Taenia solium cysticercosis in West Africa: status update

Cysticercosis is caused by the larvae of the cestode Taenia solium. Few data are available on the prevalence of this disease in pigs and humans in West African countries. The aim of this study was to provide an overview of existing data concerning the spread of this parasitosis in the countries of the Economic Community of West African States (ECOWAS) on the basis of the literature published over the last five decades. Systematic searches for publications were carried out on PubMed and Google Scholar, as well as in certain regional and local journals. From a total of 501 articles initially retrieved concerning T. solium cysticercosis in West African countries, only 120 articles were relevant for this review and therefore finally retained. For pigs, only eight out of sixteen countries of the region have reported porcine cysticercosis. Post-mortem examination of carcasses at slaughterhouses, meat inspection at butcheries or tongue inspection in herds have been the main source of data, but may not entirely reflect actual parasite distribution. For humans, only five out of sixteen countries reported epidemiological data on neurocysticercosis. Most data referred to neurocysticercosis prevalence among epileptic patients or isolated clinical cases. Furthermore, existing data are often old. Overall, T. solium cysticercosis remains largely neglected in West Africa, and its prevalence appears not to be affected by any religion in particular. There is an urgent need to promote and implement health partnerships and programs on this disease in order to collect more data and identify sensitive populations in the countries of the ECOWAS area

Development of recombinant antigens for the serodiagnosis of cysticercosis

La cysticercose est une infection parasitaire causée par le stade larvaire (métacestode) de Taenia solium (T. solium). Le cycle de vie de T. solium est complexe nécessitant deux hôtes mammifères : le porc et l'homme sont les hôtes intermédiaires, alors que seul l'homme est l’hôte définitif. L’homme développe le téniase par le biais de : (i) la consommation de viande de porc crue ou peu cuite contenant des larves de ténia; (ii) l'ingestion accidentelle d'œufs par voie oro-fécale. Lorsque les larves sont localisées dans le cerveau, l’infection est appelée neurocysticercose (NCC), une cause fréquente d'épilepsie acquise dans les régions endémiques d'Amérique latine, d'Inde, d'Asie, d'Afrique et d'Europe de l'Est. Le diagnostic précis de la NCC est basé sur la neuroimagerie et le test sérologique. Le test de référence est enzyme-linked immunoelectransfer blot utilisant des glycoprotéines purifiées par lectine de lentille (LLGP-EITB). Dans les zones d'endémie, les laboratoires ne sont pas bien équipés et les techniques d'imagerie ne sont pas accessibles à la population à risque. Le test de diagnostic rapide (TDR) de la cysticercose utilisant des antigènes recombinants très sensibles et spécifiques peut servir d'alternative pour orienter les patients suspects de NCC vers la neuroimagerie et d'autres tests. Dans la présente étude, nous avons produit des protéines recombinantes à partir de T. solium et évalué leur performance (sensibilité et spécificité) en utilisant le test enzyme-linked immunosorbent assay (ELISA). Les résultats ont été comparés au test de référence afin de déterminer les meilleurs antigènes candidats pour le sérodiagnostic de la cysticercose.Cysticercosis is a parasitic infection caused by the larval stage (metacestode) of Taenia solium (T. solium). The life cycle of T. solium is complex and requires two mammalian hosts: pigs and humans are intermediate hosts, whereas only humans are definitive hosts. Humans develop taeniasis through: (i) the consumption of raw or undercooked pork containing tapeworm larvae; (ii) the accidental ingestion of eggs via the fecal-oral route. When larvae are located in the brain, the infection is called neurocysticercosis (NCC), a frequent cause of acquired epilepsy in endemic regions of Latin America, India, Asia, Africa and Eastern Europe. Accurate diagnosis of NCC is based on neuroimaging and serological test. The gold standard is the enzyme-linked immunoelectransfer blot using lentil lectin-purified glycoproteins (LLGP-EITB). In endemic areas, laboratories are poorly equipped and imaging techniques are not accessible to the population at risk. Rapid diagnostic test (RDT) for cysticercosis using high sensitive and specific recombinant antigens can serve as alternative to refer patients with suspected NCC for neuroimaging and further tests. In the present study, we produced recombinant proteins from T. solium and evaluated their performance (sensitivity and specificity) using enzyme-linked immunosorbent assay (ELISA). The results were compared to the gold standard test to determine the best candidate antigens for serodiagnosis of cysticercosis

