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BACKGROUND: Designing, implementing, and upscaling of effective malaria vector control strategies necessitates an understanding of when and where transmission occurs. This study assessed the biting patterns of potentially infectious malaria vectors at various hours, locations, and associated human behaviors in different ecological settings in western Kenya. METHODS: Hourly indoor and outdoor catches of human-biting mosquitoes were sampled from 19:00 to 07:00 for four consecutive nights in four houses per village. The human behavior study was conducted via questionnaire surveys and observations. Species within the Anopheles gambiae complex and Anopheles funestus group were distinguished by polymerase chain reaction (PCR) and the presence of Plasmodium falciparum circumsporozoite proteins (CSP) determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Altogether, 2037 adult female anophelines were collected comprising the An. funestus group (76.7%), An. gambiae sensu lato (22.8%), and Anopheles coustani (0.5%). PCR results revealed that Anopheles arabiensis constituted 80.5% and 79% of the An. gambiae s.l. samples analyzed from the lowland sites (Ahero and Kisian, respectively). Anopheles gambiae sensu stricto (hereafter An. gambiae) (98.1%) was the dominant species in the highland site (Kimaeti). All the An. funestus s.l. analyzed belonged to An. funestus s.s. (hereafter An. funestus). Indoor biting densities of An. gambiae s.l. and An. funestus exceeded the outdoor biting densities in all sites. The peak biting occurred in early morning between 04:30 and 06:30 in the lowlands for An. funestus both indoors and outdoors. In the highlands, the peak biting of An. gambiae occurred between 01:00 and 02:00 indoors. Over 50% of the study population stayed outdoors from 18:00 to 22:00 and woke up at 05:00, coinciding with the times when the highest numbers of vectors were collected. The sporozoite rate was higher in vectors collected outdoors, with An. funestus being the main malaria vector in the lowlands and An. gambiae in the highlands. CONCLUSION: This study shows heterogeneity of anopheline distribution, high outdoor malaria transmission, and early morning peak biting activity of An. funestus when humans are not protected by bednets in the lowland sites. Additional vector control efforts targeting the behaviors of these vectors, such as the use of non-pyrethroids for indoor residual spraying and spatial repellents outdoors, are needed.

The mitochondrial marker, COII, was employed to assess the genetic structure and diversity of Anopheles funestus, a very important malaria vector in Africa that adapt and colonize different ecological niches in western Kenya. Mosquitoes were collected using mechanical aspirators in four areas (Bungoma, Port Victoria, Kombewa, and Migori) in western Kenya. Following morphological identification, PCR was used to confirm the species. The COII gene was amplified, sequenced, and analyzed to determine genetic diversity and population structure. A total of 126 (Port Victoria-38, Migori-38, Bungoma-22, and Kombewa-28) sequences of COII were used for population genetic analysis. Anopheles funestus had a high haplotype diversity (Hd = 0.97 to 0.98) but low nucleotide diversity (Π = 0.004 to 0.005). The neutrality test revealed negative Tajima's D and Fs values indicating an excess of low-frequency variation. This could be attributed to either population expansion or negative selection pressure across all the populations. No genetic or structural differentiation (Fst = -0.01) and a high level of gene flow (Gamma St, Nm = 17.99 to 35.22) were observed among the populations. Population expansion suggests the high adaptability of this species to various ecological requirements, hence sustaining its vectorial capacity and malaria transmission.

Multidrug-resistant tuberculosis (TB) (MDR-TB), or TB that is simultaneously resistant to both isoniazid (INH) and rifampicin (RIF), is a barrier to successful TB control and treatment. Stratified data on MDR-TB, particularly in the high-burden western Kenya region, remain unknown. This data is important to monitor the efficacy of TB control and treatment efforts. Herein, we determined the molecular epidemiology of drug-resistant TB and associated risk factors in western Kenya. This was a non-experimental, population-based, cross-sectional study conducted between January and August 2018. Morning sputum samples of individuals suspected of pulmonary TB were collected, processed, and screened for Mycobacterium tuberculosis (Mtb) and drug resistance using line probe assay (LPA) and Mycobacterium growth indicator tubes (MGIT) culture. MGIT-positive samples were cultured on brain heart infusion (BHII) agar media, and the presence of Mtb was validated using Immunochromatographic assay (ICA). Drug sensitivity was performed on MGIT and ICA-positive but BHI-negative samples. Statistical significance was set at P < 0.05. Of the 622 Mtb isolates, 536 (86.2%) were susceptible to RIF and INH. The rest, 86 (13.83%), were resistant to either drugs or both. A two-sample proportional equality test revealed that the MDR-TB prevalence in western Kenya (5%) did not vary significantly from the global MDR-TB estimate (3.9%) (P = 0.196). Men comprised the majority of susceptible and resistant TB (75.9% and 77.4%%, respectively). Also, compared with healthy individuals, the prevalence of HIV was significantly higher in MDR-TB patients (35.9% vs 5.6%). Finally, TB prevalence was highest in individuals aged 25–44 years, who accounted for 58.4% of the total TB cases. Evidently, the prevalence of MDRTB in western Kenya is high. Particular attention should be paid to men, young adults, and those with HIV, who bear the greatest burden of resistant TB. Overall, there is a need to refine TB control and treatment programs in the region to yield better outcomes.

Supplemental Digital Content is Available in the Text. Background: Antiretroviral therapy (ART) has decreased HIV-attributable deaths; however, children and adolescents continue to have high HIV-associated mortality. Setting: We determined the predictors of death among children and young adolescents living with HIV (CALWH) who died while in care in Western Kenya. Methods: This retrospective case–control study used electronically abstracted data of 6234 CALWH who received care in Academic Model Providing Access to Healthcare HIV clinics in Western Kenya between January 2002 and November 2022. The cases comprised CALWH who were reported dead by November 2022, while the controls constituted of matched CALWH who were alive and in care. Independent predictors of mortality were determined using univariable and multivariable Cox proportional hazard regression models. Kaplan–Meier analysis ascertained survival. Results: Of the 6234 participants enrolled, slightly more than half were male (51.7%). The mean (SD) age at the start of ART was significantly lower in cases than in controls at 6.01 (4.37) and 6.62 (4.11) (P < 0.001), respectively. An age of 11 years or older at start of ART (adjusted Hazard Ratio [aHR]: 8.36 [3.60–19.40]), both parents being alive (aHR: 3.06 [1.67–5.60]), underweight (aHR: 1.82 [1.14–2.92]), and World Health Organization stages 3 (aHR: 2.63 [1.12–6.18]) and 4 (aHR: 2.20 [0.94–5.18]) increased mortality; while school attendance (aHR: 0.12 [0.06–0.21]), high CD4+ counts >350 cells/mm3 (aHR: 0.79 [0.48–1.29]), and low first viral load <1000 copies/mL (aHR: 0.24 [0.14–0.40]) were protective. Conclusion: Independent predictors of mortality were age 11 years or older at the start of ART, orphan status, underweight, and advanced HIV disease. Beyond the provision of universal ART, care accorded to CALWH necessitates optimization through tackling individual predictors of mortality. [ABSTRACT FROM AUTHOR]

Multidrug-resistant tuberculosis (TB) (MDR-TB), or TB that is simultaneously resistant to both isoniazid (INH) and rifampicin (RIF), is a barrier to successful TB control and treatment. Stratified data on MDR-TB, particularly in the high-burden western Kenya region, remain unknown. This data is important to monitor the efficacy of TB control and treatment efforts. Herein, we determined the molecular epidemiology of drug-resistant TB and associated risk factors in western Kenya. This was a non-experimental, population-based, cross-sectional study conducted between January and August 2018. Morning sputum samples of individuals suspected of pulmonary TB were collected, processed, and screened for Mycobacterium tuberculosis (Mtb) and drug resistance using line probe assay (LPA) and Mycobacterium growth indicator tubes (MGIT) culture. MGIT-positive samples were cultured on brain heart infusion (BHII) agar media, and the presence of Mtb was validated using Immunochromatographic assay (ICA). Drug sensitivity was performed on MGIT and ICA-positive but BHI-negative samples. Statistical significance was set at P < 0.05. Of the 622 Mtb isolates, 536 (86.2%) were susceptible to RIF and INH. The rest, 86 (13.83%), were resistant to either drugs or both. A two-sample proportional equality test revealed that the MDR-TB prevalence in western Kenya (5%) did not vary significantly from the global MDR-TB estimate (3.9%) (P = 0.196). Men comprised the majority of susceptible and resistant TB (75.9% and 77.4%%, respectively). Also, compared with healthy individuals, the prevalence of HIV was significantly higher in MDR-TB patients (35.9% vs 5.6%). Finally, TB prevalence was highest in individuals aged 25–44 years, who accounted for 58.4% of the total TB cases. Evidently, the prevalence of MDRTB in western Kenya is high. Particular attention should be paid to men, young adults, and those with HIV, who bear the greatest burden of resistant TB. Overall, there is a need to refine TB control and treatment programs in the region to yield better outcomes. [ABSTRACT FROM AUTHOR]

Background: Greater social capital is associated with positive health outcomes and better HIV management. The ways by which social capital may influence household water insecurity (HHWI), a critical determinant of health among persons living with HIV, remain underexplored. Further, despite the importance of reliable water access and use for health and agricultural productivity, few studies have described the strategies smallholder farmers living with HIV use to manage water insecurity. Objective: We qualitatively explored how an agricultural intervention (provision of a treadle pump for irrigation) influenced HHWI coping strategies through its impacts on social capital among smallholder farmers living with HIV in western Kenya. Method: In 2018, we purposively recruited participants from the Shamba Maisha study, a randomized agricultural intervention (NCT02815579) that provided irrigation pumps to improve treatment outcomes and food security among smallholder farmers living with HIV in western Kenya (n = 42). Participants shared their experiences with water insecurity through go-along and photo-elicitation interviews. Data were thematically analyzed using inductively developed codes. Results: Participants described diverse strategies for coping with agricultural water insecurity. Dimensions of social capital such as feelings of belonging, connectedness, and trust influenced the use of the treadle water pump and other water access behaviors. For instance, participants reported borrowing or sharing water pumps with friends and neighbors if they felt they had a good rapport. In addition, participants indicated a willingness to engage in collective activities, such as supporting the operation of the irrigation pump during planting, when they felt sufficiently connected to a larger group. Overall, individuals in the intervention arm described greater social cohesion, reciprocity, and community connectedness than those in the control arm. Conclusion: The impact of an agricultural intervention on water access and use was described as being modified by social capital among female smallholder farmers living with HIV. Findings suggest that social capital may create an enabling environment for implementing strategies that improve the management and reduce the burden of HIV. Measuring these strategies and their associations with HIV outcomes may strengthen our understanding of resilience among female smallholder farmers living with HIV. The development of a coping strategies index and its use in a longitudinal study could help to identify pathways through which social capital influences health and the effectiveness of livelihood interventions.

