scholarly journals An increasing role of pyrethroid-resistant Anopheles funestus in malaria transmission in the Lake Zone, Tanzania

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nancy S. Matowo ◽  
Jackline Martin ◽  
Manisha A. Kulkarni ◽  
Jacklin F. Mosha ◽  
Eliud Lukole ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Anopheles Funestus ◽  
Sub Saharan Africa ◽  
North West ◽  
Vector Population ◽  
Lake Zone ◽  
Sub Saharan ◽  
Long Lasting Insecticidal Nets ◽  
Study District

AbstractAnopheles funestus is playing an increasing role in malaria transmission in parts of sub-Saharan Africa, where An. gambiae s.s. has been effectively controlled by long-lasting insecticidal nets. We investigated vector population bionomics, insecticide resistance and malaria transmission dynamics in 86 study clusters in North-West Tanzania. An. funestus s.l. represented 94.5% (4740/5016) of all vectors and was responsible for the majority of malaria transmission (96.5%), with a sporozoite rate of 3.4% and average monthly entomological inoculation rate (EIR) of 4.57 per house. Micro-geographical heterogeneity in species composition, abundance and transmission was observed across the study district in relation to key ecological differences between northern and southern clusters, with significantly higher densities, proportions and EIR of An. funestus s.l. collected from the South. An. gambiae s.l. (5.5%) density, principally An. arabiensis (81.1%) and An. gambiae s.s. (18.9%), was much lower and closely correlated with seasonal rainfall. Both An. funestus s.l. and An. gambiae s.l. were similarly resistant to alpha-cypermethrin and permethrin. Overexpression of CYP9K1, CYP6P3, CYP6P4 and CYP6M2 and high L1014S-kdr mutation frequency were detected in An. gambiae s.s. populations. Study findings highlight the urgent need for novel vector control tools to tackle persistent malaria transmission in the Lake Region of Tanzania.

scholarly journals Increasing role of pyrethroid-resistant Anopheles funestus in malaria transmission in the Lake Zone, Tanzania: implications for the evaluation of novel vector control products

2021 ◽  
Author(s):  
Nancy S. Matowo ◽  
Jackline Martin ◽  
Manisha A. Kulkarni ◽  
Jacklin F. Mosha ◽  
Eliud Lukole ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
Anopheles Funestus ◽  
Sub Saharan Africa ◽  
North West ◽  
Vector Population ◽  
Lake Zone ◽  
Sub Saharan ◽  
Study District

AbstractAnopheles funestus is playing an increasing role in malaria transmission in parts of sub-Saharan Africa, where An. gambiae s.s. has been effectively controlled by long-lasting insecticidal nets. We investigated vector population bionomics, insecticide resistance and malaria transmission dynamics in 86 study clusters in North-West Tanzania. An. funestus s.l. represented 94.5% (4740/5016) of all vectors and was responsible for the majority of malaria transmission (96.5%), with a sporozoite rate of 3.4% and average monthly entomological inoculation rate (EIR) of 4.57 per house. Micro-geographical heterogeneity in species composition, abundance and transmission was observed across the study district in relation to key ecological differences between northern and southern clusters, with significantly higher densities, proportions and EIR of An. funestus s.l. collected from the south. An. gambiae s.l. (5.5%) density, principally An. arabiensis (81.1%) and An. gambiae s.s. (18.9%), was much lower and closely correlated with seasonal rainfall. Both An. funestus s.l. and An. gambiae s.l. were similarly resistant to alpha-cypermethrin and permethrin. Overexpression of CYP9K1, CYP6P3, CYP6P4 and CYP6M2 and high L1014F-kdr mutation frequency were detected in An. gambiae s.s. populations. Study findings highlight the urgent need for novel vector control tools to tackle persistent malaria transmission in the Lake Region of Tanzania.

scholarly journals The dominant malaria vector, Anopheles funestus from rural south-eastern Tanzania, is more strongly resistant to insecticides than Anopheles arabiensis

