Prevalence and risk factors for Taenia solium cysticercosis in school-aged children: A school based study in western Sichuan, People's Republic of China

Monetary burden of neurocysticercosis on a hospitalized population in Muli County, China

Neurocysticercosis (NCC) is a potentially life-threatening condition caused by the zoonotic cestode, Taenia solium. Pigs are the typical intermediate hosts for T. solium but humans can become infected and develop NCC upon ingesting parasite eggs that are shed in the feces of an infected person. The objective of this study was to estimate the monetary burden of neurocysticercosis (NCC) on hospitalized patients from Muli County, China. Muli is an agricultural county in Liangshan Prefecture, Sichuan Province, China where pigs are raised and the zoonotic cestode, Taenia solium, is endemic. Demographic and treatment data were collected from the Muli County Health Insurance Department on hospitalized individuals with an NCC diagnosis between 2014 and 2021. These patients represent residents of Muli County that purchased health insurance and received treatment in a public hospital in Sichuan Province. Hospital costs were converted from Chinese renminbi (RMB) to United States dollars (US$) for month and year of hospitalization and adjusted for inflation. Individuals with missing hospital information were excluded from analysis. For indirect costs, annual average salary for Liangshan Prefecture working-age adults was obtained to calculate productivity losses based on number of hospitalization days and travel days to and from the hospital. Transportation costs were evaluated based on estimated bus fare to and from the hospital. Out of 70 patients identified from 2014 to 2021, 68 had complete records, of which 47.1% were male (n = 33) and the median age at first hospitalization was 34 years. Total estimated cost for these patients was US$228,341.98. Direct costs contributed 62.5% (US$142,785.25) and indirect costs were 37.5% (US$85,556.73) of the total cost. The estimated median cost per case was US$2,078.69. Individuals with a single hospitalization (n = 41) cost a median of US$1,572.03 and those with multiple hospitalizations (n = 27) cost a median of US$4,169.95. The median total cost per NCC case was 18.6% of the average wage for a Liangshan Prefecture resident in 2021. While the study was limited to those with insurance coverage, monetary burden on the local population is likely substantial. Public health policies aimed at reducing transmission should be implemented to decrease the economic burden of NCC on this region.

Parallel detection of multiple zoonotic parasites using a real-time fluorogenic loop-mediated isothermal amplification-based quadruple-sample microfluidic chip

Zoonotic parasites pose significant health risks globally. In the present study, we combined a microfluidic chip with loop-mediated isothermal amplification (on-chip LAMP) to detect five zoonotic parasites: Toxoplasma gondii, Cryptosporidium parvum, Cryptosporidium hominis, Clonorchis sinensis, and Taenia solium. This method enabled the simultaneous parallel analysis of five genetic markers from a maximum of four samples per chip. The on-chip LAMP assay was conducted in a highly automated format via the addition (by pipetting) of each sample in a single operation. The reaction was performed in volumes as low as 5 μL at a temperature of 65°C for 60 min, achieving limits of detection ranging from 10-2 to 10-3 pg./μL of recombinant plasmid DNA. All the time-to-positive values were less than 40 min, and almost all the coefficients of variation were less than 10%, even when using limit of detection concentrations for multiple pathogens, indicating robust reproducibility among replicates. The clinical sensitivity and specificity for detecting 135 field samples were 98.08 and 97.59%, respectively, compared with traditional biological methods, indicating good applicability in the detection of field samples. This on-chip LAMP assay allows for low reagent consumption, ease of operation, and multiple analyses of samples and genetic targets, and is applicable for on-site detection and the routine monitoring of multiple zoonotic parasites.

Seropositivity to Cysticercosis in School-Age Children Living in a Low-Income Municipality in the Midwest Region of Brazil

Background

Human cysticercosis (CC) is a global public health problem, especially in Latin America, including Brazil. We aimed to analyze the seroprevalence of CC among school-age children and adolescents.