Abstract Background Spatial repellents (SR) may complement current vector control tools and provide additional coverage when people are not under their bednets or are outdoors. Here we assessed the efficacy of a metofluthrin-based SR in reducing exposure to pyrethroid-resistant Anopheles funestus in Siaya County, western Kenya. Methods Metofluthrin was vaporized using an emanator configured to a liquid petroleum gas (LPG) canister, placed inside experimental huts (phase 1) or outdoors (phase 2), and evaluated for reductions in human landing rate, density, knockdown and mortality rates of An. funestus, which are present in high density in the area. To demonstrate the mosquito recruiting effect of LPG, a hut with only an LPG cooker but no metofluthrin was added as a comparator and compared with an LPG cooker burning alongside the emanator and a third hut with no LPG cooker as control. Phase 2 evaluated the protective range of the SR product while emanating from the centre of a team of mosquito collectors sitting outdoors in north, south, east and west directions at 5, 10 and 20 feet from the emanating device. Results Combustion of LPG with a cook stove increased the density of An. funestus indoors by 51% over controls with no cook stove. In contrast, huts with metofluthrin vaporized with LPG combustion had lower indoor density of An. funestus (99.3% less than controls), with knockdown and mortality rates of 95.5 and 87.7%, respectively, in the mosquitoes collected in the treated huts. In the outdoor study (phase 2), the outdoor landing rate was significantly lower at 5 and 10 feet than at 20 feet from the emanator. Conclusions Vaporized metofluthrin almost completely prevented An. funestus landing indoors and led to 10 times lower landing rates within 10 feet of the emanator outdoors, the first product to demonstrate such potential. Cooking with LPG inside the house could increase exposure to Anopheles mosquito bites, but the use of the metofluthrin canister eliminates this risk. Graphical abstract

Background: Spatial repellents (SR) may complement current vector control tools and provide additional coverage when people are not under their bednets or are outdoors. Here we assessed the efficacy of a metofluthrin-based SR in reducing exposure to pyrethroid-resistant Anopheles funestus in Siaya County, western Kenya. Methods: Metofluthrin was vaporized using an emanator configured to a liquid petroleum gas (LPG) canister, placed inside experimental huts (phase 1) or outdoors (phase 2), and evaluated for reductions in human landing rate, density, knockdown and mortality rates of An. funestus, which are present in high density in the area. To demonstrate the mosquito recruiting effect of LPG, a hut with only an LPG cooker but no metofluthrin was added as a comparator and compared with an LPG cooker burning alongside the emanator and a third hut with no LPG cooker as control. Phase 2 evaluated the protective range of the SR product while emanating from the centre of a team of mosquito collectors sitting outdoors in north, south, east and west directions at 5, 10 and 20 feet from the emanating device. Results: Combustion of LPG with a cook stove increased the density of An. funestus indoors by 51% over controls with no cook stove. In contrast, huts with metofluthrin vaporized with LPG combustion had lower indoor density of An. funestus (99.3% less than controls), with knockdown and mortality rates of 95.5 and 87.7%, respectively, in the mosquitoes collected in the treated huts. In the outdoor study (phase 2), the outdoor landing rate was significantly lower at 5 and 10 feet than at 20 feet from the emanator. Conclusions: Vaporized metofluthrin almost completely prevented An. funestus landing indoors and led to 10 times lower landing rates within 10 feet of the emanator outdoors, the first product to demonstrate such potential. Cooking with LPG inside the house could increase exposure to Anopheles mosquito bites, but the use of the metofluthrin canister eliminates this risk. [ABSTRACT FROM AUTHOR]

Understanding drivers of nutrient balances in cropping systems, and possible strategies to replenish nutrient and carbon losses from soils, is crucial for maintaining and improving soil health. We determined nitrogen, phosphorus, and potassium balances, likely trajectories of soil organic carbon (SOC) and implications of alternative management scenarios on long-term (10 to 50 year) nutrient and SOC balances for smallholder farms. Farmer interviews and modeling was used to estimate nutrient and carbon flows into and out of 35 fields from three representative farm types within three agroecological zones in western Kenya, over two growing seasons (within one year). Management scenarios representing different strategies to balance nutrients and stabilize SOC stocks were simulated and compared against current farming practices. Our results indicate that net nutrient balances were highly variable across all farms but were on average negative for nitrogen (− 25.5 kg ha−1 yr−1) and potassium (− 20.8 kg ha−1 yr−1) and slightly positive for phosphorus (2.3 kg ha−1 yr−1) across all fields. Agroecological zone and farm type did not significantly affect the overall nutrient balances, but the relative magnitude of inputs and outputs (e.g., mineral N input) was significantly higher in Vihiga (65.8 kg N ha−1 yr−1) than Busia (22 kg N ha−1 yr−1) and Nandi (34.4 kg N ha−1 yr−1); p = 0.01. Management scenarios focusing on erosion control reduced nitrogen losses by half in all zones. A residue retention scenario had the greatest impact on potassium balances (i.e., average − 49.2 kg K ha−1 yr−1 when residues were removed vs − 11.74 kg K ha−1 yr−1 when all residues were retained), while complete residue export to feed livestock (and applying the manure produced) had minimal effects on all three nutrient balances across zones. When simulating SOC stocks with the DayCent model, scenarios with erosion control, residue retention, and incorporation of a high biomass legume (lablab) resulted in at least 50% more SOC than current trends or the residue export scenario after 50 modeled years across regions. Combining these three management interventions showed promise for stabilizing SOC trajectories over a 50-year horizon. Our findings suggest that researchers, policymakers, and extension agents should emphasize erosion control, residue retention, and high biomass legumes in rotation as strategies for improving nutrient balances and SOC stocks in smallholder farming systems. [ABSTRACT FROM AUTHOR]

Abstract Background Designing, implementing, and upscaling of effective malaria vector control strategies necessitates an understanding of when and where transmission occurs. This study assessed the biting patterns of potentially infectious malaria vectors at various hours, locations, and associated human behaviors in different ecological settings in western Kenya. Methods Hourly indoor and outdoor catches of human-biting mosquitoes were sampled from 19:00 to 07:00 for four consecutive nights in four houses per village. The human behavior study was conducted via questionnaire surveys and observations. Species within the Anopheles gambiae complex and Anopheles funestus group were distinguished by polymerase chain reaction (PCR) and the presence of Plasmodium falciparum circumsporozoite proteins (CSP) determined by enzyme-linked immunosorbent assay (ELISA). Results Altogether, 2037 adult female anophelines were collected comprising the An. funestus group (76.7%), An. gambiae sensu lato (22.8%), and Anopheles coustani (0.5%). PCR results revealed that Anopheles arabiensis constituted 80.5% and 79% of the An. gambiae s.l. samples analyzed from the lowland sites (Ahero and Kisian, respectively). Anopheles gambiae sensu stricto (hereafter An. gambiae) (98.1%) was the dominant species in the highland site (Kimaeti). All the An. funestus s.l. analyzed belonged to An. funestus s.s. (hereafter An. funestus). Indoor biting densities of An. gambiae s.l. and An. funestus exceeded the outdoor biting densities in all sites. The peak biting occurred in early morning between 04:30 and 06:30 in the lowlands for An. funestus both indoors and outdoors. In the highlands, the peak biting of An. gambiae occurred between 01:00 and 02:00 indoors. Over 50% of the study population stayed outdoors from 18:00 to 22:00 and woke up at 05:00, coinciding with the times when the highest numbers of vectors were collected. The sporozoite rate was higher in vectors collected outdoors, with An. funestus being the main malaria vector in the lowlands and An. gambiae in the highlands. Conclusion This study shows heterogeneity of anopheline distribution, high outdoor malaria transmission, and early morning peak biting activity of An. funestus when humans are not protected by bednets in the lowland sites. Additional vector control efforts targeting the behaviors of these vectors, such as the use of non-pyrethroids for indoor residual spraying and spatial repellents outdoors, are needed. Graphical Abstract

