Purpose Neurocysticercosis is common in regions endemic for Taenia solium. Active-stage neurocyst... more Purpose Neurocysticercosis is common in regions endemic for Taenia solium. Active-stage neurocysticercosis can be treated with antiparasitic medication, but so far no study on efficacy and safety has been conducted in Africa. Methods We conducted a prospective cohort study on treatment of neurocysticercosis in Tanzania between August 2018 and January 2022. Patients were initially treated with albendazole (15 mg/kg/d) for 10 days and followed up for 6 months. Additionally in July 2021, all participants who then still had cysts were offered a combination therapy consisting of albendazole (15 mg/kg/d) and praziquantel (50 mg/kg/d). Antiparasitic treatment was accompanied by corticosteroid medication and anti-seizure medication if the patient had experienced epileptic seizures before treatment. Results Sixty-three patients were recruited for this study, of whom 17 had a complete follow-up after albendazole monotherapy. These patients had a total of 138 cysts at baseline, of which 58 (42...
Journal of preventive and rehabilitative medicine, Oct 6, 2020
Background: Neurocysticercosis is a leading cause of epilepsy in Taenia solium endemic regions of... more Background: Neurocysticercosis is a leading cause of epilepsy in Taenia solium endemic regions of the world accounting for about 30% of all epileptic cases. The main aim of this study was to do a Comparison of Serologic Diagnosis of Taeniosis and Cysticercosis in Field Samples from Eastern Zambia. Methods: Retrospectively collected Samples through community-based cross sectional and longitudinal studies which looked at the prevalence and incidence of human T. solium infections, respectively, and described in earlier reports were selected for this laboratory based study. Samples, with coproantigen ELISA and serum antigen ELISA which the results were known were randomly selected for this study. Results: A total of 886 serum samples were analyzed. The rT24 /rES33 EITB detected a taeniosis and cysticercosis prevalence of 5.9% and 9.5%, respectively. On performance the Kappa statistics revealed a fair agreement of rT4/rES33 EITB (Kappa value of 0.2781-0.2117) compared to coproantigen ELISA and serum antigen ELISA. Although there is not a good agreement between the antibody and antigen test. Conclusion: This study found that the performance of rT4/rES33 EITB compared to coproantigen ELISA and serum antigen ELISA were fair and because the agreement was not good between the antibody and antigen test the, selection of a test must be carefully made, with consideration of what is needed.
EFECAB (Epidemiologie et Fardeau Economique de la Cysticercosis au Burkina) was initiated in 2006... more EFECAB (Epidemiologie et Fardeau Economique de la Cysticercosis au Burkina) was initiated in 2006 with a grant funded through the Brain Disorders in the developing world - Research Across the lifespan program of the National Institutes of Health in the United States (R21NS055353) followed by a more substantial grant in 2010 (R01NS064901). The pilot grant showed that human and porcine cysticercosis were not only present in Burkina Faso, but more prevalent in two of three pilot villages. A cluster randomized controlled trial was subsequently conducted to estimate the effectiveness of a community-based educational intervention to reduce the frequency of cysticercosis in 60 villages located in 3 provinces where pigs were raised. The intervention was developed using an implementation research method which resulted in offering the Participatory Hygiene And Sanitation Transformation - Self-esteem Associative strengths Resourcefulness Action planning Responsibility approach, adapted for cys...
Background Diagnostic test evaluation includes measures of performance and assessment of operatio... more Background Diagnostic test evaluation includes measures of performance and assessment of operational characteristics. The latter focuses on end-user understanding of instructions to perform the test, ease of use, test turnaround time and ease of result interpretation. This study aimed to assess user comprehension of training for and ease of use of a Taenia solium point of care test (TS POC) evaluated in a community and hospital setting in Zambia and Tanzania, respectively. Methods The TS POC is a three-step in-house-produced rapid diagnostic test (RDT) for the simultaneous detection of taeniosis (TST) and cysticercosis (TSCC) antibodies. Data collected by administering questionnaires to 29 end-users and from the main evaluation database was analyzed quantitatively. Results End-users (28/29, 97%) perceived that the training they received for performing the test was sufficient. They performed 4080 tests, of which 80 were invalid. The community-based study and TST tests had higher inva...
