Development and Laboratory Evaluation of a Simple, Field-Applicable Coproantigen Enzyme-Linked Immunosorbent Assay for Diagnosis of Taeniasis in Northern Peru.

Coproantigen detection by enzyme-linked immunosorbent assay (coAg ELISA) is a vital tool for detecting and treating cases of Taenia solium taeniasis. However, the assay's procedures require costly materials and sophisticated equipment, which are typically inaccessible in rural settings where the disease is endemic. To overcome these barriers, we developed and evaluated a field-applicable coAg ELISA. The field coAg ELISA was developed and evaluated across four phases using known positive and negative stool samples collected from northern Peru. Phase I focused on field assay development, phase II on a small-scale performance evaluation, phase III on a large-scale evaluation, and phase IV on the use and reliability of a colorimetric scale card. All samples were processed using the field and standard assay procedures and compared using signal-to-noise ratios, correlation tests, performance characteristics, and agreement statistics where appropriate. The field coAg ELISA using reagents stored at -20°C and commercially available water and milk powder, and relying on spontaneous separation of the supernatant, had performance comparable to the standard assay. The field coAg ELISA was strongly correlated with the standard in both the small- and large-scale laboratory evaluation (r = 0.99 and r = 0.98, respectively). Finally, the field assay had an almost perfect agreement between independent readers (kappa = 0.975) and between each reader and the spectrophotometer. The field coAg ELISA demonstrated performance comparable to the standard, providing a low-cost alternative to the standard assay for identifying cases of intestinal taeniasis in a low-resource setting.

Risk mapping for Taenia solium: Applying multicriteria decision analysis in Lao PDR.

OBJECTIVES: Taenia solium is ranked the most significant global foodborne parasite and the leading cause of epilepsy in low and middle-income countries. Diagnostic challenges have hampered disease control efforts to date and WHO has called for the development of risk mapping tools to assist endemic countries. This study describes the application of multicriteria decision analysis to map the risk of T. solium in Lao PDR and acts as a case study for other endemic countries. METHODS: Multicriteria decision analysis was completed using census data on relevant risk factors in Lao PDR. Factors were weighted using an analytical hierarchy process. Village risk scores were calculated using a weighted linear combination and categorised using the Fisher-Jenks algorithm into low, medium, and high risk. District risk scores and categories were calculated using the mean village risk score for a district. Sensitivity analysis was completed by doubling and halving risk factor weights, one at a time, and assessing the standard deviation of scores and categories across all scenarios. RESULTS: A total of 2017 (23.7%) villages were classified as high risk, with 3312 (39.0%) medium and 3170 (37.3%) low risk. This resulted in 21 (14.2%) high-risk districts, 83 (56.1%) medium and 44 (29.7%) low-risk districts. The risk maps highlight two areas of interest which are high risk and low variation. The first is the northern province of Phongsaly, which is consistent with literature and anecdotal reports. The second is the southern Salavan and Xekong provinces, which have yet to be investigated in detail. CONCLUSIONS: Multicriteria decision analysis has provided a simple, rapid, and flexible approach to mapping the risk of T. solium in Lao PDR. The nature of the method means that it can be completed in any endemic country with available and appropriate risk factor data.

CystiHuman: A model of human neurocysticercosis.

INTRODUCTION: The Taenia solium tapeworm is responsible for cysticercosis, a neglected tropical disease presenting as larvae in the body of a host following taenia egg ingestion. Neurocysticercosis (NCC), the name of the disease when it affects the human central nervous system, is a major cause of epilepsy in developing countries, and can also cause intracranial hypertension, hydrocephalus and death. Simulation models can help identify the most cost-effective interventions before their implementation. Modelling NCC should enable the comparison of a broad range of interventions, from treatment of human taeniasis (presence of an adult taenia worm in the human intestine) to NCC mitigation. It also allows a focus on the actual impact of the disease, rather than using proxies as is the case for other models. METHODS: This agent-based model is the first model that simulates human NCC and associated pathologies. It uses the output of another model, CystiAgent, which simulates the evolution of pig cysticercosis and human taeniasis, adding human and cyst agents, including a model of cyst location and stage, human symptoms, and treatment. CystiHuman also accounts for delays in the appearance of NCC-related symptoms. It comprises three modules detailing cyst development, seizure probability and timing, and intracranial hypertension/hydrocephalus, respectively. It has been implemented in Java MASON and calibrated in three endemic villages in Peru, then applied to another village (Rica Playa) to compare simulation results with field data in that village. RESULTS AND DISCUSSION: Despite limitations in available field data, parameter values found through calibration are plausible and simulated outcomes in Rica Playa are close to actual values for NCC prevalence and the way it increases with age and cases with single lesions. Initial simulations further suggest that short-term interventions followed by a rapid increase in taeniasis prevalence back to original levels may have limited impacts on NCC prevalence.

