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.

Implementation of Taenia solium control measures in Bali, Indonesia: Survey findings and a historical overview.

Historically, cysticercosis cases caused by infection with the larval stage of the Taenia solium tapeworm have occurred sporadically in Bali, with taeniasis carriers found primarily in villages located in the Kubu subdistrict of Karangasem. As Bali is a well-known tourist destination, living standards are relatively high on the island, except for an area located beneath the northeast slope of the active volcano Mt. Agung (Alt. 3031 m), which includes Kubu. Over the last 30 years, pigs originating from this area have been found with T. solium cysticerci, whereas pigs from other parts of the island have not been shown to be infected. Out of 108 individuals screened via fecal sample examination in Kubu during 2019, 3 cases of T. solium taeniasis (2.8%) were identified. There was no significant difference in taeniasis prevalence from surveys conducted in 2011-2016 (1.0%, 11/1089) (p = 0.123). Out of 110 humans and 140 pigs tested serologically in Kubu during 2019, no cases of cysticercosis were identified. This is in contrast to a seroprevalence of 4.1% (42/1025) in humans during 2011-2016 and a seroprevalence of 13.1% (43/329) in pigs during 2011-2013. Over the last decade, improved drinking water and sanitary systems have been employed in addition to health education targeting primary school children, including emphasis on washing hands before eating and after defecation. This review provides previously unpublished survey data and a historical overview of T. solium infection in Bali and offers guidance on best practices to ensure that remaining pockets of transmission are addressed.

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.

A multiplex PCR for differential detection of Echinococcus granulosus sensu stricto, Echinococcus multilocularis and Echinococcus canadensis in China.

BACKGROUND: Echinococcosis caused by Echinococcus is one of the most major infectious diseases in north-west highland of China. E. granulosus sensu strict, E. multilocularis, and E. canadensis are known to be the only three species related to human health transmitting in the areas. To achieve targeted treatment and control of echinococcosis, the accurate identification and discrimination of the species are important. However, currently the available diagnostic approaches do not present ideal results either in accuracy or efficiency. METHODS: In the study, a set of primers were designed to aim at the three human-pathogenic Echinococcus species in China. The one-step multiplex PCR assay was developed and evaluated for the specificity and sensitivity. A total of 73 parasitic lesions and 41 fecal materials obtained from human and various animals collected in the clinic and the field were tested to assess the applicability of this method. RESULTS: The multiplex PCR effectively detected the individual DNA from the targeted species and their random mixtures generating with distinguishable expected size of products. The detection limit of the assay for each of the three species was 5 pg/µl when they were tested separately. When DNA mixtures of the targeted species containing the same concentration were used as templates, the lowest amount of DNA which can be detected was 50 pg/µl, 10 pg/µl and 5 pg/µl for E. granulosus s. s., E. multilocularis, and E. canadensis respectively. No cross-reactivity was observed when DNA from eight genetically close species was used as control templates. The multiplex PCR identifications of all samples were in line with the original sequencing results except for those infected with E. shiquicus, which showed negative signals in the developed assay. Of all the tested stool materials, 16 were previously found positive for Echinococcus by visual and microscopic examination. Among these 16 samples, 13 were confirmed by the multiplex PCR, and the other three tested negative. Additionally, the multiplex PCR identified another 14 positive feces from the remained 25 stool samples which absence of worms. CONCLUSIONS: The developed multiplex PCR shows advantages in fast diagnosis and large-scale epidemiological investigation, which proven to be a promising tool utilized in clinic and surveillance system.

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.

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.

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 (ß = 0.33, p < 0.05), sources of pork and pig husbandry (ß = 0.26, p < 0.001), and behavioral factors (ß = 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 (ß = 0.07, p < 0.001) and behavioral variables (ß = 0.07, p < 0.001). Both sociodemographic factors (ß = 0.07, p < 0.05) and sources of pork and pig husbandry factors (ß = 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.

[Impact of the neglected Cysticercus cellulose infection on mental health among school-aged children in Tibetan agricultural areas].