Methods

We analyzed the presence of specific IgG antibodies against Taenia solium metacestodes in 500 serum samples from elementary school children and adolescents in Jataí City, state of Goiás, Brazil. IgG antibodies against the antigenic extract of the parasite were detected and analyzed by ELISA, and specific peptides were identified by confirmatory Western Blotting test.

Results

Of the 500 study participants, 205 (41%) were male, and 295 (59%) were female. Participants aged between 4 and 18 years (mean age 8.4 years). The percentage of serum samples reactive by ELISA was 37.2%. These samples were analyzed by Western Blotting, which confirmed that the seropositivity rate was 6.2% (95% CI 2.4-14.7) in 31 samples reactive for CC-specific bands, determined in serum samples from 18 male (5-11 years old) and 13 female (4-12 years old) students.

Conclusion

The CC seroprevalence demonstrated in schoolchildren suggests that this parasitosis is endemic in the study area. Further investigations are necessary to clarify the local epidemiology of this parasitosis.

Taenia solium taeniasis and Cysticercosis Prevalence and Control Practice in China

Taenia solium taeniasis/cysticercosis is an important global food-borne zoonosis transmitted between humans and pigs. In China, the prevalence of Theridion solium taeniasis/cysticercosis has been marked decline in recent decades based on the data revealed by both national surveys and field prevalence investigations. Health education and promotion, meat inspection, and chemotherapy are unquestionably the main control measures for diseases. It is worth noting that a variety of socio-ecological variables have been identified in the process of controlling T. solium taeniasis/cysticercosis. It has become difficult for pigs to come into direct or indirect contact with or consume human excreta as pig farming practices have been shifted from traditional backyard farms to large-scale commercial pig raising systems that are still in progress. The human toilet revolution in rural areas of China has ensured hygienic separation of human excreta from contact, and thereby preventing human excreta from polluting the soil, feeds, and water. These two important fundamental preventive measures are crucial to establishing an environmental restriction between humans and pigs cannot be overlooked for interrupting or limiting T. solium transmission. In this chapter, we reviewed the epidemiology, traditional measures, and ecological determinants that significantly contributed to the dramatic decline of taeniasis/cysticercosis in China.

A review of rural and peri-urban sanitation infrastructure in South-East Asia and the Western Pacific: Highlighting regional inequalities and limited data

Rural and peri-urban communities in developing countries rely on sanitation systems which are often unsafely managed. One of the major barriers to assess safely managed sanitation is a lack of data about the existing sanitation infrastructure and levels of containment safety. The aim was to review rural and peri-urban on-site sanitation studies in order to understand different infrastructure types, associated management practices and any impacts on human health. The scope was limited to South-East Asia and Western Pacific regions in order to better identify regional inequalities. Among the 155 reviewed articles, 73 studies (47%) linked sanitation infrastructure to poor human health. Nearly all articles reported latrine ownership (n = 149, 96%) while sanitation infrastructure types were covered less frequently (n = 104, 67%). In particular, there was a lack of published literature describing back-end characteristics (dimension and materials) (n = 12, 8%) and/or management practices (n = 4, 3%). This stems from a limited application of research methodologies that characterise sanitation infrastructure and faecal sludge management (containment, emptying and on-site treatment). Inequality between regions was prevalent with three quarters of the studies on latrine back-end infrastructure from Bangladesh and India in South-East Asia. A strategic research approach is needed to address the current knowledge gaps regarding sanitation infrastructure and safe faecal sludge management.

Seroprevalence and risk factors of porcine cysticercosis: A cross-sectional study in Indonesia

Background and Aim:

Cysticercosis is a zoonotic disease with a global concern. Estimation of the prevalence and identification of potential risk factors are necessary for the prevention and control of the disease. This study aimed to estimate the seroprevalence of cysticercosis and the correlation of the increased prevalence with several potential risk factors.

Materials and Methods:

The seroprevalence of cysticercosis was conducted using an enzyme-linked immunosorbent assay (ELISA), developed by the Institute of Tropical Medicine Antwerp, to detect Cysticercus cellulosae. This study used serum samples from 62 pigs taken from two regencies on Timor Island. The data analysis was performed using SPSS software 20.0 (IBM Corp., NY, USA) to evaluate ELISA results and the strength of the relationship between risk factors and the prevalence of disease using the odds ratio (OR).

