Seroprevalence and associated risk factors of Toxoplasma gondii infection in the Korean, Manchu, Mongol and Han ethnic groups in eastern and northeastern China

Well water sources simultaneous contamination with Cryptosporidium and Acanthamoeba in East-Southeast Asia and Acanthamoeba spp. in biofilms in the Philippines

Cryptosporidium is the leading agent of waterborne parasitic protozoan outbreaks and is the second leading cause of infant mortality due to diarrhoea worldwide. Acanthamoeba spp. causes Acanthamoeba keratitis (AK) and a life-threatening condition known as granulomatous amoebic encephalitis (GAE). The present study aimed to assess the water quality of an indigenous and a rural community for waterborne parasitic protozoan contamination. Aquatic samples (n = 22) were processed by filtration of 500 mL portion through a 1.2 μm pore size glass microfiber filter and eluted for light microscopy, culture in non-nutrient agar, and PCR analysis. Overall, 36% (8/22) of the investigated aquatic samples were positive for either Cryptosporidium spp. oocysts (13%; 3/22) or Acanthamoeba spp., (36%; 8/22) or both (13%; 3/22). Cryptosporidium spp. oocysts were detected in 27% (3/11) of wet season samples only while Acanthamoeba spp. were detected in 18% (2/11) and 55% (6/11) of wet and dry season samples, respectively. Subsequently, molecular detection for Acanthamoeba species identified A. lenticulata and A. hatchetti with 98-99% BLAST similarity. This is the first report on the simultaneous contamination of Cryptosporidium and Acanthamoeba in well water sources in East-Southeast Asia, the first detection of Acanthamoeba spp. in biofilms in the Philippines, and the longest viability demonstrated for A. lenticulata in two-year-old water samples stored at room temperature.

Risk factors for Toxoplasma gondii seropositivity in the Old Order Amish

Toxoplasma gondii (T. gondii) is an important human disease-causing parasite. In the USA, T. gondii infects >10% of the population, accrues economic losses of US$3.6 billion/year, and ranks as the second leading culprit of foodborne illness-related fatalities. We assessed toxoplasmosis risk among the Old Order Amish, a mostly homogenous population with a high prevalence of T. gondii seropositivity, using a questionnaire focusing on food consumption/preparation behaviours and environmental risk factors. Analyses were conducted using multiple logistic regression. Consuming raw meat, rare meat, or unpasteurised cow or goat milk products was associated with increased odds of seropositivity (unadjusted Odds Ratios: 2.192, 1.613, and 1.718 , respectively). In separate models by sex, consuming raw meat, or consuming unpasteurised cow or goat milk products, was associated with increased odds of seropositivity among women; washing hands after touching meat with decreased odds of seropositivity among women (adjusted OR (AOR): 0.462); and cleaning cat litterbox with increased odds of seropositivity among men (AOR: 5.241). This is the first study to assess associations between behavioural and environmental risk factors and T. gondii seropositivity in a US population with high seroprevalence for T. gondii. Our study emphasises the importance of proper food safety behaviours to avoid the risk of infection.

Exposure to Toxoplasma gondii Through Consumption of Raw or Undercooked Meat: A Systematic Review and Meta-Analysis