Surveillance of mosquito vectors is critical for early detection, prevention and control of vector borne diseases. In this study we used advanced molecular tools, such as DNA barcoding in combination with novel sequencing technologies to discover new and already known viruses in genetically identified mosquito species. Mosquitoes were captured using BG sentinel traps in Western Kenya during May and July 2019, and homogenized individually before pooled into groups of ten mosquitoes. The pools and individual samples were then used for molecular analysis and to infect cell cultures. Of a total of fifty-four (54) 10-pools, thirteen (13) showed cytopathic effect (CPE) on VeroB4 cells, eighteen (18) showed CPE on C6/36 cells. Eight (8) 10-pools out of the 31 CPE positive pools showed CPE on both VeroB4 and C6/36 cells. When using reverse transcriptase polymerase chain reaction (RT-PCR), Sanger sequencing and Twist Comprehensive Viral Research Panel (CVRP) (Twist Biosciences), all pools were found negative by RT-PCR when using genus specific primers targeting alphaviruses, orthobunyaviruses and virus specific primers towards o'nyong-nyong virus, chikungunya virus and Sindbis virus (previously reported to circulate in the region). Interestingly, five pools were RT-PCR positive for flavivirus. Two of the RT-PCR positive pools showed CPE on both VeroB4 and C6/36 cells, two pools showed CPE on C6/36 cells alone and one pool on VeroB4 cells only. Fifty individual mosquito homogenates from the five RT-PCR positive 10-pools were analyzed further for flavivirus RNA. Of these, 19 out of the 50 individual mosquito homogenates indicated the presence of flavivirus RNA. Barcoding of the flavivirus positive mosquitoes revealed the mosquito species as Aedes aegypti (1), Mansonia uniformis (6), Anopheles spp (3), Culex pipiens (5), Culex spp (1), Coquilletidia metallica (2) and Culex quinquefasciatus (1). Of the 19 flavivirus positive individual mosquitoes, five (5) virus positive homogenates were sequenced. Genome sequences of two viruses were completed. One was identified as the single-stranded RNA Culex flavivirus and the other as the double-stranded RNA Hubei chryso-like virus 1. Both viruses were found in the same Anopheles spp. homogenate extracted from a sample that showed CPE on both VeroB4 and C6/36 cells. The detection of both viruses in a single mosquito homogenate indicated coinfection. Phylogenetic analyses suggested that the Culex flavivirus sequence detected was closely related to a Culex flavivirus isolated from Uganda in 2008. All four Hubei chryso-like virus 1 segments clusters closely to Hubei chryso-like virus 1 strains isolated in Australia, China and USA. Two novel strains of insect-specific viruses in Anopheles mosquitoes were detected and characterized.

Introduction: We describe the clinical spectrum of COVID-19 cases in western Kenya from 6 April 2020 to 31 May 2021, providing baseline data for further studies into COVID-19 in Kenya. Methods: We did a retrospective chart review of laboratory and inpatient files of patients diagnosed and managed for COVID-19 at the Moi Teaching and Referral Hospital in Kenya and analyzed the data using Stata® version 16 (StataCorp LP, College Station, TX, USA) and calculated measures of association at 95% CI. Results: The patients (n = 1,770) had a mean age of 43 years (SD 20 years) and 55.4% were male. Close to 70% had asymptomatic disease, with the symptomatic cases largely being respiratory in nature. One-quarter had comorbidities. The case fatality rate was 13.6% (n = 240). Male sex increased the odds of mortality by 1.69 (95% CI 1.27-2.25; p = 0.001), and the presence of comorbidities increased the odds of mortality by 3.16 (95% CI 2.38-4.18; p = 0.001). Those aged 59 years and above were 18 times more likely to die from COVID-19 than those below 15 years of age (95% CI 1.61-90.66; p = 0.015). Conclusion: COVID-19 had a significantly high mortality rate in western Kenya. Male sex and the presence of comorbidities increased the risk of severe disease and mortality. [ABSTRACT FROM AUTHOR]

IntroductionWe describe the clinical spectrum of COVID-19 cases in western Kenya from 6 April 2020 to 31 May 2021, providing baseline data for further studies into COVID-19 in Kenya.MethodsWe did a retrospective chart review of laboratory and inpatient files of patients diagnosed and managed for COVID-19 at the Moi Teaching and Referral Hospital in Kenya and analyzed the data using Stata® version 16 (StataCorp LP, College Station, TX, USA) and calculated measures of association at 95% CI.ResultsThe patients (n = 1,770) had a mean age of 43 years (SD 20 years) and 55.4% were male. Close to 70% had asymptomatic disease, with the symptomatic cases largely being respiratory in nature. One-quarter had comorbidities. The case fatality rate was 13.6% (n = 240). Male sex increased the odds of mortality by 1.69 (95% CI 1.27–2.25; p ≤ 0.001), and the presence of comorbidities increased the odds of mortality by 3.16 (95% CI 2.38–4.18; p ≤ 0.001). Those aged 59 years and above were 18 times more likely to die from COVID-19 than those below 15 years of age (95% CI 1.61–90.66; p = 0.015).ConclusionCOVID-19 had a significantly high mortality rate in western Kenya. Male sex and the presence of comorbidities increased the risk of severe disease and mortality.

Luo orphaned children derive their conceptualization of home from historical ideologies of patrilineal kinship and the local discourses of belonging situated within properly constituted marriage. Contrary to older literature that presents home as a domestic spatial arrangement, orphans understand home as a relational pathway that safeguards growth. We show that orphans use their notion of home to express feelings of vulnerability and apply their agency against adult-initiated fosterage practices. The article contributes to an enhanced understanding of Luo sociality and promotes a dynamic anthropology of relationships and child anthropology by unpacking the facets of childhood vulnerability. Our analysis points to analytic themes of contradictions and paradox in Luo kinship values in relation to child support and ambivalence in how children's agency is exercised in fosterage arrangements. [ABSTRACT FROM AUTHOR]

BackgroundUnderstanding the complex heterogeneity of risk factors that can contribute to an increased risk of malaria at the individual and household level will enable more effective use of control measures. The objective of this study was to understand individual and household factors that influence clinical malaria infection among individuals in the highlands of Western Kenya.MethodsThis was a matched case-control study undertaken in the Western Kenya highlands. Clinical malaria cases were recruited from health facilities and matched to asymptomatic individuals from the community who served as controls. Each participant was screened for malaria using microscopy. Follow-up surveys were conducted with individual households to collect socio-economic data. The houses were also checked using pyrethrum spray catches to collect mosquitoes.ResultsA total of 302 malaria cases were matched to 604 controls during the surveillance period. Mosquito densities were similar in the houses of both groups. A greater percentage of people in the control group (64.6%) used insecticide-treated bed nets (ITNs) compared to the families of malaria cases (48.3%). Use of ITNs was associated with lower level of clinical malaria episodes (odds ratio 0.51; 95% CI 0.39-0.68; P

Abstract Background Low adoption of effective health technologies increases illness morbidity and mortality worldwide. In the case of malaria, effective tools such as malaria rapid diagnostic tests (RDTs) and artemisinin-combination therapies (ACTs) are both under-used and used inappropriately. Individuals’ confidence in RDTs and ACTs likely affects the uptake of these tools. Methods In a cohort of 36 households (280 individuals) in Western Kenya observed for 30 months starting in June 2017, we examined if experience with RDTs and ACTs changes people’s beliefs about these technologies and how those beliefs affect treatment behavior. Household members requested a free RDT from the study team any time they suspected a malaria illness, and positive RDT results were treated with a free ACT. We conducted annual, monthly, and sick visit surveys to elicit beliefs about the accuracy of malaria RDT results and the effectiveness of ACTs. Beliefs were elicited on a 5-point Likert scale from “very unlikely” to “very likely.” Results Over the study period, the percentage of survey respondents that said a hypothetical negative RDT result was “very likely” to be correct increased from approximately 55% to 75%. Controlling for initial beliefs, people who had been tested at least once with an RDT in the past year had 3.6 times higher odds (95% CI [1 1.718 7.679], P = 0.001) of saying a negative RDT was “very likely” to be correct. Confidence in testing was associated with treatment behavior: those who believed a negative RDT was “very likely” to be correct had 1.78 times higher odds (95% CI [1.079 2.934], P = 0.024) of adhering to a negative RDT result (by not taking ACTs) than those who were less certain about the accuracy of negative RDTs. Adherence to a negative test also affected subsequent beliefs: controlling for prior beliefs, those who had adhered to their previous test result had approximately twice the odds (OR = 2.19, 95% CI [1.661 2.904], P

Background: There are limited data on home pregnancy test use among women in low-and-middle-income countries. A prior survey found that only 20% of women in western Kenya used a home pregnancy test to confirm their pregnancies before going to antenatal care. This qualitative study aims to understand why women do not use home pregnancy tests in early pregnancy. Methods: From April 2021 to July 2021, we interviewed women from four antenatal care clinics in Homa Bay and Siaya counties. We recruited women previously enrolled in the PrEP Implementation for Mothers in Antenatal care (PrIMA) study, a cluster-randomized trial that evaluated the best approaches to implementing PrEP in maternal and child health clinics in Western Kenya (NCT03070600). Interviews were conducted via phone, audio recorded, translated, and transcribed verbatim. We coded and analyzed the transcripts to capture factors influencing women's capability, opportunity, and motivation to use home pregnancy tests. Results: We conducted 48 semistructured interviews with women aged 21-42 years. Twenty-seven women did not use a home pregnancy test in their most recent pregnancy. Seventeen of these women reported not using a home pregnancy test before. Lack of knowledge, mistrust in the accuracy of tests, preferring to rely on signs and symptoms of pregnancy or get a test from the health facility, cost, and accessibility were key barriers to home pregnancy test use. Conclusion: Improving the uptake of home pregnancy testing during early pregnancy will require efforts to enhance community knowledge of test use and associated benefits and reduce cost burdens by making tests more affordable and accessible. [ABSTRACT FROM AUTHOR]

