
Bilali KabulaNational Institute for Medical Research · Medical Entomology
Bilali Kabula
BVM, MPhil, PhD
Research Scientist and Public Health Consultant
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57
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Introduction
Publications
Publications (57)
Background
Effective vector control interventions, notably insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are indispensable for malaria control in Tanzania and elsewhere. However, the emergence of widespread insecticide resistance threatens the efficacy of these interventions. Monitoring of insecticide resistance is, therefore,...
To keep ahead of the evolution of resistance to insecticides in mosquitoes, national malaria control programmes must make use of a range of insecticides, both old and new, while monitoring resistance mechanisms. The outdoor-biting malaria vector Anopheles arabiensis is of increasing concern for malaria transmission because it is apparently less sus...
Background Effective vector control interventions, notably insecticide-treated nets (ITNs) and indoor residual spraying (IRS), are indispensable for malaria control in Tanzania and elsewhere. However, the emergence of widespread insecticide resistance threatens the efficacy of these interventions. Monitoring of insecticide resistance is therefore c...
Background
Artemether-lumefantrine (AL) is the first line anti-malarial drug for the treatment of uncomplicated malaria in Tanzania. The World Health Organization (WHO) recommends regular efficacy monitoring of anti-malarial drugs to inform case management policy decisions. This study assessed the safety and efficacy of AL for treating uncomplicate...
Background
Artemisinin-based combination therapy (ACT) has been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The World Health Organization...
Background
The use of artemisinin-based combination therapy (ACT) is recommended by the World Health Organization for the treatment of uncomplicated falciparum malaria. Artemether-lumefantrine (AL) is the most widely adopted first-line ACT for uncomplicated malaria in sub-Saharan Africa (SSA), including mainland Tanzania, where it was introduced in...
As part of malaria nationwide monitoring and evaluation initiatives, there is an increasing trend of incorporating malaria rapid diagnostic tests (mRDTs) in surveys conducted within primary schools to detect malaria parasites. However, mRDTs based on the detection of histidine-rich protein 2 (HRP2) are known to yield false-positive results due to p...
To keep ahead of the evolution of resistance to insecticides in mosquitoes, national malaria control programmes must make use of a range of insecticides, both old and new, while monitoring resistance mechanisms. Knowledge of the mechanisms of resistance remains limited in Anopheles arabiensis , which in many parts of Africa is of increasing importa...
Background
Therapeutic efficacy studies (TESs) and detection of molecular markers of drug resistance are recommended by the World Health Organization (WHO) to monitor the efficacy of artemisinin-based combination therapy (ACT). This study assessed the trends of molecular markers of artemisinin resistance and/or reduced susceptibility to lumefantrin...
Introduction: Therapeutic efficacy studies (TESs) and detection of molecular markers of drug resistance are recommended by the World Health Organization (WHO) to monitor the efficacy of artemisinin combination therapy (ACT). This study assessed the trends of molecular markers of artemisinin resistance and/or reduced susceptibility to lumefantrine u...
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...
Background
Artemisinin-based combination therapies (ACTs) have been a major contributor to the substantial reductions in global malaria morbidity and mortality over the last decade. In Tanzania, artemether-lumefantrine (AL) was introduced as the first-line treatment for uncomplicated Plasmodium falciparum malaria in 2006. The WHO recommends regular...
Background: Use of artemisinin combination therapy (ACT) is recommended by the World Health Organization (WHO) for the treatment of uncomplicated falciparum malaria. Artemether-lumefantrine (AL) is the most widely adopted first-line ACT for uncomplicated malaria in sub-Saharan Africa (SSA), including mainland Tanzania, where it was introduced in De...
Testing and treating asymptomatic populations have the potential to reduce the population's parasite reservoir and reduce malaria transmission. Zanzibar's malaria case notification (MCN) platform collects detailed sociodemographic and epidemiological data from all confirmed malaria cases to inform programmatic decision-making. We describe the desig...
Background
In 2015, Tanzania National Malaria Control Program (NMCP) established a Longitudinal National 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...
Achieving malaria elimination requires considering both Plasmodium falciparum and non-P. falciparum infections. We determined prevalence and geographic distribution of 4 Plasmodium spp. by performing PCR on dried blood spots collected within 8 regions of Tanzania during 2017. Among 3,456 schoolchildren, 22% had P. falciparum, 24% had P. ovale spp.,...
Testing and treating asymptomatic populations has the potential to reduce the population s parasite reservoir and reduce malaria transmission. The Zanzibar electronic malaria case notification (MCN) platform collects detailed socio-demographic and epidemiological data from all confirmed malaria cases to inform programmatic decision-making. This Fie...
Background
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 monitori...
Background
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) of households with insecticide. We describe the trends and dynamics of insecticide resistance and its underlining mechanisms from...
