Samson Kiware

Samson Kiware
Ifakara Health Institute | IHI · Environmental Health and Ecological Sciences Thematic Group

Computer Science & Mathematics

About

71
Publications
17,074
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Introduction
I work as a Research Scientist at IHI with research interests in developing mathematical models for optimization of vector control tools. I support the knowledge management portfolio for the Pan African Mosquito Control Association (PAMCA) and data management and analysis for various National Malaria Control/Elimination Programs across sub-Saharan Africa. I provide consultation services for projects aimed at supporting NMCPs
Additional affiliations
January 2010 - present
Ifakara Health Institute
Position
  • Researcher
Description
  • Work on bioinformatics and mathematical modelling projects related to malaria transmission, control, and elimination

Publications

Publications (71)
Preprint
Full-text available
Background Semi-field experiments are an efficient way of assessing the impacts of potential new vector control tools (VCTs) before field trials. However, their design is critically important to ensure their results are unbiased and informative. An essential element of the design of semi-field experiments is power analysis, which empowers researche...
Article
Full-text available
To explore the effects of climate change on malaria and 20 neglected tropical diseases (NTDs), and potential effect amelioration through mitigation and adaptation, we searched for papers published from January 2010 to October 2023. We descriptively synthesised extracted data. We analysed numbers of papers meeting our inclusion criteria by country a...
Article
Full-text available
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...
Article
Full-text available
Africa and the United States are both large, heterogeneous geographies with a diverse range of ecologies, climates and mosquito species diversity which contribute to disease transmission and nuisance biting. In the United States, mosquito control is nationally, and regionally coordinated and in so much as the Centers for Disease Control (CDC) provi...
Preprint
Full-text available
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...
Article
Full-text available
The Ross-Macdonald model has exerted enormous influence over the study of malaria transmission dynamics and control, but it lacked features to describe parasite dispersal, travel, and other important aspects of heterogeneous transmission. Here, we present a patch-based differential equation modeling framework that extends the Ross-Macdonald model w...
Preprint
Full-text available
Background Despite significant progress against malaria, the use of two core interventions, namely insecticide-treated nets (ITNs) and indoor residual spraying (IRS), are becoming increasingly vulnerable due to insecticide resistance and outdoor biting by mosquitoes. One representative example is Kilombero Valley in Tanzania where transmission cont...
Preprint
Full-text available
Background: Indoor Residual Spray (IRS) has proven to be one of the most effective malaria vector control interventions in reducing malaria transmission mainly in areas with high transmission. With the support from the US President’s Malaria Initiative (PMI), Tanzania has gone through expansion of IRS implementation with different insecticides from...
Article
Full-text available
Background: Malaria remains a major public health problem in sub-Saharan Africa. The 2021 World Health Organization (WHO) World Malaria Report indicates a slowing in the decline of malaria incidence since 2015. Malaria prevalence in Zanzibar has been maintained at less than 1% since 2010, however from 2018 to 2021, the annual number of reported ma...
Article
Full-text available
Background: Zanzibar is among the few places within East Africa that have documented a significant reduction of malaria morbidity and mortality. Despite tremendous gains over the past decade, malaria transmission still persists in Zanzibar. This study aimed at understanding levels of malaria knowledge to provide recommendations that can be used to...
Preprint
Full-text available
The Ross-Macdonald model has exerted enormous influence over the study of malaria transmission dynamics and control, but it lacked features to describe parasite dispersal, travel, and other important aspects of heterogeneous transmission. Here, we present a patch-based differential equation modeling framework that extends the Ross-Macdonald model w...
Article
Full-text available
Background Estimating human exposure to mosquito vectors is crucial for the prediction of malaria transmission and intervention impact. The human landing catch method is frequently used to directly measure estimate exposure rates; however, there has been an increasing shift from this method to exposure-free alternatives, such as the mosquito electr...
Preprint
Full-text available
Background: Estimating human exposure to mosquito vectors is crucial for the prediction of malaria transmission and intervention impact. Human Landing Catches are frequently used to directly measure estimate exposure rates; however, there has been an increasing shift from this method to exposure-free alternatives such as the Mosquito Electrocuting...
