Browsing by Author "Ngowo, Halfan"

Now showing 1 - 10 of 10

Characterization of a new laboratory colony of Anopheles funestus mosquitoes established in Ifakara, Tanzania
(bioRxiv, 2025-11-24) Hape, Emmanuel; Njalambaha, Rukiyah; Muyaga, Letus; Nambunga, Ismail; Mgando, Joseph; Mwasheshi, Dickson; Nombo, Neema; Mabula, Daniel; Zengenene, Munyaradzi; Kahamba, Najat; Odero, Joel; Ngowo, Halfan; Mapua, Salum; Chaki, Prosper; Govella, Nicodem; Lyimo, Issa; Kiware, Samson; Lwetoijera, Dickson; Tarimo, Brian; Kaindoa, Emmanuel; Selvaraj, Prashanth; Tripet, Frederic; Wondji, Charles; Baldini, Francesco; Koekemoer, Lizette; Ferguson, Heather; Okumu, Fredros O.
Background: Anopheles funestus, a major vector of malaria in Africa, has proven difficult to colonize in laboratory settings, impeding research on its biology and control. After several attempts, our team recently succeeded in colonizing a strain of An. funestus from Tanzania (FUTAZ). The objective of this study was to analyse the key fitness and genotypic characteristics of these mosquitoes during multiple filial generations of laboratory adaptation and compare them to wild An. funestus from Tanzania and a pre-existing colony of An. funestus from Mozambique (FUMOZ). Methods: Measures of mating success (percentage of female mosquitoes inseminated), body size (wing length), fecundity (number of eggs laid per female), and insecticide susceptibility (percentage of 24-hour mortality after exposure to insecticides) were compared between the newly established colonies of Tanzanian An. funestus (FUTAZ colonies), the long-established FUMOZ colonies, and a colony of Anopheles arabiensis maintained in the same laboratory. The maternal lineages of the An. funestus mosquitoes were investigated through a hydrolysis probe analysis of their mitochondrial DNA to identify distinct clades, I and II. Additionally, other intragenomic variations were examined through a PCR analysis of restriction fragment length polymorphisms (RFLP) on the third domain of 28S ribosomal DNA. These molecular markers were used to compare the FUTAZ colonies, FUMOZ colonies in Tanzania and South Africa, and the wild-collected An. funestus from Tanzania. Result: The mating success and body size of FUTAZ females declined significantly from filial generations F1 to F6 relative to the founder population (F0), but then increased from F7 onwards eventually matching FUMOZ by F9. Fecundity was similar across all colonies tested. However, it took significantly longer for 50% of the females in the FUTAZ and FUMOZ colonies (over 10 days) to mate compared to females in the An. arabiensis colony (approximately 5 days). Insecticide resistance appeared to be lost during colonization, but this varied with insecticide classes. Majority of mosquitoes in the FUTAZ colony, as well as the wild-caught Tanzanian An. funestus belonged to Clade I (80.4-89.4%) and RFLP type “Y” (90.5-91.4%), while the FUMOZ colonies were mostly Clade II (65.5-88.5%) and RFLP type “MW” (90.5-91.5%). Conclusion: This study suggests that the mating success and body size of An. funestus decreases significantly during the early stages of colonization, then increase as the mosquitoes adapt to laboratory conditions. It is therefore crucial to have a large enough founder population to persist through these early generations in order to achieve stable colonization of An. funestus. The Clade and RFLP genotyping demonstrated the genetic similarities between the FUTAZ mosquitoes and wild- caught Tanzanian An. funestus, but also showed that the new colony can be distinguished from the FUMOZ colony.
