Effectiveness of a community-based educational programme in reducing the cumulative incidence and prevalence of human Taenia solium cysticercosis in Burkina Faso in 2011-14 (EFECAB): a cluster-randomised controlled trial

Abstract

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.

Funding: US National Institutes of Health (National Institute of Neurological Disorders and Stroke, Fogarty International Center, and National Institute of General Medical Sciences).

Figure 1. Location of major gold mines and of the 60 participating villages

Figure 2. Flow chart of participating villages and individuals

No villages were lost to follow-up. SCHA=severe chronic headaches. *Individuals absent at the pre-randomisation follow-up but who returned for the post-randomisation follow-up are not included. †There were six concessions in the intervention group and three concessions in the control group where two individuals were sampled at the same visit. Only data from the originally sampled individuals were kept.

Figure 3. Prior and posterior distributions of the adjusted effect of the intervention in Boulkiemdé and in Nayala and Sanguié

Variables adjusted for in the different models are reported in table 1. (A) Effectiveness measure 1 (prevalence proportion ratio adjusted for the change from baseline to the pre-randomisation period to the post-randomisation period and for clustering by village) and analytical sample 1 (participants provided a blood sample at all three visits). (B) Effectiveness measure 2 (cumulative incidence ratio adjusted for the change from seroconversion from the baseline to the pre-randomisation period and clustering by village) and analytical sample 1. (C) Effectiveness measure 1 and analytical sample 3 (participants provided blood samples at baseline and at the post-randomisation visit). (D) Effectiveness measure 1 and analytical sample 2 (participants provided a blood sample at least once). (E) Effectiveness measure 3 (cumulative incidence ratio from baseline to the post-randomisation visit) and analytical sample 3.