Results:

Serum samples from 18 out of the 62 pigs were found to be positive; the seroprevalence of cysticercosis was 29%. The results showed that an extensive farming system led to a higher prevalence of cysticercosis compared to an intensive farming system, namely, 10 out of 18 (56.6%), and that the possibility of identifying cysticercosis in pigs in an extensive farming system was 5 times greater than that in pigs in an intensive farming system. In addition, the results showed that nine out of 18 households who did not have toilet facilities were found to be seropositive, indicating a significant relationship between the risk factor of toilet availability with cysticercosis in pigs, with an OR of 4.5. In addition, the results showed that there was no significant relationship between the risk factor of the feed source and the prevalence of cysticercosis in pigs.

Conclusion:

It can be concluded that the seroprevalence of cysticercosis was 29% in domestic pigs of Timor Island. The risk factors of an extensive pig farming system andtoilet availabilityin community houses were significantly related to the possibility of cysticercosis on Timor Island.

Hyperendemicity of cysticercosis in Madagascar: Novel insights from school children population-based antigen prevalence study

Objective

Taenia solium (Ts) cysticercosis is a neglected zoonotic disease particularly prevalent in Madagascar. Few data are available for children, current data mainly rely on antibody prevalence. We sought to determine the Ts-antigen seroprevalence–determining active cysticercosis—amongst school children from various cities in Madagascar (excluding the capital) and evaluated associated risk factors.

Methods

In seven cities in Madagascar, the presence of cysticercosis in school children (n = 1751) was investigated in 2007 using the B158/B60 antigen (Ag)-ELISA.

Results

The overall prevalence based on Ag detection was 27.7% [95%CI: 10–37%]. Risk factors associated with Ag positivity were age, biotope, altitude and annual average rainfall.

Conclusion

These results highlight the high prevalence of active cysticercosis in Madagascar among school children in an urban setting. This high prevalence as well as the risk factors unraveled point to the emergency to implement appropriate Public Health measure son a national scale.

Risk factors and prevalence of taeniasis among the Karen people of Tha Song Yang District, Tak Province, Thailand

Taeniasis remains a prevalent public health problem in Thailand. National helminthiasis surveys report only the incidence of Taenia spp. eggs. The ability to differentiate Taenia species using morphological and molecular techniques is vital for epidemiological surveys. This study detected taeniasis carriers and other helminthic infections by Kato's thick smear technique and identified the Taenia species by multiplex PCR. The study subjects were the ethnic Karen people in Tha Song Yang District, Tak Province, Thailand, bordering Myanmar. In total, 983 faecal samples from villagers were examined for helminthiases. Interview-based questionnaires were used to gather information on possible risk factors for infection. The prevalence of helminth infections was 42.7% (420/983), including single (37.3%, 367/983) and mixed infections (5.4%, 53/983). The most common infection (19.23%, 189/983) was Ascaris lumbricoides, whereas taeniasis carriers comprised 2.8% (28/983). Multiplex PCR of Cox1 was used for species identification of Taenia tapeworms, eggs, or both in 22 taeniasis carriers. Most of the parasites (20 cases) were Taenia solium, with two cases of Taenia saginata. Taenia saginata asiatica was not found in the villagers examined. The analysis of 314 completed questionnaires showed that a statistically significant (p < 0.05) risk of taeniasis was correlated with being male, a history of being allowed to forage during childhood, a history of seeing tapeworm proglottids, and a history of raw or undercooked pork consumption. Health education programmes must seek to reduce and prevent reinfection in these communities.

