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.

Co-infection of pigs with Taenia solium cysticercosis and gastrointestinal parasites in Eastern and Western Uganda

A study was carried out in Kamuli and Hoima districts in Eastern and Western regions of Uganda to determine the Taenia solium porcine cysticercosis (PCC) and gastrointestinal (GI) parasites co-infection status in pigs. One hundred sixty-one households were selected randomly and visited between November and December 2019. A household questionnaire was administered, and faecal and blood samples were collected from at least one pig older than 3 months per household. A blood sample was obtained from a jugular venipuncture, and a rectal faecal sample was obtained. Taenia spp. circulating antigen levels in the sample sera were tested using a commercial enzyme-linked immunosorbent assay kit, apDia™ cysticercosis Ag ELISA. The modified McMaster technique was used to identify and quantify the GI parasites. The apparent animal-level seroprevalence for PCC was 4.8% (95% CI 2.7–7.1) and differed across the two districts (p = 0.018). At the pig herd level, the prevalence was 9.7% (95% CI 5.5–14.4). The prevalence of the different nematode eggs and coccidian oocysts in the two districts was as follows: strongyles 79.0% (95% CI 74.3–83.6), coccidia 73.3% (95% CI 68.3–78.6), Trichuris spp. 7.4% (95% CI 4.9–10.6), Strongyloides ransomi 2.1 (95% CI 0.7–3.5) and Ascaris spp. 4.9 (95% CI 2.8–7.4). Overall, across the two districts, the arithmetic mean for the oocysts per gram (OPG) for coccidia was 2042.2 ± 5776.1, and eggs per gram (EPG) were the highest in strongyles 616.1 ± 991. Overall, 57.4% of the porcine cysticercosis seropositive pigs were also positive for at least one of the gastrointestinal helminths which included strongyles, Strongyloides ransomi, Trichuris spp. and Ascaris spp. The co-infection status of pigs with both PCC and GI parasites demonstrated by this study can provide an incentive for integrating the control and management of both parasites with oxfendazole. Further studies are required to understand the feasibility of using oxfendazole including cost–benefit analysis and the acceptability by local stakeholders for the control of T. solium cysticercosis and gastrointestinal parasites in pigs.

Rapid Detection of Cysticercus cellulosae by an Up-Converting Phosphor Technology-Based Lateral-Flow Assay

Cysticercosis is a neglected tropical disease caused by the larvae of Taenia solium in pigs and humans. The current diagnosis of porcine cysticercosis is difficult, and traditional pathological tests cannot meet the needs of detection. This study established a UPT-LF assay for the detection of Cysticercus cellulosae. UCP particles were bound to two antigens, TSOL18 and GP50; samples were captured, and the signal from the UCP particles was converted into a detectable signal for analysis using a biosensor. Compared to ELISA, UPT-LF has higher sensitivity and specificity, with a sensitivity of 93.59% and 97.44%, respectively, in the case of TSOL18 and GP50 antigens and a specificity of 100% for both. Given its rapidness, small volume, high sensitivity and specificity, and good stability and reproducibility, this method could be used in the diagnosis of cysticercosis.

Validation of a spatial agent-based model for Taenia solium transmission (“CystiAgent”) against a large prospective trial of control strategies in northern Peru

Background The pork tapeworm (Taenia solium) is a parasitic helminth that imposes a major health and economic burden on poor rural populations around the world. As recognized by the World Health Organization, a key barrier for achieving control of T. solium is the lack of an accurate and validated simulation model with which to study transmission and evaluate available control and elimination strategies. CystiAgent is a spatially-explicit agent based model for T. solium that is unique among T. solium models in its ability to represent key spatial and environmental features of transmission and simulate spatially targeted interventions, such as ring strategy. Methods/Principal findings We validated CystiAgent against results from the Ring Strategy Trial (RST)–a large cluster-randomized trial conducted in northern Peru that evaluated six unique interventions for T. solium control in 23 villages. For the validation, each intervention strategy was replicated in CystiAgent, and the simulated prevalences of human taeniasis, porcine cysticercosis, and porcine seroincidence were compared against prevalence estimates from the trial. Results showed that CystiAgent produced declines in transmission in response to each of the six intervention strategies, but overestimated the effect of interventions in the majority of villages; simulated prevalences for human taenasis and porcine cysticercosis at the end of the trial were a median of 0.53 and 5.0 percentages points less than prevalence observed at the end of the trial, respectively. Conclusions/Significance The validation of CystiAgent represented an important step towards developing an accurate and reliable T. solium transmission model that can be deployed to fill critical gaps in our understanding of T. solium transmission and control. To improve model accuracy, future versions would benefit from improved data on pig immunity and resistance, field effectiveness of anti-helminthic treatment, and factors driving spatial clustering of T. solium infections including dispersion and contact with T. solium eggs in the environment.