Toxoplasma gondii is a globally distributed protozoan that mainly causes health issues in the fetuses of pregnant women who have never been exposed to this parasite and patients with deficient immune systems. Except in these vulnerable populations, the primary infection generally goes unnoticed in most healthy individuals. Apart from transplant/transfusion, congenital transmission, direct contact with infected cats or their feces, and environmental contamination (i.e., oocysts in food, water, and soil) pathways, humans can acquire the parasite through consumption of animal tissues infected by T. gondii. This meta-analysis estimated the risk of acquiring T. gondii by consuming raw or undercooked meat, regardless of which animal species are eaten. Using a random-effect model, crude and adjusted pooled measures of association (risk and odds ratio) were estimated according to study design (cohort, case-control, and cross-sectional studies). The meta-analysis included measures of heterogeneity as well as quality rating scales for each study design. Our results suggest that individuals who eat raw or undercooked meat have, respectively, 1.2-1.3 times the risk and 1.7-3.0 times the odds of T. gondii infection compared to those who thoroughly cook meat, regardless of the animal species they consume. These results align with the current understanding that adequately cooking meat inactivates the parasite and decreases the risk of transmission. Seroprevalence ranged from 1.3% to 88.6%, while the proportion of individuals eating raw or undercooked meat fluctuated from 0.7% to 98.3% across the studies in the meta-analysis. These numbers reflect various preferences with regard to eating meat (i.e., eating tartar, sausages, or salamis) as well as individual, cultural and religious food habits, and personal awareness.

Meta-analysis of Toxoplasma gondii in pigs intended for human consumption in Mainland China

Toxoplasma gondii, is one of the most important foodborne zoonotic pathogens, which can infect virtually all warm-blooded animals, including pigs, and causes severe illness in congenitally infected infants and even death in patients with AIDS. Pigs (Sus scrofa) are one of the most important intermediate hosts of T. gondii, and human transmission occurs through consumption of raw or poorly cooked pork. In this systematic review and meta-analysis, we searched Chongqing VIP, Wanfang, Chinese Web of Knowledge, PubMed, and ScienceDirect databases for published papers regarding Toxoplasma infection in pigs in China, from inception to Oct 29, 2017. Search strings included whether they reported the samples of more than 30 pigs and provided information that allowed us to establish the prevalence of Toxoplasma infection. Moreover, we excluded repeated studies, reviews, other host studies, as well as studies with inconsistent data, incomplete information, those that only provided prevalence data, and those outside of Mainland China. We extracted the numbers of pigs with Toxoplasma infection from the obtained studies, and calculated the pooled prevalence of Toxoplasma infection in the pigs using a random-effects model. The data of 44 articles (including data on 46,723 pigs) were compliant with the standards. The pooled prevalence of T. gondii infection in pigs in China was 29% (95% CI 24-34), with 25% (95% CI 18-32) in pigs sampled before 2010 and 28% (95% CI 21-36) in pigs sampled in 2010 or later. The pooled prevalence of T. gondii in pigs from Northeast China (20%, 95% CI 14-26) was significantly lower than those from other regions (North China: 40%, 95% CI 32-47; Northwest China: 32%, 95% CI 13-51; East China: 30%, 95% CI 20-41; and South China: 35%, 95% CI 26-45; Central China: 23%, 95% CI 14-31; Southwest China: 33%, 95% CI 15-52). The estimated pooled prevalence of T. gondii infection was 36% (95% CI 25-47, 8,018/21,892) in pigs tested by ELISA, 24% (95% CI 19-28, 4,304/18,608) in pigs examined by IHA, and 19% (95% CI 8-31, 1,041/6,223) in pigs detected by other methods. Moreover, 1202 of 7470 piglets were detected as T. gondii-positive, and the prevalence (17%) was lower than that in fattening pigs (25%, OR = 1.28), sows (34%, OR = 2.13), and breeding boars (35%, OR = 2.46). Our findings suggested that toxoplasmosis is common in pigs in Mainland China. It is necessary to monitor the prevalence of T. gondii in pigs, and powerful and effective regulatory measures should be undertaken to reduce human exposure to T. gondii via the consumption of pork.