New insights on the Taenia solium tapeworm using molecular tools: age-based human definitive host prevalence and deliberation on parasite life span

Information on age-based Taenia solium taeniasis prevalence is crucial for control of cysticercosis. T. solium taeniasis prevalence was determined for a village in Liangshan Prefecture, Sichuan Province, China that was co-endemic for T. solium, Taenia saginata asiatica, and Taenia saginata. Individuals who were Taenia egg-positive by stool microscopy and/or expelled tapeworms or proglottids post-treatment were diagnosed as having taeniasis. Infecting species was identified via multiplex PCR on tapeworm specimens or coproPCR followed by sequencing. In addition, initial stool samples from 10 children with taeniasis suspected of having spontaneous expulsion of tapeworms within the period between diagnosis and treatment were subject to species confirmation via coproPCR and sequencing. Of the 389 study subjects, 194 (49.9%) were diagnosed with taeniasis. Children (< 16 years of age) had a higher T. solium taeniasis prevalence (8.8%) than older individuals (2.5%) (P = 0.0127). Molecular analysis of initial stool samples from 7 of 10 children suspected of spontaneously passing tapeworms indicated 6 infections due to T. solium and 1 infection due to T. saginata. This study found that young children had a higher T. solium taeniasis prevalence than older individuals, providing additional support for the belief that adult T. solium likely has a relatively short lifespan compared to other Taenia species with human definitive hosts.

Taenia solium taeniasis/cysticercosis: From parasite biology and immunology to diagnosis and control

Infection with the pork tapeworm (Taenia solium) is responsible for a substantial global burden of disease, not only restricted to its impact on human health, but also resulting in a considerable economic burden to smallholder pig farmers due to pig cysticercosis infection. The life-cycle, parasitology and immunology of T. solium are complex, involving pigs (the intermediate host, harbouring the larval metacestode stage), humans (the definitive host, harbouring the adult tapeworm, in addition to acting as accidental intermediate hosts) and the environment (the source of infection with eggs/proglottids). We review the parasitology, immunology, and epidemiology of the infection associated with each of the T. solium life-cycle stages, including the pre-adult/adult tapeworm responsible for human taeniasis; post-oncosphere and cysticercus associated with porcine and human cysticercosis, and the biological characteristics of eggs in the environment. We discuss the burden associated, in endemic settings, with neurocysticercosis (NCC) in humans, and the broader cross-sectoral economic impact associated both with NCC and porcine cysticercosis, the latter impacting food-value chains. Existing tools for diagnostics and control interventions that target different stages of the T. solium transmission cycle are reviewed and their limitations discussed. Currently, no national T. solium control programmes have been established in endemic areas, with further work required to identify optimal strategies according to epidemiological setting. There is increasing evidence suggesting that cross-sectoral interventions which target the parasite in both the human and pig host provide the most effective approaches for achieving control and ultimately elimination. We discuss future avenues for research on T. solium to support the attainment of the goals proposed in the revised World Health Organisation neglected tropical diseases roadmap for 2021-2030 adopted at the 73rd World Health Assembly in November 2020.

Socio-economic and health costs of porcine/human cysticercosis, neurocysticercosis and epilepsy to small-scale pig producers in Tanzania

BACKGROUND

Porcine cysticercosis, human cysticercosis, neurocysticercosis, and epilepsy pose a serious public health risk and lead to economic losses to the small-scale pig farmers in Tanzania's rural areas. It also resulted in lowering the pig's prices, high treatment expenses, lower labour productivity, and social discrimination. In Tanzania, small-scale pig producers are unaware of the methods that are used to manage and prevent the diseases associated with Taenia solium.

MAIN BODY

The main goal of the reviewed article was to investigate the socio-economic and health costs of porcine/human cysticercosis, neurocysticercosis, and epilepsy on small-scale pig producers in Tanzania. Several search engines yielded 80 peer-reviewed publications, 44 of which were considered to be relevant to the study. Taenia solium cysticercosis has been reported to cause huge financial losses in the management of pigs posing a burden in terms of vaccination and treatment.

CONCLUSION

The information on porcine/human cysticercosis, neurocysticercosis, and epilepsy is still insufficient in Tanzania. Poor habits, negative perceptions, and attitudes are the result of this misinformation. This review suggests that health education should be emphasized as one of the intervention methods for eliminating all forms of cysticercosis and epilepsy in Tanzania to promote and increase awareness about all forms of cysticercosis and epilepsy in rural areas.

