Investigating molecular mechanisms of insecticide resistance in the Eastern Democratic Republic of the Congo.

BACKGROUND: Malaria vector control in the Democratic Republic of the Congo is plagued by several major challenges, including inadequate infrastructure, lack of access to health care systems and preventative measures, and more recently the widespread emergence of insecticide resistance among Anopheles mosquitoes. Across 26 provinces, insecticide resistance has been reported from multiple sentinel sites. However, to date, investigation of molecular resistance mechanisms among Anopheles vector populations in DRC has been more limited. METHODS: Adult Anopheles gambiae sensu lato (s.l.) and Anopheles funestus s.l. were collected from two sites in Sud-Kivu province and one site in Haut-Uélé province and PCR-screened for the presence of 11 resistance mutations, to provide additional information on frequency of resistance mechanisms in the eastern DRC, and to critically evaluate the utility of these markers for prospective country-wide resistance monitoring. RESULTS: L1014F-kdr and L1014S-kdr were present in 75.9% and 56.7% of An. gambiae s.l. screened, respectively, with some individuals harbouring both resistant alleles. Across the three study sites, L43F-CYP4J5 allele frequency ranged from 0.42 to 0.52, with evidence for ongoing selection. G119S-ace1 was also identified in all sites but at lower levels. A triple mutant haplotype (comprising the point mutation CYP6P4-I236M, the insertion of a partial Zanzibar-like transposable element and duplication of CYP6AA1) was present at high frequencies. In An. funestus s.l. cis-regulatory polymorphisms in CYP6P9a and CYP6P9b were detected, with allele frequencies ranging from 0.82 to 0.98 and 0.65 to 0.83, respectively. CONCLUSIONS: This study screened the most up-to-date panel of DNA-based resistance markers in An. gambiae s.l. and An. funestus s.l. from the eastern DRC, where resistance data is lacking. Several new candidate markers (CYP4J5, G119S-ace1, the triple mutant, CYP6P9a and CYP6P9b) were identified, which are diagnostic of resistance to major insecticide classes, and warrant future, larger-scale monitoring in the DRC to inform vector control decisions by the National Malaria Control Programme.

Needs and Challenges in Modelling Malaria for Emergency Contexts.

While modelling is an essential component for an understanding of the epidemiology of malaria, and for designing better control measures, it rarely considers the particular contexts encountered in emergency settings. By linking these situations with the transmission parameters our aim is to correct this bias and call for a better collaboration between relief actors.

A country-wide evaluation of infection control for tuberculosis in health-care facilities in Armenia.

INTRODUCTION: Infection control at health facilities is an important part of TB control programmes. To assess the implementation of tuberculosis infection control (TB IC) measures and barriers hindering their implementation in TB health care facilities (HCFs) in Armenia; to report the feasibility of using the WHO recommended checklist. METHODOLOGY: A cross-sectional survey using WHO TB-IC checklist and direct observations was conducted between January and May 2018. RESULTS: The survey included all 62 TB institutions in Armenia. TB HCFs in Armenia had implemented some recommended TB IC measures: offering IC training to staff (48%), shortening time to diagnosing TB to less than one day (29%) and ensuring good ventilation (60%). N95 respirators were available in all HCFs. However, barriers that hindered implementation of TB IC measures were: lack of training, a different incentive model for primary care doctors versus TB doctors and lack of space and poor conditions of the building. CONCLUSION: The use of the standardized WHO checklist in this first evaluation of TB IC measures in Armenia was found to be useful and feasible in identifying areas of weak IC implementation and barriers to achieving good infection control. Other TB programs may benefit from the use of this model of assessment, based on the WHO checklist.