Tungiasis, a World Health Organization neglected tropical disease, is caused by the female sand flea. Most clinical trials for tungiasis use expensive or impractical drugs, which are difficult for residents to use. However, in western Kenya, communities successfully treat tungiasis with sodium carbonate. We hypothesise that the topical risk-difference of 5% sodium carbonate is no more than 10% non-inferior to dimeticone (NYDA®) for tungiasis treatment. This is a protocol for a non-inferiority study, which will be randomised and with an observer-blinded control. The study will have two arms: 5% sodium carbonate and NYDA®, one on each foot, and will take place at state primary schools in Homa Bay County, Kenya. Fleas identified among school children aged 8–14 years with sand-flea lesions will be enrolled in the study. For each participant, the viability of the embedded fleas, clinical signs including inflammation, and symptoms will be monitored for seven days after treatment. The proportion of dead fleas will be compared in the primary analysis. All adverse events will be monitored throughout the study period. We expect to identify the most effective treatment between sodium carbonate and NYDA® for tungiasis, which can be adopted in the community. [ABSTRACT FROM AUTHOR]

Abstract Background Hemoglobinopathies are inheritable disorders of hemoglobin and are the most common genetic defects in humans. This is a neglected public health problem whose undiagnosis remain a major threat to its prevention and control in sub-Saharan Africa countries; thus its exact magnitude on morbidity and mortality remains poorly documented. These hemoglobin disorders have been associated with Plasmodium falciparum; therefore, the current study sought to determine its distribution in a malaria-holoendemic region of Western Kenya as part of remedial intervention recommended by World Health Organization (WHO). Method This study analyzed data conveniently selected through census from 2015 to 2020 from hematology laboratory database for patients examined in Aga Khan, Hospital, Kisumu, and its satellites in Western Kenya. A total of 247 cases were selected whose sample size was calculated using Cochran’s formula. Distribution of hemoglobinopathies based on stations, gender, and age was expressed in frequencies, proportions, bar graphs, and pie charts. Results The distribution of hemoglobinopathies had varying proportions in different locations in Western Kenya with regions that were at proximity to Lake Victoria (Kisumu 41.3%, n = 102; Busia 21.5%, n = 53; Homabay 15.4%, n = 38) recording a higher overall hemoglobinopathy proportions than those that were far from the lake that include Bungoma 5.7%, n = 14; Kakamega 4.0%, n = 10; Kitale 4.0%, n = 10; Kisii 4.0%, n = 10, and Migori 4.0% n = 10. Conclusion The study represents the burden of hemoglobinopathies in a malaria-holoendemic region of Western Kenya, and even though the present study did not include ethnicity in data collection, stations from where the data was collected are predominated by different communities; therefore, there may be an ethnic correlation in the variation of hemoglobinopathies in Western Kenya. The communities juxtaposed to the lake seems to be the most affected ethnic group along the Lake Victoria economic block region; thus, it may be erroneous to assume that the entire malaria-holoendemic region of Western Kenya has high prevalence of hemoglobin disorders without factoring ethnicity and geographical location in a properly conducted population-based prevalence study in the wider Western Kenya.

Abstract Introduction Non-communicable diseases have risen markedly over the last decade. A phenomenon that was mainly endemic in high-income countries has now visibly encroached on low and middle-income settings. A major contributor to this is a shift towards unhealthy dietary behavior. This study aimed to examine the complex interplay between people’s characteristics and the environment to understand how these influenced food choices and practices in Western Kenya. Methods This study used semi-structured guides to conduct in-depth interviews and focus group discussions with both male and female members of the community, across various socioeconomic groups, from Kisumu and Homa Bay Counties to further understand their perspectives on the influences of dietary behavior. Voice data was captured using digital voice recorders, transcribed verbatim, and translated to English. Data analysis adopted an exploratory and inductive analysis approach. Coded responses were analyzed using NVIVO 12 PRO software. Results Intrapersonal levels of influence included: Age, the nutritional value of food, occupation, perceived satiety of some foods as opposed to others, religion, and medical reasons. The majority of the participants mentioned location as the main source of influence at the community level reflected by the regional staple foodscape. Others include seasonality of produce, social pressure, and availability of food in the market. Pricing of food and distance to food markets was mentioned as the major macro-level influence. This was followed by an increase in population and road infrastructure. Conclusion This study demonstrated that understanding dietary preferences are complex. Future interventions should not only consider intrapersonal and interpersonal influences when aiming to promote healthy eating among communities but also need to target the community and macro environments. This means that nutrition promotion strategies should focus on multiple levels of influence that broaden options for interventions. However, government interventions in addressing food access, affordability, and marketing remain essential to any significant change.

Abstract Background Assisted partner service (APS) is effective for increasing HIV testing services (HTS) uptake among sexual partners of people diagnosed with HIV with rare social harm. The acceptability of APS to HTS providers is important for the quality and effectiveness of APS delivery. Within a larger ongoing implementation science study of APS in western Kenya, we qualitatively evaluated the provider acceptability of APS. Methods From May–June 2020, we conducted virtual, semi-structured in-depth interviews with 14 HTS providers recruited from 8 of 31 study health facilities in Homa Bay and Kisumu counties. Participants were selected using criteria-based purposive sampling to maximize variation on patient volume (assessed by the number of index clients tested for HIV) and APS performance (assessed by sexual partners elicitation and enrollment). Interviews inquired providers’ experiences providing APS including challenges and facilitators and the impact of contextual factors. Data were analyzed using an inductive approach. Results Overall, HTS providers found APS acceptable. It was consistently reported that doing APS was a continuous process rather than a one-day job, which required building rapport and persistent efforts. Benefits of APS including efficiency in HIV case finding, expanded testing coverage in men, and increased HIV status awareness and linkage to care motivated the providers. Provider referral was perceived advantageous in terms of independent contact with partners on behalf of index clients and efficiency in partner tracing. Challenges of providing APS included protecting clients’ confidentiality, difficulty obtaining partners’ accurate contact information, logistic barriers of tracing, and clients’ refusal due to fear of being judged for multiple sexual partners, fear of breach of confidentiality, and HIV stigma. Building rapport with clients, communicating with patience and nonjudgmental attitude and assuring confidentiality were examples of facilitators. Working in rural areas and bigger facilities, training, supportive supervision, and community awareness of APS promoted APS delivery while low salaries, lack of equipment, and high workload undermined it. Conclusions HTS providers found APS acceptable. Delivering APS as a process was the key to success. Future scale-up of APS could consider encouraging provider referral instead of the other APS methods to improve efficiency and reduce potential harm to clients.

BackgroundThere are limited data on home pregnancy test use among women in low-and-middle-income countries. A prior survey found that only 20% of women in western Kenya used a home pregnancy test to confirm their pregnancies before going to antenatal care. This qualitative study aims to understand why women do not use home pregnancy tests in early pregnancy.MethodsFrom April 2021 to July 2021, we interviewed women from four antenatal care clinics in Homa Bay and Siaya counties. We recruited women previously enrolled in the PrEP Implementation for Mothers in Antenatal care (PrIMA) study, a cluster-randomized trial that evaluated the best approaches to implementing PrEP in maternal and child health clinics in Western Kenya (NCT03070600). Interviews were conducted via phone, audio recorded, translated, and transcribed verbatim. We coded and analyzed the transcripts to capture factors influencing women's capability, opportunity, and motivation to use home pregnancy tests.ResultsWe conducted 48 semistructured interviews with women aged 21–42 years. Twenty-seven women did not use a home pregnancy test in their most recent pregnancy. Seventeen of these women reported not using a home pregnancy test before. Lack of knowledge, mistrust in the accuracy of tests, preferring to rely on signs and symptoms of pregnancy or get a test from the health facility, cost, and accessibility were key barriers to home pregnancy test use.ConclusionImproving the uptake of home pregnancy testing during early pregnancy will require efforts to enhance community knowledge of test use and associated benefits and reduce cost burdens by making tests more affordable and accessible.

Push-pull technology improves agricultural productivity. However, its long-term effect on biomass carbon and soil organic carbon (SOC) is not yet known. The aims of this study were: to assess the effect of push-pull technology on (1) biomass carbon and (2) SOC, considering climatic conditions and the length of time that push-pull had been practiced on a farm; and (3) to establish the relationship between biomass carbon and SOC on farms. Aboveground biomass carbon and SOC were measured on 36 farms in western Kenya, encompassing three contrasting sites (Bondo, Siaya and Vihiga) and six cropping systems (push-pull and five non-push-pull systems). Farms in western Kenya stock between 3.0 ± 0.3 and 4.0 ± 0.4 t C ha−1 in crop biomass and between 24.4 ± 2.1 and 37.0 ± 2.6 t C ha−1 in the soil for those practicing push-pull, and between 1.1 ± 0.3 and 2.1 ± 0.2 t C ha−1 biomass carbon and between 19.2 ± 2.1 and 31.1 ± 1.7 t C ha−1 soil carbon for those without push-pull. There was no correlation between biomass carbon and SOC. Adoption of push-pull offers opportunities to mitigate climate change through carbon sequestration in plants and soils in low-, medium- and high-rainfall environments in both long and short rain seasons. [ABSTRACT FROM AUTHOR]