2020 ◽  
Author(s):  
Polius Gerazi Pinda ◽  
Claudia Eichenberger ◽  
Halfan S Ngowo ◽  
Dickson S Msaky ◽  
Said Abbasi ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Pyrethroid Resistance ◽  
Mosquito Species ◽  
Anopheles Funestus ◽  
Indoor Residual Spraying ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Insecticide Treated Nets ◽  
South Eastern ◽  
Sub Saharan

Abstract Background: Long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) have greatly reduced malaria transmission in sub-Saharan Africa, but are threatened by insecticide resistance in dominant malaria vectors. In south-eastern Tanzania, pyrethroid-resistant Anopheles funestus now transmit more than 80% of malaria infections even in villages where the species occurs at far lower densities than other vectors such as Anopheles arabiensis.Methods: To better understand the dominance of An. funestus in these settings and improve options for its control, this study compared intensities of resistance between females of this species and those of An. arabiensis , using WHO assays with 1×, 5× and 10× insecticide doses. Additional tests were done to assess the reversibility of such resistance using synergists. The mosquitoes were collected from villages across two districts in south-eastern Tanzania.Findings: Both species were resistant to the two pyrethroids (permethrin and deltamethrin) and the organochloride (DDT) but susceptible to the organophosphate (pirimiphos-methyl) at standard baseline doses (1×). However, An. funestus as opposed to An. arabiensis was also resistant to the carbamate (bendiocarb) at standard doses (1×). An. funestus showed strong resistance to pyrethroids, surviving the 5× doses and 10× doses except in one village. Pre-exposure to the synergist, piperonyl butoxide (PBO), reversed the pyrethroid-resistance in both An. arabiensis and An. funestus achieving mortalities >98%, except for An. funestus from two villages for which permethrin-associated mortalities exceeded 90% but not 98%.Conclusions : In these communities where An. funestus now dominates malaria transmission, the species also displays much stronger resistance to pyrethroids than its counterpart, An. arabiensis, and can readily survive more classes of insecticides, including carbamates. The resistance to pyrethroids in both mosquito species appears to be mostly metabolic and can be reversed significantly using synergists such as PBO. These findings may explain the continued persistence and dominance of An. funestus despite widespread use of pyrethroid-treated LLINs, and will also inform future choices of interventions to tackle malaria transmission in this area and other similar settings. Such interventions may include PBO-based LLINs or improved IRS with compounds such as organophosphates against which the vectors are still susceptible.

Financing Energy Access in Africa

2018 ◽  
Author(s):  
Peter Kayode Oniemola ◽  
Jane Ezirigwe
Keyword(s):  
Oil And Gas ◽  
Sub Saharan Africa ◽  
Capital Investments ◽  
Energy Access ◽  
African Countries ◽  
Sustainable Technologies ◽  
Energy Technologies ◽  
Sub Saharan ◽  
Diesel Motors

To achieve universal energy access will attract huge capital investments. If sub-Saharan Africa is to realize anything close to the ambitious goals set for its energy access, then new actors, innovative funding mechanisms and sustainable technologies will have to be attracted. Finance is needed for activities such as rural electrification, clean cooking facilities, diesel motors and generators, other renewable energy technologies, oil and gas infrastructures, etc. Finance is also needed in research and development of suitable technologies and funding options as well as investment in the capacity to formulate and implement sound energy policies. This chapter examines the varied financing options for energy access in sub-Saharan Africa. It argues that with appropriate laws in place and effective mechanism for implementation, African countries can significantly engage private sector financing, international financial institutions and foreign donors. The role of the law here will be in creating an enabling environment for financing.

Human Development Paradigm for South Asia

2018 ◽  
Keyword(s):  
South Asia ◽  
Human Development ◽  
Sub Saharan Africa ◽  
Health And Nutrition ◽  
The People ◽  
Sub Saharan ◽  
Development Paradigm

In the chapter, Haq gives a snapshot of the human progress of South Asia, comparing it with other regions. He was worried about the region beginning to lag behind all other regions, including Sub-Saharan Africa. He highlights the role of the two largest economies in the region, India and Pakistan, in financing the major investment in education, health and nutrition for the people. Haq advocates some fiscal and monetary reforms are suggested to invest in human development.