La cysticercose à Taenia solium en Afrique de l’Ouest : état des lieux

International audienceCysticercosis is caused by the larvae of the cestode Taenia solium. Few data are available on the prevalence of this disease in pigs and humans in West African countries. The aim of this study was to provide an overview of existing data concerning the spread of this parasitosis in the countries of the Economic Community of West African States (ECOWAS) on the basis of the literature published over the last five decades. Systematic searches for publications were carried out on PubMed and Google Scholar, as well as in certain regional and local journals. From a total of 501 articles initially retrieved concerning T. solium cysticercosis in West African countries, only 120 articles were relevant for this review and therefore finally retained. For pigs, only eight out of sixteen countries of the region have reported porcine cysticercosis. Post-mortem examination of carcasses at slaughterhouses, meat inspection at butcheries or tongue inspection in herds have been the main source of data, but may not entirely reflect actual parasite distribution. For humans, only five out of sixteen countries reported epidemiological data on neurocysticercosis. Most data referred to neurocysticercosis prevalence among epileptic patients or isolated clinical cases. Furthermore, existing data are often old. Overall, T. solium cysticercosis remains largely neglected in West Africa, and its prevalence appears not to be affected by any religion in particular. There is an urgent need to promote and implement health partnerships and programs on this disease in order to collect more data and identify sensitive populations in the countries of the ECOWAS area

Production and evaluation of a new set of recombinant antigens for the serological diagnosis of human cysticercosis

International audienceHuman cysticercosis caused by Taenia soliun (T. soliun) is endemic in certain areas of Latin America, Asia and Sub-Saharan Africa. Neurocysticercosis (NCC) is mainly diagnosed by neuroimaging, which, in most cases, is unavailable in endemic areas. Due to their high sensitivity and specificity, serological tests such as enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) based on the glycosylated fraction of the cyst CS50 are widely used for the detection of the anti-cysticercus IgG antibodies despite their significant cost and the need of cysticercus material. Given their cost-effectivess and simplicity, immunoassays based on recombinant proteins could provide new alternatives for human cysticercosis diagnosis: such tests would be aimed at screening those people living in remote areas who need further examination. To date, however, no test using recombinant antigens is commercially available.Herein, five recombinant proteins (R14, R18, R93.1, R914.1, and R915.2) were produced, three of which (R93.1, R914.1, and R915.2) were newly identified from the cyst fluid. Evaluation of the diagnostic performance of these recombinant antigens by ELISA was done using sera from 200 epileptic and non-epileptic individuals in comparison with the WB-CS50 as the reference serological method.Recombinant proteins-based ELISA showed a level of diagnostic performance that is inferior than the reference serological method, but similar to that of the native antigen ELISA for human cysticercosis (commonly used for screening). Further optimization of expression conditions is still needed in order to improve proteins solubility and enhance diagnostic performance for human cysticercosis detection. However, this preliminary evaluation of the recombinant antigens has shown their potential valuable use for screening cysticercosis in patients with epilepsy attending dispensaries in remote areas. Future studies should be conducted to evaluate our recombinant antigens in a large group of patients with different stages of NCC, and in correlation with imaging findings

Détermination des performances de l'association de tests Elisa et Western Blot pour le diagnostic de la cysticercose porcine en Côte d'Ivoire