Human Cysticercosis in Asia: A Systematic Review and Meta-Analysis

BACKGROUND

Cysticercosis in among the neglected tropical disease caused by eating the egg of parasite Taenia solium. In this review, we aimed to verify the prevalence of human cysticercosis in different countries of Asia using systematic review and meta-analysis approach.

METHODS

Based of the protocol, reliable databases including PubMed, SCOPUS, Science Direct, Embase, and Cochrane Library from 1990-2018 were searched using a panel of keywords. Overall, 48 countries of Asia were searched in turn and data were analyzed using a category of statistical tests.

RESULTS

Out of 28 included studies, 586175 samples were collected and included in the data analysis. Based on the meta-analysis results, the overall pooled percent of cysticercosis was estimated 3.8% (95% CI: [2.0, 7.0]). According to the result of heterogeneity statistics including I-squared, chi-square, and tau-squared, it was statistically significant (Tau2 = 2.94, chi2 = 12733.31, P<0.001, I2 = 100%) therefore a random effect model was used to handle the heterogeneity of studies. To evaluate the trend of cysticercosis over the time, Cumulative meta-analysis was performed and the result showed that there was a minor upward tendency in the prevalence of cysticercosis over the time.

CONCLUSION

Although, considering the religious culture and food habits in Asia, we might have expected to witness a low prevalence of human cysticercosis, but we noticed more or less significant infection in some countries of the region. Regarding the new feature of immigration and travel between countries, all authorities are advised to take measures on controlling and monitoring the disease.

Seroepidemiological evidence for Taenia solium taeniasis/cysticercosis in three Venezuelan rural communities

Taenia solium is the most common parasite infection of the brain, causing neurocysticercosis and typically found in rural communities with free-ranging pigs. Identification of transmission in rural areas is essential for its control. Risk factors and transmission of the parasite were evaluated in three rural Venezuelan communities (Valle del Rio and Potrero Largo, Cojedes state; and Palmarito, Portuguesa state) by a questionnaire (112 households) and coprological (492 samples) and serological (433 human and 230 porcine sera) analysis, respectively. Typical risk factors were found in all three communities: free-foraging pig husbandry, deficient sanitary conditions, high open defecation and ignorance of the parasite life cycle. Coprological examinations revealed a high level of soil-transmitted parasites. Importantly, two T. solium adult worm carriers were identified in each of the three communities. Anti-metacestode antibodies and the HP10 secreted metacestode glycoprotein were detected at significant levels in human and porcine sera in Valle del Rio, Potrero Largo and Palmarito. In conclusion, these communities may be considered to be endemic for taeniasis/cysticercosis, and the instigation of an appropriate control programme is recommended.

High prevalence of taeniasis and Taenia solium cysticercosis in children in western Sichuan, China

Data in China on human Taenia infections, including Taenia solium cysticercosis, is largely lacking. We aimed to determine the prevalence of taeniasis with all three human Taenia species as well as T. solium cysticercosis in primary school-aged children in minority areas of western Sichuan, China. During April 2016 to December 2017, we did a cross-sectional study in five western Sichuan Province primary schools in Liangshan (3 schools), Ganzi (1 school) and Aba (1 school) prefectures. Diagnosis of taeniasis was made by stool microscopy for presence of Taenia eggs, as well as recovery of taeniid tapeworms or proglottids by medicinal treatment followed by species identification using multiplex PCR. Diagnosis of T. solium cysticercosis was made serologically using an ELISA with low-molecular-weight antigens purified from T. solium cyst fluid to detect specific IgG antibodies. A total of 1672 children were screened for taeniasis and 1639 were evaluated for cysticercosis antibodies. Overall prevalence of taeniasis was 7.5% but was as high as 15.6% at one school site (e.g., Shuiluo). Of the three known human Taenia species, adult T. solium tapeworms were detected in 42 children from four of the five schools (all three schools in Liangshan and one in Aba), giving a prevalence of T. solium taeniasis of 2.5% (95% confidence interval 0-6.7%). Cysticercosis antibody seropositivity by school varied from 2.3% to 15.6% (overall 7.5%). T. solium taeniasis carriers were more likely to have cysticercosis antibodies than children without T. solium taeniasis (43.6% vs 6.6%). Schools with higher prevalences of T. solium taeniasis were more likely to have children with human cysticercosis IgG antibodies. This study shows a high prevalence of taeniasis and T. solium cysticercosis in primary school-aged children in minority areas of western Sichuan, suggesting an urgent necessity for school-based disease control.