Comparison of Kato-Katz, PCR and coproantigen for the diagnosis of Taenia solium taeniasis.

Four methods were compared for the diagnosis of human taeniasis caused by Taenia solium. Fecal samples from persons living in a T. solium endemic region of Madagascar were examined for taeniid eggs by the Kato­Katz method. Subsequently, samples positive (n = 16) and negative (n = 200) for T. solium eggs were examined by (i) amplification of the fragment of small subunit of the mitochondrial ribosomal RNA (rrnS) gene using conventional polymerase chain reaction (PCR) and (ii) a nested PCR of a fragment of the T. solium Tso31 gene. Additionally, 12 egg-positive and all egg-negative samples were tested for coproantigen detection. A further 9 egg-positive fecal samples were examined using both PCRs. Of the 12 egg-positive samples tested by PCRs and coproantigen methods, 9 (75%) were positive by rrnS PCR, 3 (25%) using Tso31-nested PCR and 9 (75%) by coproantigen testing. None of the 200 egg-negative fecal samples was positive in either rrnS or Tso31-nested PCR. Twenty of the 25 egg-positive samples (80%) were positive in rrnS PCR, and DNA sequencing of PCR amplicons was obtained from 18 samples, all confirmed to be T. solium. Twelve of the 25 egg-positive samples (48%) were positive in the Tso31-nested PCR, all of which were also positive by rrnS PCR. It is suggested that species-specific diagnosis of T. solium taeniasis may be achieved by either coprological examination to detect eggs or coproantigen testing, followed by rrnS PCR and DNA sequencing to confirm the tapeworm species in egg-positive or coproantigen-positive samples.

Why are tapeworm carriers so difficult to find? A methodological proposal for their search and recovery.

Neurocysticercosis, caused by the larval stage of Taenia solium, is a life-threatening condition and the most severe form of the disease. Yet, despite being a required link in the parasite life cycle, tapeworm carriers are rarely reported. This study is aimed to find and evaluate T. solium carriers, describing some characteristics of these patients and the treatment. Taeniasis cases were searched for in various Mexican states from 1983 to 2016. Previous informed consent, tapeworm-carrier patients were administered with niclosamide and a saline purge. Parasite specimens were recovered and identified, both morphologically and by PCR. From 117 treated patients, Taenia sp. specimens were obtained from 46 subjects (47.8%). From these, complete parasites were recovered from 42 (90.5%), and only detached proglottids from 4 patients. Cases were more frequent in Morelos, Chiapas, and Guerrero. More than one adult cestode was recovered from 4 patients (9.5%). To improve treatment efficacy and adherence, the drug was administered in late afternoon, resulting a high recovery yield of complete parasites (90.5%). The success rate of deworming campaigns in areas of Mexico and the world that are endemic for Taenia sp. could be improved by administering the treatment at times that do not interfere with the patients' daily activities, and national health authorities could apply this simple strategy to help eradication efforts in endemic areas. The detection of carriers will only be possible through the coordinated efforts of public and private health services, a better education of the general population to improve self-detection, and adequate, personalized diagnostic procedures for suspect cases.

Knowledge, attitudes and practices related to Taenia solium cysticercosis and taeniasis in Tanzania.