Adoption of improved cassava varieties in Nigeria: Insights from DNA fingerprinting versus self-reporting varietal identification approaches

2021 ◽  
pp. 003072702199003
Author(s):  
Patience Ifeyinwa Opata ◽  
Oguejiofor Joseph Okorie ◽  
Juliana Chinasa Iwuchukwu ◽  
Chukwuma Otum Ume ◽  
Oyakhilomen Oyinbo
Keyword(s):  
Measurement Errors ◽  
Empirical Studies ◽  
Sub Saharan Africa ◽  
Limited Attention ◽  
Adoption Studies ◽  
Hidden Hunger ◽  
Varietal Identification ◽  
Sub Saharan ◽  
Cassava Varieties

Much of the empirical studies on crop varietal adoption in Sub-Saharan Africa relied on self-reported adoption in farm-household surveys, which is prone to measurement errors. In addition, farmers’ perceptions of consumption-related varietal traits in adoption studies has received limited attention compared with production-related traits. Using DNA-based and self-reported adoption measures, we analyze the adoption of improved cassava varieties (ICVs) with a focus on the extent of varietal misidentification, the sensitivity of the drivers of adoption to varietal misidentification and the role of farmers’ perceptions of biofortification trait in adoption decisions. We find that the adoption rate of ICVs is relatively high using both DNA-based and self-reported adoption measures, but there is notable misclassification in varietal adoption. We find that the mismatch in DNA-based and self-reported adoption measures leads to some variation in the factors that influence the likelihood and intensity of adoption of ICVs. This suggests that appropriate varietal identification helps in better understanding of the drivers of adoption. In addition, we find that despite the observed varietal misclassification, farmers’ perceptions of biofortification trait is significantly correlated with the probability and intensity of adoption of ICVs using both DNA-based and self-reported varietal identification. This suggests that inclusion of biofortification trait in cassava matters for both the likelihood and extent of adoption of ICVs. The latter lends credence to the emerging policy interests in breeding programs for biofortified crops to address hidden hunger in Nigeria.

scholarly journals Insights into factors sustaining persistence of high malaria transmission in forested areas of sub-Saharan Africa: the case of Mvoua, South Cameroon

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dominique Mieguim Ngninpogni ◽  
Cyrille Ndo ◽  
Patrick Ntonga Akono ◽  
Anicet Nguemo ◽  
Amine Nguepi ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Malaria Transmission ◽  
Anopheles Funestus ◽  
Mortality Rates ◽  
Molecular Techniques ◽  
Sub Saharan Africa ◽  
World Health ◽  
Enzyme Linked Immunosorbent Assay ◽  
Pyrethroid Insecticides ◽  
Kisumu Strain