Poor marital satisfaction is associated with high-risk sexual behavior and HIV transmission. We tested whether a counselor-led couple education and counseling intervention dubbed Waya (paternal aunt) would improve marital satisfaction and reduce HIV risk behavior among married couples in Kisumu County, western Kenya. In a pre–post design, we enrolled 60 heterosexual married couples at high risk for HIV to undergo five 1-h couple education and counseling sessions over 56 days. We collected self-reported data on marital satisfaction, the number of sex partners, and condom use with extramarital partners at pre- and post-intervention visits. We used Wilcoxon and McNemar tests to examine the association of our intervention with marital relationship satisfaction and reduction in HIV risk sexual behavior. The intervention was associated with marital relationship satisfaction score improvement from a median of 5 (interquartile range [IQR], 4–5) to 6 (IQR, 6–7) among men and 4 (IQR, 3–5) to 6 (IQR, 5–6) among women (p <.01). The intervention was also associated with reducing HIV risk sexual behaviors depicted by a reduction in the number of sex partners in the past one month and an increase in consistent extramarital condom use. The number of sex partners reduced from a median of 2 (IQR, 1–2) to 1 (IQR, 1–2) and consistent extramarital condom use increased from 4% at baseline to 56% among men. Our intervention was associated with improvements in marital relationship satisfaction and reductions in HIV high-risk behaviors necessary for achieving epidemic control in HIV hotspots such as fishing communities in western Kenya. [ABSTRACT FROM AUTHOR]

Push-pull technology improves agricultural productivity. However, its long-term effect on biomass carbon and soil organic carbon (SOC) is not yet known. The aims of this study were: to assess the effect of push-pull technology on (1) biomass carbon and (2) SOC, considering climatic conditions and the length of time that push-pull had been practiced on a farm; and (3) to establish the relationship between biomass carbon and SOC on farms. Aboveground biomass carbon and SOC were measured on 36 farms in western Kenya, encompassing three contrasting sites (Bondo, Siaya and Vihiga) and six cropping systems (push-pull and five non-push-pull systems). Farms in western Kenya stock between 3.0 ± 0.3 and 4.0 ± 0.4 t C ha−1 in crop biomass and between 24.4 ± 2.1 and 37.0 ± 2.6 t C ha−1 in the soil for those practicing push-pull, and between 1.1 ± 0.3 and 2.1 ± 0.2 t C ha−1 biomass carbon and between 19.2 ± 2.1 and 31.1 ± 1.7 t C ha−1 soil carbon for those without push-pull. There was no correlation between biomass carbon and SOC. Adoption of push-pull offers opportunities to mitigate climate change through carbon sequestration in plants and soils in low-, medium- and high-rainfall environments in both long and short rain seasons.

Abstract Background The gold standard for diagnosing Plasmodium falciparum infection is microscopic examination of Giemsa-stained peripheral blood smears. The effectiveness of this procedure for infection surveillance and malaria control may be limited by a relatively high parasitaemia detection threshold. Persons with microscopically undetectable infections may go untreated, contributing to ongoing transmission to mosquito vectors. The purpose of this study was to determine the magnitude and determinants of undiagnosed submicroscopic P. falciparum infections in a rural area of western Kenya. Methods A health facility-based survey was conducted, and 367 patients seeking treatment for symptoms consistent with uncomplicated malaria in Homa Bay County were enrolled. The frequency of submicroscopic P. falciparum infection was measured by comparing the prevalence of infection based on light microscopic inspection of thick blood smears versus real-time polymerase chain reaction (RT-PCR) targeting P. falciparum 18S rRNA gene. Long-lasting insecticidal net (LLIN) use, participation in nocturnal outdoor activities, and gender were considered as potential determinants of submicroscopic infections. Results Microscopic inspection of blood smears was positive for asexual P. falciparum parasites in 14.7% (54/367) of cases. All of these samples were confirmed by RT-PCR. 35.8% (112/313) of blood smear negative cases were positive by RT-PCR, i.e., submicroscopic infection, resulting in an overall prevalence by RT-PCR alone of 45.2% compared to 14.7% for blood smear alone. Females had a higher prevalence of submicroscopic infections (35.6% or 72 out of 202 individuals, 95% CI 28.9–42.3) compared to males (24.2%, 40 of 165 individuals, 95% CI 17.6–30.8). The risk of submicroscopic infections in LLIN users was about half that of non-LLIN users (OR = 0.59). There was no difference in the prevalence of submicroscopic infections of study participants who were active in nocturnal outdoor activities versus those who were not active (OR = 0.91). Patients who participated in nocturnal outdoor activities and use LLINs while indoors had a slightly higher risk of submicroscopic infection than those who did not use LLINs (OR = 1.48). Conclusion Microscopic inspection of blood smears from persons with malaria symptoms for asexual stage P. falciparum should be supplemented by more sensitive diagnostic tests in order to reduce ongoing transmission of P. falciparum parasites to local mosquito vectors.

Abstract Background Tick-borne pathogens (TBPs) are of global importance, especially in sub-Saharan Africa where they represent a major constraint to livestock production. Their association with human disease is also increasingly recognized, signalling their zoonotic importance. It is therefore crucial to investigate TBPs prevalence in livestock populations and the factors associated with their presence. We set out to identify TBPs present in cattle and to determine associated risk factors in western Kenya, where smallholder livestock production is important for subsistence and market-driven income. Results Tick-borne pathogen infections in blood samples collected from cattle at livestock markets and slaughterhouses between May 2017 and January 2019 were identified by high-resolution melting analysis and sequencing of PCR products of genus-specific primers. Of the 422 cattle sampled, 30.1% (127/422) were infected with at least one TBP, while 8.8% (37/422) had dual infections. Anaplasma spp. (19.7%) were the most prevalent, followed by Theileria (12.3%), Ehrlichia (6.6%), and Babesia (0.2%) spp. Sequence analysis of the TBPs revealed them to be Anaplasma platys-like organisms (13.5%), Theileria velifera (7.4%), Anaplasma marginale (4.9%), Theileria mutans (3.1%), Theileria parva (1.6%), and Babesia bigemina (0.2%). Ehrlichia ruminantium, Rickettsia spp., and arboviruses were not detected. Exotic breeds of cattle were more likely to be infected with A. marginale compared to local breeds (OR: 7.99, 95% CI: 3.04–22.02, p

BackgroundIn sub-Saharan Africa, malaria interventions over the last decades have been successful in reducing both mortality and morbidity. In western Kenya however some areas experience contrasting outcomes of the ongoing interventions while the causes for this observation remains not yet clearly known.MethodsThe WHO insecticide (deltamethrin) susceptibility test of the common malaria vectors was studied. Multiple surveys on household use and hospital prescriptions of antimalarial drugs from 2003 to 2015 were done. Along with this, cross sectional surveys on their availability in the local drug dispensing outlets were also done in 2015. Monthly precipitations and air temperature data was collected along with systematic review on abundance and composition of common malaria vectors in the study area before and during interventions. The above factors were used to explain the possible causes of contrasting outcome of malaria interventions between the three study sites.ResultsAreas with malaria resurgence or sustained high transmission (Kombewa and Marani) showed higher composition of Anopheles funestus sensu lato (s.l.) than the previously abundant Anopheles gambiae sensu stricto (s.s.) and the later had higher composition to an area with a sustained infection decline (Iguhu). Anopheles gambiae s.l. from Kombewa showed highest resistance (50% mortality) upon exposure to WHO deltamethrin discriminating dosage of 0.75% while those from Marani and Iguhu had reduced resistance status (both had a mean mortality of 91%). Sampled An. funestus s.l. from Marani were also highly resistant to deltamethrin as 57% of the exposed vectors survived. An increasing of mean air temperature by 2 °C was noted for Marani and Iguhu from 2013 to 2015 and was accompanied by an increased rainfall at Marani. Community drug use and availability in selling outlets along with prescription in hospitals were not linked to the struggling control of the disease.ConclusionsThe malaria vector species composition shift, insecticide resistance and climatic warming were the likely cause of the contrasting outcome of malaria intervention in western Kenya. Surveillance of malaria parasite and vector dynamics along with insecticide resistance and vector biting behaviour monitoring are highly recommended in these areas.

Background: Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control interventions on molecular markers of Plasmodium falciparum drug resistance using parasites obtained from humans and mosquitoes at discrete time points. Methods: Dried blood spot samples collected in 2012 and 2017 community surveys in Asembo, Kenya were genotyped by Sanger sequencing for markers associated with resistance to SP (Pfdhfr, Pfdhps), CQ, AQ, lumefantrine (Pfcrt, Pfmdr1) and artemisinin (Pfk13). Temporal trends in the prevalence of these markers, including data from 2012 to 2017 as well as published data from 1996, 2001, 2007 from same area, were analysed. The same markers from mosquito oocysts collected in 2012 were compared with results from human blood samples. Results: The prevalence of SP dhfr/dhps quintuple mutant haplotype C50I51R59N108I164/S436G437E540A581A613 increased from 19.7% in 1996 to 86.0% in 2012, while an increase in the sextuple mutant haplotype C50I51R59N108I164/H436G437E540A581A613 containing Pfdhps-436H was found from 10.5% in 2012 to 34.6% in 2017. Resistant Pfcrt-76 T declined from 94.6% in 2007 to 18.3% in 2012 and 0.9% in 2017. Mutant Pfmdr1-86Y decreased across years from 74.8% in 1996 to zero in 2017, mutant Pfmdr1-184F and wild Pfmdr1-D1246 increased from 17.9% to 58.9% in 2007 to 55.9% and 90.1% in 2017, respectively. Pfmdr1 haplotype N86F184S1034N1042D1246 increased from 11.0% in 2007 to 49.6% in 2017. No resistant mutations in Pfk13 were found. Prevalence of Pfdhps-436H was lower while prevalence of Pfcrt-76 T was higher in mosquitoes than in human blood samples. Conclusion: This study showed an increased prevalence of dhfr/dhps resistant markers over 20 years with the emergence of Pfdhps-436H mutant a decade ago in Asembo. The reversal of Pfcrt from CQ-resistant to CQ-sensitive genotype occurred following 19 years of CQ withdrawal. No Pfk13 markers associated with artemisinin resistance were detected, but the increased haplotype of Pfmdr1 N86F184S1034N1042D1246 was observed. The differences in prevalence of Pfdhps-436H and Pfcrt-76 T SNPs between two hosts and the role of mosquitoes in the transmission of drug resistant parasites require further investigation. [ABSTRACT FROM AUTHOR]