OBJECTIVE: To determine the impact of Cysticercus cellulose (C. cellulose) infection on mental health among school-aged children in Tibetan agricultural areas of Sichuan Province.
 Methods: In October 2015, all primary schools located in Tibetan agricultural areas in Yajiang, Ruoergai, and Muli county of Sichuan Province were selected as the research sites. All school-aged children at five- and six-grade were enrolled for the study by a multistage stratified cluster sampling method. Antibodies against C. cellulose were detected. Mental Health Test and questionnaire survey were conducted for school-aged children to collect data. The impact of C. cellulose infection on mental health among school-aged children was analyzed with the multilevel linear regression.
 Results: A total of 2 453 school-aged children were investigated. The C. cellulose seropositive rate was 6.03% (148/2 453). There were 0.16% (4/2 453) patients with seropositive accompanied by seizure, 2.28% (56/2 453) with seropositive accompanied by headache, 2.08% (51/2 453) with seropositive accompanied by frequent weak, and 0.41% (10/2 453) were seropositive accompanied by frequent nausea. The rate of C. cellulose infection was 4.53% (111/2 453). The mean score of the mental health test was 6.59±2.61. There were significant difference in score of mental health test in children whose demographic characteristics were different. The mental health scores of school-aged children were clustered at the school level. After controlling the factors of demographic characteristics, the result of multilevel model demonstrated that the factor of school-aged children with C. cellulose seropositive accompanied by headache was statistically significant (ß=1.14, P=0.017).
 Conclusion: The status of C. cellulose infection among school-aged children in Tibetan agricultural areas is not optimistic. C. cellulose infection has impacted on mental health of local school-aged children. It is necessary to strengthen the prevention and control of C. cellulose infection in epidemic area.

[A Social Network Perspective on the Transmission of Cysticercuscellulose Infections in Tibetan School Children in Sichuan].

OBJECTIVE: To determine the transmission characteristics of Cysticercuscellulose infections from a social network perspective in Tibetan school children in Sichuan. METHODS: A cluster sampling strategy was adopted to select two primary schools with high level of Cysticercuscellulose infections in the Tibetan agriculture areas of Liangshan prefecture, Sichuan province. All of the students from the selected schools were enrolled in the study. Their social network data, including classroom seating, dormitory roommates, best playmates, and those who shared meals and snacks etc, were collected by trained investigators. Stool and blood samples of the students were collected for parasite detection. The transmission network of Cysticercuscellulose infections and the overall social network of school children were analysed. RESULTS: A total of 644 children participated in the study. Taenia solium were found in 6.11% of the stool samples and 13.25% blood samples returned with seropositive. The transmission was centered around the sources of infections: dormitory-clustering in the boarding school and playmate-clustering in the day school. The overall social network analysis revealed "core people" (more relationships), "information disseminators" (closer to other nodes) and "information hubs" (between two nodes) in both schools. CONCLUSION: Close contacts in dormitories and playgrounds are the main sources of transmission of cysticercosis in the Tibetan schools. The "core people" "information disseminators" and "information hubs" are critical for the prevention and control of cysticercosis in the future.

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

BACKGROUND: Taenia solium cysticercosis affects millions of impoverished people worldwide and can cause neurocysticercosis, an infection of the central nervous system which is potentially fatal. Children may represent an especially vulnerable population to neurocysticercosis, due to the risk of cognitive impairment during formative school years. While previous epidemiologic studies have suggested high prevalence in rural China, the prevalence in children as well as risk factors and impact of disease in low-resource areas remain poorly characterized. METHODOLOGY/PRINCIPAL FINDINGS: Utilizing school based sampling, we conducted a cross-sectional study, administering a questionnaire and collecting blood for T. solium cysticercosis antibodies in 2867 fifth and sixth grade students across 27 schools in west Sichuan. We used mixed-effects logistic regression models controlling for school-level clustering to study associations between risk factors and to characterize factors influencing the administration of deworming medication. Overall prevalence of cysticercosis antibodies was 6%, but prevalence was significantly higher in three schools which all had prevalences of 15% or higher. Students from households owning pigs (adjusted odds ratio [OR] 1.81, 95% CI 1.08-3.03), from households reporting feeding their pigs human feces (adjusted OR 1.49, 95% CI 1.03-2.16), and self-reporting worms in their feces (adjusted OR 1.85, 95% CI 1.18-2.91) were more likely to have cysticercosis IgG antibodies. Students attending high prevalence schools were more likely to come from households allowing pigs to freely forage for food (OR 2.26, 95% CI 1.72-2.98) and lacking a toilet (OR 1.84, 95% CI 1.38-2.46). Children who were boarding at school were less likely to have received treatment for gastrointestinal worms (adjusted OR 0.58, 95% CI 0.42-0.80). CONCLUSIONS/SIGNIFICANCE: Our study indicates high prevalences of cysticercosis antibodies in young school aged children in rural China. While further studies to assess potential for school-based transmission are needed, school-based disease control may be an important intervention to ensure the health of vulnerable pediatric populations in T. solium endemic areas.