Common predators and factors influencing their abundance in Anopheles funestus aquatic habitats in rural south-eastern Tanzania
(PLOS ONE, 2023-06-26) Mahenge, Herieth; Muyaga, Letus; Nkya, Joel; Kifungo, Khamis; Kahamba, Najat; Ngowo, Halfan; Kaindoa, Emmanuel
Background The role of larval predators in regulating the Anopheles funestus population in various malaria-endemic countries remains relatively unknown. This study aimed to investigate the common predators that co-exist with Anopheles funestus group larvae and evaluate factors that influence their abundance in rural south-eastern Tanzania. Methods Mosquito larvae and predators were sampled concurrently using standard dipper (350 ml) or 10 L bucket in previously identified aquatic habitats in selected villages in southern Tan zania. Predators and mosquito larvae were identified using standard identification keys. All positive habitats were geo-located and their physical features characterized. Water physico chemical parameters such as dissolved oxygen (DO), pH, electrical conductivity (EC), total dissolved solids (TDS) and temperature were also recorded. Results A total of 85 previously identified An. funestus aquatic habitats in nine villages were sampled for larvae and potential predators. A total of 8,295 predators were sampled. Of these Coena grionidae 57.7% (n = 4785), Corixidae 12.8% (n = 1,060), Notonectidae 9.9% (n = 822), Aeshnidae 4.9% (n = 405), Amphibian 4.5% (n = 370), Dytiscidae 3.8% (n = 313) were com mon. A total of 5,260 mosquito larvae were sampled, whereby Anopheles funestus group were 60.3% (n = 3,170), Culex spp. 24.3% (n = 1,279), An. gambie s.l. 8.3% (n = 438) and other anophelines 7.1% (n = 373). Permanent and aquatic habitats larger than 100m2 were positively associated with An. funestus group larvae (P<0.05) and predator abundance(P<0.05). Habitats with submerged vegetation were negatively associated with An. funestus group larvae (P<0.05). Only dissolved oxygen (DO) was positively and significantly affect the abundance of An. funestus group larvae (P<0.05). While predators’ abundance was not impacted by all physicochemical parameters. Conclusion Six potential predator families were common in aquatic habitats of An. funestus group lar vae. Additional studies are needed to demonstrate the efficacy of different predators on lar val density and adult fitness traits. Interventions leveraging the interaction between mosquitoes and predators can be established to disrupt the transmission potential and sur vival of the An. funestus mosquitoes
Dietary diversity among households living in Kilombero district, in Morogoro region, South-Eastern Tanzania
(Elsevier B.V., 2021-06-11) Minja, Elihaika; Swai, Johnson; Mponzi, Winifrida; Ngowo, Halfan; Okumu, Fredros; Gerber, Markus; Pühse, Uwe; Long, Kurt; Utzinger, Jürg; Lang, Christin; Beckmann, Johanna; Finda, Marceline
Background: Adequate nutrition is essential for good health and active life. However, diets in most low and middle-income households lack diversity, especially in settings where people eat predominantly starchy foods. In this study, we assessed the associations between socio-economic status and household dietary diversity in families living in South-eastern Tanzania. Method: A cross-sectional questionnaire was administered to 925 parents of school children in four wards in South-eastern Tanzania, as part of a trial; assessing the effects of physical activity and micronutrient supplementation on overall growth, health and well-being of school children. The dietary intake was assessed by 24-h dietary recall and dietary diversity score (DDS) was calculated. Socio-economic status was derived from a weighted score using principal component analysis (PCA). Multinomial logistic regression was used to investigate the association between dietary diversity and socio-economic status. This baseline data assessment was completed in July and August 2019. Results: Cereals, oils and fats were the most consumed food groups, legumes were the most common source of protein and fish was the most common animal protein. More than three quarters of the households had medium dietary diversity (MDD). Higher household education and large farm size were the only factors significantly associated with having high dietary diversity. Conclusion: A majority of the households in South-eastern Tanzania have medium dietary diversity, comprised of cereal, fats and oils and proteins. Having high dietary diversity was associated with higher education and large farm sizes. Improving community members’ knowledge and awareness of nutritional benefits could improve the dietary diversity at household level.