C o r r e s p o n d e n c e Potential Elimination of Active Taenia solium Transmission in Africa ... more C o r r e s p o n d e n c e Potential Elimination of Active Taenia solium Transmission in Africa To the Editor: Taeniasis and cysticercosis due to Taenia solium are major foodborne parasitic zoonoses that severely affect public health, social, and economic sectors, with the burden of neurocysticercosis estimated at 2,788,426 disabilityadjusted life-years. 1 A study involving an integrated intervention program in humans and pigs showed elimination of transmission of T. solium in Peru. 2 This study provided important proof of concept; however, similar studies of T. solium elimination have not been completed in sub-Saharan Africa, where the prevalence of this infection and the level of poverty are higher than in Peru. 3 We conducted the CYSTISTOP study (Clinical Trials.gov number, NCT02612896), which involved a 2-year integrated intervention in humans and pigs in eastern Zambia, where taeniasis and cysticercosis are hyperendemic, to evaluate the feasibility of eliminating T. solium in sub-Saharan Africa. The prevalence of porcine cysticercosis (the primary outcome measure, as determined by carcass dissection) and the prevalence of hu
Taenia spp. are responsible for a substantial health and economic burden in affected populations.... more Taenia spp. are responsible for a substantial health and economic burden in affected populations. Knowledge of the fate of the eggs of Taenia spp. in the environment and of other factors facilitating the transmission of eggs to intermediate hosts is important for the control/elimination of infections caused by Taenia spp. The aim of this systematic review was to summarize current knowledge of the factors influencing the survival and dispersal of Taenia spp. eggs in the environment. Publications retrieved from international databases were systematically reviewed. Of the 1465 papers initially identified, data were ultimately extracted from 93 papers. The results of this systematic review indicate that survival is favoured at moderate temperatures (0–20 °C). Humidity seems to affect the survival of Taenia spp. eggs more than temperature. Under field circumstances, Taenia spp. eggs have been found to survive for up to 1 year. Taenia spp. eggs are commonly found on vegetables (0.9–30%) a...
Infections with Taenia solium cause significant public health and economic losses worldwide. Desp... more Infections with Taenia solium cause significant public health and economic losses worldwide. Despite effective control tools, long-term sustained control/elimination of the parasite has not been demonstrated to date. Success of intervention programs is dependent on their acceptability to local communities. Focus group discussions (FGDs) and questionnaires (QS) were conducted in two study communities in eastern Zambia to assess local perceptions and acceptance of two piloted intervention strategies: one targeting pigs only ('control' study arm), and one integrated human-and pig-based ('elimination') strategy. QS (n = 227) captured data regarding participation in project activities, knowledge and perceptions of T. solium and of the interventional drugs used in the study. FGDs (n = 18) discussed perceived advantages and disadvantages of the interventions and of the project's delivery and value. QS data revealed 67% of respondents participated in at least one educational activity, and 80% correctly identified at least one disease targeted by the education. All elimination study arm respondents (n = 113) had taken the human treatment, and 98% intended to do so next time. Most (70%) indicated willingness to pay for future treatments (median 0.20 USD per dose). Of pig-owning respondents, 11/12 (92%) had allowed their pigs to be treated/vaccinated and all intended to do so again next time. Four pig owners indicated willingness to pay 0.10-0.50 USD per dose of treatment or vaccine. FGD feedback revealed positive perceptions of interventions; people reported improved health in themselves and their pigs, and fewer cysticerci in pork. Latrine use, hand washing, meat inspection and proper cooking of pork had reportedly increased since the program's inception. Preliminary assessment indicates that the piloted intervention methods are generally acceptable to the communities. The reported willingness of many respondents to pay for the medications would contribute to the feasibility of long-term, government-led T. solium intervention programs in future. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Background Taenia solium is a neglected zoonotic parasite endemic throughout many low-income coun... more Background Taenia solium is a neglected zoonotic parasite endemic throughout many low-income countries worldwide, including Zambia, where it causes human and pig diseases with high health and socioeconomic burdens. Lack of knowledge is a recognized risk factor, and consequently targeted health educational programs can decrease parasite transmission and disease occurrence in endemic areas. Preliminary assessment of the computer-based education program 'The Vicious Worm' in rural areas of eastern Zambia indicated that it was effective at increasing knowledge of T. solium in primary school students. The aim of this study was to evaluate the impact of 'The Vicious Worm' on knowledge retention by reassessing the same primary school students one year after the initial education workshops. Methodology/Principal findings Follow-up questionnaires were administered in the original three primary schools in eastern Zambia in 2017, 12 months after the original workshops. In total, 86 pupils participated in the follow-up sessions, representing 87% of the initial workshop respondents. Knowledge of T. solium at 'follow-up' was significantly higher than at the initial 'pre' questionnaire administered during the Vicious Worm workshop that took place one year earlier. While some specifics of the parasite's life cycle were not completely understood, the key messages for
BackgroundTaenia solium taeniasis/(neuro)cysticercosis is a neglected parasitic zoonosis with sig... more BackgroundTaenia solium taeniasis/(neuro)cysticercosis is a neglected parasitic zoonosis with significant economic and public health impacts. Neurocysticercosis is responsible for 30% cases of acquired epilepsy in endemic areas. Diagnosis and case management of neurocysticercosis/taeniasis in resource-limited endemic countries is challenging. Reliable, inexpensive and easy to use diagnostic tools with sufficient sensitivity and specificity are currently not available. A new point-of-care (POC) test based on recombinant rT24H and rES33 proteins developed by the Centre for Disease Control in Atlanta (US) which combines diagnosis of taeniasis and cysticercosis has been developed, however, its performance at community level is not known. The aim of this study is therefore, to evaluate the diagnostic performance of this test in a community setting.MethodsThe study site is Mtandaza community, Sinda district, Eastern Province of Zambia. The diagnostic accuracy is being evaluated for taenia...
