Athanase Millogo

Seroprevalence to the Antigens of Taenia solium Cysticercosis among Residents of Three Villages in Burkina Faso: A Cross-Sectional Study

Background There is limited published information on the prevalence of human cysticercosis in West Africa. The aim of this pilot study was to estimate the prevalence of Taenia solium cysticercosis antigens in residents of three villages in Burkina Faso. Methods/Principal Findings Three villages were selected: The village of Batondo, selected to represent villages where pigs are allowed to roam freely; the village of Pabré, selected to represent villages where pigs are usually confined; and the village of Nyonyogo, selected because of a high proportion of Muslims and limited pig farming. Clustered random sampling was used to select the participants. All participants were asked to answer an interview questionnaire on socio-demographic characteristics and to provide a blood sample. The sera were analysed using an AgELISA. The prevalence of “strong” seropositive results to the presence of antigens of the larval stages of T. solium was estimated as 10.3% (95%CI: 7.1%–14.3%), 1.4% (0.4%–3.5%) and 0.0% (0.0%–2.1%) in the 763 participants who provided a blood sample in Batondo, Pabré and Nyonyogo, respectively. The prevalence of “weak” seropositive test results to the presence of antigens of the larval stages of T. solium was 1.3% (0.3%–3.2%), 0.3% (0.0%–1.9%) and 4.5% (2.0%–8.8%) in Batondo, Pabré and Nyonyogo, respectively. The multivariate logistic regression, which included only Batondo and Pabré, showed that village, gender, and pork consumption history were associated with AgELISA seroprevalence. Conclusions/Significance This study illustrates two major points: 1) there can be large variation in the prevalence of human seropositivity to the presence of the larval stages of T. solium cysticercosis among rural areas of the same country, and 2) the serological level of the antigen, not just whether it is positive or negative, must be considered when assessing prevalence of human cysticercosis antigens.

Prevalence case-control study of epilepsy in three Burkina Faso villages.

To estimate the association between the prevalence of epilepsy and potential risk factors in three Burkina Faso villages.

Prevalence of neurocysticercosis among people with epilepsy in rural areas of Burkina Faso

Purpose:  To estimate the lifetime prevalence of neurocysticercosis (NCC)–associated epilepsy and the proportion of NCC among people with epilepsy in three Burkina Faso villages.

Occurrence of natural Anopheles arabiensis swarms in an urban area of Bobo-Dioulasso city, Burkina Faso, West Africa

The swarming behaviour of natural populations of Anopheles arabiensis was investigated by conducting transect surveys on 10 consecutive days, around dusk, from March to April and from September to October 2012 in Dioulassoba, a district of Bobo-Dioulasso city in Burkina Faso (West Africa). Swarms were observed outside, around identified larval breeding sites on the banks of the Houet River, as well as in the open-air courtyards found at the centre of many homes in the region. Swarms were found to occur in open sunlit spaces, mostly located above physical or visual cues somehow visually distinct from the surrounding area. Overall 67 and 78 swarms were observed, respectively, during the dry season (March-April) and the rainy season (September-October) of 2012, between 1.5m and 4.5m above the ground at their centre. 964 mosquitoes were collected and analysed from dry season swarms, of which most were male, and all were An. arabiensis, as were the few resting mosquitoes collected indoors. Larvae collected from breeding sites found on the banks of the Houet River mostly consisted of An. arabiensis and only a minority of Anopheles coluzzii (formerly identified as An. gambiae M form). Of 1694 mosquitoes analysed from 78 swarms in the rainy season collections, a few An. gambiae (formerly known as An. gambiae S form) males were identified, and the remainders were An. arabiensis. The majority of larvae collected during the wet season from the same breeding sites were identified as An. arabiensis followed by An. coluzzii and An. gambiae. The same pattern of species composition was observed in resting mosquitoes, though the proportion of An. arabiensis was less overwhelming. These data support the conclusion that An. arabiensis is the most prevalent species in this area, though the difference in species composition when using different population sampling techniques is noteworthy. Further studies are required for more detailed investigations of male dispersal, feeding behaviour and mating patterns in this urban setting.

Prevalence of and Factors Associated with Human Cysticercosis in 60 Villages in Three Provinces of Burkina Faso

Background Taenia solium, a zoonotic infection transmitted between humans and pigs, is considered an emerging infection in Sub-Saharan Africa, yet individual and community-level factors associated with the human infection with the larval stages (cysticercosis) are not well understood. This study aims to estimate the magnitude of association of individual-level and village-level factors with current human cysticercosis in 60 villages located in three Provinces of Burkina Faso. Methodology/Principal Findings Baseline cross-sectional data collected between February 2011 and January 2012 from a large community randomized-control trial were used. A total of 3609 individuals provided serum samples to assess current infection with cysticercosis. The association between individual and village-level factors and the prevalence of current infection with cysticercosis was estimated using Bayesian hierarchical logistic models. Diffuse priors were used for all regression coefficients. The prevalence of current cysticercosis varied across provinces and villages ranging from 0% to 11.5%. The results obtained suggest that increased age, being male and consuming pork as well as a larger proportion of roaming pigs and percentage of sand in the soil measured at the village level were associated with higher prevalences of infection. Furthermore, consuming pork at another village market had the highest increased prevalence odds of current infection. Having access to a latrine, living in a household with higher wealth quintiles and a higher soil pH measured at the village level decreased the prevalence odds of cysticercosis. Conclusions/Significance This is the first large-scale study to examine the association between variables measured at the individual-, household-, and village-level and the prevalence odds of cysticercosis in humans. Factors linked to people, pigs, and the environment were of importance, which further supports the need for a One Health approach to control cysticercosis infection.