Background: Low adoption of effective health technologies increases illness morbidity and mortality worldwide. In the case of malaria, effective tools such as malaria rapid diagnostic tests (RDTs) and artemisinin-combination therapies (ACTs) are both under-used and used inappropriately. Individuals' confidence in RDTs and ACTs likely affects the uptake of these tools.Methods: In a cohort of 36 households (280 individuals) in Western Kenya observed for 30 months starting in June 2017, we examined if experience with RDTs and ACTs changes people's beliefs about these technologies and how those beliefs affect treatment behavior. Household members requested a free RDT from the study team any time they suspected a malaria illness, and positive RDT results were treated with a free ACT. We conducted annual, monthly, and sick visit surveys to elicit beliefs about the accuracy of malaria RDT results and the effectiveness of ACTs. Beliefs were elicited on a 5-point Likert scale from "very unlikely" to "very likely."Results: Over the study period, the percentage of survey respondents that said a hypothetical negative RDT result was "very likely" to be correct increased from approximately 55% to 75%. Controlling for initial beliefs, people who had been tested at least once with an RDT in the past year had 3.6 times higher odds (95% CI [1 1.718 7.679], P = 0.001) of saying a negative RDT was "very likely" to be correct. Confidence in testing was associated with treatment behavior: those who believed a negative RDT was "very likely" to be correct had 1.78 times higher odds (95% CI [1.079 2.934], P = 0.024) of adhering to a negative RDT result (by not taking ACTs) than those who were less certain about the accuracy of negative RDTs. Adherence to a negative test also affected subsequent beliefs: controlling for prior beliefs, those who had adhered to their previous test result had approximately twice the odds (OR = 2.19, 95% CI [1.661 2.904], P < 0.001) of saying that a hypothetical negative RDT was "very likely" to be correct compared to those who had not adhered.Conclusions: Our results suggest that greater experience with RDTs can not only increase people's confidence in their accuracy but also improve adherence to the test result. [ABSTRACT FROM AUTHOR]

The up-surging population in sub-Saharan Africa (SSA) has led to the conversion of more land for agricultural purposes. Resilient land utilization types that input carbon to the soil are key in enhancing climate change mitigation. However, there are limited data on different land utilization types' contribution to climate mitigation through carbon input to soils. The study aims to quantify carbon stock across different land utilization types (LUT) practiced in Western Kenya. The following land utilization types were studied: agroforestry M (agroforestry with Markhamia lutea), sole sorghum, agroforestry L (agroforestry with Leucaena leucocephalaI), sole maize, and grazing land replicated thrice. To determine soil bulk density, SOC concentration, and soil carbon stock, soil samples were collected at depths of 0–5, 5–10, 10–20, and 20–30 cm from different LUTs. A PROC ANOVA was used to determine the difference in soil bulk density, SOC, and SOC stock between different LUTs and depths. The four variables differed across the LUTs and depths. A high soil bulk density was observed at 0–5 cm under grazing land (1.6 g cm−3) and the lowest under agroforestry M (1.30 g cm−3). Conversely, the soil bulk density was low at 20–30 cm under grazing land. The 0–5 cm depth accounted for a high share of SOC and SOC stock under Agroforestry M, while the 10–20 and 20–30 cm depth accounted for the high share of SOC stock under agroforestry L. The study showed differences in SOC across the different depths and LUTs. The findings highlight that agroforestry L and agroforestry M are promising interventions toward climate mitigation through carbon induction to soils. [ABSTRACT FROM AUTHOR]

Introduction: Non-communicable diseases have risen markedly over the last decade. A phenomenon that was mainly endemic in high-income countries has now visibly encroached on low and middle-income settings. A major contributor to this is a shift towards unhealthy dietary behavior. This study aimed to examine the complex interplay between people's characteristics and the environment to understand how these influenced food choices and practices in Western Kenya. Methods: This study used semi-structured guides to conduct in-depth interviews and focus group discussions with both male and female members of the community, across various socioeconomic groups, from Kisumu and Homa Bay Counties to further understand their perspectives on the influences of dietary behavior. Voice data was captured using digital voice recorders, transcribed verbatim, and translated to English. Data analysis adopted an exploratory and inductive analysis approach. Coded responses were analyzed using NVIVO 12 PRO software. Results: Intrapersonal levels of influence included: Age, the nutritional value of food, occupation, perceived satiety of some foods as opposed to others, religion, and medical reasons. The majority of the participants mentioned location as the main source of influence at the community level reflected by the regional staple foodscape. Others include seasonality of produce, social pressure, and availability of food in the market. Pricing of food and distance to food markets was mentioned as the major macro-level influence. This was followed by an increase in population and road infrastructure. Conclusion: This study demonstrated that understanding dietary preferences are complex. Future interventions should not only consider intrapersonal and interpersonal influences when aiming to promote healthy eating among communities but also need to target the community and macro environments. This means that nutrition promotion strategies should focus on multiple levels of influence that broaden options for interventions. However, government interventions in addressing food access, affordability, and marketing remain essential to any significant change. [ABSTRACT FROM AUTHOR]

Background: Hemoglobinopathies are inheritable disorders of hemoglobin and are the most common genetic defects in humans. This is a neglected public health problem whose undiagnosis remain a major threat to its prevention and control in sub-Saharan Africa countries; thus its exact magnitude on morbidity and mortality remains poorly documented. These hemoglobin disorders have been associated with Plasmodium falciparum; therefore, the current study sought to determine its distribution in a malaria-holoendemic region of Western Kenya as part of remedial intervention recommended by World Health Organization (WHO). Method: This study analyzed data conveniently selected through census from 2015 to 2020 from hematology laboratory database for patients examined in Aga Khan, Hospital, Kisumu, and its satellites in Western Kenya. A total of 247 cases were selected whose sample size was calculated using Cochran's formula. Distribution of hemoglobinopathies based on stations, gender, and age was expressed in frequencies, proportions, bar graphs, and pie charts. Results: The distribution of hemoglobinopathies had varying proportions in different locations in Western Kenya with regions that were at proximity to Lake Victoria (Kisumu 41.3%, n = 102; Busia 21.5%, n = 53; Homabay 15.4%, n = 38) recording a higher overall hemoglobinopathy proportions than those that were far from the lake that include Bungoma 5.7%, n = 14; Kakamega 4.0%, n = 10; Kitale 4.0%, n = 10; Kisii 4.0%, n = 10, and Migori 4.0% n = 10. Conclusion: The study represents the burden of hemoglobinopathies in a malaria-holoendemic region of Western Kenya, and even though the present study did not include ethnicity in data collection, stations from where the data was collected are predominated by different communities; therefore, there may be an ethnic correlation in the variation of hemoglobinopathies in Western Kenya. The communities juxtaposed to the lake seems to be the most affected ethnic group along the Lake Victoria economic block region; thus, it may be erroneous to assume that the entire malaria-holoendemic region of Western Kenya has high prevalence of hemoglobin disorders without factoring ethnicity and geographical location in a properly conducted population-based prevalence study in the wider Western Kenya. [ABSTRACT FROM AUTHOR]

Background: Assisted partner service (APS) is effective for increasing HIV testing services (HTS) uptake among sexual partners of people diagnosed with HIV with rare social harm. The acceptability of APS to HTS providers is important for the quality and effectiveness of APS delivery. Within a larger ongoing implementation science study of APS in western Kenya, we qualitatively evaluated the provider acceptability of APS. Methods: From May–June 2020, we conducted virtual, semi-structured in-depth interviews with 14 HTS providers recruited from 8 of 31 study health facilities in Homa Bay and Kisumu counties. Participants were selected using criteria-based purposive sampling to maximize variation on patient volume (assessed by the number of index clients tested for HIV) and APS performance (assessed by sexual partners elicitation and enrollment). Interviews inquired providers' experiences providing APS including challenges and facilitators and the impact of contextual factors. Data were analyzed using an inductive approach. Results: Overall, HTS providers found APS acceptable. It was consistently reported that doing APS was a continuous process rather than a one-day job, which required building rapport and persistent efforts. Benefits of APS including efficiency in HIV case finding, expanded testing coverage in men, and increased HIV status awareness and linkage to care motivated the providers. Provider referral was perceived advantageous in terms of independent contact with partners on behalf of index clients and efficiency in partner tracing. Challenges of providing APS included protecting clients' confidentiality, difficulty obtaining partners' accurate contact information, logistic barriers of tracing, and clients' refusal due to fear of being judged for multiple sexual partners, fear of breach of confidentiality, and HIV stigma. Building rapport with clients, communicating with patience and nonjudgmental attitude and assuring confidentiality were examples of facilitators. Working in rural areas and bigger facilities, training, supportive supervision, and community awareness of APS promoted APS delivery while low salaries, lack of equipment, and high workload undermined it. Conclusions: HTS providers found APS acceptable. Delivering APS as a process was the key to success. Future scale-up of APS could consider encouraging provider referral instead of the other APS methods to improve efficiency and reduce potential harm to clients. [ABSTRACT FROM AUTHOR]

Improving agricultural productivity to improve food security and feed the future generation is needed. One of the ways to achieve this is by adopting low-cost solutions such as soil carbon enhancing practices (SCEPs). Given the complexity of adoption decisions, technologies are either adopted as substitutes or complements. A structured survey was utilized to collect data from 334 households in Western Kenya to estimate the impact of adopting SCEPs in combination and identify challenges hindering the adoption of the technologies. Two models, namely a multinomial endogenous treatment effect model and a multi-valued treatment effect model under conditional independence, were utilized to assess the impact of adoption on maize yield. Key variables established to influence adoption were literacy level, tenure security, and market participation. It was further revealed that adopting farmyard manure, intercropping, and a combination of intercropping and farmyard manure had a significant and positive impact on maize yield. This creates a need to promote the adoption of low-cost SCEPs to increase productivity and food security.