A preliminary study to assess the use of a "Snakes and Ladders" board game in improving the knowledge of elementary school children about taeniasis

The Snakes and Ladders board game was modified so that it contained information on taeniasis. A quantitative approach was used to evaluate if elementary school children were able to answer correctly more questions about Taenia saginata and Taenia solium transmission and control after playing the game compared to before playing the game. In total, 78 children (9-12 years of age) from Dukuh elementary school in Karangasem District, Bali, Indonesia, were evaluated. The children were asked to complete a pre- and post-test assessment before and after playing the game a single time. Overall proportion of correct answers was 40.3% before playing the game and 58.8% after playing the game. There was a greater proportion of correct answers for questions pertaining to the transmission route for T. saginata (p < 0.001) and T. solium (p < 0.001), human infection type with T. solium (p = 0.035) and T. saginata (p < 0.001), and animal infection type with T. solium or T. saginata (p < 0.001) after playing the game compared to before playing the game. However, there was no significant difference for any question for the youngest grade level. Use of this popular board game appears to be a promising tool for teaching older (10 years of age and above) children about taeniasis in endemic areas.

A multiplex PCR assay for the simultaneous detection of Taenia hydatigena, T. multiceps, T. pisiformis, and Dipylidium caninum infections

Background

Taenia hydatigena, T. multiceps, T. pisiformis, and Dipylidium caninum are four common large and medium-sized tapeworms parasitizing the small intestine of dogs and other canids. These parasites cause serious impact on the health and development of livestock. However, there are, so far, no commercially available molecular diagnostic kits capable of simultaneously detecting all four parasites in dogs. The aim of the study was therefore to develop a multiplex PCR assay that will accurately detect all four cestode infections in one reaction.

Methods

Specific primers for a multiplex PCR were designed based on corresponding mitochondrial genome sequences, and its detection limit was assessed by serial dilutions of the genomic DNAs of tapeworms examined. Furthermore, field samples of dog feces were tested using the developed assay.

Results

A multiplex polymerase chain reaction (PCR) assay was developed based on mitochondrial DNA (mtDNA) that accurately and simultaneously identify four cestode species in one reaction using specific fragment sizes of 592, 385, 283, and 190 bp for T. hydatigena, T. multiceps, T. pisiformis, and D. caninum, respectively. The lowest DNA concentration detected was 1 ng for T. hydatigena, T. multiceps and T. pisiformis, and 0.1 ng for D. caninum in a 25 μl reaction system. This assay offers high potential for the rapid detection of these four tapeworms in host feces simultaneously.

Conclusions

This study provides an efficient tool for the simultaneous detection of T. hydatigena, T. multiceps, T. pisiformis, and D. caninum. The assay will be potentially useful in epidemiological studies, diagnosis, and treatment of these four cestodes infections during prevention and control program.

Taeniasis and cysticercosis in Asia: A review with emphasis on molecular approaches and local lifestyles

Taeniasis is an important parasitic condition in Asia, especially since all three human-infecting Taenia spp., Taenia solium, Taenia saginata, and Taenia asiatica are found in this region. These three species are believed to be sympatrically distributed, with the largest disease burden found in remote and rural areas where people raise pigs and cattle in a traditional manner. Recent studies revealed that T. asiatica and T. saginata are genetically-related sister species that are not completely reproductively isolated from each other. Current evidence indicates that most T. asiatica adult worms are hybrid-derived descendants. Moving forward, nuclear DNA analysis will be critical in further assessing the species circulating locally. Lifestyle choices, such as the consumption of undercooked meat, are important in maintaining the life cycles of these parasites. In addition, poor hygiene and sanitation, in highly endemic areas, make disease control difficult, resulting in the need for sustainable education programs. An overview of the present situation of taeniasis and cysticercosis in Asia is provided, followed by a discussion of molecular approaches to species assessment and the impact of human lifestyles on parasite transmission.