Cryptic diversity in hymenolepidid tapeworms infecting humans.

An adult hymenolepidid tapeworm was recovered from a 52-year-old Tibetan woman during a routine epidemiological survey for human taeniasis/cysticercosis in Sichuan, China. Phylogenetic analyses based on sequences of nuclear 28S ribosomal DNA and mitochondrial cytochrome c oxidase subunit 1 showed that the human isolate is distinct from Hymenolepis diminuta and Hymenolepis nana, the common parasites causing human hymenolepiasis. Proglottids of the human isolate were unfortunately unsuitable for morphological identification. However, the resultant phylogeny demonstrated the human isolate to be a sister species to Hymenolepis hibernia from Apodemus mice in Eurasia. The present data clearly indicate that hymenolepidid tapeworms causing human infections are not restricted to only H. diminuta and H. nana.

[Endemic situation and control progress of taeniasis in western China].

Taeniasis, caused by Taenia species, is one of the common zoonoses in China, particularly in the western region of China. Up to now, not enough attention has been given in the high prevalence and high burden of the diseases. In order to study the endemic patterns and control strategies of taeniasis, a series of epidemiological investigations, molecular researches and pilot control activities have been conducted in recent years. This paper reviews the relevant publications in taeniasis research over the last 10 years.

Cystic echinococcoses in Mongolia: molecular identification, serology and risk factors.

BACKGROUND: Cystic echinococcosis (CE) is a globally distributed cestode zoonosis that causes hepatic cysts. Although Echinococcus granulosus sensu stricto (s.s.) is the major causative agent of CE worldwide, recent molecular epidemiological studies have revealed that E. canadensis is common in countries where camels are present. One such country is Mongolia. METHODOLOGY/PRINCIPAL FINDINGS: Forty-three human hepatic CE cases that were confirmed histopathologically at the National Center of Pathology (NCP) in Ulaanbaatar (UB) were identified by analysis of mitochondrial cox 1 gene as being caused by either E. canadensis (n=31, 72.1%) or E. granulosus s.s. (n=12, 27.9%). The majority of the E. canadensis cases were strain G6/7 (29/31, 93.5%). Twenty three haplotypes were identified. Sixteen of 39 CE cases with data on age, sex and province of residence were citizens of UB (41.0%), with 13 of the 16 cases from UB caused by E. canadensis (G6/7) (81.3%). Among these 13 cases, nine were children (69.2%). All pediatric cases (n  =  18) were due to E. canadensis with 17 of the 18 cases (94.4%) due to strain G6/7. Serum samples were available for 31 of the 43 CE cases, with 22 (71.0%) samples positive by ELISA to recombinant Antigen B8/1 (rAgB). Nine of 10 CE cases caused by E. granulosus s.s. (90.0%) and 13 of 20 CE cases by E. canadensis (G6/7) (65.0%) were seropositive. The one CE case caused by E. canadensis (G10) was seronegative. CE cases caused by E. granulosus s.s. showed higher absorbance values (median value 1.131) than those caused by E. canadensis (G6/7) (median value 0.106) (p  =  0.0137). CONCLUSION/SIGNIFICANCE: The main species/strains in the study population were E. canadenis and E. granulossus s.s. with E. canadensis the predominant species identified in children. The reason why E. canadensis appears to be so common in children is unknown.

The present situation of human taeniases and cysticercosis in Asia.

Three human Taenia species, Taenia solium, Taenia saginata, and Taenia asiatica, are endemic in rural regions of Asia, with these species sympatrically distributed in parts of Thailand and China. The pork tapeworm, T. solium, is the most pathogenic to humans, causing cysticercosis and neurocysticercosis (NCC). Due to its public health impact, T. solium taeniasis/cysticercosis is one of 17 neglected tropical diseases (NTDs) prioritized by the World Health Organization. In this review, the current status of taeniasis and NCC in several Asian countries will be presented as will possible prevention and control strategies. Among the known T. solium endemic areas in Asia, Bali, Indonesia is of high importance due to the risk of tourists becoming infected. Therefore, special attention will be given to ongoing control initiatives in Bali.