Background
Tanzania has made remarkable progress in reducing malaria burden and aims to transition from malaria control to sub-national elimination. In 2013, electronic weekly and monthly reporting platforms using the District Health Information System 2 (DHIS2) were introduced. Weekly reporting was implemented through the mobile phone-based Integr...
Background Tanzania has made remarkable progress in reducing malaria burden and aims to transition from malaria control to sub-national elimination. In 2013, electronic weekly and monthly reporting platforms using the District Health Information System 2 (DHIS2) were introduced. Weekly reporting was implemented through the mobile phone-based Integr...
Studies of insecticide resistance provide insights into the capacity of populations to show rapid evolutionary responses to contemporary selection. Malaria control remains heavily dependent on pyrethroid insecticides, primarily in long lasting insecticidal nets (LLINs). Resistance in the major malaria vectors has increased in concert with the expan...
Efforts to achieve malaria elimination need to consider both falciparum and non-falciparum infections. The prevalence and geographic distribution of four Plasmodium species were determined by real-time PCR using dried blood spots collected during the 2017 School Malaria Parasitological Survey of eight regions of Tanzania. Among 3,456 schoolchildren...
Background
Transmission of malaria in sub-Saharan Africa has become increasingly stratified following decades of malaria control interventions. The extent to which environmental and land cover risk factors for malaria may differ across distinct strata of transmission intensity is not well known and could provide actionable targets to maximize the s...
Insecticide resistance provides both a pressing threat to the control of vector-borne diseases and insights into the remarkable capacity of natural populations to show rapid evolutionary responses. Malaria control remains heavily dependent on deployment of insecticides, primarily in long lasting insecticide treated nets (LLINs), but resistance in t...
Abstract Background Over the past two decades, Zanzibar substantially reduced malaria burden. As malaria decreases, sustainable improvements in control interventions may increasingly depend on accurate knowledge of malaria risk factors to further target interventions. This study aimed to investigate the risk factors associated with malaria infectio...
Background
Over the past two decades, Zanzibar substantially reduced malaria burden. As malaria decreases, sustainable improvements in prevention and control interventions may increasingly depend on accurate knowledge of malaria risk factors to further target interventions. This study aimed to investigate the risk factors associated with malaria in...
Identification of partial sweeps, which include both hard and soft sweeps that have not currently reached fixation, provides crucial information about ongoing evolutionary responses. To this end, we introduce partialS/HIC, a deep learning method to discover selective sweeps from population genomic data. partialS/HIC uses a convolutional neural netw...
Insecticide resistance provides both an increasingly pressing threat to the control of vector-borne diseases and insights into the remarkable capacity of natural populations to show rapid evolutionary responses to contemporary selection. Malaria control remains heavily dependent on deployment of pyrethroid insecticides, primarily in long lasting in...
Data elements from Coconut were integrated into DHIS2 by using an application programming interface (API). The integrated data are synchronized daily. Four data elements from Coconut were integrated into DHIS2: y Malaria cases by type of diagnosis y Malaria cases by age y Malaria cases by gender y Malaria case classification Figure 1. Data flow fro...
Background: Insecticide-treated nets (ITNs) are highly effective in reducing morbidity and mortality from malaria. However, it is widely accepted that ITNs-if not retreated 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,...
Vector-borne disease control relies on efficient vector surveillance, mostly carried out using traps whose number and locations are often determined by expert opinion rather than a rigorous quantitative sampling design. In this work we propose a framework for ecological sampling design which in its preliminary stages can take into account environme...
Background:
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...
Vector-borne disease control relies on efficient vector surveillance, mostly carried out using traps whose number and locations are often determined by expert opinion rather than a rigorous quantitative sampling design. In this work we first propose a framework for ecological sampling design which in its preliminary stages can take into account env...
Background:
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 car...
Background
The success of malaria vector control is threatened by widespread pyrethroid insecticide resistance. However, the extent to which insecticide resistance impacts transmission is unclear. The objective of this study was to examine the association between the DDT/pyrethroid knockdown resistance mutation Vgsc-1014S, commonly termed kdr, and...
Background: The National Institute for Medical Research, Amani centre, in collaboration with National Malaria Control Programme, has been conducting annual insecticide resistance surveillance since 1999, aimed at early detection of resistance to insecticides used for malaria control in Tanzania. The Standard WHO method for larvae collection and rea...
Background
Pyrethroid resistance has been slower to emerge in Anopheles arabiensis than in An. gambiae s.s and An. funestus and, consequently, studies are only just beginning to unravel the genes involved. Permethrin resistance in An. arabiensis in Lower Moshi, Tanzania has been linked to elevated levels of both P450 monooxygenases and β-esterases....