Correlates of School Children's Handwashing: A Study in Tibetan Primary Schools

Hand hygiene, including handwashing by children, has been reported to contribute to the prevention of various infectious conditions. This study aims to explore the correlates of handwashing behavior among 1690 fourth to sixth grade primary school students in 19 Tibetan primary schools (Golog, Qinghai, China). The theory of reasoned action (TRA) was applied. Data was collected by questionnaire. Structural equation modeling (SEM) analysis showed that students' attitude (β = 0.22, 95% CI 0.13-0.31) and subjective norms in terms of compliance to teachers', parents' and peers' suggestions to wash hands (β = 0.09, 95% CI 0.01-0.18) were directly associated with students' handwashing behavior. Students' knowledge (β = 0.04, 95% CI 0.03-0.07) had an indirect association with handwashing behavior, mediated by students' attitudes and subjective norms. Subjective norms (β = 0.12, 95% CI 0.07-0.17) were also indirectly correlated with handwashing through students' attitudes. Therefore, our study supported the theory of reasoned action through our findings that students' attitude and knowledge, and also attitudes from teachers, parents and peers were correlated with student handwashing behavior. Students reported higher level of compliance to teachers than to their parents and classmates. Based on this information, we recommend teacher-involved participatory hygiene education to promote students' handwashing behaviors in areas at high risk for infectious diseases that can be prevented by handwashing.

Extensive disseminated cysticercosis: a case report in Yunnan province, China

BACKGROUND

Cysticercosis is spreading all over the world and it is a major health problem in most countries of Latin America, Africa, and Asia. Extensive disseminated cysticercosis is relatively rare and fewer than 120 case have been reported in the worldwide. We reported a rare case of extensive disseminated cysticercosis in Yunan province, China.

CASE PRESENTATION

A rare case of extensive disseminated cysticercosis, in a 61-year-old male Chinese was detected from Yunnan province in 2018. Clinical and etiological examination was performed, as well as the epidemiological investigation.

CONCLUSION

The life cycle of T. solium in the area where the case came from is complete. We expect this case could raise the attentions to the control of Taenia solium infection and subsequent cysticercosis there.

Structural Equation Modeling (SEM) of Cysticercosis in School-Aged Children in Tibetan Rural Farming Areas of Western China: Implications for Intervention Planning

Neurocysticercosis (NCC) significantly contributes to morbidity in developing countries. We recently published a study of prevalence and risk factors in school-aged children in three mountainous areas in Sichuan province of western China. Using structural equation modeling (SEM) on data from that study to guide intervention planning, here we examine risk factors grouped into three broad interventional categories: sociodemographics, human behavior, and sources of pork and pig husbandry. Because neuroimaging is not easily available, using SEM allows for the use of multiple observed variables (serological tests and symptoms) to represent probable NCC cases. Data collected from 2608 students was included in this analysis. Within this group, seroprevalence of cysticercosis IgG antibodies was 5.4%. SEM results showed that sociodemographic factors (β = 0.33, p < 0.05), sources of pork and pig husbandry (β = 0.26, p < 0.001), and behavioral factors (β = 0.33, p < 0.05) were all directly related to probable NCC in school-aged children. Sociodemographic factors affected probable NCC indirectly via sources of pork and pig husbandry factors (β = 0.07, p < 0.001) and behavioral variables (β = 0.07, p < 0.001). Both sociodemographic factors (β = 0.07, p < 0.05) and sources of pork and pig husbandry factors (β = 0.10, p < 0.01) affected probable NCC indirectly via behavioral variables. Because behavioral variables not only had a large direct effect but also served as a critical bridge to strengthen the effect of sociodemographics and sources of pork and pig husbandry on probable NCC, our findings suggest that interventions targeting behavioral factors may be the most effective in reducing disease.

