The obtained sequences of TOX-element and COI were identical to those of T. gondii deposited in GenBank.

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The obtained SAG2 sequences were clustered with T. gondii Type I isolates.