Insecticide resistance exerts significant fitness costs in immature stages of Anopheles gambiae in western Kenya.

BACKGROUND: Despite increasing documentation of insecticide resistance in malaria vectors against public health insecticides in sub-Saharan Africa, there is a paucity of information on the potential fitness costs of pyrethroid resistance in malaria vectors, which is important in improving the current resistant management strategies. This study aimed to assess the fitness cost effects of insecticide resistance on the development and survival of immature Anopheles gambiae from western Kenya. METHODS: Two-hour old, first instar larvae (L1) were introduced and raised in basins containing soil and rainwater in a semi-field set-up. Each day the number of surviving individuals per larval stage was counted and their stage of development were recorded until they emerged as adults. The larval life-history trait parameters measured include mean larval development time, daily survival and pupal emergence. Pyrethroid-resistant colony of An. gambiae sensu stricto and susceptible colony originating from the same site and with the same genetic background were used. Kisumu laboratory susceptible colony was used as a reference. RESULTS: The resistant colony had a significantly longer larval development time through the developmental stages than the susceptible colony. The resistant colony took an average of 2 days longer to develop from first instar (L1) to fourth instar (L4) (8.8 ± 0.2 days) compared to the susceptible colony (6.6 ± 0.2 days). The development time from first instar to pupa formation was significantly longer by 3 days in the resistant colony (10.28 ± 0.3 days) than in susceptible colony (7.5 ± 0.2 days). The time from egg hatching to adult emergence was significantly longer for the resistant colony (12.1 ± 0.3 days) than the susceptible colony (9.6 ± 0.2 days). The pupation rate (80%; 95% (CI: 77.5-83.6) vs 83.5%; 95% (CI: 80.6-86.3)) and adult emergence rate (86.3% vs 92.8%) did not differ between the resistant and susceptible colonies, respectively. The sex ratio of the females to males for the resistant (1:1.2) and susceptible colonies (1:1.07) was significantly different. CONCLUSION: The study showed that pyrethroid resistance in An. gambiae had a fitness cost on their pre-imaginal development time and survival. Insecticide resistance delayed the development and reduced the survivorship of An. gambiae larvae. The study findings are important in understanding the fitness cost of insecticide resistance vectors that could contribute to shaping resistant management strategies.

Needs assessment of community health workers to enhance efficient delivery of their services for community case management of malaria in Kenya.

BACKGROUND: Malaria continues to be the leading cause of morbidity and mortality in Africa. Community Case Management of malaria (CCMm) which is undertaken by engaging Community Health Workers (CHWs) to effectively address management of malaria cases in some endemic communities was explored in this study. The aim was to assess the needs of CHWs that would help sustain and retain their services to enhance the efficient delivery of CCMm. METHODS: Using semi-structured questionnaires, data on the needs of CHWs was gathered through a qualitative study consisting of in-depth interviews and focus group discussions (FGDs) conducted among study participants in five districts in western Kenya. The study participants comprised of 100 CHWs, 100 mothers of children under five years and 25 key informants made up of public health officers and clinicians involved in the CCMm. The interviews were conducted in English and Swahili or Dholuo, the local language. The recorded audio interviews were transcribed later. The analysis was done using NVivo version 7 software and transcripts were coded after which themes related to the objectives of the study were identified. RESULTS: All the study participants recognized the need to train and update CHWs on their work as well as remunerating them for their services to enhance efficient delivery of services. The CHWs on their part perceived the provision of gloves, rapid diagnostic test kits (RDTs), lancets, cotton wool and ethanol, bins (to dispose of RDTs and lancets), together with drugs for treating clients as the essential needs to undertake CCMm in the communities. Other logistical needs and incentives mentioned by CHWs and key informants for the successful delivery of CCMm included: gumboots, raincoats, torch lights, mobile phones, means of transportation (bicycles and motorbikes), uniforms and ID cards for identification. CONCLUSIONS: CHWs would perform tasks better and their services retained for a sustainable CCMm if: properly incentivized; offered refresher trainings (and updates) on malaria; and equipped with the requisite tools identified in this study.

Long-lasting microbial larvicides for controlling insecticide resistant and outdoor transmitting vectors: a cost-effective supplement for malaria interventions.

