Browsing by Author "Shirima, GloriaSalome"

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Assessing the role of community involvement and capacity building in larviciding applications for malaria control in Africa: A scoping review
(Elsevier, 2025-08-14) Shirima, GloriaSalome; Masserey, Thiery; Gervas, Hamenyimana; Chitnis, Nakul; Kiware, Samson; Mirau, Silas
Larviciding offers a supplementary approach in malaria vector control, particularly when applied through community engagement and capacity building. A scoping review was performed to evaluate existing larviciding delivery mechanisms and their impacts on African malaria control. A scoping review was conducted following the PRISMA-ScR guidelines. The search strategy utilized Medical Subject Headings (MeSH) and free-text terms related to “malaria”, “larvicide”, “community engagement” and “mosquito control”. The databases PubMed, Scopus, and Embase were searched for relevant literature published until December 2024. Inclusion criteria focused on studies addressing community engagement in delivering larviciding within African settings. After applying inclusion and exclusion criteria, 32 papers were ultimately included in the analysis. The studies spanned 13 African countries, primarily in sub-Saharan regions, with findings indicating that larviciding significantly reduced mosquito density and, in some cases, malaria incidence. Community engagement strategies varied, with workshops and participatory meetings targeting various stakeholders to enhance awareness and ownership of larviciding programmes. Community engagement and capacity building were critical to success- fully implementing larviciding programmes. While challenges, such as logistical barriers, lack of awareness, and financial constraints, persist, integrating technological innovations and strengthening monitoring systems can enhance the sustainability of these efforts.
Elevating larval source management as a key strategy for controlling malaria and other vector-borne diseases in Africa
(BMC, 2025-02-07) Okumu, Fredros; Moore, Sarah; Selvaraj, Prashanth; Yafin, Arnon; Juma, Elijah; Shirima, GloriaSalome; Majambere, Silas; Hardy, Andy; Knols, Bart; Msugupakulya, Betwel; Finda, Marceline; Kahamba, Najat; Thomsen, Edward; Ahmed, Ayman; Zohdy, Sarah; Chaki, Prosper; DeChant, Peter; Fornace, Kimberly; Govella, Nicodem; Gowelo, Steven; Hakizimana, Emmanuel; Hamainza, Busiku; Ijumba, Jasper; Jany, William; Kafy, Hmooda; Kaindoa, Emmanuel; Kariuki, Lenson; Kiware, Samson; Kweka, Eliningaya; Lobo, Neil; Marrenjo, Dulcisária; Matoke-Muhia, Damaris; Mbogo, Charles; McCann, Robert; Monroe,n April; Ndenga, Bryson; Ngowo, Halfan; Ochomo, Eric; Opiyo, Mercy; Reithinger, Richard; Sikaala, Chadwick; Tatarsky, Allison; Takudzwa, David; Trujillano, Fedra; Sherrard-Smith, Ellie
Larval source management (LSM) has a long history of advocacy and successes but is rarely adopted where funds are limited. The World Health Organization (WHO) guidelines on malaria prevention recommend the use of LSM as a supplementary intervention to the core vector control methods (insecticide-treated nets and indoor residual spraying), arguing that its feasibility in many settings can be limited by larval habitats being numerous, transient, and difficult to find or treat. Another key argument is that there is insufficient high-quality evidence for its effectiveness to support wide-scale implementation. However, the stagnation of progress towards malaria elimination demands that we consider additional options to the current emphasis on insecticidal commodities targeting adult mosquitoes inside homes. This letter is the result of a global, crossdisciplinary collaboration comprising: (a) detailed online expert discussions, (b) a narrative review of countries that have eliminated local malaria transmission, and (c) a mathematical modeling exercise using two different approaches. Together, these efforts culminated in seven key recommendations for elevating larval source management as a strategy for controlling malaria and other mosquito-borne diseases in Africa (Box 1). LSM encompasses the use of larvicide (a commodity) as well as various environmental sanitation measures. Together, these efforts lead to the long-term reduction of mosquito populations, which benefits the entire community by controlling both disease vector and nuisance mosquitoes. In this paper, we argue that the heavy reliance on large-scale cluster-randomized controlled trials (CRTs) to generate evidence on epidemiological endpoints restricts the recommendation of approaches to only those