Prevalence of extra-intestinal porcine helminth infections and assessment of sanitary conditions of pig slaughter slabs in Dar es Salaam city, Tanzania

Epidemiology of Porcine Cysticercosis in Eastern and Southern Africa: Systematic Review and Meta-Analysis

Taenia solium cysticercosis is the most common cause of acquired epilepsy in pig-raising and pork-consuming parts of Africa, Latin America, and Asia. This review aimed to systematically compile and synthesize data on the epidemiology of porcine cysticercosis in the Eastern and Southern Africa (ESA) region. Comprehensive searching strategies were employed to retrieve the studies published or reported between January 1,1997 and March 1, 2021, from Pub Med, Hinari, and Google Scholar databases and search platforms. The identified studies that met the inclusion criteria were then appraised for methodological quality. Finally, 44 studies obtained from nine countries were selected and included in this review. Relevant data were extracted using standardized templates for qualitative synthesis and meta-analysis. The overall pooled prevalence estimate of porcine cysticercosis in the ESA region was 17% (95% CI: 14-20%). The prevalence level between and within countries showed high variability. The pooled estimate showed high heterogeneity among the reports (the inverse variance index value (I2) of 98.99%, p < 0.05). The meta-analysis sub-grouped by the type of diagnostic test showed the pooled prevalence estimate of 27% (95% CI: 9-50) by carcass dissection; 23% (95% CI: 14-33) by Antibody-based immunodiagnostic techniques; 23% (95% CI: 18-29) by antigen detecting (Ag)-ELISA, 12% (95% CI: 7-18) by meat inspection, and 9% (95% CI: 7-11) by lingual examination. The meta-analysis sub-grouped by region showed a relatively higher pooled prevalence estimate for the Southern region 22% (95% CI: 15-30) compared to 13% (95% CI: 11-15) in the Eastern region. The highest country-based pooled prevalence was obtained from South Africa (33%, 95% CI: 20-48) and Zambia (22%, 95% CI: 16-29), whereas the lowest pooled prevalence was identified in Madagascar (5%, 95% CI: 4-5) and Rwanda (7%, 95% CI: 6-8). The lack of latrine, traditional pig husbandry practices, unprotected water sources, and increase in age were identified as significant risk factors for the occurrence of porcine cysticercosis in the pooled studies. The findings of this review will provide context-specific input to prioritize the possible intervention programs for T. solium control in the ESA region. More sensitive and specific test-based prevalence estimates, detailed risk factor investigations, and financial losses analysis are needed to establish feasible control strategies.

Systematic Review Registration

http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42021238931.

Prevalence and molecular characterization of cystic hydatidosis in livestock slaughtered in southern Mozambique

Hydatid disease is a parasitic zoonosis caused by genotypes of the genus Echinococcus. This disease inflicts economic loses in livestock and cause public health burden in resource poor mostly in developing countries. The aim of this study was to determine the prevalence and identity of the genotypes responsible for hydatid cysts in cattle, goats and pigs slaughtered at selected abattoirs of southern provinces of Mozambique. Cysts were collected from liver and lungs and hydatid confirmation was made by cystic membrane observation and visualization of protoscoleces by light microscope. Thirty-two hydatid cysts from 817 cattle and two from 68 pigs were collected from local slaughterhouses and slabs. DNA was extracted from protoscoleces of each cyst together with the cystic membrane and amplified based on the mitochondrial subunit 1 of the cox1 and nad1 gene. The overall prevalence of hydatid cysts was 3.9% in cattle, 2.9% in pigs and none of the goats were found with cysts. All cysts collected from cattle and pigs were identified as Echinococcus ortleppi (G5) with a minimum homology of 99% on BLAST analysis. Our results confirm the presence of E. ortleppi in cattle and pigs in southern Mozambique at a low prevalence and further studies are recommended to determine the risk factors favoring the transmission of this zoonotic parasite in the resource-poor livestock farming communities of this region.