ROP9, MIC3, and SAG2 are heparin-binding proteins in Toxoplasma gondii and involved in host cell attachment and invasion

Toxoplasma gondii (T. gondii) is an obligatory intracellular parasite that can infect varieties of warm-blooded animals, including humans and birds. Heparan sulfate (HS) is widely distributed on the eukaryotic cell surface of vertebrates and can inhibit T. gondii invasion. In this study, we investigated the transcription and expression of the level of TgROP9, TgMIC3, and TgSAG2 in T. gondii RH strain, and found that the expression levels of these three proteins in invading parasites were higher compared to those free ranging parasites. The recombinant proteins showed specific binding activity to both heparin and host cell surface. Incubation of these proteins with the host cells could block T. gondiiinvasion. Furthermore, protein-specific antibodies also blocked parasite invasion. Antibodies in the sera of T. gondii infected individuals recognized the recombinant TgROP9, TgMIC3, and TgSAG2, which suggested the exposure of these proteins to human immune system. Mice immunized with the three proteins exhibited protective immunity against lethal challenge. The data collectively suggested that these parasitic proteins may be used as candidate antigens for development of anti-toxoplasmosis vaccine.

Prevalence and risk factors for pterygium: a cross-sectional study in Han and Manchu ethnic populations in Hebei, China

AIMS

To investigate the prevalence, ethnic differences and associated risk factors for pterygium in Han and Manchu populations aged 40-79 years in Hebei province, China.

DESIGN

Cross-sectional study, as a part of the China National Health Survey.

SETTING

Hebei province, China.

PARTICIPANTS

A multistage cluster sampling method with urbanisation level-based stratification was used to select participants for this study. A total of 4591 individuals over 40 years were recruited for this study. Inclusive criteria: (1) residents who had been living in Hebei for more than 1 year; (2) Han individuals with both parents being Han, or Manchu individuals with both parents being Manchu; (3) underwent ophthalmic examinations and (4) information in the questionnaire was complete.

MAIN OUTCOME MEASURES

Multiple logistic regression analysis was used to evaluate the association between pterygium prevalence and factors of interest.

RESULTS

A total of 3790 individuals (2351 Hans and 1439 Manchus) met the study criteria, of which 248 were diagnosed with pterygium (6.5%). There was no significant difference between the prevalence rates in Hans (6.2%) and Manchus (7.2%) (p=0.232). Multivariate analysis revealed that the risk factors for grade 2 or higher pterygium were increasing age (p<0.001) and rural residence (OR 1.83; 95% CI 1.11 to 3.02; p=0.018), while the protective factors include gender (female) (OR 0.58; 95% CI 0.37 to 0.88; p=0.011), cigarette smoking (OR 0.53; 95% CI 0.34 to 0.83; p=0.005) and myopia (OR 0.50; 95% CI 0.33 to 0.77; p=0.002). Premature menopause (OR 2.66; 95% CI 1.05 to 6.72; p=0.038) increased the risk of grade 2 or higher pterygium in females, while higher high-density lipoprotein (HDL) (OR 1.94; 95% CI 1.08 to 3.47; p=0.027) was a risk factor of grade 2 or higher pterygium in males.

CONCLUSION

The overall prevalence of pterygium in Han and Manchu population in Hebei, China was approximately 6.1%. There were no differences in the prevalence of pterygium between Hans and Manchus, and the race was not a risk factor. This is the first study to report on the positive association between premature menopause and pterygium in females and between higher HDL levels and pterygium in males.

Toxoplasma gondii Infection in Dustmen in Northeastern China: A Case-Control Seroprevalence Study

Background

Toxoplasmosis is caused by an intracellular parasite Toxoplasma gondii, which can infect many hosts including humans.

Methods

In order to estimate whether dustmen are more susceptible to T. gondii, a case-control study was conducted containing 332 dustmen from Jilin and Heilongjiang in Northeastern China, as well as 332 general populations from the same regions as control subjects. Serum samples were tested IgG and IgM antibodies to T. gondii using the enzyme-linked immunosorbent assay (ELISA).