BACKGROUND: Taenia solium cysticercosis/taeniasis (TSCT) is reported to be endemic in pig producing areas around the world, causing significant disease burden and economic losses. METHODS: This cross-sectional study aimed at assessing Knowledge, Attitudes and Practices (KAP) regarding TSCT in four districts, namely Mbulu, Mpwapwa, Mbinga, and Rungwe in Tanzania. Data on KAP were collected through questionnaire-based interviews and household infrastructure observations. RESULTS: Knowledge about porcine cysticercosis was good, particularly among pig keepers across the districts. Many participants had heard about the pork tapeworm (T. solium taeniasis), and the knowledge about signs/symptoms and treatment was fair, but the means of transmission and prevention measures were often unknown. Whilst most participants were familiar with epilepsy, no one knew anything about human cysticercosis and the link between cysticercosis and epileptic seizures. A similar trend is reflected through the attitudes toward the low risk perception of cysticercosis infection. Not surprisingly, the risk perception of the infection with the pork tapeworm was low too. Many participants reported not washing their hands before eating or after using the toilet which highlights potential risks for the development of human cysticercosis. Albeit nearly every participant reported using the toilet always, household observations revealed that toilets were either lacking or had no complete walls. Generally, household observations revealed a discrepancy between questionnaire answers on the one hand and the availability of toilet and handwashing facilities and the confinement of pigs on the other hand. CONCLUSION: This study demonstrates knowledge gaps and adverse practices which may hinder and/or slow down the control/elimination of T. solium in endemic countries. The study results are also useful for appropriate designing of TSCT health interventions that need to be planned carefully, taking into account the local context and designing TSCT in partnership with the local communities from the beginning to the end applying a One Health approach to allow the possible sustained and best impacts.

High frequency of Taenia solium antigen positivity in patients admitted for neurological disorders in the Rural Hospital of Mosango, Democratic Republic of Congo.

BACKGROUND: The epidemiology of human cysticercosis and neurocysticercosis, caused by the larval stage of the pork tapeworm Taenia solium, is not well known in the Democratic Republic of Congo (DRC). Within a multicenter etiological and diagnostic study conducted by the NIDIAG consortium ("Better Diagnosis for Neglected Infections") and investigating several challenging syndromes, we consecutively evaluated from 2012 to 2015 all patients older than 5 years presenting with neurological disorders (neurology cohort) and with fever > 7 days (persistent fever cohort) at the rural hospital of Mosango, province of Kwilu, DRC. In both cohorts, etiological diagnosis relied on a systematic set of reference laboratory assays and on pre-established clinical case definitions. No neuroimaging was available in the study hospital. In this study, we determined the frequency of T. solium infection in both cohorts and explored in the neurology cohort its association with specific neurological presentations and final etiological diagnoses. METHODS: We conducted a post-hoc descriptive and analytic study on cysticercosis in the neurology and persistent fever cohorts, based on the presence in serum samples of circulating T. solium antigen using the B158/B60 enzyme-linked immunosorbent assay (ELISA) and of cysticercosis IgG using the LDBIO Cysticercosis Western Blot IgG assay. RESULTS: For the neurology cohort, 340 samples (of 351 enrolled patients) were available for analysis (males: 46.8%; mean age: 38.9 years). T. solium antigen positivity was found in 43 participants (12.6%; 95% confidence interval [CI] 9.3-16.7%), including 9 of 60 (15%) patients with epilepsy. Among the 148 samples available from the persistent fever cohort (males: 39.9%; mean age: 19.9 years), 7 were positive in the T. solium antigen ELISA (4.7%; 95% CI 1.9-9.5%; P = 0.009 when compared to the neurology cohort). No significant association was found within the neurology cohort between positivity and clinical presentation or final diagnoses. Of note, the IgG antibody-detecting assay was found positive in only four (1.3%) of the participants of the neurology cohort and in none of the persistent fever cohort. CONCLUSIONS: T. solium antigen positivity was found in at least 10% of patients admitted with neurological disorders in the Kwilu province, DRC, with no specific pattern of presentation. Further neuroimaging studies should be used to confirm whether neurocysticercosis is prevalent in this region.

Molecular characterization of Cysticercus tenuicollis isolates from sheep in the Nile Delta, Egypt and a review on Taenia hydatigena infections worldwide.