Article
Full-text available
Background Low-level of malaria transmission persist in Zanzibar despite high coverage of core vector control interventions. This study was carried out in hot-spot sites to better understand entomological factors that may contribute to residual malaria transmission in Zanzibar. Methods A total of 135 households were randomly selected from six site...
Preprint
Full-text available
Background: Low-level of malaria transmission persist in Zanzibar despite high coverage of core vector control interventions. This study was carried out in hot-spot shehias to better understand entomological factors that may contribute to residual malaria transmission in Zanzibar. Methods: A total of 135 households were randomly selected from six s...
Article
Full-text available
Background: Effective targeting and evaluation of interventions that protect against adult malaria vectors requires an understanding of how gaps in personal protection arise. An improved understanding of human and mosquito behaviour, and how they overlap in time and space, is critical to estimating the impact of insecticide-treated nets (ITNs) and...
Article
Full-text available
In vector control, it is widely accepted that killing adult mosquitoes would sharply reduce the proportion of old mosquitoes and cause the greatest changes to malaria transmission. The principle is based on a mathematical model of the sporozoite rate (the proportion of infective mosquitoes) that emphasized changes in mosquito age. Killing adult mos...
Article
Full-text available
An amendment to this paper has been published and can be accessed via the original article.
Article
Full-text available
As every country in the world struggles with the ongoing COVID-19 pandemic, it is essential that as many people as possible understand the epidemic containment, elimination and exclusion strategies required to tackle it. Simplified arithmetic models of COVID-19 transmission, control and elimination are presented in user-friendly Shiny and Excel for...
Article
Full-text available
Background: Zanzibar provides a good case study for malaria elimination. The islands have experienced a dramatic reduction in malaria burden since the introduction of effective vector control interventions and case management. Malaria prevalence has now been maintained below 1% for the past decade and the islands can feasibly aim for elimination....
Article
Full-text available
After mating, female mosquitoes need animal blood to develop their eggs. In the process of acquiring blood, they may acquire pathogens, which may cause different diseases in humans such as malaria, zika, dengue, and chikungunya. Therefore, knowing the parity status of mosquitoes is useful in control and evaluation of infectious diseases transmitted...
Article
Full-text available
Mosquitoes are important vectors for pathogens that infect humans and other vertebrate animals. Some aspects of adult mosquito behavior and mosquito ecology play an important role in determining the capacity of vector populations to transmit pathogens. Here, we re-examine factors affecting the transmission of pathogens by mosquitoes using a new app...
Preprint
Full-text available
Half the world's population is already under lock-down and the remainder will have to follow if the ongoing novel coronavirus 2019 (COVID-19) virus pandemic is to be contained. Faced with such brutally difficult decisions, it is essential that as many people as possible understand (1) why lock-down interventions represent the only realistic way for...
Preprint
Full-text available
Background After mating, female mosquitoes need animal blood to develop their eggs. In the process of acquiring blood, they may acquire pathogens, which may cause different diseases to humans such as malaria, zika, dengue, and chikungunya. Therefore, knowing the parity status of mosquitoes is useful in control and evaluation of infectious diseases...
Poster
Full-text available
The poster is presenting results on the first study reporting the use of an autoencoder and artificial neural network-based method to estimate parity status of wild mosquitoes using near infrared spectroscopy. We prove our method on four different datasets with wild An. arabiensis and An. gambiae collected from Ifakara Tanzania, Muleba Tanzania and...
Preprint
Full-text available
Background: Zanzibar provides a good case study for malaria elimination. The islands have experienced a dramatic reduction in malaria burden since the introduction of effective vector control interventions and case management. Malaria prevalence has now been maintained below 1% for the past decade and the islands can feasibly aim for elimination. M...
Preprint
Full-text available
Background Zanzibar provides a good case study for malaria elimination. The islands have experienced a dramatic reduction in malaria burden since the introduction of effective vector control interventions and case management. Malaria prevalence has now been maintained below 1% for the past decade and the islands can feasibly aim for elimination. M...