Background Individuals diagnosed with neurocysticercosis often present with epilepsy and sometime... more Background Individuals diagnosed with neurocysticercosis often present with epilepsy and sometimes with progressively worsening severe chronic headaches (WSCH). While cross-sectional associations between seropositivity to cysticercal antigens and epilepsy have been reported, few large scale studies have been conducted in West Africa and none have measured the association between seropositivity to cysticercal antigens and headaches. This study aimed at filling these knowledge gaps by estimating the strength of the cross-sectional association between seropositivity to cysticercal antigens and the prevalence of epilepsy and WSCH in 60 villages of Burkina Faso, West Africa. Methodology/Principal findings Baseline data from a cluster randomized controlled trial collected from January 2011 to February 2012 in 60 villages across three provinces in Burkina Faso were used. Between 78 and 80 individuals were screened for epilepsy and WSCH in each village, and those screened positive were confirmed by a physician. Seventy-five percent of all participants were asked to provide a blood sample to test for Taenia solium cysticercus circulating antigens. Hierarchical multivariable logistic models were used to measure the association
Background The effectiveness of drug-free interventions in controlling human cysticercosis is not... more Background The effectiveness of drug-free interventions in controlling human cysticercosis is not well known. We aimed to estimate the effectiveness of a community-based educational intervention in reducing the frequency of human cysticercosis in Burkina Faso. Methods We did a cluster-randomised controlled trial between 2011 and 2014. 60 eligible villages from three provinces (Boulkiemdé, Sanguié, and Nayala) were randomly allocated to the intervention or control group. Villages raising pigs, that were not a regional capital or located on a main road, that were more than 20 km from Ouagadougou or 5 km from one another, were eligible. In each village, 60 participants were asked for blood samples at baseline, 18 months later (before randomisation), and 18 months after randomisation. Villages were block randomised (1:1) by pig-raising department immediately after the pre-randomisation visit. The intervention aimed to improve knowledge of Taenia solium transmission and control through screening and structured discussion of a 52-min movie, and to increase community self-efficacy through a Self-esteem, Associative strengths, Resourcefulness, Action planning, Responsibility (SARAR) approach via the Participatory Hygiene and Sanitation Transformation (PHAST) model. The primary outcome was active cysticercosis, defined as the presence of circulating antigens detected by use of B158/B60 ELISA. Effectiveness measured at the village level was estimated by use of three Bayesian hierarchical models. This study is registered with ClinicalTrials.gov, number NCT0309339. Findings Two villages in the same randomisation block were excluded, resulting in a final sample size of 58 villages. Overall, the intervention tended towards a decrease in the cumulative incidence of active cysticercosis from baseline to after randomisation (adjusted cumulative incidence ratio 0•65, 95% Bayesian credible interval [95% CrI] 0•39-1•05) and a decrease in active cysticercosis prevalence from baseline to after randomisation (adjusted prevalence proportion ratio 0•84; 95% CrI 0•59-1•18). The intervention was shown to be effective in Nayala and Sanguié but not in Boulkiemdé. Interpretation Community-engaged participatory interventions can be effective at reducing the incidence and prevalence of cysticercosis in some low-resource settings.
Cognitive impairment and quality of life (Qol) are important to assess the burden of epilepsy and... more Cognitive impairment and quality of life (Qol) are important to assess the burden of epilepsy and neurocysticercosis (NCC), which are common but neglected in Sub-Saharan Africa (SSA). The aims of this study were to assess cognitive performance and Qol of people with epilepsy (PWE) in Zambia and to explore differences in PWE with and without NCC. In this community based, cross-sectional case-control-study, 47 PWE and 50 healthy controls completed five neuropsychological tests (Mini Mental State Examination (MMSE), Digit Span, Selective Reminding Test (SRT), Spatial Recall Test (SPART), Test Battery of Attentional Performance (TAP)) and a World Health Organization (WHO) questionnaire of Qol. Comparisons were made between PWE (n=47) and healthy controls (n=50) and between PWE with NCC (n=28) and without NCC (n=19), respectively, using Analysis of Covariance (ANCOVA) and Linear Models (LMs) while correcting for confounders such as age, sex, and schooling years, and adjusting for multipl...
Why pigs are free-roaming: Communities' perceptions, knowledge and practices regarding pig manage... more Why pigs are free-roaming: Communities' perceptions, knowledge and practices regarding pig management and taeniosis/cysticercosis in a Taenia solium endemic rural area in Eastern Zambia.Veterinary Parasitology http://dx.
Le « DALY Calculator » est disponible via le package « DALY » en R. Installation Pour télécharger... more Le « DALY Calculator » est disponible via le package « DALY » en R. Installation Pour télécharger et installer ce package, tapez la commande suivante dans la console R: install.packages("DALY") Chaque fois que vous souhaitez utiliser « DALY Calculator », le package « DALY » doit être chargé dans l'environment R, en tapant la commande suivante dans la console R: library(DALY) Mise en route Pour calculer des DALYs avec le « DALY Calculator », les cinq étappes suivantes doivent être suivies: Output Par défaut, la moyenne, la médiane et un intervalle de crédibilité à 95% des AVPs, AVIs, DALYs et des cas d'incidents et de décès seront imprimés sur la console R. En plus, un histogramme des DALYs avec distribution de densité et intervalle de crédibilité sera affiché. Des sorties numériques et graphiques plus avancées peuvent être obtenues en enregistrant la sortie du « DALY Calculator » à un objet R, qui peut être manipulé dans l'environnement R.