Genotypic relationships between Taenia saginata, Taenia asiatica and their hybrids.

Partial sequences of the DNA polymerase delta (pold) gene from Taenia saginata-like adult worms were sequenced. Phylogenetic analysis revealed that pold gene sequences were clearly divided into two clades, differing from each other in five to seven nucleotides. There is little doubt that T. saginata and Taenia asiatica were once separated into two distinct taxa as has been concluded in previous studies. On the other hand, most of the adult worms, which were identified as T. asiatica using mitochondrial DNA, were homozygous for an allele that originated from the allele of T. saginata via single nucleotide substitution. These results indicate that most of the adult worms, which had been called T. asiatica, are not actually 'pure T. asiatica' but instead originated from the hybridization of 'pure T. saginata' and 'pure T. asiatica'.

Advances in diagnosis and spatial analysis of cysticercosis and taeniasis.

Human cysticercosis, caused by accidental ingestion of eggs of Taenia solium, is one of the most pathogenic helminthiases and is listed among the 17 WHO Neglected Tropical Diseases. Controlling the life-cycle of T. solium between humans and pigs is essential for eradication of cysticercosis. One difficulty for the accurate detection and identification of T. solium species is the possible co-existence of two other human Taenia tapeworms (T. saginata and T. asiatica, which do not cause cysticercosis in humans). Several key issues for taeniasis/cysticercosis (T/C) evidence-based epidemiology and control are reviewed: (1) advances in immunological and molecular tools for screening of human and animals hosts and identification of Taenia species, with a focus on real-time detection of taeniasis carriers and infected animals in field community screenings, and (2) spatial ecological approaches that have been used to detect geospatial patterns of case distributions and to monitor pig activity and behaviour. Most recent eco-epidemiological studies undertaken in Sichuan province, China, are introduced and reviewed.

Detection of human taeniases in Tibetan endemic areas, China.

Detection of taeniasis carriers of Taenia solium is essential for control of cysticercosis in humans and pigs. In the current study, we assessed the positive detection rate of a self-detection tool, stool microscopy with direct smear and coproPCR for taeniasis carriers in endemic Tibetan areas of northwest Sichuan. The self-detection tool through questioning about a history of proglottid expulsion within the previous one year showed an overall positive detection rate of more than 80% for Taenia saginata, T. solium and T. asiatica. The positive detection rate was similar for T. saginata and T. solium. In 132 taeniid tapeworm carriers, 68 (51·5%) were detected by microscopy and 92 (69·7%) were diagnosed by coproPCR. A combination of microscopy and coproPCR increased the positive detection rate to 77·3%. There remained 10 cases (7·6%) coproPCR negative but microscopy positive. Due to the high cost and complicated process, coproPCR is required for the identification of Taenia species only when necessary, though it had a significant higher positive detection rate than microscopy. Combined use of self-detection and stool microscopy are recommended in community-based mass screening for taeniases in this Tibetan area or in other situation-similar endemic regions.

Transmission ecosystems of Echinococcus multilocularis in China and Central Asia.

From continental to regional scales, the zoonosis alveolar echinococcosis (AE) (caused by Echinococcus multilocularis) forms discrete patches of endemicity within which transmission hotspots of much larger prevalence may occur. Since the late 80s, a number of hotspots have been identified in continental Asia, mostly in China, wherein the ecology of intermediate host communities has been described. This is the case in south Gansu, at the eastern border of the Tibetan plateau, in south Ningxia, in the western Tian Shan of Xinjiang, and in the Alay valley of south Kyrgyzstan. Here we present a comparative natural history and characteristics of transmission ecosystems or ecoscapes. On this basis, regional types of transmission and their ecological characteristics have been proposed in a general framework. Combining climatic, land cover and intermediate host species distribution data, we identified and mapped 4 spatially distinct types of transmission ecosystems typified by the presence of one of the following small mammal 'flagship' species: Ellobius tancrei, Ochotona curzoniae, Lasiopodomys brandtii or Eospalax fontanierii. Each transmission ecosystem had its own characteristics which can serve as a reference for further in-depth research in the transmission ecology of E. multilocularis. This approach may be used at fine spatial scales to characterize other poorly known transmission systems of the large Eurasian endemic zone, and help in consideration of surveillance systems and interventions.