Preprint
Full-text available
Mosquitoes are important vectors for pathogens of humans and other vertebrate animals. Some aspects of adult mosquito behavior and mosquito ecology play an important role in determining the capacity of vector populations to transmit pathogens. Here, we re-examine factors affecting the transmission of pathogens by mosquitoes using a new approach. Un...
Article
Full-text available
Background Near infrared spectroscopy (NIRS) is currently complementing techniques to age-grade mosquitoes. NIRS classifies lab-reared and semi-field raised mosquitoes into < or ≥ 7 days old with an average accuracy of 80%, achieved by training a regression model using partial least squares (PLS) and interpreted as a binary classifier. Methods and...
Article
Full-text available
Background: Autodissemination of pyriproxyfen (PPF), i.e. co-opting adult female mosquitoes to transfer the insect growth regulator, pyriproxyfen (PPF) to their aquatic habitats has been demonstrated for Aedes and Anopheles mosquitoes. This approach, could potentially enable high coverage of aquatic mosquito habitats, including those hard to locat...
Preprint
Full-text available
Background Near infrared spectroscopy (NIRS) is currently complementing techniques to age-grade mosquitoes. NIRS classifies lab-reared and semi-field raised mosquitoes into < or ≥ 7 days old with an average accuracy of 80%, achieved by training a regression model using partial least squares (PLS) and interpreted as a binary classifier. Methods and...
Article
Full-text available
As Africa-wide malaria prevalence declines, an understanding of human movement patterns is essential to inform how best to target interventions. We fitted movement models to trip data from surveys conducted at 3–5 sites throughout each of Mali, Burkina Faso, Zambia and Tanzania. Two models were compared in terms of their ability to predict the obse...
Article
Full-text available
Background: The effectiveness of long-lasting insecticidal-treated nets (LLINs) and indoor residual spraying (IRS) for malaria control is threatened by resistance to commonly used pyrethroid insecticides. Rotations, mosaics, combinations, or mixtures of insecticides from different complementary classes are recommended by the World Health Organizat...
Article
Full-text available
Background Despite great achievements by insecticide-treated nets (ITNs) and indoor residual spraying (IRS) in reducing malaria transmission, it is unlikely these tools will be sufficient to eliminate malaria transmission on their own in many settings today. Fortunately, field experiments indicate that there are many promising vector control interv...
Data
Model schematic diagram. Flow diagram for the mosquito ecological model, mosquito SEI model, and human SI model. (TIF)
Data
Illustrations of the impact of indoor interventions. The schematic illustrates the probability of mosquito being repelled or killed upon encountering indoor interventions. (TIF)
Data
Illustrations of VCOM’s simple graphic user interface. (TIF)
Data
Parameter values for the vector and human components of the model. (DOCX)
Data
Basic parameter estimates for the vector ecology and control model. (DOCX)
Data
Evaluating the impact of combining ITNs at 50% and 80% coverage with additional tools against An. funestus. (TIF)
Data
Parameter for the effectiveness of all interventions considered. (DOCX)
Data
Brief description of the model parameter values. (DOCX)
Data
VCOM software—User graphical interface. (DOCX)
Data
Targeting mosquito on multiple fronts. The schematic highlights opportunities for vector control to target biological and environmental mosquito resources. (TIF)
Data
Sensitivity analysis results for An. funestus. (TIF)
Data
Full details of the mathematical models. (DOCX)
Article
Full-text available
Protecting individuals and households against mosquito bites with long-lasting insecticidal nets (LLINs) or indoor residual spraying (IRS) can suppress entire populations of unusually efficient malaria vector species that predominantly feed indoors on humans. Mosquitoes which usually feed on animals are less reliant on human blood, so they are far...
Article
Full-text available
Residual malaria transmission can persist despite high coverage with effective long-lasting insecticidal nets (LLINs) and/or indoor residual spraying (IRS), because many vector mosquitoes evade them by feeding on animals, feeding outdoors, resting outdoors or rapidly exiting from houses after entering them. However, many of these behaviours that re...
Poster
Full-text available
Despite great achievements by long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS), research demonstrates that these tools are insufficient to eliminate malaria transmission in many settings today. Protective coverage from these interventions is attenuated where mosquitoes can access blood resources from non-human hosts...