A community-based longitudinal study was performed in the Eastern Province of Zambia, in which re... more A community-based longitudinal study was performed in the Eastern Province of Zambia, in which repeated serological samplings were done to determine the incidence of human cysticercosis. Three sampling rounds were carried out at six months intervals. A total of 867 participants presented for all three samplings. All samples were tested for the presence of cysticercus antigens using a monoclonal antibody-based enzyme-linked immunosorbent assay (sero-Ag-ELISA), while a randomly selected sub-sample of 161 samples from each sampling round was tested for specific antibodies using a commercial enzyme-linked immunoelectrotransfer blot (EITB) assay. Stool samples (n = 226) were also collected during the final round of sampling for taeniosis diagnosis by coprology and coproantigen ELISA. Cysticercosis seroprevalence varied from 12.2% to 14.5% (sero-Ag) and from 33.5% to 38.5% (sero-Ab) during the study period. A taeniosis prevalence of 11.9% was determined. Incidence rates of 6300 (sero-Ag, per 100000 persons-year) and 23600 (sero-Ab, per 100000 persons-year) were determined. Seroreversion rates of 44% for sero-Ag and 38.7% for sero-Ab were recorded over the whole period. In conclusion, this study has shown the dynamic nature of T. solium infections; many of the people at risk become (re)infected due to the high environmental contamination, with a high number turning seronegative within a year after infection. An important number of infections probably never fully establish, leading to transient antibody responses and short-term antigen presence.
Purpose-To estimate the association between the prevalence of epilepsy and potential risk factors... more Purpose-To estimate the association between the prevalence of epilepsy and potential risk factors in three Burkina Faso villages. Methods-Three villages were selected based on local reports of high numbers of epilepsy cases and pig-rearing practices. One person aged 7 or older was selected at random from all households of selected concessions for epilepsy screening and blood sampling. Epilepsy was confirmed by a physician using the ILAE definition. The cross-sectional associations between epilepsy and selected factors and sero-response to the antigens of Taenia solium were estimated using a Bayesian hierarchical logistic regression. Prevalence odds ratios (POR) and their 95% Credible Intervals (95%BCI) were estimated. Results-Of 888 individuals interviewed, 39 of 70 screened positive were confirmed to have epilepsy for a lifetime prevalence of 4.5% (95%CI: 3.3-6.0). The prevalence of epilepsy was associated with a positive reaction to cysticercosis Ag-ELISA serology (POR=3.1, 95% BCI= 1.0;8.3), past pork consumption (POR=9.7, 95% BCI=2.5;37.9), and being salaried or a trader compared to a farmer or housewife (POR=2.9, 95% BCI= 1.2;6.4).
Taenia solium is a neglected zoonotic parasite. The performances of existing tools for the diagno... more Taenia solium is a neglected zoonotic parasite. The performances of existing tools for the diagnosis of porcine cysticercosis need further assessment, and their shortcomings call for alternatives. The objective of this study was to evaluate the performance of tongue palpation and circulating antigen detection for the detection of porcine cysticercosis in naturally infected pigs of slaughter age compared to full carcass dissections (considered the gold standard). Additionally, alternative postmortem dissection procedures were investigated. A total of 68 rural pigs of slaughter age randomly selected in the Eastern Province of Zambia were dissected. Dissections were conducted on full carcasses (or half carcass in case cysticerci were already detected in the first half), including all the organs. Total cysticercus counts, location and stages were recorded and collected cysticerci were identified morphologically and molecularly. All sera were analysed with the B158/B60 antigen detecting ...
The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapi... more The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapid diagnostic tests for cysticercosis. The new prototype two-strip, Taenia solium point of care test (TS POC) detects antibodies against taeniosis (TS POC T) and cysticercosis (TS POC CC). This study evaluated the diagnostic performance of the TS POC CC in the Sinda district in eastern Zambia. A sample of 1254 participants was recruited and tested with the TS POC. Out of the 1249 participants with a valid TS POC result, 177 (14%) tested positive while 1072 (86%) tested negative. All individuals with a positive TS POC and a subset of negative TS POC participants were selected for serum sampling, and were subjected to the recombinant glycoprotein T24H enzyme-linked immunoelectrotransfer blot (rT24H EITB) and the serum B60/158 (serum Ag) enzyme-linked immunosorbent assay (Ag ELISA). Performance characteristics were estimated using a Bayesian approach with probabilistic constraints. Based on ...
Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/... more Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/or are expensive, require sophisticated equipment, infrastructure and trained manpower, and therefore are not community deployable. A recently-developed, multi-strip, T. solium point-of-care test (TS POC) for simultaneous detection of tapeworm (TS POC T) and cysticercus (TS POC CC) human antibodies was evaluated for diagnostic accuracy on consecutively recruited community participants in Sinda district, Zambia. All participants were tested using the TS POC test. All test-positives and 20% of the test-negative participants were invited to give a blood and stool sample for reference testing. Three different reference tests were used for taeniosis diagnosis: recombinant rES33 enzyme-linked immunoelectrotransfer blot (rES33 EITB), copro PCR and copro Ag ELISA. Bayesian analysis with probabilistic constraints was used to estimate sensitivity and specificity. In total, 1254 participants were t...