International audienceSerological diagnosis of cysticercosis allows a detection of the disease on living pigs. It routinely uses Elisa as ascreening test and Western blot (Eitb) as a confirmatory test. The aim of this study was to assess the performance of the Elisa/ Eitb association in order to improve decision-making for the control of this pathology in Côte d’Ivoire. A group of 246 ofsamples of pigs serums, divided into 123 negative for Elisa and 123 positive for Elisa were drawn at random and were analyzedby the Western blot test. Thus, a contingency table was used to analyze the characteristics of the screening test (Elisa) throughthe parameters of sensitivity (Sp), specificity (Sp). These performances of diagnostic of the combination of Elisa / Eitb tests wasevaluated according to texts design in serial or mixed-strategy. The data obtained for these two patterns were compared. Theoverall results showed good sensitivity (Se = 76.2%) with average specificity (Sp = 55.4%). The diagnostic performanceevaluation of the combination of Elisa / Eitb tests gave 13% serial positives and 17% in the mixed regimen, a difference of 4%.Also, on a total of 123 sreums negatives analyzed by Eitb, 10 or (8.13%) were found positives, corresponding to a loss linked tothe screening of samples by Elisa.Le diagnostic sérologique de la cysticercose permet une détection de la maladie chez les porcs vivants. Il utilise couramment l’Elisa comme test de screening et le Western blot (Eitb) comme test de confirmation. L’objectif de cette étude était d’évaluer les performances de l ’association Elisa / Eitb afin d’améliorer les prises de décision pour le contrôle de cette pathologie en Côte d’Ivoire. Un ensemble de 246 échantillons de sérums porcs, repartis en 123 négatifs en Elisa et 123 positifs en Elisa ont été tirés au hasard et ont été analysés par le test de Western blot. Ainsi, un tableau de contingences a servi à l’analyse des caractéristiques du test de screening (Elisa) à travers les paramètres de sensibilité (Sp), spécificité (Sp). Ces performances de diagnostic de l’association des tests Elisa / Eitb ont été évaluées selon les schémas de test en série ou de stratégie mixte. Les données obtenues pour ces deux schémas ont été comparées. Les résultats globaux ont montré une bonne sensibilité (Se = 76,2%) avec une spécificité moyenne (Sp = 55,4%). L’évaluation des performances de diagnostic de l’association des tests Elisa / Eitb ont donné 13% de positifs en série et 17% en schéma mixte soit un écart de 4%. Aussi, sur un total, 123 sérums négatifs analysés par Eitb, 10 soit (8,13%) se sont révélés positifs, correspondant une perte liée au screening des échantillons par l’Elisa

Serodiagnosis of human cysticercosis for epidemiological studies in low-income countries is the ELISA "screening" strategy accurate

International audienceBackground: Serodiagnosis of cysticercosis uses two serological tests, ELISA and Western blot, which are carried on sequentially.Only the samples positive in Elisa are confirmed with Western blot. The objective of this study was to assess the agreement betweenthe ELISA and Western blot to evaluate false negative generate by ELISA alone. Methods: This is a retrospective study conductedon samples randomly drawn at random from a serum bank constituted during two cross-sectional surveys carried out in thedepartments of Dabou and Agboville, in the south of Côte d'Ivoire. These two sero-epidemiological studies were conducted onrandomly selected asymptomatic subjects. The sera selected for this ancillary study were all tested using both native antigen Elisaand western blot methods. Western blot (EITB) was used as reference test. Sensitivity, specificity, false positive and false negativerates of the Elisa test were determined against EITB results. Results: A total of 594 sera (297 positives / 297 negatives in ELISA),were tested by Western blot. The sensitivity and specificity of the ELISA were 82.6% and 79.5%, respectively. The false negativeand false positive rates of ELISA were 16.5% and 21.6%, respectively. A strong agreement was observed between these two testswith a Cohen's Kappa value equal to 0.62. Conclusion: These data reveal that the Elisa test alone is not sufficient for theserodiagnosis of cysticercosis. When used for diagnosis in symptomatic patient, ELISA alone is not sufficient to avoid thediagnostic. Elisa-negative patient who presents a critical clinical picture must be tested by Western blot

Cross-sectional Study on Traditional Pork Rearing Practices and Cysticercosis in the South Part of Ivory Coast

