Publications by authors named "G. Otieno"

Background: Sickle cell disease, a debilitating, inherited haemolytic anaemia with premature morbidity and mortality, affects millions globally. Mitapivat, a first-in-class, oral, allosteric activator of pyruvate kinase, improves red blood cell survival by increasing ATP and diminishes sickling by decreasing 2,3-diphosphoglycerate. We aimed to evaluate the efficacy and safety of mitapivat in patients with sickle cell disease.

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  • The study assessed bone mineral density (BMD) in older HIV-positive individuals in Kenya as they enrolled in a clinical trial, focusing on participants aged 60 and above.
  • A total of 296 Black African participants were included, with findings indicating a high prevalence of osteoporosis (37.5%) and osteopenia (47.3%) among them, alongside calculated fracture risks.
  • The research highlighted challenges in diagnosing osteoporosis due to limited access to dual-energy x-ray absorptiometry (DXA) in Kenya, showing a negative correlation between fracture risk probabilities and femoral neck BMD.
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rVSVΔG-ZEBOV-GP and Ad26.ZEBOV, MVA-BN-Filo are WHO-prequalified vaccination regimens against Ebola virus disease (EVD). Challenges associated with measuring long-term clinical protection warrant the evaluation of immune response kinetics after vaccination.

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The development of novel improved varieties adapted to unstable environmental conditions is possible through the genetic diversity of breeding materials. Potato is among the most important food crops worldwide, however, there are still significant hindrances to breeding gains attributed to its autotetraploid and highly heterozygous genome. Bacterial wilt caused by the species complex (RSSC) is an important disease affecting potato among many economically important crops worldwide.

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  • Researchers conducted surveillance for avian influenza viruses in domestic and wild birds near Lake Victoria, Kenya, due to nearby outbreaks in other countries.
  • They tested over 14,000 specimens and found that 3.9% of poultry samples and 0.2% of wild bird fecal samples were positive for the virus, with most poultry infections being H9N2.
  • Despite not detecting highly pathogenic H5N8, the study emphasizes the risk of HPAI virus introduction and establishment in the region, particularly through live bird markets.
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  • Initial SARS-CoV-2 transmission peaked in densely populated areas of Kenya, gradually spreading to remote regions like Kajiado County, which struggle with inadequate healthcare.
  • In a study from March 2020 to March 2022, dry blood spots (DBS) were collected from patients to detect SARS-CoV-2 IgG antibodies using ELISA, revealing a seropositivity rate of 7.3%.
  • High seropositivity was found among the elderly and males, with the Mashuru and Meto health facilities showing the highest rates, indicating significant SARS-CoV-2 transmission in these underserved pastoralist communities.
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A globally implemented unified phylogenetic classification for human respiratory syncytial virus (HRSV) below the subgroup level remains elusive. We formulated global consensus of HRSV classification on the basis of the challenges and limitations of our previous proposals and the future of genomic surveillance. From a high-quality curated dataset of 1,480 HRSV-A and 1,385 HRSV-B genomes submitted to GenBank and GISAID (https://www.

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We examined the association between serum aflatoxin B1-lysine adduct (AFB1-lys) levels in pregnant women and adverse pregnancy outcomes (low birthweight, miscarriage and stillbirth) through a nested matched case-control study of pregnant women enroled at ≤28 weeks' gestation in Mombasa, Kenya, from 2017 to 2019. Cases comprised women with an adverse birth outcome, defined as either delivery of a singleton infant weighing <2500 g, or a miscarriage, or a stillbirth, while controls were women who delivered a singleton live infant with a birthweight of ≥2500 g. Cases were matched to controls at a ratio of 1:2 based on maternal age at enrolment, gestational age at enrolment and study site.

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Background: Influenza is a significant contributor to acute respiratory infections (ARI), and children < 5 years are at increased risk of severe influenza disease. In Kenya the influenza vaccine is not included in the Kenya Expanded Programme on Immunization (KEPI). To inform roll-out of a national influenza vaccination program, we implemented an influenza vaccine demonstration project in Nakuru and Mombasa counties in Kenya from 2019 to 2021 and set out to establish factors driving influenza vaccine acceptance and hesitancy among caregivers of children aged 6-23 months.

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Background: Falciparum malaria remains a global health problem. Two vaccines, based on the circumsporozoite antigen, are available. RTS, S/AS01 was recommended for use in 2021 following the advice of the World Health Organisation (WHO) Strategic Advisory Group of Experts (SAGE) on Immunization and WHO Malaria Policy Advisory Group (MPAG).

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In this study, chemically activated fat-free powdered Moringa oleifera seed biomass (MOSB) was synthesized, characterized, and utilized as a cost-effective biosorbent for the abstraction of progesterone (PGT) hormone from synthetic wastewater. Natural PGT is a human steroid hormone from the progestogen family. Synthetic PGT is approved for the regulation of the menstrual cycle, aiding contraception, and is administered as a hormone replacement therapy in menopausal and post-menopausal women.

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A systems analysis was conducted to determine the potential molecular mechanisms underlying differential immunogenicity and protective efficacy results of a clinical trial of the radiation-attenuated whole-sporozoite PfSPZ vaccine in African infants. Innate immune activation and myeloid signatures at prevaccination baseline correlated with protection from P. falciparum parasitemia in placebo controls.