Purpose Neurocysticercosis is common in regions endemic for Taenia solium. Active-stage neurocyst... more Purpose Neurocysticercosis is common in regions endemic for Taenia solium. Active-stage neurocysticercosis can be treated with antiparasitic medication, but so far no study on efficacy and safety has been conducted in Africa. Methods We conducted a prospective cohort study on treatment of neurocysticercosis in Tanzania between August 2018 and January 2022. Patients were initially treated with albendazole (15 mg/kg/d) for 10 days and followed up for 6 months. Additionally in July 2021, all participants who then still had cysts were offered a combination therapy consisting of albendazole (15 mg/kg/d) and praziquantel (50 mg/kg/d). Antiparasitic treatment was accompanied by corticosteroid medication and anti-seizure medication if the patient had experienced epileptic seizures before treatment. Results Sixty-three patients were recruited for this study, of whom 17 had a complete follow-up after albendazole monotherapy. These patients had a total of 138 cysts at baseline, of which 58 (42...
Journal of preventive and rehabilitative medicine, Oct 6, 2020
Background: Neurocysticercosis is a leading cause of epilepsy in Taenia solium endemic regions of... more Background: Neurocysticercosis is a leading cause of epilepsy in Taenia solium endemic regions of the world accounting for about 30% of all epileptic cases. The main aim of this study was to do a Comparison of Serologic Diagnosis of Taeniosis and Cysticercosis in Field Samples from Eastern Zambia. Methods: Retrospectively collected Samples through community-based cross sectional and longitudinal studies which looked at the prevalence and incidence of human T. solium infections, respectively, and described in earlier reports were selected for this laboratory based study. Samples, with coproantigen ELISA and serum antigen ELISA which the results were known were randomly selected for this study. Results: A total of 886 serum samples were analyzed. The rT24 /rES33 EITB detected a taeniosis and cysticercosis prevalence of 5.9% and 9.5%, respectively. On performance the Kappa statistics revealed a fair agreement of rT4/rES33 EITB (Kappa value of 0.2781-0.2117) compared to coproantigen ELISA and serum antigen ELISA. Although there is not a good agreement between the antibody and antigen test. Conclusion: This study found that the performance of rT4/rES33 EITB compared to coproantigen ELISA and serum antigen ELISA were fair and because the agreement was not good between the antibody and antigen test the, selection of a test must be carefully made, with consideration of what is needed.
EFECAB (Epidemiologie et Fardeau Economique de la Cysticercosis au Burkina) was initiated in 2006... more EFECAB (Epidemiologie et Fardeau Economique de la Cysticercosis au Burkina) was initiated in 2006 with a grant funded through the Brain Disorders in the developing world - Research Across the lifespan program of the National Institutes of Health in the United States (R21NS055353) followed by a more substantial grant in 2010 (R01NS064901). The pilot grant showed that human and porcine cysticercosis were not only present in Burkina Faso, but more prevalent in two of three pilot villages. A cluster randomized controlled trial was subsequently conducted to estimate the effectiveness of a community-based educational intervention to reduce the frequency of cysticercosis in 60 villages located in 3 provinces where pigs were raised. The intervention was developed using an implementation research method which resulted in offering the Participatory Hygiene And Sanitation Transformation - Self-esteem Associative strengths Resourcefulness Action planning Responsibility approach, adapted for cys...
Background Diagnostic test evaluation includes measures of performance and assessment of operatio... more Background Diagnostic test evaluation includes measures of performance and assessment of operational characteristics. The latter focuses on end-user understanding of instructions to perform the test, ease of use, test turnaround time and ease of result interpretation. This study aimed to assess user comprehension of training for and ease of use of a Taenia solium point of care test (TS POC) evaluated in a community and hospital setting in Zambia and Tanzania, respectively. Methods The TS POC is a three-step in-house-produced rapid diagnostic test (RDT) for the simultaneous detection of taeniosis (TST) and cysticercosis (TSCC) antibodies. Data collected by administering questionnaires to 29 end-users and from the main evaluation database was analyzed quantitatively. Results End-users (28/29, 97%) perceived that the training they received for performing the test was sufficient. They performed 4080 tests, of which 80 were invalid. The community-based study and TST tests had higher inva...
C o r r e s p o n d e n c e Potential Elimination of Active Taenia solium Transmission in Africa ... more C o r r e s p o n d e n c e Potential Elimination of Active Taenia solium Transmission in Africa To the Editor: Taeniasis and cysticercosis due to Taenia solium are major foodborne parasitic zoonoses that severely affect public health, social, and economic sectors, with the burden of neurocysticercosis estimated at 2,788,426 disabilityadjusted life-years. 1 A study involving an integrated intervention program in humans and pigs showed elimination of transmission of T. solium in Peru. 2 This study provided important proof of concept; however, similar studies of T. solium elimination have not been completed in sub-Saharan Africa, where the prevalence of this infection and the level of poverty are higher than in Peru. 3 We conducted the CYSTISTOP study (Clinical Trials.gov number, NCT02612896), which involved a 2-year integrated intervention in humans and pigs in eastern Zambia, where taeniasis and cysticercosis are hyperendemic, to evaluate the feasibility of eliminating T. solium in sub-Saharan Africa. The prevalence of porcine cysticercosis (the primary outcome measure, as determined by carcass dissection) and the prevalence of hu
Taenia spp. are responsible for a substantial health and economic burden in affected populations.... more Taenia spp. are responsible for a substantial health and economic burden in affected populations. Knowledge of the fate of the eggs of Taenia spp. in the environment and of other factors facilitating the transmission of eggs to intermediate hosts is important for the control/elimination of infections caused by Taenia spp. The aim of this systematic review was to summarize current knowledge of the factors influencing the survival and dispersal of Taenia spp. eggs in the environment. Publications retrieved from international databases were systematically reviewed. Of the 1465 papers initially identified, data were ultimately extracted from 93 papers. The results of this systematic review indicate that survival is favoured at moderate temperatures (0–20 °C). Humidity seems to affect the survival of Taenia spp. eggs more than temperature. Under field circumstances, Taenia spp. eggs have been found to survive for up to 1 year. Taenia spp. eggs are commonly found on vegetables (0.9–30%) a...