Optimal control analysis of Taenia saginata bovine cysticercosis and human taeniasis

Bovine cysticercosis and human taeniasis are neglected food-borne diseases that pose challenge to food safety, human health and livelihood of rural livestock farmers. In this paper, we have formulated and analyzed a deterministic model for transmission dynamics and control of taeniasis and cysticercosis in humans and cattle respectively. The analysis shows that both the disease free equilibrium (DFE) and endemic equilibrium (EE) exist. To study the dynamics of the diseases, we derived the basic reproduction number R 0 by next generation matrix method which shows whether the diseases die or persist in humans and cattle. The diseases clear if R 0 < 1 and persist when R 0 > 1. The normalized forward sensitivity index is used to derive sensitive indices of model parameters. Sensitivity analysis results indicate that human's and cattle's recruitment rates, infection rate of cattle from contaminated environment, probability of humans to acquire taeniasis due to consumption of infected meat, defecation rate of humans with taeniasis and the consumption rate of raw or undercooked infected meat are the most positive sensitive parameters whereas the natural death rates for humans, cattle, Taenia saginata eggs and the proportion of unconsumed infected meat are the most negative sensitive parameters in diseases' transmission. These results suggest that control measures such as improving meat cooking, meat inspection and treatment of infected humans will be effective for controlling taeniasis and cysticercosis in humans and cattle respectively. The optimal control theory is applied by considering three time dependent controls which are improved meat cooking, vaccination of cattle, and treatment of humans with taeniasis when they are implemented in combination. The Pontryagin's maximum principle is adopted to find the necessary conditions for existence of the optimal controls. The Runge Kutta order four forward-backward sweep method is implemented in Matlab to solve the optimal control problem. The results indicate that a strategy which focuses on improving meat cooking and treatment of humans with taeniasis is the optimal strategy for diseases' control.

Evidence for Transmission of Taenia solium Taeniasis/Cysticercosis in a Rural Area of Northern Rwanda

Cysticercosis is a parasitic infection caused by the metacestode larval stage (cysticercus) of Taenia solium. In humans, cysticercosis may infect the central nervous system and cause neurocysticercosis, which is responsible for over 50,000 deaths per year worldwide and is the major cause of preventable epilepsy cases, especially in low-income countries. Cysticercosis infection is endemic in many less developed countries where poor hygiene conditions and free-range pig management favor their transmission. A cross-sectional study was conducted in 680 children from a rural primary school in Gakenke district (Northern province of Rwanda). Stool samples were collected from participants and analyzed using the Kato-Katz method (KK), formol-ether concentration (FEC), and/or copro-antigen enzyme-linked immunosorbent assay (CoAg-ELISA) to detect taeniasis. Blood samples were collected and analyzed using enzyme-linked immunoelectrotransfer blot (EITB) and antigen enzyme-linked immunosorbent assay (Ag-ELISA) to detect human cysticercosis. The overall proportion of taeniasis positivity was 0.3% (2/680), and both cases were also confirmed by CoAg-ELISA. A total of 13.3% (76/572) of the children studied were positive to cysticercosis (T. solium-specific serum antibodies detected by EITB), of whom 38.0% (27/71) had viable cysticercus (T. solium antigens by Ag-ELISA). This study provides evidence of the highest cysticercosis prevalence reported in Rwanda in children to date. Systematic investigations into porcine and human cysticercosis as well as health education and hygiene measures for T. solium control are needed in Gakenke district.

Echinococcosis in humans and animals in Southern Africa Development Community countries: A systematic review

The taeniid Echinococcus is the causative agent of the zoonotic disease echinococcosis/hydatidosis and is associated with economic losses in livestock production. This review summarizes available scientific literature on circulating species of Echinococcus in humans, wild and domestic animals in countries of Southern Africa Development Community, and identifies knowledge gaps and recommend research priorities. Data were systematically accessed from Google Scholar, MEDLINE/PubMed and from library resources from December 2017 to June 2019. Meta-analysis was conducted in STATA program and heterogeneity and prevalence values were pooled by host species with 95% confidence interval. In intermediate hosts, the overall prevalence of Echinococcus by meat inspection was 10% (CI: 9-11%) in small ruminants, 7% (CI: 5-8%) in cattle, 1% (CI: 0-1%) in pigs and 9% (CI: 0-29%) in wild herbivores. In canids by CoproAg-ELISA and necropsy the prevalence was of 10% (CI: 8-10%) and 6% (CI: 3-10%) respectively. A high level of heterogeneity (I2 > 65%) was observed for all study groups. Echinococcus equinus, E. canadensis, E ortleppi and E. felidis were reported from wildlife and E. ortleppi, E. granulosus s. s. and E. canadensis from humans. There is paucity of research in echinococcosis and gaps in prevalence reports over time in both humans and animals in the SADC region and we recommend an increase in future studies on the epidemiology of disease, risk factors for transmission in animals and humans and its relation with human health specially in the advent of HIV pandemic following a "One Health" approach.