Taenia hydatigena in pigs in Burkina Faso: A cross-sectional abattoir study.

Taenia hydatigena is a non-zoonotic cestode that has canines as definitive hosts and ruminants and pigs as intermediate hosts. In pigs, its presence causes cross-reactivity in serological testing for Taenia solium cysticercosis. Therefore, knowledge on the occurrence of T. hydatigena is paramount for validly estimating the seroprevalence of T. solium cysticercosis in pigs. In a cross-sectional abattoir study, we estimated the prevalence of T. hydatigena in pigs slaughtered in Koudougou, Burkina Faso. Carcasses of 452 pigs were examined by investigators for perceived and suspected T. hydatigena cysticercus lesions in the abdominal cavity or on the surface of abdominal organs. Routine meat inspection was performed by local inspectors to identify T. solium cysticerci. All lesions were subjected to PCR-RFLP analysis in order to differentiate Taenia spp. Additionally, individual blood samples were examined for the presence of circulating cysticercus antigens using the B158/B60 Ag-ELISA. Perceived T. hydatigena cysticerci were found in 13 pigs, whereas meat inspectors found seven carcasses infected with T. solium cysticerci. All were confirmed by molecular analysis. Of pigs with other suspected lesions, mostly located in the liver, 27 and six were found to harbour T. hydatigena and T. solium cysticerci, respectively. Overall, 8.8% of pigs (40/452) were found infected with T. hydatigena and 2.9% (13/452) with T. solium. Of these positive pigs, one was found infected with both Taenia spp. (0.2%, 1/452). Blood samples of 48.5% of pigs (219/452) were positive in the Ag-ELISA. Pigs with confirmed cysts of T. hydatigena and T. solium had a positive Ag-ELISA result in 57.5% (23/40) and 61.5% (8/13) of cases, respectively. The observed T. hydatigena prevalence in this study is relatively high in comparison to other studies in Africa. Estimates of the occurrence of active porcine T. solium infection using the B158/B60 Ag-ELISA should therefore be adjusted for the presence of T. hydatigena. The low level of T. solium infection detected upon meat inspection in this study is likely an underestimation of the true prevalence since routine meat inspection shows poor sensitivity and pigs perceived to be infected based on tongue palpation are rarely sent to official abattoirs.

Development of a health education intervention strategy using an implementation research method to control taeniasis and cysticercosis in Burkina Faso

BackgroundTaeniasis and cysticercosis are two diseases caused by Taenia solium, a parasite transmitted between humans and pigs, leading to considerable economic loss and disabilities. Transmission of the parasite is linked to environmental and behavioural factors such as inadequate sanitation and hygiene, poor pig management, and consumption of infected pork. This study used implementation research method to design a health education intervention strategy for reducing T. solium infections in Burkina Faso, a country endemic for the parasite.MethodsEighteen group discussions were conducted with 8–18 participants each in three villages. In addition, structured interviews were conducted among 4 777 participants and 2 244 pig owners, who were selected through cluster random sampling in 60 villages of three provinces of Burkina Faso. Both approaches assessed knowledge and practices related to T. solium. The information obtained was used to develop a community-adapted health education intervention strategy to control taeniasis and cysticercosis in Burkina Faso.ResultsThe group discussions revealed that participants had a poor quality of life due to the diseases as well as inadequate access to latrines, safe water, and healthcare services. In addition, it was found that pig production was an important economic activity, especially for women. Furthermore, financial and knowledge constraints were important limitations to improved pig management and latrine construction. The survey data also showed that open defecation and drinking unboiled water were common behaviours, enhanced by a lack of knowledge regarding the transmission of the parasite, perceived financial barriers to the implementation of control measures, lack of public sensitization, as well as a lack of self-efficacy towards control of the parasite. Nevertheless, the perceived financial benefits of controlling porcine cysticercosis could be emphasized by an education program that discourages open defecation and encourages drinking safe water. The final intervention strategy included a Participatory Hygiene and Sanitation Transformation (PHAST) approach, as well as a 52-min film and an accompanying comic booklet.ConclusionsThe main problem in the study communities regarding the transmission of T. solium cysticercosis is the random disposal of human faeces, which can be contaminated with parasite eggs. Prevention of open defecation requires the building of latrines, which can be quite problematic in economically challenged settings. Providing the community with the skills to construct durable latrines using low-cost locally available materials would likely help to resolve this problem. Further studies are required to implement and evaluate the T. solium control strategy developed in this study.