Infections with Taenia solium cause significant public health and economic losses worldwide. Desp... more Infections with Taenia solium cause significant public health and economic losses worldwide. Despite effective control tools, long-term sustained control/elimination of the parasite has not been demonstrated to date. Success of intervention programs is dependent on their acceptability to local communities. Focus group discussions (FGDs) and questionnaires (QS) were conducted in two study communities in eastern Zambia to assess local perceptions and acceptance of two piloted intervention strategies: one targeting pigs only ('control' study arm), and one integrated human-and pig-based ('elimination') strategy. QS (n = 227) captured data regarding participation in project activities, knowledge and perceptions of T. solium and of the interventional drugs used in the study. FGDs (n = 18) discussed perceived advantages and disadvantages of the interventions and of the project's delivery and value. QS data revealed 67% of respondents participated in at least one educational activity, and 80% correctly identified at least one disease targeted by the education. All elimination study arm respondents (n = 113) had taken the human treatment, and 98% intended to do so next time. Most (70%) indicated willingness to pay for future treatments (median 0.20 USD per dose). Of pig-owning respondents, 11/12 (92%) had allowed their pigs to be treated/vaccinated and all intended to do so again next time. Four pig owners indicated willingness to pay 0.10-0.50 USD per dose of treatment or vaccine. FGD feedback revealed positive perceptions of interventions; people reported improved health in themselves and their pigs, and fewer cysticerci in pork. Latrine use, hand washing, meat inspection and proper cooking of pork had reportedly increased since the program's inception. Preliminary assessment indicates that the piloted intervention methods are generally acceptable to the communities. The reported willingness of many respondents to pay for the medications would contribute to the feasibility of long-term, government-led T. solium intervention programs in future. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Background Taenia solium is a neglected zoonotic parasite endemic throughout many low-income coun... more Background Taenia solium is a neglected zoonotic parasite endemic throughout many low-income countries worldwide, including Zambia, where it causes human and pig diseases with high health and socioeconomic burdens. Lack of knowledge is a recognized risk factor, and consequently targeted health educational programs can decrease parasite transmission and disease occurrence in endemic areas. Preliminary assessment of the computer-based education program 'The Vicious Worm' in rural areas of eastern Zambia indicated that it was effective at increasing knowledge of T. solium in primary school students. The aim of this study was to evaluate the impact of 'The Vicious Worm' on knowledge retention by reassessing the same primary school students one year after the initial education workshops. Methodology/Principal findings Follow-up questionnaires were administered in the original three primary schools in eastern Zambia in 2017, 12 months after the original workshops. In total, 86 pupils participated in the follow-up sessions, representing 87% of the initial workshop respondents. Knowledge of T. solium at 'follow-up' was significantly higher than at the initial 'pre' questionnaire administered during the Vicious Worm workshop that took place one year earlier. While some specifics of the parasite's life cycle were not completely understood, the key messages for
BackgroundTaenia solium taeniasis/(neuro)cysticercosis is a neglected parasitic zoonosis with sig... more BackgroundTaenia solium taeniasis/(neuro)cysticercosis is a neglected parasitic zoonosis with significant economic and public health impacts. Neurocysticercosis is responsible for 30% cases of acquired epilepsy in endemic areas. Diagnosis and case management of neurocysticercosis/taeniasis in resource-limited endemic countries is challenging. Reliable, inexpensive and easy to use diagnostic tools with sufficient sensitivity and specificity are currently not available. A new point-of-care (POC) test based on recombinant rT24H and rES33 proteins developed by the Centre for Disease Control in Atlanta (US) which combines diagnosis of taeniasis and cysticercosis has been developed, however, its performance at community level is not known. The aim of this study is therefore, to evaluate the diagnostic performance of this test in a community setting.MethodsThe study site is Mtandaza community, Sinda district, Eastern Province of Zambia. The diagnostic accuracy is being evaluated for taenia...