The mitochondrial marker, COII, was employed to assess the genetic structure and diversity of Anopheles funestus, a very important malaria vector in Africa that adapt and colonize different ecological niches in western Kenya. Mosquitoes were collected using mechanical aspirators in four areas (Bungoma, Port Victoria, Kombewa, and Migori) in western Kenya. Following morphological identification, PCR was used to confirm the species. The COII gene was amplified, sequenced, and analyzed to determine genetic diversity and population structure. A total of 126 (Port Victoria-38, Migori-38, Bungoma-22, and Kombewa-28) sequences of COII were used for population genetic analysis. Anopheles funestus had a high haplotype diversity (Hd = 0.97 to 0.98) but low nucleotide diversity (Π = 0.004 to 0.005). The neutrality test revealed negative Tajima’s D and Fs values indicating an excess of low-frequency variation. This could be attributed to either population expansion or negative selection pressure across all the populations. No genetic or structural differentiation (Fst = −0.01) and a high level of gene flow (Gamma St, Nm = 17.99 to 35.22) were observed among the populations. Population expansion suggests the high adaptability of this species to various ecological requirements, hence sustaining its vectorial capacity and malaria transmission.

Schistosome parasites cause a chronic inflammatory disease in humans, and recent studies have emphasized the importance of control programs for understanding the aquatic phases of schistosomiasis transmission. The host‐seeking behavior of larval schistosomes (miracidia) for their snail intermediate hosts plays a critical role in parasite transmission. Using field‐derived strains of Kenyan snails and parasites, we tested two main hypotheses: (1) Parasites prefer the most compatible host, and (2) parasites avoid hosts that are already infected. We tested preference to three Biomphalaria host snail taxa (B. pfeifferi, B. sudanica, and B. choanomphala), using allopatric and sympatric Schistosoma mansoni isolates and two different nonhost snail species that co‐occur with Biomphalaria, Bulinus globosus, and Physa acuta. We also tested whether schistosomes avoid snail hosts that are already infected by another trematode species and whether competitive dominance played a role in their behavior. Preference was assessed using two‐way choice chambers and by visually counting parasites that moved toward competing stimuli. In pairwise comparisons, we found that S. mansoni did not always prefer the more compatible snail taxon, but never favored an incompatible host over a compatible host. While parasites preferred B. pfeifferi to the nonhost species B. globosus, they did not significantly prefer B. pfeifferi versus P. acuta, an introduced species in Kenya. Finally, we demonstrated that parasites avoid infected snails if the resident parasite was competitively dominant (Patagifer sp.), and preferred snails infected with subordinates (xiphidiocercariae) to uninfected snails. These results provide evidence of "fine tuning" in the ability of schistosome miracidia to detect hosts; however, they did not always select hosts that would maximize fitness. Appreciating such discriminatory abilities could lead to a better understanding of how ecosystem host and parasite diversity influences disease transmission and could provide novel control mechanisms to improve human health. [ABSTRACT FROM AUTHOR]

Background: Haemoglobinopathies are inherited haemoglobin disorders that result in anaemia characterised by erythrocyte anisopoikilocytosis. Red cell distribution width (RDW) measures anisopoikiloytosis and is readily reported by haematology analysers as a complete blood count parameter. The utility of RDW as a diagnostic marker of haemoglobinopathies in Kenya remains undetermined and undocumented. Objective: This study aimed to determine the diagnostic efficacy of RDW in discriminating haemoglobinopathy and haemoglobinopathy-free cases in Kenya. Methods: The case-control study used randomly selected haematology analyser outputs for haemoglobinopathy-free (241, 49.4%) and haemoglobinopathy cases (247, 50.1%) aged 1 month to 66 years old tested in the Aga Khan Hospital, Kisumu, and its satellite centres in western Kenya from 01 January 2015 to 31 December 2020. Results were verified using high performance liquid chromatography. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic power of RDW as a biomarker for sickle cell disease (SCD) and sickle cell trait phenotypes and β-thalassaemia. Results: The RDW showed diagnostic significance in SCD phenotypes at 21.1 ROC curve coordinate with 67.7% sensitivity, 90.0% specificity, 0.789 accuracy, 70.5% positive predictive validity, 88.8% negative predictive validity, 6.77 positive likelihood ratio, 0.36 negative likelihood ratio and 18.94 (11.4–31.4) odds ratio. Conclusion: An RDW of 21.1% is potentially a predictor of SCD haemoglobin phenotypes and should be included in the haematology screening algorithm as a critical value, above which suspected cases qualify to be investigated for SCD.

Abstract Schistosome parasites cause a chronic inflammatory disease in humans, and recent studies have emphasized the importance of control programs for understanding the aquatic phases of schistosomiasis transmission. The host‐seeking behavior of larval schistosomes (miracidia) for their snail intermediate hosts plays a critical role in parasite transmission. Using field‐derived strains of Kenyan snails and parasites, we tested two main hypotheses: (1) Parasites prefer the most compatible host, and (2) parasites avoid hosts that are already infected. We tested preference to three Biomphalaria host snail taxa (B. pfeifferi, B. sudanica, and B. choanomphala), using allopatric and sympatric Schistosoma mansoni isolates and two different nonhost snail species that co‐occur with Biomphalaria, Bulinus globosus, and Physa acuta. We also tested whether schistosomes avoid snail hosts that are already infected by another trematode species and whether competitive dominance played a role in their behavior. Preference was assessed using two‐way choice chambers and by visually counting parasites that moved toward competing stimuli. In pairwise comparisons, we found that S. mansoni did not always prefer the more compatible snail taxon, but never favored an incompatible host over a compatible host. While parasites preferred B. pfeifferi to the nonhost species B. globosus, they did not significantly prefer B. pfeifferi versus P. acuta, an introduced species in Kenya. Finally, we demonstrated that parasites avoid infected snails if the resident parasite was competitively dominant (Patagifer sp.), and preferred snails infected with subordinates (xiphidiocercariae) to uninfected snails. These results provide evidence of “fine tuning” in the ability of schistosome miracidia to detect hosts; however, they did not always select hosts that would maximize fitness. Appreciating such discriminatory abilities could lead to a better understanding of how ecosystem host and parasite diversity influences disease transmission and could provide novel control mechanisms to improve human health.

Background: Haemoglobinopathies are inherited haemoglobin disorders that result in anaemia characterised by erythrocyte anisopoikilocytosis. Red cell distribution width (RDW) measures anisopoikiloytosis and is readily reported by haematology analysers as a complete blood count parameter. The utility of RDW as a diagnostic marker of haemoglobinopathies in Kenya remains undetermined and undocumented. Objective: This study aimed to determine the diagnostic efficacy of RDW in discriminating haemoglobinopathy and haemoglobinopathy-free cases in Kenya. Methods: The case-control study used randomly selected haematology analyser outputs for haemoglobinopathy-free (241, 49.4%) and haemoglobinopathy cases (247, 50.1%) aged 1 month to 66 years old tested in the Aga Khan Hospital, Kisumu, and its satellite centres in western Kenya from 01 January 2015 to 31 December 2020. Results were verified using high performance liquid chromatography. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic power of RDW as a biomarker for sickle cell disease (SCD) and sickle cell trait phenotypes and β-thalassaemia. Results: The RDW showed diagnostic significance in SCD phenotypes at 21.1 ROC curve coordinate with 67.7% sensitivity, 90.0% specificity, 0.789 accuracy, 70.5% positive predictive validity, 88.8% negative predictive validity, 6.77 positive likelihood ratio, 0.36 negative likelihood ratio and 18.94 (11.4–31.4) odds ratio. Conclusion: An RDW of 21.1% is potentially a predictor of SCD haemoglobin phenotypes and should be included in the haematology screening algorithm as a critical value, above which suspected cases qualify to be investigated for SCD. [ABSTRACT FROM AUTHOR]