The predator­prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

Prevalence and risk factors of Taenia hydatigena in dogs, pigs, and cattle in the Central Highlands of Vietnam.

Taenia hydatigena is a globally distributed canine tapeworm. The canine tapeworm results in economic impacts for farmers owing to organ condemnation. T. hydatigena utilizes dogs and other carnivores as definitive hosts while swine and ruminants serve as intermediate hosts. T. hydatigena is endemic in Vietnam; however, information on the prevalence and risk factors associated with infection is scarce. This cross-sectional study aims to identify the prevalence of T. hydatigena taeniasis in dogs and T. hydatigena cysticercosis in pigs and cattle. The risk factors associated with taeniasis in dogs were identified using a fixed effects logistic regression model and quantified using population attributable fractions. The prevalence of T. hydatigena taeniasis in dogs and T. hydatigena cysticercosis in pigs and cattle was 10.31% (95% CI 8.21 to 12.84%), 7.60% (95% CI 6.34 to 9.08%), and 11.11% (95% CI 7.63 to 11.81%), respectively; these levels were lower than those reported in other regions of Vietnam. The population attributable fraction of risk factors associated with T. hydatigena taeniasis in dogs for dogs living in proximity of an abattoir, those having access to raw pork or beef viscera, and those living in multi-dog households were 80%, 19%, and 7%, respectively. This current study identified and quantified the risk factors for taeniasis in dogs thus advocating for targeted community intervention programs to break the lifecycle of T. hydatigena in Dak Lak province.

Human Taeniasis and Cysticercosis and Related Factors in Phu Tho Province, Northern Vietnam.

Several factors presumed to facilitate the transmission of Taenia spp. were reported in Vietnam. We conducted a cross-sectional study taking questionnaires from 1,185 participants, and collecting 1,151 sera and 1,036 stool samples in northern Vietnam. Sera were examined for circulating antigens of Taenia solium cysticerci using ELISA, stools for Taenia eggs by Kato-Katz smear, and copro-antigens by ELISA. Ag-ELISA revealed 4.6% antigen positivity, indicating infection with viable cysticerci. Taenia eggs were detected in 1.5% of participants. Copro-antigens were found in 2.8% of participants. Eating raw meat and/or vegetables was significantly associated with the presence of copro-antigen (OR=8.6, 95% CI: 1.16-63.9, P=0.01). Considering the high taeniasis prevalence and the associated threat, public health attention should be given to treat the tapeworm carriers in the projected areas.

Epidemiology of Taenia solium infection in the Russian Federation in the last 20 years: a systematic review.

Taenia solium is a zoonotic parasite that causes taeniasis and cysticercosis in humans (as final hosts) and cysticercosis in pigs (as intermediate hosts). The Russian Federation (RF) is traditionally considered as endemic for this zoonosis. However, the epidemiological data on T. solium infection have not been reviewed for the past 20 years, in which time dynamic economical and societal changes have occurred in the RF. The aim of this systematic review was to analyse the status of T. solium infection in RF in the 2000-2019 period. A literature search was conducted, which collected published articles, grey literature and official data on the epidemiology of T. solium taeniasis and cysticercosis in the RF published from 2000. From a total of 2021 articles and 24 official reports originally returned by the search, data were extracted from 12 full text articles and 11 official reports. Taenia solium taeniasis was continuously reported in the RF between 2000 and 2019, with a tenfold decrease in the incidence, from 0.2 per 100,000 population in 2000 to 0.023/100,000 in 2019. Also, the number of administrative units where taeniasis was detected continuously decreased. Cysticercosis in pigs had a declining trend after 2006. In conclusion, although decreasing, T. solium infection is still endemic in several regions and suspected to be endemic in most of the RF.

Consumer knowledge and practices to pork safety in two Taenia solium cysticercosis endemic districts in Eastern Cape Province of South Africa.