Clinical features and prognosis of amyotrophic lateral sclerosis in Africa: the TROPALS study

Objective We describe and compare the sociodemographic and clinical features, treatments, and prognoses and survival times of patients with amyotrophic lateral sclerosis (ALS) in Africa. Methodology We conducted a multicentre, hospital-based cohort study in Africa. Patients with ALS diagnosed in the neurology departments of participating hospitals from 2005 to 2017 were included. Subgroup analysis was performed by subcontinent. Survival analyses were conducted using the Cox proportional hazards model. Results Nine centres from eight African countries participated. A total of 185 patients with ALS were included: 114 from Northern Africa, 41 from Western Africa and 30 from Southern Africa. A male predominance (male to female ratio 2.9) was evident. The median age at onset was 53.0 years (IQR 44.5–64.0 years). The onset was bulbar in 22.7%. Only 47 patients (26.3%) received riluzole, mainly in Northern and Western Africa. The median survival from the time of diagnosis was 14.0 months (95% CI 10.7 to 17.2 months). The median survival was longer in Northern Africa (19.0 months, 95% CI 10.8 to 27.2 months) than in Western (4.0 months, 95% CI 0.8 to 7.1 months) and Southern (11.0 months, 95% CI 5.6 to 16.4 months) Africa (Breslow test, p<0.0001). Both subcontinental location and riluzole treatment independently affected survival. Conclusion More African patients with ALS were male and younger and exhibited a lower proportion of bulbar onset compared with patients with ALS from Western nations. Survival was consistent with that in Western registers but far shorter than what would be expected for young patients with ALS. The research improves our understanding of the disease in Africa.

Factors Associated with the 18-Month Cumulative Incidence of Seroconversion of Active Infection with Taenia solium Cysticercosis: A Cohort Study among Residents of 60 Villages in Burkina Faso

Abstract. Taeniasis/cysticercosis (CC) is an important disease complex with significant burden. This large-scale cohort study aimed at estimating and exploring individual- and village-level factors associated with the cumulative incidences of seroconversion (SC) and seroreversion (SR) of active human CC in three provinces of Burkina Faso. In 60 villages, blood samples were collected and interviews regarding sociodemographic variables and knowledge, attitude, and practices toward the disease complex were conducted at baseline and 18-month follow-up (N = 2,211), with the presence of active CC being determined using the B158/B60 antigen enzyme-linked immunosorbent assay (Ag-ELISA). The 18-month Ag SC and SR were estimated at 3.3% (95% confidence interval [CI]: 2.6; 4.2%) and 35.8% (95% CI: 24.5; 48.5%), respectively. Marked provincial differences were found for the 18-month Ag SC (Boulkiemde: cumulative incidence ratio [CIR]: 2.41 (95% CI: 1.21; 4.78) and Nayala: CIR: 3.28 (95% CI: 1.37; 7.84), compared with Sanguie), while not being significantly associated with other sociodemographic factors. A continued refraining from pork consumption was associated with a lower 18-month Ag SC (CIR: 0.55 [95% CI: 0.28; 1.07]), whereas at the village level, the percentage of households owning pigs was associated with a higher 18-month Ag SC (CIR: 1.03 [95% CI: 1.01; 1.05]). In conclusion, this is one of few cohort studies and the first to have enough power to assess possible causal links between individual- and village-level variables and CC in humans. Variables linked to province, pig raising, and pork consumption behaviors were found to cause Ag SC in humans. The latter results further support the importance of adopting a One Health approach to the control of CC.

Evaluating the Recombinant T24H Enzyme-Linked Immunoelectrotransfer Blot Assay for the Diagnosis of Neurocysticercosis in a Panel of Samples from a Large Community-Based Randomized Control Trial in 60 Villages in Burkina Faso

Current guidelines for the diagnosis of neurocysticercosis (NCC) recommend the use of the lentil lectin-bound glycoprotein enzyme-linked immunoelectrotransfer blot assay (LLGP-EITB) as the reference standard for serological testing. In response to the drawbacks involved with the use of the LLGP-EITB, a recombinant T24H antigen (rT24H) EITB assay was developed, with promising results. However, the test has yet to be evaluated among individuals from sub-Saharan Africa (SSA). The aim of the present study was to investigate the performance of the rT24H EITB assay for the detection of NCC cases in a panel of serum samples (N = 366, of which 173 patients presented with epileptic seizures and/or severe chronic headaches, and 193 matched manifestation-free participants) collected as part of a large community-based trial in Burkina Faso. A perfect agreement between the rT24H EITB and the native gp24 (and its homodimer, gp42) LLGP-EITB was found (kappa value of 1.0). Furthermore, among patients with the neurological manifestations of interest who underwent a computed tomography scan, the rT24H EITB and native antigen LLGP-EITB had a comparable ability to correctly identify NCC cases with multiple viable (rT24H: sensitivity: 80.0%), single viable (66.7%), and calcified/degenerating cysts only (25.0%), albeit for multiple viable and calcified cysts, the rT24H estimated sensitivity seemed lower, but more uncertain, than previously reported. The rT24H EITB specificity was high (98.2%) and in line with previous studies. This study confirms the value of the recombinant rT24H EITB as an alternative to the native antigen LLGP-EITB for the diagnosis of NCC in a SSA community setting.