Seroprevalence of Porcine Cysticercosis in South-Eastern Côte d'Ivoire

: Background : porcine cysticercosis is an endemic parasitic zoonosis in many developing countries. The objective was to estimate the seroprevalence of porcine cysticercosis in traditional pig farms in the departments of Dabou, Aboisso and Agboville where blood samples were taken from pigs and analyzed by ELISA (IgG) and western blot. Data on farming practices and pig characteristics were collected. Categorical variables were compared with the Chi2 test and continuous variables with the Student test. Multivariate logistic regression models were constructed to identify risk factors. Results: A total of 668 pigs were sampled from 116 farms. The seroprevalence of cysticercosis was estimated at 13.2%. Overweight [ORa=2.6; 95%CI(1.3-4.9)] and fat pigs [ORa=2.3; 95%CI(1.0-4.8)] were twice as likely to be seropositive for cysticercosis. This risk was increased in farms using well water for drinking [aOR=2.5; 95%CI(1.0-6.3)] as well as those reporting veterinary care of the animals (ORa=2.9; 95%CI (1.2-7.3)). Conclusions: This study demonstrated the circulation of T. solium in pig farms in southern Côte d'Ivoire.

Prevalence of Porcine Cysticercosis in India: A Meta-Analysis

Porcine cysticercosis (PCC) caused due to Taenia solium a tapeworm; is one of the important neglected tropical diseases with a significant zoonotic importance. In view of the underdeveloped swine husbandry practices coupled with negligence of people towards hygienic food habits, a comprehensive estimate on the presence of porcine cysticercosis in India will be helpful for planning control measure. We performed a systematic literature review regarding data about PCC epidemiology in India and meta-analyses for its prevalence in different zones of country and the methods employed for detection and based on this discussed possible control strategies. A total 27 studies spanned over period from 2000 to 2019 from different parts of India were included for meta-analysis which were obtained through a systematic search from online free databases. The overall prevalence using random effects model was found 5.21% with substantial heterogeneity (I2 = 96.52, p = 0.0001). However subgroup analysis revealed higher prevalence due to smaller sample size and also method of detection has also significant effect on the pooled data. Considering the zoonotic significance as well as economic losses to pork industry, control strategies need to be devised with regards to health monitoring, improvements in ante-mortem diagnostics, hygienic meat practices coupled with education to both the producers and consumers about this important disease through one health approach.

A qualitative assessment of the context and enabling environment for the control of Taenia solium infections in endemic settings