Background: The gold standard for diagnosing Plasmodium falciparum infection is microscopic examination of Giemsa-stained peripheral blood smears. The effectiveness of this procedure for infection surveillance and malaria control may be limited by a relatively high parasitaemia detection threshold. Persons with microscopically undetectable infections may go untreated, contributing to ongoing transmission to mosquito vectors. The purpose of this study was to determine the magnitude and determinants of undiagnosed submicroscopic P. falciparum infections in a rural area of western Kenya. Methods: A health facility-based survey was conducted, and 367 patients seeking treatment for symptoms consistent with uncomplicated malaria in Homa Bay County were enrolled. The frequency of submicroscopic P. falciparum infection was measured by comparing the prevalence of infection based on light microscopic inspection of thick blood smears versus real-time polymerase chain reaction (RT-PCR) targeting P. falciparum 18S rRNA gene. Long-lasting insecticidal net (LLIN) use, participation in nocturnal outdoor activities, and gender were considered as potential determinants of submicroscopic infections. Results: Microscopic inspection of blood smears was positive for asexual P. falciparum parasites in 14.7% (54/367) of cases. All of these samples were confirmed by RT-PCR. 35.8% (112/313) of blood smear negative cases were positive by RT-PCR, i.e., submicroscopic infection, resulting in an overall prevalence by RT-PCR alone of 45.2% compared to 14.7% for blood smear alone. Females had a higher prevalence of submicroscopic infections (35.6% or 72 out of 202 individuals, 95% CI 28.9–42.3) compared to males (24.2%, 40 of 165 individuals, 95% CI 17.6–30.8). The risk of submicroscopic infections in LLIN users was about half that of non-LLIN users (OR = 0.59). There was no difference in the prevalence of submicroscopic infections of study participants who were active in nocturnal outdoor activities versus those who were not active (OR = 0.91). Patients who participated in nocturnal outdoor activities and use LLINs while indoors had a slightly higher risk of submicroscopic infection than those who did not use LLINs (OR = 1.48). Conclusion: Microscopic inspection of blood smears from persons with malaria symptoms for asexual stage P. falciparum should be supplemented by more sensitive diagnostic tests in order to reduce ongoing transmission of P. falciparum parasites to local mosquito vectors. [ABSTRACT FROM AUTHOR]

Summary: Production of cereal crops in sub-Saharan Africa is threatened by parasitic striga weeds and attack by stemborers and the invasive fall armyworm (FAW), compounded by increasing hot and dry conditions. A climate-smart push-pull technology (PPT) significantly reduces effects of these biotic challenges. To improve further resilience of the system to climate change, more adapted and suitable companion plants were identified and integrated in a new version of PPT, termed 'third generation PPT'. Our study evaluates field performance and farmer opinions of this new version in comparison with the earlier version, climate-smart PPT, and farmers' own practices of growing maize in controlling stemborers, FAW, and striga weeds. Trials were conducted across five locations in western Kenya for two cropping seasons in the year 2019 following a one-farm one-replicate completely randomized design. We assessed infestation on striga, stemborers, and FAW, and yield performance of the three cropping systems. We also sought the opinions of the hosting farmers through semi-structured questionnaires that were administered through individual interviews. Both PPT plots recorded significantly (P < 0.05) lower striga count, FAW, and stemborer damage, and higher grain yield than in plots that followed farmers' own practices. There was no statistically significant difference between the two PPT plots except for stemborer damage for which the third generation PPT recorded higher damage than the climate-smart PPT. However, farmers preferred the third generation PPT for important traits possessed by its companion plants which their counterparts in climate-smart PPT are deficient. The cultivar Xaraes was rated as 'very good' for resistance to spider mites, biomass yield, and drought tolerance while Desmodium incanum was rated 'very good' for seed production and drought tolerance. The third generation PPT is based on companion crops that are more resilient to hot and dry conditions which are increasing rapidly in prevalence with climate change. This version therefore presents a better option to upscale the technology and meet different needs of farmers especially in arid and semi-arid conditions. [ABSTRACT FROM AUTHOR]

Background: Tick-borne pathogens (TBPs) are of global importance, especially in sub-Saharan Africa where they represent a major constraint to livestock production. Their association with human disease is also increasingly recognized, signalling their zoonotic importance. It is therefore crucial to investigate TBPs prevalence in livestock populations and the factors associated with their presence. We set out to identify TBPs present in cattle and to determine associated risk factors in western Kenya, where smallholder livestock production is important for subsistence and market-driven income. Results: Tick-borne pathogen infections in blood samples collected from cattle at livestock markets and slaughterhouses between May 2017 and January 2019 were identified by high-resolution melting analysis and sequencing of PCR products of genus-specific primers. Of the 422 cattle sampled, 30.1% (127/422) were infected with at least one TBP, while 8.8% (37/422) had dual infections. Anaplasma spp. (19.7%) were the most prevalent, followed by Theileria (12.3%), Ehrlichia (6.6%), and Babesia (0.2%) spp. Sequence analysis of the TBPs revealed them to be Anaplasma platys-like organisms (13.5%), Theileria velifera (7.4%), Anaplasma marginale (4.9%), Theileria mutans (3.1%), Theileria parva (1.6%), and Babesia bigemina (0.2%). Ehrlichia ruminantium, Rickettsia spp., and arboviruses were not detected. Exotic breeds of cattle were more likely to be infected with A. marginale compared to local breeds (OR: 7.99, 95% CI: 3.04–22.02, p < 0.001). Presence of ticks was a significant predictor for Anaplasma spp. (OR: 2.18, 95% CI: 1.32–3.69, p = 0.003) and Ehrlichia spp. (OR: 2.79, 95% CI: 1.22–7.23, p = 0.022) infection. Cattle sampled at slaughterhouses were more likely to be positive for Anaplasma spp. (OR: 1.64, 95% CI: 1.01–2.70, p = 0.048) and A. marginale (OR: 3.84, 95% CI: 1.43–12.21, p = 0.012), compared to those sampled at livestock markets. Conclusion: This study reports TBP prevalence and associated risk factors in western Kenya, factors which are key to informing surveillance and control measures. [ABSTRACT FROM AUTHOR]

This paper analyses the effects of gender and institutional support services on commercialisation patterns of maize by female-headed households (FHHs) and male-headed households (MHHs) in Western Kenya. Using primary household survey data from 297 maize farmers, we estimate a Tobit model and a treatment effect model to assess the determinants and gender-induced differences in commercialisation patterns, respectively. Results show that commercialisation levels of FHHs and MHHs were significantly and variably affected by institutional support services. The exogenous switching treatment effect model showed that the commercialisation intensity gap between MHHs and FHHs is explained by both observable and unobservable characteristics. [ABSTRACT FROM AUTHOR]

Abstract Background Genetic diversity of ABO blood, glucose-6-phosphate dehydrogenase (G6PD) deficiency and haemoglobin type and their ability to protect against malaria vary geographically, ethnically and racially. No study has been carried out in populations resident in malaria regions in western Kenya. Method A total of 574 malaria cases (severe malaria anaemia, SMA = 137 and non-SMA = 437) seeking treatment at Vihiga County and Referral Hospital in western Kenya, were enrolled and screened for ABO blood group, G6PD deficiency and haemoglobin genotyped in a hospital-based cross-sectional study. Result When compared to blood group O, blood groups A, AB and B were not associated with SMA (P = 0.380, P = 0.183 and P = 0.464, respectively). Further regression analysis revealed that the carriage of the intermediate status of G6PD was associated with risk to SMA (OR = 1.52, 95%CI = 1.029–2.266, P = 0.035). There was, however, no association between AS and SS with severe malaria anaemia. Co-occurrence of both haemoglobin type and G6PD i.e. the AA/intermediate was associated with risk to SMA (OR = 1.536, 95%CI = 1.007–2.343, P = 0.046) while the carriage of the AS/normal G6PD was associated with protection against SMA (OR = 0.337, 95%CI = 0.156–0.915, P = 0.031). Conclusion Results demonstrate that blood group genotypes do not have influence on malaria disease outcome in this region. Children in Vihiga with blood group O have some protection against malaria. However, the intermediate status of G6PD is associated with risk of SMA. Further, co-inheritance of sickle cell and G6PD status are important predictors of malaria disease outcome. This implies combinatorial gene function in influencing disease outcome.

Abstract Background A lot of emphasis is often placed on modern governance systems and little or no attention is given to traditional governance practices which remain largely undocumented. The study aimed at finding out important traditional and modern governance practices that regulate traditional medicine sector in Western Kenya. Materials and methods The study was carried out in selected market centres of Western Kenya where the identified traditional medicine practitioners (TMPs) sell their traditional medicine. All consenting TMPs and professional experts were interviewed with the aid of a semi-structured questionnaire. Purposive sampling design with elements of snowball techniques was employed in tracing competent traditional medicine (TM) experts and relevant professional experts. The data collected was processed in Microsoft Excel and descriptive statistics performed. Pearson’s chi-square statistics was carried out to determine the significance of the traditional and modern governance data sets using the STATA software. Results Modern governance practices were not significantly different in all the market centres surveyed (p = 0.080). Equally, the traditional governance practices were also not significantly different in all the selected market centres (p = 1.000). Conclusions Traditional governance practices play an important role in the governance of traditional medicine and are shaped by the socio-cultural beliefs of the local communities. Modern governance practices, on the other hand, are widely perceived as top downregulation of the traditional medicine growing industry.

Abstract Background Naturally acquired immunity (NAI), which is characterized by protection against overt clinical disease and high parasitaemia, is acquired with age and transmission intensity. The role of NAI on the efficacy of anti-malarial drugs, including artemisinin-based combinations used as the first-line treatment for uncomplicated Plasmodium falciparum, has not been fully demonstrated. This study investigated the role of NAI in response to artemisinin-based combination therapy (ACT), in symptomatic patients living in western Kenya, a high malaria transmission area. Methods Sera samples from malaria immune participants (n = 105) in a therapeutic efficacy study were assessed for in vitro growth inhibitory activity against the 3D7 strain of P. falciparum using a fluorescent-based growth inhibition assay (GIA). Participants’ age and parasite clearance parameters were used in the analysis. Pooled sera from malaria naïve participants (n = 6) with no Plasmodium infection from malaria non-endemic regions of Kenya was used as negative control. Results The key observations of the study were as follows: (1) Sera with intact complement displayed higher GIA activity at lower (1%) serum dilutions (p