Taenia solium taeniosis and cysticercosis literature in Tanzania provides research evidence justification for control: A systematic scoping review

Background

Despite Taenia solium taeniosis/cysticercosis (TSTC) having been put high on the global agenda of neglected tropical diseases (NTDs), which over the last years has received a lot of attention, there has been no control programmes in place in sub-Saharan Africa, a highly endemic region. This could be attributed to lack of awareness of many stakeholders on the burden and impact of T. solium. This information is essential in guiding TSTC policies, practices and research agendas as well as encouraging cross-sectoral collaboration in the control of this important zoonotic parasite using a One Health approach. National elimination of the parasite is the foundation for global eradication. This will require that substantial country-level information is provided to all key stakeholders. We have mapped out TSTC research evidence in Tanzania to inform on disease burden and potential for integrated control measures.

Methodology/Principal findings

A scoping review of all TSTC studies undertaken in Tanzania and published up to December 2018 was conducted. The articles were searched from PUBMED, AJOL, Google Scholar and Google in general. Fifty-one (51) articles met the inclusion criteria and were reviewed. Prevalence of taeniosis of 2.3% - 5.2% was estimated based on copro-antigen ELISA while human cysticercosis of >16% was estimated based on serum antigen ELISA (Ag-ELISA) or IgG Western Blot. Neurocysticercosis (NCC) contributed significantly to epilepsy in adults. Farm prevalence of porcine cysticercosis were 6.0% - 17.4% (lingual examination) and 1.5% - 33.3% (Ag-ELISA). Slaughter-slab prevalence were 0% - 18.2% (routine meat inspection). Lacking latrines, watering pigs with river or pond water, and feeding pigs with potato peels were associated with porcine cysticercosis prevalence. Washing hands by dipping method increased the risk of human cysticercosis. In 2012, the number of DALYs/1000 person-years for NCC-associated epilepsy was 0.7 (95% UI, 0.2–1.6), around 5 million USD (95% UI, 797,535–16,933,477) were spent due to NCC-associated epilepsy and nearly 3 million USD (95% UI, 1,095,960–5,366,038) were potentially lost due to porcine cysticercosis. Three rounds of annual treatment of school-age children with praziquantel significantly reduced prevalence of taeniosis and porcine cysticercosis. Health education was efficacious in improving knowledge and attitudes favourable for control of TSTC while a single dose of oxfendazole 30 mg/kg body weight was efficacious in eliminating T. solium cysticerci from pig musculature.

Conclusions/Significance

The observed high burden of TSTC and the significant contribution of NCC to epilepsy in Tanzania warrant urgent interventions. Evaluation of best control options should make use of disease transmission dynamics models such as cystiSim, taking into account findings from the field based intervention studies. In addition, locally adapted management guidelines for people suffering from NCC are urgently needed.

A Slaughterhouse Survey for Porcine Circovirus Type 2 in Commercial Pigs in Ibadan, Southwest Nigeria

Porcine circovirus type 2 (PCV2) is recognized as one of the most important agents of reproductive disorders in gilts and sows worldwide. It is associated with considerable economic losses in the swine industry due to the unthriftiness, and variable morbidity and mortality it causes in pigs. In spite of the devastation caused by this virus to the global pig industry, there is little or no report of its occurrence in Nigeria. Hence, a slaughterhouse based survey was conducted to determine the prevalence of PCV2 infections in pigs in Ibadan, southwest Nigeria. Using a commercial ELISA kit, 364 pig sera collected from a major abattoir were screened for IgG antibodies against PCV2. The overall prevalence of anti-PCV2 antibodies in the pigs was 1.4 % (5/364), with more female pigs (4/237, 1.7 %) being seropositive than males (1/127, 0.8 %). Since there is no routine vaccination against this swine disease in Nigeria, thus the antibodies detected in the pig sera indicated a natural exposure to the virus. The absence of clinical disease in the pigs also suggests the possibility of a carrier status for these animals and shows that they could serve as hosts for the perpetuation of the disease. These findings underscore the need for continuous surveillance for PCV2 among pigs in Nigeria in order to determine its contribution to production losses incurred in the Nigerian swine industry and aid the development of prevention and control strategies against the disease.

