Background: In 2015, Tanzania National Malaria Control Programme (NMCP) established a longitudinal malaria vector entomological surveillance (MVES). The MVES is aimed at a periodical assessment of malaria vector composition and abundance, feeding and resting behaviours, and Plasmodium falciparum infection in different malaria epidemiological strata to guide the NMCP on the deployment of appropriate malaria vector interventions. This work details the dynamics of malaria vector composition and transmission in different malaria epidemiological strata.
View Article and Find Full Text PDFBackground: Insecticide resistance is a serious threat to the continued effectiveness of insecticide-based malaria vector control measures, such as long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). This paper describes trends and dynamics of insecticide resistance and its underlying mechanisms from annual resistance monitoring surveys on Anopheles gambiae sensu lato (s.l.
View Article and Find Full Text PDFAnopheline mosquito insecticide resistance is a major threat to malaria control efforts and ultimately countries' ability to eliminate malaria. Using publicly available and published data we conducted spatial analyses to document and model the geo-spatial distribution of Anopheles gambiae s.l.
View Article and Find Full Text PDFBMC Public Health
September 2021
Two new arabinofuranosidetridecanol, namely 1,2-tridecanediol-1--α-L-5'-acetylarabinofuranoside () and 1,2-tridecanediol-1--α-L-arabinofuranoside () together with known compound, 1,2-tridecanediol () were isolated from exudate. Compound showed larvicidal activity against (LC = 40.66 µg/mL) (LC = 22.
View Article and Find Full Text PDFBackground: As insecticide-treated nets (ITNs) wear out and are disposed, some household members are prioritized to use remaining ITNs. This study assessed how nets are allocated within households to individuals of different age categories as ITNs are lost or damaged and as new ITNs are obtained. The study also explored how ITN allocation affects ITN durability.
View Article and Find Full Text PDFSeveral trials and reviews have outlined the potential role of larviciding for malaria control in sub-Saharan Africa (SSA) to supplement the core indoor insecticide-based interventions. It has been argued that widespread use of long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) interventions in many parts of Africa result in many new areas with low and focal malaria transmission that can be targeted with larvicides. As some countries in SSA are making good progress in malaria control, larval source management, particularly with bacterial larvicides, could be included in the list of viable options to maintain the gains achieved while paving the way to malaria elimination.
View Article and Find Full Text PDFBackground: Insecticide-treated net (ITN) durability, measured through physical integrity and bioefficacy, must be accurately assessed in order to plan the timely replacement of worn out nets and guide procurement of longer-lasting, cost-effective nets. World Health Organization (WHO) guidance advises that new intervention class ITNs be assessed 3 years after distribution, in experimental huts. In order to obtain information on whole-net efficacy cost-effectively and with adequate replication, a new bioassay, the Ifakara Ambient Chamber Test (I-ACT), a semi-field whole net assay baited with human host, was compared to established WHO durability testing methods.
View Article and Find Full Text PDFBackground: Lymphatic filariasis (LF) control in most countries of sub-Saharan Africa is based on annual mass drug administration (MDA) with a combination of ivermectin and albendazole, in order to interrupt transmission. However, attaining and maintaining high treatment coverage has been a challenge in many LF control programmes. This study was designed to elucidate reasons for continued transmission of LF in an endemic area of Tanga, northeastern Tanzania, where control activities based on MDA had been in place for eight years by the time of this study in 2012.
View Article and Find Full Text PDFBackground: The population of sub-Saharan Africa is currently estimated to be 1245 million and is expected to quadruple by the end of the century, necessitating the building of millions of homes. Malaria remains a substantial problem in this region and efforts to minimise transmission should be considered in future house planning. We studied how building elements, which have been successfully employed in southeast Asia to prevent mosquitos from entering and cooling the house, could be integrated in a more sustainable house design in rural northeastern Tanzania, Africa, to decrease mosquito density and regulate indoor climate.
View Article and Find Full Text PDFBackground: Insecticide-treated nets (ITNs) are highly effective in reducing morbidity and mortality from malaria. However, it is widely accepted that ITNs - if not re-treated - lose their effectiveness with time and eventually need to be replaced. This study sought to determine the social, ethical, and cultural issues related to the lifecycle of ITNs, which includes net ownership, usage, maintenance, reuse, recycling, disposal, and replacement.
View Article and Find Full Text PDFObjective: Malaria vectors control interventions are designed to cause immediate killing or shorten mosquito lives, therefore does not allow enough time for the development of the parasites to infective stage. The wall lining is new malaria vectors control intervention in Tanzania where its impact on age structure is not well known. Therefore this study aimed at determining the impact of non-pyrethroid durable wall lining on the age structure of malaria vectors.