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 different intervention packages for malaria control under varying intensities of pyrethroid resistance
(Malaria Journal, 2025-11-19) Gervas, Hamenyimana; Mayengo, Maranya; Mlacha, Yeromin; Ngowo, Halfan; Okumu, Fredros; Selvaraj, Prashanth
Background Malaria control in sub-Saharan Africa faces significant challenges from biological threats, such as insec- ticide resistance and adaptive vector behaviours, as well as increasing financial constraints, which necessitate stra- tegic intervention planning to maximize impact. This study assesses the effectiveness of combining vector control methods, case management, and immunoprevention to reduce malaria in Tanzania, considering varying intensities of insecticide resistance in the main vector species. Methods A compartmental model was developed to simulate malaria transmission, incorporating the dominant vectors: Anopheles funestus (anthropophilic and endophilic) and Anopheles arabiensis (zoophilic and exophilic). The model was used to analyse the impacts of insecticide-treated nets (ITNs), indoor residual spraying (IRS), and biolar- vicides, used singly or in combinations, under varying intensities of pyrethroid resistance. The analysis was further expanded to explore the impacts of adding case management (treatment using artemisinin-based combinations) and immunization (RTS,S/AS01 and R21/Matrix-M vaccines). Results At moderate levels of pyrethroid resistance (50%), achieving at least 71% ITN coverage combined with either 50% IRS or 32% biolarvicide coverage reduces the effective reproduction number (Re ) to below 1. How- ever, at high resistance levels (exceeding 75%), the effective reproduction number (Re ) consistently remains above 1, irrespective of the type or combination of vector control interventions. Adding immunization (≥ 40% coverage) to ITNs (80% coverage), along with effective treatment (80% coverage), can further reduce the proportion of infec- tious individuals to <20% and Re below 1, even under high resistance intensities. Conclusions Compared to ITNs alone, combining ITNs with IRS and/or biolarvicides greatly improves malaria control at low to moderate intensities of pyrethroid resistance but yields no additional benefits at high resistance intensi- ties. However, integrating these vector control strategies with immunization and effective case management using artemisinin-based combination therapy (ACT) further enhances impact by reducing both parasite transmission and the infectious reservoir
Preferred resting surfaces of dominant malaria vectors inside different house types in rural south-eastern Tanzania
(Springer Nature, 2020-01-15) Msugupakulya, Betwel J.; Kaindoa, Emmanuel W.; Ngowo, Halfan; Kihonda, Japhet M.; Kahamba, Najat F.; Msaky, Dickson S.; Matoke-Muhia, Damaris; Tungu, Patrick K.; Okumu, Fredros O.
Background: Malaria control in Africa relies extensively on indoor residual spraying (IRS) and insecticide-treated nets (ITNs). IRS typically targets mosquitoes resting on walls, and in few cases, roofs and ceilings, using contact insecticides. Unfortunately, little attention is paid to where malaria vectors actually rest indoors, and how such knowledge could be used to improve IRS. This study investigated preferred resting surfaces of two major malaria vectors, Anopheles funestus and Anopheles arabiensis, inside four common house types in rural south-eastern Tanzania. Methods: The assessment was done inside 80 houses including: 20 with thatched roofs and mud walls, 20 with thatched roofs and un-plastered brick walls, 20 with metal roofs and un-plastered brick walls, and 20 with metal roofs and plastered brick walls, across four villages. In each house, resting mosquitoes were sampled in mornings (6 a.m.–8 a.m.), evenings (6 p.m.–8 p.m.) and at night (11 p.m.–12.00 a.m.) using Prokopack aspirators from multiple surfaces (walls, undersides of roofs, foors, furniture, utensils, clothing, curtains and bed nets). Results: Overall, only 26% of An. funestus and 18% of An. arabiensis were found on walls. In grass-thatched houses, 33–55% of An. funestus and 43–50% of An. arabiensis rested under roofs, while in metal-roofed houses, only 16–20% of An. funestus and 8–30% of An. arabiensis rested under roofs. Considering all data together, approximately 40% of mosquitoes rested on surfaces not typically targeted by IRS, i.e. foors, furniture, utensils, clothing and bed nets. These proportions were particularly high in metal-roofed houses (47–53% of An. funestus; 60–66% of An. arabiensis). Conclusion: While IRS typically uses contact insecticides to target adult mosquitoes on walls, and occasionally roofs and ceilings, signifcant proportions of vectors rest on surfaces not usually sprayed. This gap exceeds one-third of malaria mosquitoes in grass-thatched houses, and can reach two-thirds in metal-roofed houses. Where feld opera‑ tions exclude roofs during IRS, the gaps can be much greater. In conclusion, there is need for locally-obtained data on mosquito resting behaviours and how these infuence the overall impact and costs of IRS. This study also emphasizes the need for alternative approaches, e.g. house screening, which broadly tackle mosquitoes beyond areas reachable by IRS and ITNs.