Porcine cysticercosis (Taenia solium and Taenia asiatica): mapping occurrence and areas potentially at risk in East and Southeast Asia

Background

Due to the relative short life span and the limited spatial movement, porcine cysticercosis is an excellent indicator of current local active transmission. The aim of this study was to map at province-level, the occurrence of T. solium and T. asiatica in pigs and areas at risk of transmission to pigs in East and Southeast Asia, based on the density of extensive pig production systems and confirmed reports of porcine cysticercosis.

Methods

This study covered East and Southeast Asia, which consist of the following countries: Brunei, Cambodia, China, East Timor, Indonesia, Japan, Laos, Malaysia, Mongolia, Myanmar, North Korea, Philippines, Singapore, South Korea, Thailand and Vietnam. Literature searches were carried out to identify current epidemiological data on the occurrence of porcine cysticercosis caused by T. solium and T. asiatica infections. Modelled densities of pigs in extensive production systems were mapped and compared to available data on porcine cysticercosis.

Results

Porcine cysticercosis was confirmed to be present during the period 2000 to 2018 in eight out of the 16 countries included in this study. Taenia solium porcine cysticercosis was confirmed from all eight countries, whereas only one country (Laos) could confirm the presence of T. asiatica porcine cysticercosis. Province-level occurrence was identified in five countries (Cambodia, Indonesia, Laos, Myanmar, and Vietnam) across 19 provinces. Smallholder pig keeping is believed to be widely distributed throughout the region, with greater densities predicted to occur in areas of China, Myanmar, Philippines and Vietnam.

Conclusions

The discrepancies between countries reporting taeniosis and the occurrence of porcine cysticercosis, both for T. solium and T. asiatica, suggests that both parasites are underreported. More epidemiological surveys are needed to determine the societal burden of both parasites. This study highlights a straightforward approach to determine areas at risk of porcine cysticercosis in the absence of prevalence data.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3203-z) contains supplementary material, which is available to authorized users.

The epidemiology of Taenia spp. infection and Taenia solium cysticerci exposure in humans in the Central Highlands of Vietnam

BACKGROUND

Vietnam is endemic for taeniasis and T. solium cysticercosis. Despite this, information on the epidemiological characteristics of the diseases in the Central Highlands of Vietnam are poorly described. The aims of this study were to determine the epidemiological characteristics of taeniasis (Taenia spp.) and T. solium cysticerci exposure in humans in Dak Lak province in the Central Highlands, Vietnam.

METHODS

This cross-sectional study was carried out in six villages in three districts of Dak Lak. A total of 190 households were visited. From each household, between one and five individuals were asked to donate a single faecal and blood sample and respond to a questionnaire. Serum samples were subjected to lentil lectin purified glycoprotein enzyme-linked immunoelectrotransfer blot assay to detect antibodies against T. solium cysticerci. Multiplex real-time PCR was used to detect Taenia spp. infection in faecal samples. A fixed-effects logistic regression model was developed to identify factors associated with the probability of Taenia spp. infection or T. solium cysticerci exposure risk. The contribution of each of identified factor was quantified using population attributable fractions.

RESULTS

The prevalence of seroexposure to T. solium in Dak Lak was 5% (95% CI 3% to 8%). Consumption of raw vegetables, sourcing drinking water from lakes, streams or ponds and the practice of outdoor defaecation were identified as primary risk factors for the prevalence of T. solium cysticerci exposure, while consuming undercooked pork and beef, pork tongue and observing Taenia proglottids in stool were associated with Taenia spp. infection. Consumption of raw vegetables attributed to 74% of T. solium cysticerci exposure-positive cases and consumption of undercooked beef attributed to 77% of taeniasis cases in these communities.

CONCLUSIONS

The prevalence of T. solium seroexposure in Dak Lak is consistent with those reported in other regions of Vietnam. The identified risk factors associated with the prevalence of T. solium seroexposure and taeniasis infection in Dak Lak are modifiable and thus advocate for targeted community intervention programs to mitigating these risks.