The major foci of pyrethroid resistance in 1990 to 2010 were in West and Central African populations of
Anopheles gambiae s.s. Pyrethroid resistance in Anopheles arabiensis has been reported in several
countries of East and Central Africa. Four cross-sectional surveys of A. arabiensis in Lower Moshi were
conducted in 2009, 2011, 2012 and 2013 to de...
Objective:
Insecticide resistance molecular markers can provide sensitive indicators of resistance development in Anopheles vector populations. Assaying these makers is of paramount importance in the resistance monitoring programme. We investigated the presence and distribution of knock-down resistance (kdr) mutations in Anopheles gambiae s.l. in...
Background: The emergence of pyrethroid resistance in the malaria vector, Anopheles arabiensis, threatens to undermine the considerable gains made towards eliminating malaria on Zanzibar. Previously, resistance was restricted to the island of Pemba while mosquitoes from Unguja, the larger of the two islands of Zanzibar, were susceptible. Here, we c...
The emergence of pyrethroid resistance in the malaria vector, Anopheles arabiensis, threatens to undermine the considerable gains made towards eliminating malaria on Zanzibar. Previously, resistance was restricted to the island of Pemba while mosquitoes from Unguja, the larger of the two islands of Zanzibar, were susceptible. Here, we characterised...
The development of insecticide resistance is a threat to the control of malaria in Africa. We report the findings of a national survey carried out in Tanzania in 2011 to monitor the susceptibility of malaria vectors to pyrethroid, organophosphate, carbamate and DDT insecticides, and compare these findings with those identified in 2004 and 2010. Sta...
The aim of the study was to monitor the insecticide susceptibility status of malaria vectors in 12 sentinel districts of Tanzania.
WHO standard methods were used to detect knock-down and mortality in the wild female Anopheles mosquitoes collected in sentinel districts. The WHO diagnostic doses of 0.05% deltamethrin, 0.05% lambdacyhalothrin, 0.75% p...
In Sub Saharan Africa where most of the malaria cases and deaths occur, members of the Anopheles gambiae species complex and Anopheles funestus species group are the important malaria vectors. Control efforts against these vectors in Tanzania like in most other Sub Saharan countries have failed to achieve the set objectives of eliminating transmiss...
An entomological survey to determine resting behaviour and species composition of malaria vectors was carried out in Uyui District in western Tanzania in May 2009. Mosquitoes were collected using indoor resting catch, window exit trap and outdoor "bed-net" techniques. They mosquitoes were identified using morphological key and polymerase chain reac...
Malaria is endemic in Ghana as in most countries of sub-Saharan Africa. This study was
conducted to characterize Anopheles gambiae s.l. and determine pyrethroid resistance profiles relative to
physicochemical properties of breeding habitats in Accra, Ghana. Eight aquatic habitats containing
Anopheles larvae were identified and from each habitat, la...
As part of the feasibility study for an onchocerciasis vector elimination project we investigated the isolation of the Tukuyu focus in Tanzania from possible vector re-invasion. This was achieved by examining the distribution of the Simulium damnosum complex vector cytospecies outside the focus to look for potential sources of re-invasion. Besides...
A study involving 105 smallholder dairy farmers was conducted in Kibaha and Morogoro districts, Tanzania to characterise husbandry practices, milk production constraints; and farmers\' knowledge on milk-borne zoonoses. About 50% of the farmers in Kibaha (n=57) and 60% in Morogoro (n=48) were employed in formal public and private sectors, and hired...
A purposive cross-sectional epidemiological study was conducted in the Tukuyu Onchocerciasis focus in south-western Tanzania in 2004, ten years after launching the ivermectin mass treatment programme, and 23 years after establishing focal parasite prevalence. The objective was to assess contemporary Onchocerciasis clinical and parasitological situa...
To measure pyrethroid susceptibility in populations of malaria vectors and nuisance-biting mosquitoes in Tanzania and to test the biological efficacy of current insecticide formulations used for net treatment.
Anopheles gambiae Giles s.l., An. funestus Giles s.l. and Culex quinquefasciatus Say were collected during three national surveys and two in...
A cross-sectional study involving 64 smallholder dairy cattle was carried out in urban and peri-urban areas of Dodoma municipality situated in the semiarid central part of Tanzania in order to determine milking practices and prevalence of mastitis, bovine tuberculosis and brucellosis. Nineteen pastoral herds were also included in the study. A quest...
Summary A study was carried out to establish the prevalence and determinants of mastitis and milk-borne zoonoses in smallholder dairy farms in Kibaha and Morogoro districts (Tanzania). A total of 57 herds comprising 114 milking cows in Kibaha and 48 herds consisting of 96 milking animals in Morogoro were included in the study. A questionnaire surve...