The issues of pyrethroid resistance and outdoor malaria parasite transmission have prompted the WHO to call for the development and adoption of viable alternative vector control methods. Larval source management is one of the core malaria vector interventions recommended by the Ministry of Health in many African countries, but it is rarely implemented due to concerns on its cost-effectiveness. New long-lasting microbial larvicide can be a promising cost-effective supplement to current vector control and elimination methods because microbial larvicide uses killing mechanisms different from pyrethroids and other chemical insecticides. It has been shown to be effective in reducing the overall vector abundance and thus both indoor and outdoor transmission. In our opinion, the long-lasting formulation can potentially reduce the cost of larvicide field application, and should be evaluated for its cost-effectiveness, resistance development, and impact on non-target organisms when integrating with other malaria vector control measures. In this opinion, we highlight that long-lasting microbial larvicide can be a potential cost-effective product that complements current front-line long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) programs for malaria control and elimination. Microbial larviciding targets immature mosquitoes, reduces both indoor and outdoor transmission and is not affected by vector resistance to synthetic insecticides. This control method is a shift from the conventional LLINs and IRS programs that mainly target indoor-biting and resting adult mosquitoes.

Challenges of achieving sustainable community health services for community case management of malaria.

BACKGROUND: Community Case Management of malaria (CCMm) using Community Health Workers (CHWs) is an approach to improve access to timely and effective malaria case management in malaria endemic countries. So far the programme has been shown to be effective in many communities in sub-Saharan Africa. However, questions remain on the sustainability of this programme due to the high dropout cases of CHWs given their modest remuneration. The aim of the study was to identify challenges of achieving sustainable community health services for CCMm. METHODS: A community based qualitative study was conducted in five districts in western Kenya where CCMm was being undertaken. In-depth interviews and focus group discussions were conducted with the CHWs, mothers of children under-five years and key informants such as public health officers and clinicians involved in the CCMm. The interviews were audio recorded and conducted in English, Swahili and the local language. Recorded interviews were transcribed. Analysis was conducted using NVivo version 7 software, where transcripts were coded after which themes related to the objectives of the study were identified. RESULTS: The community members, the CHWs and stakeholders perceived CCMm as an important approach for reducing the burden of malaria. Key informants perceived lack of basic supplies (RDTs, gloves), drugs, inadequate remuneration of CHWs and lack of basic working equipment as challenges for CCM. CHWs highlighted that lack of drugs and basic supplies such as gloves at the health facilities, inadequate community sensitization by health workers, inadequate stipend to meet basic needs, as challenges of achieving sustainable CCMm. Some clinicians perceived that CHWs should not be given Artemisinin-based combination therapy (ACT) as part of the CCMm since they might misuse them. CONCLUSION: This study shows that for CCMm to be sustainable, concerted efforts from stakeholders are needed to boost the programme. Commodities needed for implementation of the programme need to be readily available and the morale of the CHWs who undertake CCMm needs boosting.

Building Sustainable Local Capacity for Global Health Research in West Africa.

BACKGROUND: Global health research in resource-limited countries has been largely sponsored and led by foreign institutions. Thus, these countries' training capacity and productivity in global health research is limited. Local participation at all levels of global health knowledge generation promotes equitable access to evidence-based solutions. Additionally, leadership inclusive of competent local professionals promotes best outcomes for local contextualization and implementation of successful global health solutions. Among the sub-Saharan African regions, West Africa in particular lags in research infrastructure, productivity, and impact in global health research. OBJECTIVE: In this paper, experts discuss strategies for scaling up West Africa's participation in global health evidence generation using examples from Ghana and Nigeria. METHODS: We conducted an online and professional network search to identify grants awarded for global health research and research education in Ghana and Nigeria. Principal investigators, global health educators, and representatives of funding institutions were invited to add their knowledge and expertise with regard to strengthening research capacity in West Africa. FINDINGS: While there has been some progress in obtaining foreign funding, foreign institutions still dominate local research. Local research funding opportunities in the 2 countries were found to be insufficient, disjointed, poorly sustained, and inadequately publicized, indicating weak infrastructure. As a result, research training programs produce graduates who ultimately fail to launch independent investigator careers because of lack of mentoring and poor infrastructural support. CONCLUSIONS: Research funding and training opportunities in Ghana and Nigeria remain inadequate. RECOMMENDATIONS: We recommend systems-level changes in mentoring, collaboration, and funding to drive the global health research agenda in these countries. Additionally, research training programs should be evaluated not only by numbers of individuals graduated but also by numbers of independent investigators and grants funded. Through equitable collaborations, infrastructure, and mentoring, West Africa can match the rest of Africa in impactful global health research.