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  • Tracking livestock abortion patterns can help develop policies to reduce disease risk and reproductive losses in Kenya's livestock industry.
  • A year-long active surveillance study covered 52% of Kenya’s land area, with significant abortion rates particularly in arid and semi-arid regions, where sheep and goats accounted for the majority of the cases.
  • The findings highlight the need for more research on the true scale of livestock abortions and the relationship between pathogens, climate, and environmental factors in these areas.
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Background: Shigellosis mainly affects children under 5 years of age living in low- and middle-income countries, who are the target population for vaccination. There are, however, limited data available to define the appropriate timing for vaccine administration in this age group. Information on antibody responses following natural infection, proxy for exposure, could help guide vaccination strategies.

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  • * The study enrolled 2,312 pregnant women under 28 weeks gestation in coastal Kenya and tracked them until delivery, finding that 20.9% experienced adverse outcomes, with specific rates for stillbirths, miscarriages, and congenital anomalies reported.
  • * Key risk factors identified include febrile illnesses during pregnancy, previous poor birth outcomes, and high blood pressure, which significantly increase the likelihood of adverse birth outcomes.
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The Nile perch (Lates niloticus L.) commercial fishery for Lake Victoria in East Africa is an important source of revenue and employment. We focused on shifts in food web structure and total mercury (THg) bioaccumulation and biomagnification in Nile perch, and lower food web items collected from Winam Gulf (Kenya) sampled 24 years apart (1998 and 2022).

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Background: Though persons of African descent have one of the widest genetic variability, genetic polymorphisms of drug-metabolising enzymes such as N-Acetyltransferase-2 (NAT2) are understudied. This study aimed to identify prevalent NAT2 single nucleotide polymorphisms (SNPs) and infer their potential effects on enzyme function among Kenyan volunteers with tuberculosis (TB) infection. Genotypic distribution at each SNP and non-random association of alleles were evaluated by testing for Hardy-Weinberg Equilibrium (HWE) and Linkage Disequilibrium (LD).

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A growing literature suggests that plasma levels of tau phosphorylated at amino acid 217 (pTau217) performs similarly to cerebrospinal fluid (CSF) biomarkers and PET imaging to detect amyloid pathology and to provide diagnostic and prognostic information in Alzheimer's disease (AD), but a significant limiting factor thus far has been a lack of widely available immunoassays. We evaluated a novel pTau217 S-PLEX® assay developed by Meso Scale Discovery (MSD; Rockville, MD) in plasma from 131 individuals with AD confirmed by CSF biomarkers and controls. Technical performance of the assay was excellent with an LLOQ of 1.

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The recently emerged coronavirus disease 2019 (COVID-19) has caused considerable morbidity and mortality worldwide and disrupted health services. We describe the effect of the COVID-19 pandemic on utilization of childhood vaccination services during the pandemic. Using a mixed methods approach combining retrospective data review, a cross-sectional survey, focus group discussions among care givers and key informant interviews among nurses, we collected data between May and September 2021 in Mombasa and Nakuru counties.

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Introduction: Zinc deficiency is a common health problem among people who rely heavily on cereal-based foods. Consequently, most people from low-income families, particularly young children in Sub-Saharan Africa, who rely mainly on cereal-based meals, have suffered from Zinc deficiency-related health issues. It is therefore recommended that children who show signs of zinc deficiency like poor growth and cognitive impairment be fed zinc-rich meals; however, in severe cases, they should be given zinc supplements to reduce risks of morbidity and mortality.

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We assessed whether the immunogenicity of the two-dose Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen with a 56-day interval between doses was affected by exposure to malaria before dose 1 vaccination and by clinical episodes of malaria in the period immediately after dose 1 and after dose 2 vaccinations. Previous malaria exposure in participants in an Ebola vaccine trial in Sierra Leone (ClinicalTrials.

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A non-optimal vaginal microbiome (VMB) is typically diverse with a paucity of and is often associated with bacterial vaginosis (BV) and sexually transmitted infections (STIs). Although compositional characterization of the VMB is well-characterized, especially for BV, knowledge remains limited on how different groups of bacteria relate to incident STIs, especially among adolescents. In this study, we compared the VMB (measured via 16S ribosomal RNA gene amplicon sequencing) of Kenyan secondary school girls with incident STIs (composite of chlamydia, gonorrhea, and trichomoniasis) to those who remained persistently negative for STIs and BV over 30 months of follow-up.

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We have adopted an open bioinformatics ecosystem to address the challenges of bioinformatics implementation in public health laboratories (PHLs). Bioinformatics implementation for public health requires practitioners to undertake standardized bioinformatic analyses and generate reproducible, validated and auditable results. It is essential that data storage and analysis are scalable, portable and secure, and that implementation of bioinformatics fits within the operational constraints of the laboratory.

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Objectives: This review aimed at identifying the elements of integrated care models for cardiometabolic multimorbidity in sub-Saharan Africa (SSA) and their effects on clinical or mental health outcomes including systolic blood pressure (SBP), blood sugar, depression scores and other patient-reported outcomes such as quality of life and medication adherence.

Design: Systematic review and meta-analysis using the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

Data Sources: We systematically searched PubMed, Embase, Scopus, Web of Science, Global Health CINAHL, African Journals Online, Informit, PsycINFO, ClinicalTrials.

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Recent studies link increased ozone (O3) and carbon dioxide (CO2) levels to alteration of plant performance and plant-herbivore interactions, but their interactive effects on plant-pollinator interactions are little understood. Extra floral nectaries (EFNs) are essential organs used by some plants for stimulating defense against herbivory and for the attraction of insect pollinators, e.g.

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