Article
The failure of the Global Malaria Eradication Program (GMEP) during the 1960s highlighted the relevance of human movement to both re-introducing parasites in elimination settings and spreading drug-resistant parasites widely. Today, given the sophisticated surveillance of human movement patterns and key traveler groups, it is hoped that interventio...
Article
Full-text available
Background As malaria prevalence declines in many parts of the world due to widescale control efforts and as drug-resistant parasites begin to emerge, a quantitative understanding of human movement is becoming increasingly relevant to malaria control. However, despite its importance, significant knowledge gaps remain regarding human movement, parti...
Article
Full-text available
Background Standardized schemas, databases, and public data repositories are needed for the studies of malaria vectors that encompass a remarkably diverse array of designs and rapidly generate large data volumes, often in resource-limited tropical settings lacking specialized software or informatics support. Results Data from the majority of mosqu...
Article
Full-text available
In the Tanzanian city of Dar es Salaam, high coverage of long-lasting insecticidal nets (LLINs), larvicide application (LA) and mosquito-proofed housing, was complemented with improved access to artemisinin-based combination therapy and rapid diagnostic tests by the end of 2012. Three rounds of city-wide, cluster-sampled cross-sectional surveys o...
Article
Full-text available
Background The significance of malaria transmission occurring outdoors has risen even in areas where indoor interventions such as long-lasting insecticidal nets and indoor residual spraying are common. The actual contamination rates and effectiveness of recently developed outdoor mosquito control device, the mosquito landing box (MLB), on densities...
Article
Full-text available
Background: Large-cage experiments indicate pyriproxifen (PPF) can be transferred from resting sites to aquatic habitats by Anopheles arabiensis--malaria vector mosquitoes to inhibit emergence of their own offspring. PPF coverage is amplified twice: (1) partial coverage of resting sites with PPF contamination results in far higher contamination co...
Article
Full-text available
Eliminating malaria requires vector control interventions that dramatically reduce adult mosquito population densities and survival rates. Indoor applications of insecticidal nets and sprays are effective against an important minority of mosquito species that rely heavily upon human blood and habitations for survival. However, complementary approac...
Article
Full-text available
Background In order to sustain the gains achieved by current malaria control strategies, robust surveillance systems that monitor dynamics of vectors and their roles in malaria transmission over time are essential. This longitudinal study demonstrates the trends in malaria vector dynamics and their relative contribution to malaria transmission in h...
Article
Full-text available
Malaria vector control strategies that target adult female mosquitoes are challenged by the emergence of insecticide resistance and behavioural resilience. Conventional larviciding is restricted by high operational costs and inadequate knowledge of mosquito-breeding habitats in rural settings that might be overcome by the juvenile hormone analogue,...
Article
Full-text available
One of the main challenges to malaria elimination is the resilience of vectors, such as Anopheles arabiensis, that evade lethal exposure to insecticidal control measures or express resistance to their active ingredients. This study investigated a novel technology for population control that sterilizes mosquitoes using pyriproxyfen, a juvenile hormo...
Article
Full-text available
The suppression of indoor malaria transmission requires additional interventions that complement the use of insecticide treated nets (ITNs) and indoor residual spraying (IRS). Previous studies have examined the impact of house structure on malaria transmission in areas of low transmission. This study was conducted in a high transmission setting and...
Article
Full-text available
Background Indoor residual insecticide spraying (IRS) and long-lasting insecticide treated nets (LLINs) are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. Methods A deterministic model of mosquito life cycle processes was adapted to allow parame...
Article
Full-text available
High coverage of personal protection measures that kill mosquitoes dramatically reduce malaria transmission where vector populations depend upon human blood. However, most primary malaria vectors outside of sub-Saharan Africa can be classified as "very zoophagic," meaning they feed occasionally (<10% of blood meals) upon humans, so personal protect...
Article
Full-text available
Mosquitoes, which evade contact with long-lasting insecticidal nets and indoor residual sprays, by feeding outdoors or upon animals, are primary malaria vectors in many tropical countries. They can also dominate residual transmission where high coverage of these front-line vector control measures is achieved. Complementary strategies, which extend...