The societal cost of Taenia solium cysticercosis in Tanzania

Taenia solium is a zoonotic parasite prevalent in many low income countries throughout Latin America, Asia and sub-Saharan Africa, including Tanzania. The parasite is recognized as a public health threat; however the burden it poses on populations of Tanzania is unknown. The aim of this study was to estimate the societal cost of T. solium cysticercosis in Tanzania, by assessing both the health and economic burden. The societal cost of T. solium cysticercosis was assessed in humans and pigs based on data obtained by a systematic review. Experts' opinion was sought in cases where data were not retrievable. The health burden was assessed in terms of annual number of neurocysticercosis (NCC) associated epilepsy incident cases, deaths and disability-adjusted life years (DALYs), while the economic burden was assessed in terms of direct and indirect costs imposed by NCC-associated epilepsy and potential losses due to porcine cysticercosis. Based on data retrieved from the systematic review and burden assessments, T. solium cysticercosis contributed to a significant societal cost for the population. The annual number of NCC-associated epilepsy incident cases and deaths were 17,853 (95% Uncertainty Interval (UI), 5666-36,227) and 212 (95% UI, 37-612), respectively. More than 11% (95% UI, 6.3-17) of the pig population was infected with the parasite when using tongue examination as diagnostic method. For the year 2012 the number of DALYs per thousand person-years for NCC-associated epilepsy was 0.7 (95% UI, 0.2-1.6). Around 5 million USD (95% UI, 797,535-16,933,477) were spent due to NCC-associated epilepsy and nearly 3 million USD (95% UI, 1,095,960-5,366,038) were potentially lost due to porcine cysticercosis. Our results show that T. solium imposes a serious public health, agricultural and economic threat for Tanzania. We urge that a One Health approach, which involves the joint collaboration and effort of veterinarians, medical doctors, agricultural extension officers, researchers and relevant governmental agencies, is taken to find sustainable solutions for prevention, control and elimination of T. solium.

Taenia solium taeniosis/cysticercosis and the co-distribution with schistosomiasis in Africa

Background

This study aimed to map the distribution of Taenia solium taeniosis/cysticercosis and the co-distribution with schistosomiasis in Africa. These two major neglected tropical diseases are presumed to be widely distributed in Africa, but currently the level of co-distribution is unclear.

Methods

A literature search on T. solium taeniosis/cysticercosis was performed to compile all known studies on the presence of T. solium and apparent prevalence of taeniosis and porcine cysticercosis in Africa. Studies were geo-referenced using an online gazetteer. A Bayesian framework was used to combine the epidemiological data on the apparent prevalence with external information on test characteristics to estimate informed district-level prevalence of taeniosis and porcine cysticercosis. Districts with T. solium taeniosis/cysticercosis presence were cross-referenced with the Global Neglected Tropical Diseases Database for schistosomiasis presence.

Results

The search strategies identified 141 reports of T. solium in Africa from 1985 to 2014 from a total of 476 districts in 29 countries, 20 with porcine cysticercosis, 22 with human cysticercosis, and 16 with taeniosis, in addition to 2 countries identified from OIE reports. All 31 countries were considered, on national scale, to have co-distribution with schistosomiasis. Presence of both parasites was confirmed in 124 districts in 17 countries. The informed prevalence of taeniosis and porcine cysticercosis were estimated for 14 and 41 districts in 10 and 13 countries, respectively.

Conclusions

With the paucity of data, T. solium infection is grossly under-reported and expected to be more widespread than this study suggests. In areas where co-distribution occurs there is a need for increased emphasis on evaluation of integrated intervention approaches for these two helminth infections and allocation of resources for evaluating the extent of adverse effects caused by mass drug administration.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-0938-7) contains supplementary material, which is available to authorized users.

Productivity and parasitic infections of pigs kept under different management systems by smallholder farmers in Mbeya and Mbozi districts, Tanzania

An on farm experiment was carried out to assess the effects of production systems on the performance of local pigs kept by smallholder farmers. Six villages from Mbeya and Mbozi districts, Tanzania were purposely selected based on the prominent pig production systems: free range, semi-confinement and total confinement. Fifteen pig keeping households were randomly selected from each village to participate in the study. A participatory rural appraisal and structured questionnaire were used for collecting information from the households on pig production and reproduction performance. In addition, a total of 180 weaner pigs, 2-3 months old, were purchased and randomly allocated to the 90 participating households. The pigs were subjected to three production systems: free range (M1), confinement with local diet (M2) and confinement with a compounded diet and anthelmintic treatment (M3). The anthelmintic treatment (piperazine citrate) was administered at 1 g per kg body weight. Faecal and blood samples were collected at month three of the experiment to assess the burden of intestinal helminths and sero-prevalence of Taenia solium cysticercosis, respectively. Sows kept under free range system were reported to have smaller litter size both at farrowing and at weaning compared to those kept under confinement. The experiment showed pigs under M3 had higher (P < 0.05) liveweight gains (136 g/day) compared to pigs in M2 (73 g/day) and M1 (68 g/day). In addition, pigs in M3 had higher body length and heart girth size with the feed to gain ratio of 8.5. Free range pigs tended to have lower faecal egg counts for most worm species compared to permanently confined pigs. Sero-prevalence of Taenia solium cysticercosis was 26%, with village prevalence ranging from 8 to 52%. Although pigs kept in M3 performed better than the rest, the compounded feed was too expensive for the farmers to afford. Locally available feed types combined with vitamin and mineral supplements may be a more sustainable option.