interventions that can be measured by functional units and deliver relatively uniform impact and, therefore, are more likely to receive financial support for conducting these trials. The explicit impacts of LSM may be better captured by using alternative evaluation approaches, especially high-quality operational data and a recognition of locally distinct outcomes and tailored strategies. LSM contributions are also evidenced by the widespread use of LSM strategies in nearly all countries that have successfully achieved malaria elimination. Two modelling approaches demonstrate that a multifaceted strategy, which incorporates LSM as a central intervention alongside other vector control methods, can effectively mitigate key biological threats such as insecticide resistance and outdoor biting, leading to substantial reductions in malaria cases in representative African settings. This argument is extended to show that the available evidence is sufficient to establish the link between LSM approaches and reduced disease transmission of mosquito-borne illnesses. What is needed now is a significant boost in the financial resources and public health administration structures necessary to train, employ and deploy local-level workforces tasked with suppressing mosquito populations in scientifically driven and ecologically sensitive ways. In conclusion, having WHO guidelines that recognize LSM as a key intervention to be delivered in multiple contextualized forms would open the door to increased flexibility for funding and aid countries in implementing the strategies that they deem appropriate. Financially supporting the scale-up of LSM with high-quality operations monitoring for vector control in combination with other core tools can facilitate better health. The global health community should reconsider how evidence and funding are used to support LSM initiatives.
Modelling the impact of larviciding as a supplementary malaria vector control intervention in rural south-eastern Tanzania: A district-level simulation study
(medRxiv, 2025-11-15) Shirima, GloriaSalome; Fairbanks, Emma; Tegemeo, Gavana; Kiwelu, Gerald; Nambunga, Ismail; Mlacha, Yeromin; Mirau, Silas; Chaki, Prosper; Chitnis, Nakul; Kiware, Samson
Combining larviciding with insecticide treated nets (ITNs) can reduce malaria transmission, but 42 most modelling analyses use generalized scenarios rather than local contexts. In Tanzania and 43 other countries, larviciding is increasingly being prioritized in national strategies, with growing 44 advocacy for its broader implementation, to achieving sustained malaria reduction. District- 45 specific modelling is therefore essential to capture variation in transmission ecology, seasonality, 46 and varying coverage levels, providing evidence that is both rigorous and actionable for malaria 47 control programs. The Vector Control Optimization Model (VCOM) was adapted and extended to 48 incorporate local seasonality, simulating the impact of larviciding across a range of coverage levels 49 combined with ITNs. The model was parameterized using district-level field-data on mosquito 50 mortality collected before (2016-2017) and after (2019-2021) larviciding implementation. 51 Mosquito mortality rates were estimated using Bayesian inference. Outcomes were evaluated 52 specifically for Anopheles gambiae s.l. including annual entomological inoculation rates (EIR) and 53 mosquito density. Sensitivity analysis explored the influence of key parameters driving 54 transmission in this scenario study. The immature mosquito mortality rate due to larviciding is 55 estimated to be 61% based on field data. VCOM simulation showed that, at 80%, ITNs coverage, 56 larviciding substantially reduced mosquito densities and EIR. Specifically, combining ITNs at 57 80% and larviciding coverage ≥ 60% lowered EIR below 1, the threshold required to interrupt 58 malaria transmission. Sensitivity analyses highlighted the high impact of targeting immature 59 mosquitoes, suggesting larviciding can effectively complement ITNs to control vectors, including 60 invasive species like An. stephensi, regardless of feeding preference, resting, and biting behaviors, 61 which hinder the effectiveness of most vector control tools. This study provides local evidence 62 that larviciding is an effective complement to ITNs for interrupting malaria transmission. 63 Implementation should leverage innovative approaches, such as drones for precise mapping and 64 targeted application of biological larvicides, to maximize coverage, and scalability for district- 65 level malaria control and elimination