BACKGROUND: Globally, Taenia solium can cause cysticercosis in humans (including neurocysticercosis) and in pigs through ingestion of eggs and taeniasis in humans through ingestion of raw/undercooked pork contaminated with mature cysts. It is now recognised globally as one of the most prevalent food-borne parasitic diseases. The majority of cases have been reported in developing countries where consumption of food produced under unhygienic conditions is prevalent, exacerbated by lack of food safety education. The aim of this study was to determine the knowledge and practices of consumers towards pork safety in two districts of the Eastern Cape Province of South Africa, where T. solium cysticercosis is endemic in pigs and humans. METHODS: Three-hundred-and-sixty-one (361) participants were conveniently interviewed on consumer knowledge (harmfulness of T. solium cysticercosis, ability to identify cysts, trustworthiness of registered butcheries and legal requirements) and practices (storage of pork and method(s) of cooking pork safely) through a structured questionnaire. Chi-square for association of variables was used to compare differences in the districts. RESULTS: Overall, 73.1% of the study group from both districts agreed that pork forms an important part of their diet. Consumers (54.2%: 189/349) agreed that pork infected with T. solium cysts could be harmful, and 57.3% (188/328) indicated their inability to identify T. solium cysts in pork when slaughtered at home. Although 69.5% (234/352) trusted pork bought from butcheries, only 52.2% (187/358) were aware that butcheries must present a registration certificate in order to operate. This coincides with the fact that very few (< 10%) were aware of the legal requirements in terms of disease control, slaughter and food preparation. Most consumers (88.7%: 268/302) kept pork in the fridge and only 11.3% (34/302) kept it in a freezer (p = 0.02). Although not significantly different between the districts (p = 0.15), consumers in Alfred Nzo (71.4%: 152/213) and OR Tambo (61.2%: 74/12) mostly cooked pork as a stew, followed by braai/barbeque and frying or baking. This was in line with the fact that consumers in Alfred Nzo (79%: 147/186) and OR Tambo (80.8%: 120) preferred well-cooked pork; the main reason for this was the belief that cooking kills germs (43.6%: 121/277) followed by rendering the meat tasty (26.4%: 73/277). CONCLUSIONS: Consumers surveyed in the two districts were somewhat aware that T. solium cysticercosis could be harmful, although some were not able to identify T. solium cysts in pork. They also lacked sufficient knowledge regarding butchery certification and other legal requirements related to disease control, slaughter and food preparation. Practices related to cooking have the potential to promote the transmission of human taeniasis and the fact that most respondents preferred stewed pork could be a positive sign, as the cysts are destroyed during the cooking process. Results from this study are useful for the development of a control and prevention strategy targeted towards consumers, and the creation of awareness of food safety, with special emphasis on T, solium cysticercosis.

Morphometric, genetic diversity and phylogenetic analysis of Taenia hydatigena (Pallas, 1766) larval stage in Iranian livestock.

Cysticercus tenuicollis as metacestode of Taenia hydatigena is the most prevalent taeniid species in livestock. Eighty-eight C. tenuicollis samples were collected from sheep (n = 44) and goats (n = 44) of the northern Iran from 2015 to 2016. The isolated parasites were characterized by morphometric keys. The DNA of the larval stage was extracted, amplified and sequenced targeting mitochondrial 12S rRNA and Cox 1 markers. A significant difference in larval rostellar hook length was observed in 12S rRNA haplotypes. Analysis of molecular variance of 12S rRNA indicated a moderate genetic diversity in the C. tenuicollis isolates. The pairwise sequence distance of C. tenuicollis showed an intra-species diversity of 0.3-0.5% and identity of 99.5-100%. Using the 12S rRNA sequence data we found a moderate genetic difference (Fst; 0.05421) in C. tenucollis isolates collected from livestock of the northern and southeastern regions of Iran. We concluded that the genetic variants of C. tenuicollis are being undoubtedly distributing mostly in different parts of Iran. Further studies with a larger number of T. hydatigena isolates collected from various intermediate and definitive hosts are needed to study this evolutionary assumption and also to determine the apparent genetic differences observed in the studied regions.

Human Taeniases in Slovakia (2010-2019): Genetic Analysis of Taenia saginata Isolates.