Results

The overall anti-T. gondii IgG was 15.06% (50/332) in dustmen compared with 9.64% (32/332) in the controls (P = 0.0337). Also, 5 (1.51%) dustmen had anti-T. gondii IgM antibodies compared with 2 (0.60%) control individuals (P = 0.2543). A significant association was only found between dustmen and level of T. gondii IgG in comparison with the control subjects. Seroprevalence of T. gondii IgG antibodies in male dustmen was significant higher than male control subjects (P = 0.0399). Dustmen from Jilin had the significant higher T. gondii IgG rate (P = 0.0143), in comparison with the control subjects from Jilin. Moreover, dustmen raising cat at home had the significant higher T. gondii IgG rate (P = 0.0097), in comparison with the control subjects. Risk factor analysis suggested that raising cat at home and not having habits of washing hand before eating were mainly related to the T. gondii infection in dustmen.

Conclusions

This is the first record of seroprevalence of T. gondii infection in dustmen in Jilin and Heilongjiang provinces in Northeastern China. These findings also suggest that the government departments should pay close attention to the toxoplasmosis in dustmen in Northeastern China.

Toxoplasma gondii Infection in Diabetes Mellitus Patients in China: Seroprevalence, Risk Factors, and Case-Control Studies

The association between Toxoplasma gondii (T. gondii) infection and diabetes mellitus remains controversial. With the improvement of living standards, the prevalence rate of diabetes is steadily increasing in China. Thus, it is necessary to explore the possible association between toxoplasmosis and diabetes mellitus in China. Hence, case-control studies were conducted to explore the T. gondii seroprevalence and identify the risk factors and possible transmission routes of T. gondii infection in different types of diabetes, including type 1 diabetes (T1DM), type 2 diabetes (T2DM), and gestational diabetes (GDM) patients in China. Four hundred serum samples for each type of diabetes mellitus, matched with 400 control subjects for each group, were collected and examined for anti-T. gondii IgG and IgM antibodies using commercially available enzyme immunoassay kits. The total T. gondii seroprevalence in T1DM, T2DM, and GDM patients was 16.50%, 23.50%, and 21.25%, respectively. Each type of diabetes mellitus patients had a significantly higher T. gondii seroprevalence than the control subjects. Multivariate regression identified three variables as risk factors for T. gondii infection in diabetes patients, including keeping cats at home and consumption of raw oysters for T1DM patients and consumption of raw/undercooked meat and raw oysters for T2DM patients, which may help to guide future research and control policies in diabetes mellitus patients.

Seroprevalence and Related Factors of Toxoplasma gondii in Pigeons Intended for Human Consumption in Northern China

Toxoplasma gondii, the causative agent of toxoplasmosis, is carried by a range of intermediate hosts, including pigeons. Eating raw or undercooked pigeon meat, as is common in regions of China, can easily pass on a potentially fatal T. gondii infection. However, there are little data about the seroprevalence and genotypes of T. gondii infection in pigeons. In this study, a total of 963 pigeon blood samples were collected from Jilin Province, Liaoning Province, and Inner Mongolia Autonomous Region in China between August 2015 and December 2016. The overall seroprevalence of T. gondii was 10.80% (104/963), with 8.80% (41/466) in males and 12.68% (63/497) in females. The seroprevalence of T. gondii in different regions varied from 9.04% (17/188) in Jilin City to 13.16% (20/152) in Shenyang City, a relatively high prevalence. The seroprevalence of T. gondii in juvenile pigeons (6.38%, 18/282) was significantly lower than in adults (86/681, p < 0.05). These findings could provide useful data for the execution of effective control measures against T. gondii infection in pigeons and/or other hosts. More importantly, the findings also suggest that pigeons should not be eaten raw.