Preliminary evaluation of Community-Led Total Sanitation for the control of Taenia solium cysticercosis in Katete District of Zambia

Taenia solium taeniasis/cysticercosis is a zoonotic disease endemic in sub-Saharan Africa. It is associated with poor sanitary practices, free-range pig husbandry and lack of disease awareness in endemic communities. A comparative research was conducted with pre and post-intervention assessments in nine villages to evaluate Community-Led Total Sanitation (CLTS) as an intervention measure for the control of porcine cysticercosis in Katete District in the Eastern Province of Zambia. Blood samples were collected from pigs for circulating antigen detection and a questionnaire focused on the household was administered to a total of 153 respondents whose pigs were examined (64 pre-intervention, 89 post-intervention), in order to obtain information on general demographic characteristics, pig husbandry practices, sanitation practices and associated knowledge and awareness of T. solium infections. The first sampling was conducted prior to the implementation of the CLTS and second sampling eight months after triggering of CLTS in the selected villages. A total of 379 pig serum samples were examined using the B158/B60 Ag-ELISA to detect T. solium cysticercosis, 104 pre-intervention and 275 post-intervention, of which 14 (13.5%) and 45 (16.4%) were positive, respectively. Wald test p-values were computed to assess significant differences in the variables of interest mentioned above for the pre and post CLTS. The research revealed that CLTS as a control measure did not significantly improve T. solium infections in pigs. The research also revealed that the sanitation practices and awareness of cysticercosis did not change. It is recommended that a longer term evaluation be undertaken when the villages have been declared open defaecation free. In addition, the research recommends that health education, mass drug treatment and pig vaccination be incorporated, as an essential component of prevention and control programmes for T. solium infections.

Assessment of sanitary conditions of unregistered pig slaughter slabs and post mortem examination of pigs for Taenia solium metacestodes in Kaduna metropolis, Nigeria

Background

A number of studies document the prevalence of Taenia solium infections in Nigeria, yet these studies do not cover porcine cysticercosis in private home slaughter slabs where there is no routine meat inspection and backyard pig keeping, slaughtering and sale are common practice.

Methods

An environmental and sanitary assessment was conducted within two unregistered home pig slaughter slabs in selected parts of the Kaduna metropolis in Nigeria. Slaughter premises were inspected for availability of basic facilities and questionnaires were used to elicit necessary informative data. Butchers were examined for taeniasis by stool microscopy and copro-antigen enzyme linked immunosorbent assay (copro-Ag ELISA) to ascertain T. solium – taeniasis. Pigs slaughtered at the premises were examined for cysticerci.

Results

Home slaughter conditions were substandard, unhygienic and lacked the basic facilities of a proper slaughterhouse. Prevalence of porcine cysticercosis was 9.3%. The butchers participating in the study had very poor knowledge of T. solium infections and 30% tested positive for taeniasis by copro-Ag ELISA at the time of the study.

Conclusion

Home slaughter of pigs in the areas studied should be considered and integrated as a component of prevention and control programmes – particularly through educational interventions – in order to equip individuals involved with a good understanding of the risks associated with animal husbandry and human practices.

Electronic supplementary material

The online version of this article (doi:10.1186/2049-9957-3-45) contains supplementary material, which is available to authorized users.

The risk factors for human cysticercosis in Mbulu District, Tanzania

The objective of this study was to explore the reasons for the persistence of human cysticercosis (HCC) transmission in Mbulu District, northern Tanzania. The study was carried out in 25 villages, whereby five major risks were identified. The risks were indiscriminate defaecation and improper use of toilets; a free-range system of keeping pigs; indiscriminate or unregulated slaughtering and inadequate meat hygiene and inspection; consumption of undercooked and porcine cysticerci infected pork; and social structure and roles. All of the identified risks were backed up by the immanent lifestyles of the community involved. These findings are important for the development of intervention strategies in the study area.