Drivers of Echinococcus multilocularis transmission in China: small mammal diversity, landscape or climate?

BACKGROUND: Human alveolar echinococcocosis (AE) is a highly pathogenic zoonotic disease caused by the larval stage of the cestode E. multilocularis. Its life-cycle includes more than 40 species of small mammal intermediate hosts. Therefore, host biodiversity losses could be expected to alter transmission. Climate may also have possible impacts on E. multilocularis egg survival. We examined the distribution of human AE across two spatial scales, (i) for continental China and (ii) over the eastern edge of the Tibetan plateau. We tested the hypotheses that human disease distribution can be explained by either the biodiversity of small mammal intermediate host species, or by environmental factors such as climate or landscape characteristics. METHODOLOGY/FINDINGS: The distributions of 274 small mammal species were mapped to 967 point locations on a grid covering continental China. Land cover, elevation, monthly rainfall and temperature were mapped using remotely sensed imagery and compared to the distribution of human AE disease at continental scale and over the eastern Tibetan plateau. Infection status of 17,589 people screened by abdominal ultrasound in 2002-2008 in 94 villages of Tibetan areas of western Sichuan and Qinghai provinces was analyzed using generalized additive mixed models and related to epidemiological and environmental covariates. We found that human AE was not directly correlated with small mammal reservoir host species richness, but rather was spatially correlated with landscape features and climate which could confirm and predict human disease hotspots over a 200,000 km(2) region. CONCLUSIONS/SIGNIFICANCE: E. multilocularis transmission and resultant human disease risk was better predicted from landscape features that could support increases of small mammal host species prone to population outbreaks, rather than host species richness. We anticipate that our study may be a starting point for further research wherein landscape management could be used to predict human disease risk and for controlling this zoonotic helminthic.

Usefulness of pumpkin seeds combined with areca nut extract in community-based treatment of human taeniasis in northwest Sichuan Province, China.

Taeniasis refers to the infection with adult tapeworms of Taenia spp. in the upper small intestine of humans, which is also a cause of cysticercosis infection in either both humans and/or animals. Currently the most commonly applied anthelminthics for treatment of taeniasis are praziquantel and niclosamide. Praziquantel is very effective, but has the risk of induction of epileptic seizures or convulsions in carriers with asymptomatic concurrent neurocysticercosis. In contrast, niclosamide is safe and effective, but is not readily available in many endemic countries including China. In the current community-based study, we assessed the curative effect of either pumpkin seeds or areca nut extract alone in taeniasis, and also looked at synergistic effects of these two herb drugs on tapeworms. In the study group with the pumpkin seed/areca nut extract treatment, 91 (79.1%) of 115 suspected taeniasis cases (with a history of expulsion of proglottids within the previous one year) released whole tapeworms, four (3.5%) expelled incomplete strobila, and no tapeworms or proglottids were recovered in the remaining 20 cases. In these 115 persons, 45 were confirmed as taeniasis before treatment by microscopy and/or coproPCR. Forty (88.9%) of 45 confirmed cases eliminated intact worms following treatment. The mean time period for complete elimination of tapeworms in 91 taeniasis cases was 2 h (range 20 min to 8 h 30 min), and 89.0% (81) of 91 patients discharged intact worms within 3h after drug administration. In Control Group A with treatment of pumpkin seeds alone, 75.0% (9/12) of confirmed taeniasis cases expelled whole tapeworms, but the mean time period for complete elimination was about 14 h 10 min (range 3 h 20 min to 21 h 20 min), which was much longer than that (2 h) for the study group, whereas in Control Group B treated with areca nut extract alone, only 63.6% (7/11) of taeniasis cases discharged whole tapeworms, and the mean time period was 6 h 27 min (range 1-22 h). Mild side effects included nausea and dizziness in about 46.3% of patients with the pumpkin seeds/areca nut extract treatment, but all discomforts were transient and well tolerated. In conclusion, a synergistic effect of pumpkin seed and areca nut extract on Taenia spp. tapeworms was confirmed in the current study, primarily in producing an increased rate of effect on tapeworm expulsion (average time 2 h for combination vs 6-21 h for individual extracts). The pumpkin seed/areca combined treatment was indicated to be safe and highly effective (89%) for human taeniasis.