Seroprevalence and risk factors of Toxoplasma gondii infection in horses in Jilin Province and Inner Mongolia Autonomous Region, northern China

Toxoplasmosis is caused by the protozoon Toxoplasma gondii that can infect almost all warm-blooded hosts including horses and humans. Horse meat is one of the most important meat products for human consumption. However, data on seroprevalence of T. gondii in horses intended for human consumption in Northern China is scarce. Thus, a total of 614 serum samples were collected from Jilin Province and Inner Mongolia Autonomous Region (IMAR) between 2015 and 2017, and were detected the seroprevalence for T. gondii by indirect hemagglutination assay test. In the prevalence study, the overall seroprevalence of T. gondii in horses was 17.92% (110/614) by IHA test, at the cut- off 1:64. Horses collected from Changchun (13.58%, P = 0.02) has a significantly lower seroprevalence than those from Meihekou City (21.72%) and Tongliao City (22.81%). Moreover, a significant difference of T. gondii seroprevalence was found between horses ages at less than 12 months (22.75%) and ≥12 months or higher (16.42%, P = 0.002). To our knowledge, this is the first report of seroprevalence of T. gondii in horses in Jilin and IMAR, Northern China. Logistic regression suggested that age and geographical location of horses were identified as risk factors. These findings will provide the useful data for controlling and preventing toxoplasmosis in horses and/or other hosts in China.

Seroprevalence and associated risk factors of Toxoplasma gondii among Manchu pregnant women in northeastern China

Toxoplasma gondii is an intracellular protozoan parasite infecting human and almost all warm-blooded animals. It may cause several severe symptoms if pregnant women infection with T. gondii, including misbirth. A cross-sectional study was conducted containing 313 Manchu pregnant women attending antenatal care from 2016 to 2017 in Jilin province, northeastern China, and were assessed by enzyme-link immunosorbent assay and the study utilized univariate analysis to identify the potential risk factors for T. gondii infection. Of the 313 investigated Manchu pregnant women, 51 (16.29%, 95% CI 12.2-20.4) were tested as T. gondii-seropositive, with 47 (15.02%) seropositive for T. gondii IgG antibodies and 8 (2.56%) IgM positive. The seroprevalence of T. gondii in different age groups varied from 13.50% (8.7-18.3) to 23.90% (13.9-41.9). Pregnant raising cat at home has a significantly higher seroprevalence of T. gondii than no cat at home. Pregnant consuming raw/undercooked meat has a significantly higher T. gondii seroprevalence than individuals did not consuming raw/undercooked meat. This is the first study of T. gondii infection seroprevalence in Manchu pregnant women. Risk factors analysis suggested that seroprevalence of T. gondii in investigated Manchu pregnant women was mainly related to consumption of raw/undercooked meat and raising cat at home. The findings will provide key and baseline data for prevention and control of toxoplasmosis among Manchu pregnant women and other people.

Animal influence on water, sanitation and hygiene measures for zoonosis control at the household level: A systematic literature review

INTRODUCTION

Neglected zoonotic diseases (NZDs) have a significant impact on the livelihoods of the world's poorest populations, which often lack access to basic services. Water, sanitation and hygiene (WASH) programmes are included among the key strategies for achieving the World Health Organization's 2020 Roadmap for Implementation for control of Neglected Tropical Diseases (NTDs). There exists a lack of knowledge regarding the effect of animals on the effectiveness of WASH measures.

OBJECTIVES

This review looked to identify how animal presence in the household influences the effectiveness of water, hygiene and sanitation measures for zoonotic disease control in low and middle income countries; to identify gaps of knowledge regarding this topic based on the amount and type of studies looking at this particular interaction.

METHODS

Studies from three databases (Medline, Web of Science and Global Health) were screened through various stages. Selected articles were required to show burden of one or more zoonotic diseases, an animal component and a WASH component. Selected articles were analysed. A narrative synthesis was chosen for the review.

RESULTS

Only two studies out of 7588 met the inclusion criteria. The studies exemplified how direct or indirect contact between animals and humans within the household can influence the effectiveness of WASH interventions. The analysis also shows the challenges faced by the scientific community to isolate and depict this particular interaction.