Background Individuals diagnosed with neurocysticercosis often present with epilepsy and sometime... more Background Individuals diagnosed with neurocysticercosis often present with epilepsy and sometimes with progressively worsening severe chronic headaches (WSCH). While cross-sectional associations between seropositivity to cysticercal antigens and epilepsy have been reported, few large scale studies have been conducted in West Africa and none have measured the association between seropositivity to cysticercal antigens and headaches. This study aimed at filling these knowledge gaps by estimating the strength of the cross-sectional association between seropositivity to cysticercal antigens and the prevalence of epilepsy and WSCH in 60 villages of Burkina Faso, West Africa. Methodology/Principal findings Baseline data from a cluster randomized controlled trial collected from January 2011 to February 2012 in 60 villages across three provinces in Burkina Faso were used. Between 78 and 80 individuals were screened for epilepsy and WSCH in each village, and those screened positive were confirmed by a physician. Seventy-five percent of all participants were asked to provide a blood sample to test for Taenia solium cysticercus circulating antigens. Hierarchical multivariable logistic models were used to measure the association
Background The effectiveness of drug-free interventions in controlling human cysticercosis is not... more Background The effectiveness of drug-free interventions in controlling human cysticercosis is not well known. We aimed to estimate the effectiveness of a community-based educational intervention in reducing the frequency of human cysticercosis in Burkina Faso. Methods We did a cluster-randomised controlled trial between 2011 and 2014. 60 eligible villages from three provinces (Boulkiemdé, Sanguié, and Nayala) were randomly allocated to the intervention or control group. Villages raising pigs, that were not a regional capital or located on a main road, that were more than 20 km from Ouagadougou or 5 km from one another, were eligible. In each village, 60 participants were asked for blood samples at baseline, 18 months later (before randomisation), and 18 months after randomisation. Villages were block randomised (1:1) by pig-raising department immediately after the pre-randomisation visit. The intervention aimed to improve knowledge of Taenia solium transmission and control through screening and structured discussion of a 52-min movie, and to increase community self-efficacy through a Self-esteem, Associative strengths, Resourcefulness, Action planning, Responsibility (SARAR) approach via the Participatory Hygiene and Sanitation Transformation (PHAST) model. The primary outcome was active cysticercosis, defined as the presence of circulating antigens detected by use of B158/B60 ELISA. Effectiveness measured at the village level was estimated by use of three Bayesian hierarchical models. This study is registered with ClinicalTrials.gov, number NCT0309339. Findings Two villages in the same randomisation block were excluded, resulting in a final sample size of 58 villages. Overall, the intervention tended towards a decrease in the cumulative incidence of active cysticercosis from baseline to after randomisation (adjusted cumulative incidence ratio 0•65, 95% Bayesian credible interval [95% CrI] 0•39-1•05) and a decrease in active cysticercosis prevalence from baseline to after randomisation (adjusted prevalence proportion ratio 0•84; 95% CrI 0•59-1•18). The intervention was shown to be effective in Nayala and Sanguié but not in Boulkiemdé. Interpretation Community-engaged participatory interventions can be effective at reducing the incidence and prevalence of cysticercosis in some low-resource settings.
Cognitive impairment and quality of life (Qol) are important to assess the burden of epilepsy and... more Cognitive impairment and quality of life (Qol) are important to assess the burden of epilepsy and neurocysticercosis (NCC), which are common but neglected in Sub-Saharan Africa (SSA). The aims of this study were to assess cognitive performance and Qol of people with epilepsy (PWE) in Zambia and to explore differences in PWE with and without NCC. In this community based, cross-sectional case-control-study, 47 PWE and 50 healthy controls completed five neuropsychological tests (Mini Mental State Examination (MMSE), Digit Span, Selective Reminding Test (SRT), Spatial Recall Test (SPART), Test Battery of Attentional Performance (TAP)) and a World Health Organization (WHO) questionnaire of Qol. Comparisons were made between PWE (n=47) and healthy controls (n=50) and between PWE with NCC (n=28) and without NCC (n=19), respectively, using Analysis of Covariance (ANCOVA) and Linear Models (LMs) while correcting for confounders such as age, sex, and schooling years, and adjusting for multipl...
Why pigs are free-roaming: Communities' perceptions, knowledge and practices regarding pig manage... more Why pigs are free-roaming: Communities' perceptions, knowledge and practices regarding pig management and taeniosis/cysticercosis in a Taenia solium endemic rural area in Eastern Zambia.Veterinary Parasitology http://dx.
Le « DALY Calculator » est disponible via le package « DALY » en R. Installation Pour télécharger... more Le « DALY Calculator » est disponible via le package « DALY » en R. Installation Pour télécharger et installer ce package, tapez la commande suivante dans la console R: install.packages("DALY") Chaque fois que vous souhaitez utiliser « DALY Calculator », le package « DALY » doit être chargé dans l'environment R, en tapant la commande suivante dans la console R: library(DALY) Mise en route Pour calculer des DALYs avec le « DALY Calculator », les cinq étappes suivantes doivent être suivies: Output Par défaut, la moyenne, la médiane et un intervalle de crédibilité à 95% des AVPs, AVIs, DALYs et des cas d'incidents et de décès seront imprimés sur la console R. En plus, un histogramme des DALYs avec distribution de densité et intervalle de crédibilité sera affiché. Des sorties numériques et graphiques plus avancées peuvent être obtenues en enregistrant la sortie du « DALY Calculator » à un objet R, qui peut être manipulé dans l'environnement R.