Abstract Background In Mvoua, a village situated in a forested area of Cameroon, recent studies have reported high prevalence of Plasmodium falciparum infection among the population. In order to understand factors that can sustain such a high malaria transmission, we investigated the biology of Anopheles vectors and its susceptibility to insecticides, as well as long-lasting insecticidal net (LLIN) coverage, use and bio-efficacy. Methods A longitudinal entomological survey was conducted from July 2018 to April 2019. Adult mosquitoes were collected using the human landing catch (HLC) method and identified using morphological and molecular techniques. Anopheles gambiae (s.l.) larvae were sampled from several stagnant water pools throughout the village and reared to generate F1 adults. The presence of P. falciparum circumsporozoite antigen was detected in the heads and thoraces of mosquitoes collected as adults using an enzyme-linked immunosorbent assay. The insecticide susceptibility status of the local An. gambiae (s.l.) F1 population to the pyrethroid insecticides deltamethrin 0.5% and permethrin 0.75% was determined using World Health Organization-tube bioassays, while the frequency of the knockdown resistance (kdr) mutation was determined by PCR. Coverage, use and physical integrity of LLINs were assessed in households, then cone assays were used to test for their bio-efficacy on both the reference insecticide-susceptible Kisumu strain and on field F1 An. gambiae (s.l.) Results In total, 110 Anopheles mosquitoes were collected, of which 59.1% were identified as Anopheles funestus (s.l.), 38.18% as An. gambiae (s.l.) and 2.72% as An. ziemanii. Anopheles funestus was the most abundant species except in the long rainy season, when An. gambiae (s.l.) predominated (65.8%). In the dry seasons, vectors were principally endophagous (76% of those collected indoors) while they tended to be exophagous (66% of those collected outdoors) in rainy seasons. High Plasmodium infection was observed in An. gambiae (s.l.) and An. funestus, with a circumsporozoitic rate of 14.29 and 10.77%, respectively. Anopheles gambiae (s.l.) was highly resistant to pyrethroid insecticides (mortality rates: 32% for permethrin and 5% for deltamethrin) and harbored the kdr-L1014F mutation at a high frequency (89.74%). Of the 80 households surveyed, only 47.69% had achieved universal coverage with LLNs. Around 70% of the LLINs sampled were in poor physical condition, with a proportionate hole index > 300. Of the ten LLNs tested, eight were effective against the An. gambiae reference insecticide-susceptible Kisumu strain, showing mortality rate of > 80%, while none of these LLINs were efficient against local An. gamabie (s.l.) populations (mortality rates < 11.5%). Conclusion A combination of elevated P. falciparum infection in Anopheles vector populations, insufficient coverage and loss of effectiveness of LLINs due to physical degradation, as well as high resistance to pyrethroid insecticides is responsible for the persistence of high malaria transmission in forested rural area of Mvoua, Cameroon.

scholarly journals Circular Bioeconomy Research for Development in Sub-Saharan Africa: Innovations, Gaps, and Actions

2021 ◽  
Vol 13 (4) ◽  
pp. 1926 ◽  
Author(s):  
Shiferaw Feleke ◽  
Steven Michael Cole ◽  
Haruna Sekabira ◽  
Rousseau Djouaka ◽  
Victor Manyong
Keyword(s):  
Gap Analysis ◽  
Farming Systems ◽  
Crop Productivity ◽  
Sub Saharan Africa ◽  
International Institute ◽  
The Public ◽  
Secondary Sources ◽  
Use Efficiency ◽  
Sub Saharan

The International Institute of Tropical Agriculture (IITA) has applied the concept of ‘circular bioeconomy’ to design solutions to address the degradation of natural resources, nutrient-depleted farming systems, hunger, and poverty in sub-Saharan Africa (SSA). Over the past decade, IITA has implemented ten circular bioeconomy focused research for development (R4D) interventions in several countries in the region. This article aims to assess the contributions of IITA’s circular bioeconomy focused innovations towards economic, social, and environmental outcomes using the outcome tracking approach, and identify areas for strengthening existing circular bioeconomy R4D interventions using the gap analysis method. Data used for the study came from secondary sources available in the public domain. Results indicate that IITA’s circular bioeconomy interventions led to ten technological innovations (bio-products) that translated into five economic, social, and environmental outcomes, including crop productivity, food security, resource use efficiency, job creation, and reduction in greenhouse gas emissions. Our gap analysis identified eight gaps leading to a portfolio of five actions needed to enhance the role of circular bioeconomy in SSA. The results showcase the utility of integrating a circular bioeconomy approach in R4D work, especially how using such an approach can lead to significant economic, social, and environmental outcomes. The evidence presented can help inform the development of a framework to guide circular bioeconomy R4D at IITA and other research institutes working in SSA. Generating a body of evidence on what works, including the institutional factors that create enabling environments for circular bioeconomy approaches to thrive, is necessary for governments and donors to support circular bioeconomy research that will help solve some of the most pressing challenges in SSA as populations grow and generate more waste, thus exacerbating a changing climate using the linear economy model.

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