A review of pig pathology in Tanzania

The approximately 1.58 million pigs in Tanzania represent 3.7% of the national population of quadruped meat-producing animals. Pigs are kept mainly by small producers who own 99.5% of the national stock in units that average 3.04 animals (range 2-48). Government policy has had little practical application. African swine fever, foot-and-mouth disease and Cysticercosis are important diseases. The first two are notifiable diseases under Tanzania legislation; the last has widespread distribution and relevance as a major zoonosis. Ascariasis (Ascaris suum), hydatidosis (Echinococcus granulosus), leptospirosis (Leptospira interrogans) and thermophilic Campylobacter are other zoonoses associated with pigs. Gastrointestinal helminths and external parasites, especially Sarcoptes scabiei, are common. Risk factors associated with cysticercosis for humans working with pigs or eating their meat include the free-range or semi-confined management systems, the use of rivers or ponds as a source of water, lack of household sanitation, informal home slaughter, pork not being inspected at slaughter slabs and undercooked and barbecued meat. Pigs are a minor component of Tanzania's livestock sector but there is potential for increasing their contribution to human welfare. Prospects are enhanced by the shorter life cycle, greater number of young produced per year and the possibility of producing high-quality animal protein at a lower cost than meat produced by cattle and small ruminants.

Prevalence and risk factors associated with human Taenia solium infections in Mbozi District, Mbeya Region, Tanzania

Background

Taenia solium cysticercosis/taeniosis is emerging as a serious public health and economic problem in many developing countries. This study was conducted to determine prevalence and risk factors of human T. solium infections in Mbeya Region, Tanzania.

Methods and Findings

A cross-sectional survey was conducted in 13 villages of Mbozi district in 2009. Sera of 830 people (mean 37.9±11.3 years (SD); 43% females) were tested for circulating cysticerci antigen (Ag-ELISA) and antibody (Ab-ELISA). A subset of persons found seropositive by Ag-ELISA underwent computed tomography (CT) scan of the brain for evidence of neurocysticercosis. Stool samples from 820 of the same participants were tested for taeniosis by copro-antigens (copro-Ag-ELISA) and formol-ether concentration technique. Cases of T. solium taeniosis were confirmed serologically by EITB assay (rES38). A questionnaire was used for identification of risk factors. Active cysticercosis by positive Ag-ELISA was found in 139 (16.7%) persons while anti-cysticercal antibodies were detected in 376 (45.3%) persons by Ab-ELISA. Among 55 persons positive for Ag-ELISA undergoing CT scan, 30 (54.6%) were found to have structures in the brain suggestive of neurocysticercosis. Using faecal analysis, 43 (5.2%) stool samples tested positive for taeniosis by copro-Ag-ELISA while Taenia eggs were detected in 9 (1.1%) stool samples by routine coprology. Antibodies specifically against adult T. solium were detected in 34 copro-Ag-ELISA positive participants by EITB (rES38) indicating T. solium taeniosis prevalence of 4.1%. Increasing age and hand washing by dipping in contrast to using running water, were found associated with Ag-ELISA seropositivity by logistic regression. Gender (higher risk in females) and water source were risk factors associated with Ab-ELISA seropositivity. Reported symptoms of chronic severe headaches and history of epileptic seizures were found associated with positive Ag-ELISA (p≤0.05).

Conclusion

The present study indicates T. solium infection in humans is highly endemic in the southern highlands of Tanzania.

Cysticercosis caused by the zoonotic pork tapeworm, Taenia solium, is emerging as a serious public health and agricultural problem in sub-Saharan Africa. Surveys have shown cysticercosis in pigs to be highly prevalent in multiple foci in Tanzania, and a hospital-based study in the northern highlands indicated neurocysticercosis as an important cause of epileptic seizures in humans. We present here a cross-sectional community-based survey on the prevalence and risk factors of human cysticercosis and taeniosis conducted in the southern highlands – the major pig-producing area of the country. The most striking findings were that more than 15% of people surveyed were found to have active cysticercosis and nearly half of them were found to have been exposed to larval T. solium indicating a high level of environmental contamination with T. solium eggs. This was supported by finding over 4% of people having had T. solium tapeworms. A subset of persons found positive serologically for active cysticercosis underwent brain scanning and more than half of them were found to have neurocysticercosis. This strong evidence that T. solium cysticercosis/neurocysticercosis/taeniosis is highly endemic in the southern highlands of Tanzania demands urgent attention of regional and national authorities to combat the parasite.