Physical and insecticidal durability of Interceptor®, Interceptor® G2, and PermaNet® 3.0 insecticide-treated nets in Burkina Faso: results of durability monitoring in three sites from 2019 to 2022.

BACKGROUND: National Malaria Programmes (NMPs) monitor the durability of insecticide-treated nets (ITNs) to inform procurement and replacement decisions. This is crucial for new dual active ingredients (AI) ITNs, for which less data is available. Pyrethroid-only ITN (Interceptor®) and dual AI (Interceptor® G2, and PermaNet® 3.0) ITNs were assessed across three health districts over 36 months in southern Burkina Faso to estimate median ITN survival, insecticidal efficacy, and to identify factors contributing to field ITN longevity. METHODS: Durability was monitored through a prospective study of a cohort of nets distributed during the 2019 mass campaign. Three health districts were selected for their similar pyrethroid-resistance, environmental, epidemiological, and population profiles. Households were recruited after the mass campaign, with annual household questionnaire follow-ups over three years. Each round, ITNs were withdrawn for bioassays and chemical residue testing. Key measures were the percentage of cohort ITNs in serviceable condition, insecticidal effectiveness, and chemical residue content against target dose. Cox proportional hazard models were used to identify determinants influencing ITN survival. RESULTS: At endline, the median useful life was 3.2 (95% CI 2.5-4.0) years for PermaNet® 3.0 ITNs in Orodara, 2.6 (95% CI 1.9-3.2) years for Interceptor® G2 ITNs in Banfora and 2.4 (95% CI 1.9-2.9) years for Interceptor® ITNs in Gaoua. Factors associated with ITN survival included cohort ITNs from Orodara (adjusted hazard ratio (aHR) = 0.58, p = 0.026), households seeing less rodents (aHR = 0.66, p = 0.005), female-headed households (aHR = 0.66, p = 0.044), exposure to social behavior change (SBC) messages (aHR = 0.52, ≤ 0.001) and folding nets when not in use (aHR = 0.47, p < 0.001). At endline, PermaNet® 3.0 ITN recorded 24-h mortality of 26% against resistant mosquitos on roof panels, with an 84% reduction in PBO content. Interceptor® G2 ITN 72-h mortality was 51%, with a 67% reduction in chlorfenapyr content. Interceptor® ITN 24-h mortality was 71%, with an 84% reduction in alpha-cypermethrin content. CONCLUSION: Only PermaNet® 3.0 ITNs surpassed the standard three-year survival threshold. Identified protective factors should inform SBC messaging. Significant decreases in chemical content and resulting impact on bioefficacy warrant more research in other countries to better understand dual AI ITN insecticidal performance.

Cephalometric norms of a Burkina Faso population.

INTRODUCTION: After a clinical examination, in order to implement an appropriate treatment planning, additional examinations such as lateral cephalograms, were performed. They were submitted to a cephalometric analysis such as the Tweed-Merrifield analysis. These cephalometric analyses based on a synthesis of aesthetic criteria established for a Caucasian European-American white people population could not serve as the reference for an African population. The aim of our study was to help establish the cephalometric norms of the Tweed-Merrifield's craniofacial and aesthetic analysis for a consulting population in the city of Ouagadougou. MATERIALS AND METHODS: This is a retrospective cross-sectional descriptive study conducted on a sample of lateral cephalograms selected among the files of patients consulting in the department of dental surgery at the Yalgado Ouédraogo university hospital centre of Ouagadougou. The patients were selected upon their balanced facial aesthetics. The same operator using acetate paper traced cephalogram on radiographs and collected the angular and linear values for the analysis. RESULTS: A total of 84 cephalograms, 42 male lateral cephalograms and the same number of females, were included. Their age ranged from 11 to 21 years old, with a mean age of 14.34 years. The mean SNA angle was 84.94°±2.59, the ANB angle was 4.88°. The vertical dimension was within the mean values, which was not the case for the mandibular incisor axis, very tipped buccally with an IMPA angle of 95.97°. The profile of the African subject was characterized by a closed Z angle. CONCLUSION: The profile of the African subject was rather prognathic, the maxilla and the mandible were prominent in relation to the cranial base. The maxillary-mandibular relationship is Ballard's class II. The typical alveolar biprotrusion must be considered as an ethnical data, which our treatment plans must consider.