Background Taenia solium (T. solium), is a zoonotic helminth causing three diseases namely; taeniasis (in humans), neurocysticercosis (NCC, in humans) and porcine cysticercosis (PCC, in pigs) and is one of the major foodborne diseases by burden. The success or failure of control options against this parasite in terms of reduced prevalence or incidence of the diseases may be attributed to the contextual factors which underpin the design, implementation, and evaluation of control programmes. Methodology/Principal findings The study used a mixed method approach combining systematic literature review (SLR) and key informant interviews (KII). The SLR focused on studies which implemented T. solium control programmes and was used to identify the contextual factors and enabling environment relevant to successful inception, planning and implementation of the interventions. The SLR used a protocol pre-registered at the International prospective register of systematic reviews (PROSPERO) number CRD42019138107 and followed PRISMA guidelines on reporting of SLR. To further highlight the importance and interlinkage of these contextual factors, KII were conducted with researchers/implementers of the studies included in the SLR. The SLR identified 41 publications that had considerations of the contextual factors. They were grouped into efficacy (10), effectiveness (28) and scale up or implementation (3) research studies. The identified contextual factors included epidemiological, socioeconomic, cultural, geographical and environmental, service and organizational, historical and financial factors. The enabling environment was mainly defined by policy and strategies supporting T. solium control. Conclusion/Significance Failure to consider the contextual factors operating in target study sites was shown to later present challenges in project implementation and evaluation that negatively affected expected outcomes. This study highlights the importance of fully considering the various domains of the context and integrating these explicitly into the plan for implementation and evaluation of control programmes. Explicit reporting of these aspects in the resultant publication is also important to guide future work. The contextual factors highlighted in this study may be useful to guide future research and scale up of disease control programmes and demonstrates the importance of close multi-sectoral collaboration in a One Health approach.

Low Prevalence of Cysticercosis and Trichinella Infection in Pigs in Rural Cambodia

Cysticercosis and Trichinella spp. infection are parasitic zoonoses prevalent among pigs in Southeast Asia, where pork is the most important source of meat. In rural Cambodia, many pigs are raised extensively in family backyards, and information regarding the prevalence in rural small-scale pig production is very limited. This study was conducted in four provinces in north-eastern Cambodia to determine the seroprevalence of porcine cysticercosis and Trichinella spp. infection in rural villages, and to identify possible risk factors. Only households with less than 10 pigs above three months old were eligible. In total, 139 households participated, and 242 blood samples were collected. Farmers were interviewed about food and hygiene habits, disease knowledge and practices. The serum samples were analysed by ELISA to determine antigens to Taenia spp. cysticerci or antibodies to Trichinella spp. muscle larvae. Positivity among the pigs was 11.2% (95% CI 7.5–15.8) for Taenia spp. cysts and 2.5% (95% CI 0.9–5.4) for Trichinella spp. Cysticerci were more common in the province Preah Vihear (p < 0.001) than in the other provinces. Risk factors associated with porcine cysticercosis were management systems for the pigs and access to human faeces (p < 0.001). Trichinella spp. infection in pigs was more common in the province Ratanakiri (p = 0.001). The main risk factor associated with Trichinella spp. transmission was feeding pigs with food waste (p = 0.048). More men had heard about cysticercosis than women (p = 0.002), and men also consumed undercooked pork meat to a greater extent (p = 0.004). Although the present study is relatively small, several risk factors could be identified for porcine infection with Taenia spp. and Trichinella spp., which can be used to guide future interventions to improve both porcine and human health in these provinces.

Porcine Cysticercosis Seroprevalence and Potential Transmission Risk Factors in Iringa District Council, Tanzania

Background Porcine cysticercosis is endemic in Tanzania, especially in the southern, central part and northern highlands of the country. The disease reduces meat quality and affects pig industry. This study investigated porcine cysticercosis prevalence and possible risk factors for reference in preparation for sustainable control measures. Methods Current seroprevalence and potential risk factors were studied in selected ward/villages of Iringa district council, in the southern highland of Tanzania, prior to a digital health education intervention. A total of 346 pigs from 88 households of Izazi, Migoli and Mlowa wards were studied using an enzyme-linked immunosorbent assay (ELISA), which detects Taenia species antigens (Ag) in sera. Questionnaire used to dig information on pig management and sanitation and hygiene practices. Results The AgELISA detected 22.3% of the surveyed pigs as positive for porcine cysticercosis. The detected porcine cysticercosis seropositivity ranged between 21.3% and 25.7% per individual ward, with at least one seropositive pig in 53.4% of the surveyed households. Confining pigs was significantly related to low porcine cysticercosis seropositivity (OR = 2.426; 95% CI = 1.202–5.300; p = 0.026), whereas scavenging pigs had two times chance of being Ag-ELISA seropositive. Conclusions Pig confinement and feeding skills and community sensitization on hygiene and sanitation are recommended. Therefore, practical ways of delivering health education to rural communities such as the studied community should be investigated.