Taenia saginata and Taenia solium, known as beef and pork tapeworm, are foodborne pathogens of global importance having a substantial impact on human health and economy. The study aimed to summarize the occurrence of human Taenia spp. infection in past 10 years in Slovakia based on reports of clinicians and diagnostic laboratories to Public Health Authority of the Slovak Republic. Altogether, 19 human cases were reported in Slovakia in 2010-2019, with the incidence of infection ranging from 0.00 to 0.12/100,000 inhabitants per year. In two patients T. saginata infection was confirmed molecularly. Nucleotide sequences of the analyzed nad1 gene fragments derived from both patients were identical and in a phylogenetic tree clustered together with T. saginata Tsa isolate (AM503345), as well as with a homologous sequence of the completely sequenced mitochondrial genome of T. saginata. Similarly, cox1 nucleotide sequences derived from one of the patients and isolates from Asia and/or Europe were identical. A cluster for cox1 partial gene sequence was placed separately from closely related Taenia asiatica and/or T. solium isolates in the phylogenetic tree.

Molecular Diagnosis of Taenia saginata Tapeworms from Two Residents of Northern Cambodia.

Taenia saginata infection has seldom been reported in Cambodia. In this study, we performed a survey of intestinal parasites in 1,156 residents of Preah Vihear and Stung Treng Provinces in 2018. The results revealed that 26 (2.4%) cases were positive for Taenia spp. eggs. In order to obtain the strobilae of the tapeworms, 2 patients in Preah Vihear were treated with praziquantel and purged with magnesium salts. The proglottids expelled after the medication were morphologically and molecularly analyzed to determine the species. The main uterine lateral braches in gravid proglottids were >15 in number suggesting that they are either T. saginata or Taenia asiatica. The sequences of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and 2 nuclear loci, elongation factor-1 alpha (ef1) and ezrin-radixin-moesin-like protein (elp), were identical to the sequences of T. saginata available in GenBank but distant from Taenia solium, T. asiatica, and T. saginata-T. asiatica hybrid. This is the first report of the presence of T. saginata in the northern part of Cambodia bordering Lao PDR based on a molecular confirmation.

Occurrence of Taenia species in pigs in slaughterhouses in Phu Tho province, northern Vietnam.

Pigs act as the intermediate hosts of the zoonotic tapeworms Taenia solium and Taenia asiatica, as well as of the non-zoonotic Taenia hydatigena. In Vietnam, human taeniasis and cysticercosis have been reported throughout the country; however, data on porcine cysticercosis are scarce. Our study aimed to estimate the prevalence of Taenia spp. in slaughtered pigs in two districts in Phu Tho, a mountainous province in northern Vietnam from where neurocysticercosis patients commonly originate. The carcasses of 399 pigs from 51 small-scale abattoirs were checked for cysticerci, while tongue, liver, masseter muscles, diaphragm and heart were sliced and examined. Retrieved cysticerci underwent polymerase chain reaction-restriction fragment length polymorphism and sequencing for species confirmation. Blood was also collected to detect antibodies by lentil lectin-purified glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP-EITB) and recombinant T24H antigen (rT24H)-EITB and circulating antigens by B158/B60 Ag-ELISA. In two pigs, T. asiatica cysticerci were found, confirming the presence of the parasite in pigs in Vietnam at a low prevalence (0.5%; 95% exact confidence interval (CI): 0-1.19%). Cysticerci of T. solium were found in none of the pigs, although one serum sample was positive for antibodies in both LLGP-EITB and rT24H-EITB. Furthermore, a high prevalence of T. hydatigena cysticercosis was observed (18.0%; 95% Wilson score CI: 14.6-22.1%). In more than half of the T. hydatigena-positive pigs, circulating antigens were detected by Ag-ELISA, confirming that this test cannot be used to diagnose T. solium cysticercosis in this region. Finally, Spirometra erinaceieuropaei was found in one pig liver. It is the first record of this zoonotic cestode species in pigs in Vietnam. Overall, the findings confirmed the complex epidemiology of Taenia spp. in pigs in Vietnam.

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.

Stepwise approach for the control and eventual elimination of Taenia solium as a public health problem.