Risk of Aedes-borne diseases in and around the Tanzanian seaport of Tanga despite community members being more concerned about malaria
(BioMed Central, 2024-12-18) Abas, Amri; Simfukwe, Alfred; Masalu, John; Kahamba, Najat; Nambunga, Ismail; Msaky, Dickson; Limwagu, Alex; Kipekepeke, Abdallah; Wergin, Carsten; Njalambaha, Rukiyah; Kemibala, Elison; Seleman, Amour; Mlacha, Yeromin; Finda, Marceline; Beisel, Uli; Kimaro, Esther; Ngowo, Halfan; Okumu, Fredros
Background Increased global trade, while beneficial economically, can also increase the spread of vector-borne diseases, particularly those transmitted by Aedes mosquitoes spreading via trade routes. Given the heightened trade- induced activity at ports of entry, it is particularly crucial to assess the risk of mosquito-borne diseases in these set- tings. This study compared the risks of Aedes-borne disease in and around the eastern Tanzanian seaport of Tanga. Methods A 200 m × 200 m grid-based system was used to sample mosquitoes within the port area, and in surround- ing areas at 2 km, 2.5 km, and 5 km away, between June and December 2023. We characterized mosquito breeding habitats, collected mosquito larvae using standard dippers and tested susceptibility of raised adult Aedes aegypti populations to different insecticides. Adult mosquitoes were collected using BG sentinel traps (daytime) and Centers for Disease Control (CDC) light traps (night-time). Additionally, more than 200 port users and neighboring residents were surveyed to assess their experiences with and perceptions of mosquito biting and disease risks. Results There were 2931 breeding sites, with (60.8%, n = 1782) positive for Aedes larvae. The percentage of water- holding containers infested with Aedes immatures, i.e., the container index (CI), was highest in the port area (66.2%), and lowest 5 km away (44.6%). The port area also had a greater proportion of temporary breeding sites (64.9%) than did the surrounding areas. The adult mosquito surveys revealed 20,449 mosquito species including: Culex quinquefasciatus (56.2%), Mansonia uniformis (38.6%), Ae. aegypti (5.1%), Anopheles gambiae (0.1%), and Anoph- eles funestus. Ae. aegypti were more abundant in the port area than in the surrounding areas (P < 0.001), whereas Culex sp., and Mansonia sp., were significantly outside (P < 0.001). Adult Anopheles sp., were found only in the port area, but Anopheles larvae were found both within and outside the port areas. Tests on Ae. aegypti sp., revealed susceptibility to bendiocarb and DDT, and resistance to permethrin. Awareness of mosquito-borne diseases among respondents was high for malaria (64.8%), but low for dengue (26.3%) and Chikungunya (1.7%). Most respond- ents reported being bothered by mosquitoes mostly at night (53.4%) or in the evening (40.7%). In addition to insecti- cidal bednets, which are used primarily against malaria, preventive measures for Aedes-borne diseases are limited. Conclusions This study identified significant potential risk of Aedes species, specifically Ae. aegypti sp., and associated diseases, but low perception of risk and inadequate personal protection measures in the study area. This low percep- tion of risk highlights the need to improve public knowledge of the transmission and control of Aedes-borne diseases.
Semi-field evaluation of aquatic predators for the control of Anopheles funestus in rural south-eastern Tanzania
(Springer Nature, 2024-08-02) Mahenge, Herieth; Muyaga, Letus; Nkya, Joel; Kafwenji, Andrew; Mwalugelo, Yohana; Kahamba, Najat; Ngowo, Halfan; Kaindoa, Emmanuel
Background Biological control is a promising alternative or complementary approach for controlling vector populations in response to the spread of insecticide resistance in malaria vectors. This study evaluated the efficacy of three selected potential predators on the density and fitness parameters of Anopheles funestus larvae in rural Tanzania. Methods Common predator families Aeshnidae (dragonflies), Coenagrionidae (damselflies), and Notonectidae (backswimmers) and An. funestus group larvae were collected from natural aquatic habitats in rural south-eastern Tanzania. Predators were starved for 12-h while An. funestus larvae were given fish food before starting the experiment. Anopheles funestus larvae were placed into artificial habitats containing predators, exposing them to potential predation. The number of surviving An. funestus larvae were counted every 24-h. An emergence traps were placed at the top of artificial habitats to capture emerging mosquitoes. Emerged mosquitoes were monitored until they died. Female wings were measured and used as a proxy for body size. Generalized linear mixed models (GLMM) with binomial variates at 95% CI and Cox proportional hazard models were used to assess the proportion of dead mosquitoes and the daily survival determined. Results There were significant differences in the number of emerged mosquitoes between the treatment and control groups (P<0.001). Thus, all predator species played a significant role in reducing the density of An. funestus mosquitoes (P<0.001). Furthermore, these predators had notable effects on the fitness parameters and survival of emerged mosquitoes (P<0.001). Among the three predators studied, Coenagrionidae (damselflies) were most efficient followed by Notonectidae (backswimmers), with Aeshnidae (dragonflies) being the least efficient. Conclusion Selected aquatic predators have the potential to reduce the survival and density of An. funestus larvae. They might eventually be included within an integrated malaria vector control strategy, ultimately leading to a reduction in malaria transmission.