Posted 24 Aug, 2020 on Research SquareInternational audienceIn West africa, pig meat know as pork is often supplied by traditional farms in rural areas. This pratice causes important sanitary risk by lack of veterinary control of farms and slaughterhouses in rural areas. The objective of this study was to describe pig husbandry practices used in southern Côte d'Ivoire in order to establish a surveillance system for cysticercosis disease. This survey was carried out among traditional pig breeders living in villages of the district of Dabou, Aboisso and Agboville. The data collected focused on the profile of producers and on the characteristics of the farms. A total of 321 breeders have been identified (Dabou 72 (22.4%), Aboisso 26 (8.1%) and Agboville 223 (69.5%)). Most of the herders were male (87.8%). A total of 3663 heads of pigs were counted with a majority of young pigs (60.2%) and females (29.3%) for 10.5% of male breeders. The local race was predominant (80.6 %) for only 15.5% of half-caste races. Most of the farms used permanent divagation rearing (53.3%). Following investigation of the herds, pigs were randomly samples in all the villages of the three areas using quota methods. Animals were blood sampled and serums were analyzed using Ac-ELISA and Western Blot. Among 639 animals selected, 13,20 % had antibodies against cysticercosis with large variations from one village to another. The study highlights that, in this region, pig farming remains essentially traditional, with free grazing of animals which constitutes a major sanitary risk especially for Taenia solium

Seroprevalence of Cysticercosis among Epileptic Patients Attending Neurological Units in the Urban Area of Abidjan

International audienceCysticercosis is one of the main causes of secondary epilepsy in sub-Saharan Africa. To estimate the seroprevalence of cysticercosis among epileptic patients, we conducted a cross-sectional study of patients attending neurology consultation in Abidjan, Côte d’Ivoire. Methods: Patients’ socio-demographic and lifestyle data were collected as well as blood samples for serological testing using ELISA and Western blot based on IgG antibodies detection. For qualitative variables comparison, Chi2 or Fisher tests were used; a Student’s t-test was used to compare quantitative variables. A multivariate logistic regression model was fit to identify risks factors. Results: Among 403 epileptic patients included in the study, 55.3% were male; the median age was 16.9 years; 77% lived in Abidjan; 26.5% were workers. Most patients included in the study had tonic-clonic seizures (80%), and 11.2% had focal deficit signs. The seroprevalence of cysticercosis was 6.0%. The risk was higher in patients over 30 years old (aOR = 5.1 (1.3–20.0)) than in patients under 16. The risk was also considerably high in patients who reported epileptics in the family (aOR = 5 (1.7–14.6)). The risk was three-fold less in females than in males. Conclusions: This study highlighted the exposure of epileptic patients to Taenia solium larvae in an urban area. The risk of positive serology was increased with age, male gender, and family history of epilepsy

Seroprevalence of porcine cysticercosis in traditional farms in South-Eastern Côte d'Ivoire

Background: Porcine cysticercosis is an endemic parasitic zoonosis in many developing countries. The objective of this study was to estimate the seroprevalence of porcine cysticercosis in traditional pig farms in the departments of Dabou, Aboisso and Agboville. Methods: Blood samples were taken from pigs and analyzed by ELISA (IgG) and western blot. Data on farming practices and pig characteristics were collected. Multivariate logistic regression models were constructed to identify risk factors. Results: A total of 668 pigs were sampled from 116 farms and 639 samples were analyzed. The seroprevalence of cysticercosis was estimated at 13.2%. Overweight [OR = 2.6; 95%CI (1.3–4.9)] and fat pigs [OR = 2.3; 95%CI (1.0–4.8)] were twice as likely to be seropositive for cysticercosis. This risk was increased in farms using well water for drinking [OR = 2.5; 95%CI (1.0–6.3)] as well as those reporting veterinary care of the animals (OR = 2.9; 95%CI (1.2–7.3)). Conclusions: This study demonstrated the circulation of Taenia solium in pig farms in southern Côte d'Ivoire