View Article and Find Full Text PDFBackground: Malaria vector control in Tanzania is based on use of long-lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS), which both rely on the use of chemical insecticides. The effectiveness of these control tools is endangered by the development of insecticide resistance in the major malaria vectors. This study was carried out to monitor the susceptibility status of major malaria vectors to insecticides used for IRS and LLINs in mainland Tanzania.
View Article and Find Full Text PDFIntroduction: Lymphatic filariasis (LF) is a chronic nematode infection transmitted by mosquitoes and in sub-Saharan Africa it is caused by Wuchereria bancrofti. The disease was targeted for global elimination by 2020 using repeated community-wide mass drug administration (MDA) distributed in endemic areas. However, recently, there has been a growing recognition of the potential role of including vector control as a supplement to MDA to achieve elimination goal.
View Article and Find Full Text PDFBackground: Despite considerable reductions in malaria achieved by scaling-up long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), maintaining sustained community protection remains operationally challenging. Increasing insecticide resistance also threatens to jeopardize the future of both strategies. Non-pyrethroid insecticide-treated wall lining (ITWL) may represent an alternate or complementary control method and a potential tool to manage insecticide resistance.
View Article and Find Full Text PDFBackground: Long-lasting insecticidal nets (LLINs) are the first line choice for malaria vector control in sub-Saharan Africa, with most countries adopting universal coverage campaigns. However, there is only limited information on LLIN durability under user conditions. Therefore, this study aimed to assess the durability of Olyset(®) LLINs distributed during campaigns between 2009 and 2011 in Tanzania.
View Article and Find Full Text PDFBackground: Experimental huts are simplified, standardized representations of human habitations that provide model systems to evaluate insecticides used in indoor residual spray (IRS) and long-lasting insecticidal nets (LLINs) to kill disease vectors. Hut volume, construction materials and size of entry points impact mosquito entry and exposure to insecticides. The performance of three standard experimental hut designs was compared to evaluate insecticide used in LLINs.
View Article and Find Full Text PDFBackground: Insecticide-treated nets are the primary method of preventing malaria. To remain effective, the pyrethroid insecticide must withstand multiple washes over the lifetime of the net. ICON(®) Maxx is a 'dip-it-yourself' kit for long-lasting treatment of polyester nets.
View Article and Find Full Text PDFBackground: Widespread and large scale use of ivermectin in humans and domestic animals can have unexpected effects on non-target organisms. As a search for a possible explanation for an observed longitudinal decline in density of anopheline vector mosquitoes, but not in Culex quinquefasciatus, in an area of north-eastern Tanzania which has been exposed to ivermectin mass drug administration, this study assessed and compared the effect of human ivermectin treatment on blood feeding Anopheles gambiae and Cx. quinquefasciatus.
View Article and Find Full Text PDFBackground: Studies on the East African coast have shown a recent dramatic decline in malaria vector density and change in composition of sibling species of the Anopheles gambiae complex, paralleled by a major decline in malaria incidence. In order to better understand the ongoing changes in vector-parasite dynamics in the area, and to allow for appropriate adjustment of control activities, the present study examined the composition, and malaria and lymphatic filarial infection, of sibling species of the Anopheles funestus group. Similar to the An.
View Article and Find Full Text PDFBackground: Lymphatic filariasis (LF) control started in Tanga Region of Tanzania in 2004, with annual ivermectin/albendazole mass drug administration (MDA). Since then, the current project has monitored the effect in communities and schools in rural areas of Tanga District. In 2013, after 8 rounds of MDA, spot check surveys were added in the other 7 districts of Tanga Region, to assess the regional LF status.
View Article and Find Full Text PDFResistance of mosquitoes to insecticides is mainly attributed to their adaptation to insecticide-based vector control interventions. Although pesticides used in agriculture have been frequently mentioned as an additional force driving the selection of resistance, only a few studies were dedicated to validate this hypothesis. The objective of this study was to investigate the effect of exposure of the malaria mosquito, Anopheles gambiae s.
View Article and Find Full Text PDFBackground: Plants represent one of the most accessible resources available for mosquito control by communities in Tanzania. However, no documented statistics exist for their contribution in the management of mosquitoes and other insects except through verbal and some publications. This study aimed at assessing communities' knowledge, attitudes and practices of using plants as an alternative method for mosquito control among selected communities in a malaria-prone area in Tanzania.
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