Susceptibility status of major malaria vectors to novaluron, an insect growth regulator South-Eastern Tanzania
(Pan African Medical Journal, 2022-04-05) Justinian, Amos; Muyaga, Letus; Ngowo, Halfan; Urio, Naomi; Vianney, John‑Mary; Lwetoijera, Dickson
Introduction: application of Insect Growth Regulator (IGR) such as pyriproxyfen has shown a promising result in controlling malaria transmitting mosquitoes through autodissemination technique. Novaluron that inhibits the chitin development at mosquito larval stage present a promising candidate IGR for rotation with pyriproxyfen to prevent a chance of resistance development. This study assessed the susceptibility of immature stages of Anopheles arabiensis, Anopheles gambiae and Anopheles funestus to novaluron. Methods: susceptibility bioassays using technical grade novaluron (98% active ingredient) were performed inside the semi-field system using first instar larvae of Anopheles species. For each tested species, a total of 1500 larvae were used in the bioassay. Concentration range of 0.01 mg/l to 2 mg/l of novaluron were tested to establish Lethal Concentration (LC) sufficient to kills 50%, 90% and 99% of the exposed larvae by using log-dose response analysis. Results: of the tested mosquitoes, Anopheles gambiae were highly susceptible to novaluron followed by An. arabiensis and then An. funestus. Lethal concentrations, LC50, LC90 and LC99 (95%CI) in mg/l for An. gambiae were 0.018, 0.332 and 2.001 respectively. For An. arabiensis were 0.026, 0.546 and 2.013; and for An. funestus were 0.032, 1.00 and 5.580. High larval mortality was recorded at high concentration (2mg/L), with 80% mortality within 3 days post exposure. Conclusion: the study demonstrates the efficacy of novaluron in controlling Anopheles mosquito species at immature stages via larval mortality. These findings warrant further testing of novaluron for autodissemination by different vector species for its inclusion in rotation to prevent development of resistance.
Using pastoralist community knowledge to locate and treat dry-season mosquito breeding habitats with pyriproxyfen to control Anopheles gambiae s.l. and Anopheles funestus s.l. in rural Tanzania
(Springer Nature, 2021-01-06) Lupenza, Eliza; Kihonda, Japhet; Limwagu, Alex; Ngowo, Halfan; Sumaye, Robert; Lwetoijera, Dickson
Fundamentally, larviciding with pyriproxyfen (PPF) has potential to complement Long Lasting Insecticide Nets (LLINs) and indoor residual sprays (IRS) in settings where resistance to pyrethroids and residual malaria transmission exist. In this study, we evaluated the field effectiveness of larviciding using PPF to reduce dry season productivity of mosquito breeding habitats that were located by pastoralists within the study area. Using pastoralist knowledge, dry season breeding habitats in Mofu village rural Tanzania were located and monitored for larval productivity for a period of 8 months before PPF intervention. During the intervention, six out of twelve breeding habitats were treated with Sumilarv 0.5G PPF granules. The impact of deposited PPF was monitored by recording emergence inhibition of larvae collected from treated habitats compared to the appropriate control group for a period of three months and half post-intervention. During baseline, the average proportion (+SD) of adult emerged was similar between two clusters, with (0.89 + 0.22) for the control cluster and (0.93 + 0.16) for the treatment cluster of breeding habitats. Following treatment with PPF, the average proportion (+SD) of adult emerged in the treated breeding habitats was significantly low (0.096 + 0.22) compared to adults that emerged from larvae in the untreated habitats (0.99 + 0.22) (p < 0.0001). Of all emerged adults, approximately 94% were An. gambiae s.l. and the remaining 6% were An. funestus s.l. This is the first study demonstrating the usefulness of engaging pastoralist community to locate and identify hard to find mosquito breeding habitats. Reduced productivity of the targeted habitats with PPF offers prospect of implementing PPF larviciding in dry season when habitats are few and permanent to control mosquito population in rural settings.