BACKGROUND: Taenia solium taeniosis/cysticercosis is a public health and agricultural problem, especially in low-income countries, and has been ranked the top foodborne parasitic hazard globally. In 2012, the World Health Organization published a roadmap that called for a validated strategy for T. solium control and elimination by 2015. This goal has not been met, and validated evidence of effective control or elimination in endemic countries is still incomplete. Measuring and evaluating success of control programmes remains difficult, as locally acceptable targets have not been defined as part of the 2012 roadmap nor from other sources, and the performance of tools to measure effect are limited. DISCUSSION: We believe that an international agreement supported by the tripartite World Health Organization, Food and Agriculture Organization of the United Nations, and World Organisation for Animal Health is needed to facilitate endemic countries in publicising SMART (Specific, Measurable, Achievable/attainable, Relevant, Time-bound) country-level control target goals. These goals should be achievable through locally acceptable adoption of options from within a standardised 'intervention tool-kit', and progress towards these goals should be monitored using standardised and consistent diagnostics. Several intervention tools are available which can contribute to control of T. solium, but the combination of these - the most effective control algorithm - still needs to be identified. In order to mount control efforts and ensure political commitment, stakeholder engagement and funding, we argue that a stepwise approach, as developed for Rabies control, is necessary if control efforts are to be successful and sustainable. CONCLUSIONS: The stepwise approach can provide the framework for the development of realistic control goals of endemic areas, the implementation of intervention algorithms, and the standardised monitoring of the evaluation of the progress towards obtaining the control target goals and eventually elimination.

Prevalence and clinical outcomes of Plasmodium falciparum and intestinal parasitic infections among children in Kiryandongo refugee camp, mid-Western Uganda: a cross sectional study.

BACKGROUND: The prevalence of Plasmodium falciparum and Intestinal Parasitic Infections (IPIs) - with the corresponding pathogenesis among children remain uncertain. This study aimed at determining the prevalence and the outcomes (including anaemia) of the respective infections and co-infections. Anaemia is a condition in which the number of red blood cells transporting oxygen to the various body parts is not sufficient to meet the needs of the body. METHODS: This was a cross sectional study conducted among 476-refugee camp school children. Kato-Katz technique was used to screen stool samples for intestinal parasites. Microscopy was used for malaria testing while the portable Haemoglobin (Hb) calorimeter was used to measure haemoglobin concentration. RESULTS: The overall prevalence of the mixed infections was 63.03%. Plasmodium falciparum was most prevalent of the single infections 262(55.04%) followed by Taenia spp. 14 (2.9%), Schistosoma mansoni 12(2.5%), Giardia lamblia 7 (2.9%), Trichuris trichiura 2(0.4%), Hookworm 2(0.4%) and Strongyloides stercoralis 1(0.2%). The odds of developing simple or uncomplicated malaria infection or anaemia was 14 times higher in individuals with dual co-infection with Plasmodium falciparum + Taenia sp. compared to single parasitic infection (Odds = 14.13, P = 0.019). Co-infection with Plasmodium falciparum + Taenia spp, was a strong predictor of Malaria and anaemia. CONCLUSION: This study shows that Plasmodium falciparum and Taenia spp. co-infections is a stronger predictor of malaria and anaemia. The prevalence of malaria and anaemia remains higher than the other regions in Uganda outside restricted settlements. The findings of this study underline the need for pragmatic intervention programmes to reduce burden of the co-infections in the study area and similar settlements.

Parasites and epilepsy: Understanding the determinants of epileptogenesis.

There is a large body of evidence suggesting that parasites could be a major preventable risk factor for epilepsy in low- and middle-income countries. We review potentially important substrates for epileptogenesis in parasitic diseases. Taenia solium is the most widely known parasite associated with epilepsy, and the risk seems determined mainly by the extent of cortical involvement and the evolution of the primary cortical lesion to gliosis or to a calcified granuloma. For most parasites, however, epileptogenesis is more complex, and other favorable host genetic factors and parasite-specific characteristics may be critical. In situations where cortical involvement by the parasite is either absent or minimal, parasite-induced epileptogenesis through an autoimmune process seems plausible. Further research to identify important markers of epileptogenesis in parasitic diseases will have huge implications for the development of trials to halt or delay onset of epilepsy.