A community-based longitudinal study was performed in the Eastern Province of Zambia, in which re... more A community-based longitudinal study was performed in the Eastern Province of Zambia, in which repeated serological samplings were done to determine the incidence of human cysticercosis. Three sampling rounds were carried out at six months intervals. A total of 867 participants presented for all three samplings. All samples were tested for the presence of cysticercus antigens using a monoclonal antibody-based enzyme-linked immunosorbent assay (sero-Ag-ELISA), while a randomly selected sub-sample of 161 samples from each sampling round was tested for specific antibodies using a commercial enzyme-linked immunoelectrotransfer blot (EITB) assay. Stool samples (n = 226) were also collected during the final round of sampling for taeniosis diagnosis by coprology and coproantigen ELISA. Cysticercosis seroprevalence varied from 12.2% to 14.5% (sero-Ag) and from 33.5% to 38.5% (sero-Ab) during the study period. A taeniosis prevalence of 11.9% was determined. Incidence rates of 6300 (sero-Ag, per 100000 persons-year) and 23600 (sero-Ab, per 100000 persons-year) were determined. Seroreversion rates of 44% for sero-Ag and 38.7% for sero-Ab were recorded over the whole period. In conclusion, this study has shown the dynamic nature of T. solium infections; many of the people at risk become (re)infected due to the high environmental contamination, with a high number turning seronegative within a year after infection. An important number of infections probably never fully establish, leading to transient antibody responses and short-term antigen presence.
Purpose-To estimate the association between the prevalence of epilepsy and potential risk factors... more Purpose-To estimate the association between the prevalence of epilepsy and potential risk factors in three Burkina Faso villages. Methods-Three villages were selected based on local reports of high numbers of epilepsy cases and pig-rearing practices. One person aged 7 or older was selected at random from all households of selected concessions for epilepsy screening and blood sampling. Epilepsy was confirmed by a physician using the ILAE definition. The cross-sectional associations between epilepsy and selected factors and sero-response to the antigens of Taenia solium were estimated using a Bayesian hierarchical logistic regression. Prevalence odds ratios (POR) and their 95% Credible Intervals (95%BCI) were estimated. Results-Of 888 individuals interviewed, 39 of 70 screened positive were confirmed to have epilepsy for a lifetime prevalence of 4.5% (95%CI: 3.3-6.0). The prevalence of epilepsy was associated with a positive reaction to cysticercosis Ag-ELISA serology (POR=3.1, 95% BCI= 1.0;8.3), past pork consumption (POR=9.7, 95% BCI=2.5;37.9), and being salaried or a trader compared to a farmer or housewife (POR=2.9, 95% BCI= 1.2;6.4).
Taenia solium is a neglected zoonotic parasite. The performances of existing tools for the diagno... more Taenia solium is a neglected zoonotic parasite. The performances of existing tools for the diagnosis of porcine cysticercosis need further assessment, and their shortcomings call for alternatives. The objective of this study was to evaluate the performance of tongue palpation and circulating antigen detection for the detection of porcine cysticercosis in naturally infected pigs of slaughter age compared to full carcass dissections (considered the gold standard). Additionally, alternative postmortem dissection procedures were investigated. A total of 68 rural pigs of slaughter age randomly selected in the Eastern Province of Zambia were dissected. Dissections were conducted on full carcasses (or half carcass in case cysticerci were already detected in the first half), including all the organs. Total cysticercus counts, location and stages were recorded and collected cysticerci were identified morphologically and molecularly. All sera were analysed with the B158/B60 antigen detecting ...
The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapi... more The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapid diagnostic tests for cysticercosis. The new prototype two-strip, Taenia solium point of care test (TS POC) detects antibodies against taeniosis (TS POC T) and cysticercosis (TS POC CC). This study evaluated the diagnostic performance of the TS POC CC in the Sinda district in eastern Zambia. A sample of 1254 participants was recruited and tested with the TS POC. Out of the 1249 participants with a valid TS POC result, 177 (14%) tested positive while 1072 (86%) tested negative. All individuals with a positive TS POC and a subset of negative TS POC participants were selected for serum sampling, and were subjected to the recombinant glycoprotein T24H enzyme-linked immunoelectrotransfer blot (rT24H EITB) and the serum B60/158 (serum Ag) enzyme-linked immunosorbent assay (Ag ELISA). Performance characteristics were estimated using a Bayesian approach with probabilistic constraints. Based on ...
Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/... more Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/or are expensive, require sophisticated equipment, infrastructure and trained manpower, and therefore are not community deployable. A recently-developed, multi-strip, T. solium point-of-care test (TS POC) for simultaneous detection of tapeworm (TS POC T) and cysticercus (TS POC CC) human antibodies was evaluated for diagnostic accuracy on consecutively recruited community participants in Sinda district, Zambia. All participants were tested using the TS POC test. All test-positives and 20% of the test-negative participants were invited to give a blood and stool sample for reference testing. Three different reference tests were used for taeniosis diagnosis: recombinant rES33 enzyme-linked immunoelectrotransfer blot (rES33 EITB), copro PCR and copro Ag ELISA. Bayesian analysis with probabilistic constraints was used to estimate sensitivity and specificity. In total, 1254 participants were t...
Uploads
Papers by Pierre Dorny