CONCLUSION

The dearth of studies examining animal-WASH interactions is explained by the difficulties associated with studying environmental interventions and the lack of collaboration between the WASH and Veterinary Public Health research communities. Further tailored research under a holistic One Health approach will be required in order to meet the goals set in the NTDs Roadmap and the 2030 Agenda for Sustainable Development.

Exposure to Toxoplasma gondii in the Roma and Non-Roma Inhabitants of Slovakia: A Cross-Sectional Seroprevalence Study

The lifestyle, health and social status of the Roma are generally below the standards characteristic for the non-Roma population. This study aimed to find out the seropositivity to Toxoplasma gondii (T. gondii) in the population of Roma living in segregated settlements and to compare it with the prevalence of antibodies in the non-Roma population from the catchment area of eastern Slovakia. The seroprevalence of antibodies to T. gondii was significantly higher in the Roma group (45.0%) than in non-Roma inhabitants (24.1%). A statistically significant difference was also recorded between the two non-Roma groups in the study, 30.4% of those from the catchment area and 19.7% from the non-catchment area were seropositive. Univariate logistic regression confirmed poverty and higher age to be significant risk factors influencing the seropositivity to T. gondii. Of the clinical symptoms analyzed in the study, only muscle and back pain were associated with seropositivity to T. gondii. The close contact of Roma with an environment contaminated by different infectious agents and the insufficient hygiene, lower level of education, poverty, lack of water and household equipment and high number of domestic animals increase the risk of infectious diseases in the Roma settlements and subsequently the spread of communicable diseases at the national or even international level.

Seroprevalence and risk factors associated with Toxoplasma gondii infection in domestic rabbits and humans

A cross-sectional study was conducted from September 2014 to December 2015 to determine seroprevalence and potential risk factors associated with Toxoplasma gondii (T. gondii) infection in domestic rabbits and humans in Egypt. In total 290 blood samples were collected from humans (n=140) and slaughtered rabbits (n=150) and were analyzed using ELISA for T. gondii IgM and IgG antibodies. T. gondii IgM and IgG antibodies were detected in, respectively, 9 (6%) and 40 (26.7%) of 150 rabbits raised in Cairo, Qalyubia, and Sharkia Governorates, Egypt. Corresponding overall seroprevalences for human participants were 5.7% and 35.7%, respectively. Rabbit age, management (farm, backyard and pet shop) and the presence of cats at rabbit raising areas were significantly associated with the seroprevalence of T. gondii IgG antibodies. T. gondii IgG antibodies seropositivity in pregnant participants and rabbit butchers were 0.17 and 0.63 times lower than immunocompromised participants, respectively. However, participants who consumed undercooked rabbit meat was 7.59 times higher than participants who consumed meat from other sources. The results indicate that domestic rabbits are a potential source of T. gondii infections in human in Egypt. Thus, dissemination of protective measures is essential, especially for rabbit butchers and immunocompromised individuals.

Seroprevalence and associated risk factors of Toxocara infection in Korean, Manchu, Mongol, and Han ethnic groups in northern China

Toxocariasis is a very prevalent zoonotic disease worldwide. Recently, investigators have focused more on Toxocara spp. seroprevalence in humans. Information regarding Toxocara seroprevalence in people from different ethnic backgrounds in China is limited. For this study, blood samples were collected from a total of 802 Han, 520 Korean, 303 Manchu, and 217 Mongol subjects from Jilin and Shandong provinces. The overall Toxocara seroprevalence was 16·07% (14·21% Han, 20·58% Korean, 11·22% Manchu, 18·89% Mongol). Living in suburban or rural areas, having dogs at home, exposure to soil, and consumption of raw/undercooked meat were risk factors for Toxocara infection. Exposure to soil was identified as the major risk factor for Toxocara seropositivity in all of the tested ethnicities. To the best of our knowledge, this is the first report concerning Toxocara infection in Manchus and Mongols in China. The present study provided baseline data for effective prevention strategies of toxocariasis in northeast China and recommends improvements in personal hygiene standards to achieve this goal.