Publications by authors named "Grieven P Otieno"

Stratifying women using their medical history pre-pregnancy may allow early identification of women at high-risk of Hypertensive disorders of pregnancy (HDP), a common and high-burden obstetrical complication. This would allow the establishment of early preventative approaches, however, most research into pregestational conditions comes from data taken during pregnancy. To address this gap, we conducted a systematic review with meta-analysis, adhering to PRISMA and MOOSE guidelines.

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Introduction: Application of data science in maternal, newborn, and child health (MNCH) across Africa is variable with limited documentation. Despite efforts to reduce preventable MNCH morbidity and mortality, progress remains slow. Accurate data are crucial for holding countries accountable for tracking progress towards achieving the Sustainable Development Goal 3 targets on MNCH.

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Pneumonia remains a major cause of mortality and morbidity. Most molecular diagnoses of viruses rely on polymerase chain reaction (PCR) assays that however can fail due to primer mismatch. We investigated the performance of routine virus diagnostics in Kilifi, Kenya, using random-primed viral next generation sequencing (viral NGS) on respiratory samples which tested negative for the common viral respiratory pathogens by a local standard diagnostic panel.

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The natural history and transmission patterns of endemic human coronaviruses are of increased interest following the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In rural Kenya 483 individuals from 47 households were followed for six months (2009-10) with nasopharyngeal swabs collected twice weekly regardless of symptoms. A total of 16,918 swabs were tested for human coronavirus (hCoV) OC43, NL63 and 229E and other respiratory viruses using polymerase chain reaction.

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Article Synopsis
  • * Researchers sequenced the genomes of 111 positive cases, finding a predominance of the B/Victoria lineage and evidence of genetic reassortment between lineages.
  • * The findings reveal a high number of IBV strain introductions and significant genetic variation, suggesting that broad immunity vaccines are necessary for effective influenza control in the region.
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Randomized controlled trials of licensed oral rotavirus group A (RVA) vaccines, indicated lower efficacy in developing countries compared to developed countries. We investigated the pooled effectiveness of Rotarix in Africa in 2019, a decade since progressive introduction began in 2009. A systematic search was conducted in PubMed to identify studies that investigated the effectiveness of routine RVA vaccination in an African country between 2009 and 2019.

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Respiratory viruses are primary agents of respiratory tract diseases. Knowledge on the types and frequency of respiratory viruses affecting school-children is important in determining the role of schools in transmission in the community and identifying targets for interventions. We conducted a one-year (term-time) surveillance of respiratory viruses in a rural primary school in Kilifi County, coastal Kenya between May 2017 and April 2018.

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Article Synopsis
  • Human rhinovirus (HRV) is the leading cause of the common cold and can cause severe respiratory issues, especially in vulnerable individuals; this study aimed to analyze HRV in a rural Kenyan primary school setting.
  • Over a year, 1859 nasopharyngeal swabs were collected from students and teachers with respiratory symptoms, resulting in 307 HRV-positive cases, with a higher prevalence in younger students than older ones.
  • HRV-A was the most prevalent species, with substantial genetic diversity observed, including 47 different genotypes, and no single genotype was constantly present across all terms of the study.
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Human coronaviruses (HCoVs) circulate endemically in human populations, often with seasonal variation. We describe the long-term patterns of paediatric disease associated with three of these viruses, HCoV-NL63, OC43 and 229E, in coastal Kenya. Continuous surveillance of pneumonia admissions was conducted at the Kilifi county hospital (KCH) located in the northern coastal region of Kenya.

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Background: Kenya introduced the monovalent G1P [8] Rotarix® vaccine into the infant immunization schedule in July 2014. We examined trends in rotavirus group A (RVA) genotype distribution pre- (January 2010-June 2014) and post- (July 2014-December 2018) RVA vaccine introduction.

Methods: Stool samples were collected from children aged < 13 years from four surveillance sites across Kenya: Kilifi County Hospital, Tabitha Clinic Nairobi, Lwak Mission Hospital, and Siaya County Referral Hospital (children aged < 5 years only).

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Article Synopsis
  • Influenza viruses, particularly A(H3N2), rapidly evolve due to immune-driven selection, with notable changes in the hemagglutinin (HA) protein affecting how they are recognized by the immune system.
  • A study conducted in Kilifi, Kenya from 2009 to 2017 utilized next-generation sequencing to analyze 101 whole genomes of the A(H3N2) virus from patients with respiratory illnesses, revealing significant genetic divergence from existing vaccine strains and the formation of multiple genetic clades.
  • The findings indicate that A(H3N2) viruses in Kilifi are continually evolving, highlighting the necessity for ongoing genetic and antigenic surveillance to inform vaccine strain selection for future flu seasons.
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Background: Monovalent rotavirus vaccine, Rotarix (GlaxoSmithKline), was introduced in Kenya in July 2014 and is recommended to infants as oral doses at ages 6 and 10 weeks. A multisite study was established in 2 population-based surveillance sites to evaluate vaccine impact on the incidence of rotavirus-associated hospitalizations (RVHs).

Methods: Hospital-based surveillance was conducted from January 2010 to June 2017 for acute diarrhea hospitalizations among children aged <5 years in 2 health facilities in Kenya.

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  • Human metapneumovirus (HMPV) is a significant cause of respiratory illness and pneumonia in children, especially in areas with limited resources, but the understanding of its spread and impact is still lacking.
  • In a study conducted in Kenya from 2007 to 2016, researchers analyzed nasal samples from children under 5 years with pneumonia, finding HMPV in 4.1% of samples, with annual prevalence fluctuating and peaks occurring mostly between October and April.
  • Genetic analysis of HMPV revealed various subgroups, with no significant difference in pneumonia severity among them, indicating a complex but interconnected global transmission of the virus.
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Background: Rotavirus remains a leading cause of pediatric diarrheal illness and death worldwide. Data on rotavirus vaccine effectiveness in sub-Saharan Africa are limited. Kenya introduced monovalent rotavirus vaccine (RV1) in July 2014.

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Kenya introduced the monovalent Rotarix® rotavirus group A (RVA) vaccine nationally in mid-2014.  Long-term surveillance data is important prior to wide-scale vaccine use to assess the impact on disease and to investigate the occurrence of heterotypic strains arising through immune selection. This report presents baseline data on RVA genotype circulation patterns and intra-genotype genetic diversity over a 7-year period in the pre-vaccine era in Kilifi, Kenya, from 2002 to 2004 and from 2010 to 2013.

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Article Synopsis
  • Human rhinovirus (HRV) is the leading cause of upper respiratory infections, with 168 different types that provide strong immunity only to the same type and weak immunity to others, making its transmission patterns complex and understudied.
  • Between December 2015 and November 2016, a study collected nasopharyngeal swabs from patients across nine outpatient facilities to analyze HRV prevalence and diversity, detecting HRV in 18.4% of samples, with successful sequencing of 77.3%.
  • Findings revealed varying temporal persistence patterns among HRV types, indicating frequent community invasions, and showed spatial clustering of similar types in nearby health facilities, suggesting both rapid spread and multiple separate invasions of the virus types.
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We report on infection patterns in 5 households (78 participants) delineating the natural history of human rhinovirus (HRV). Nasopharyngeal collections were obtained every 3-4 days irrespective of symptoms, over a 6-month period, with molecular screening for HRV and typing by sequencing VP4/VP2 junction. Overall, 311/3468 (8.

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  • Human coronavirus NL63 (HCoV-NL63) is a common respiratory pathogen linked to both mild and severe infections, with individuals experiencing reinfections throughout their lives.
  • In a study conducted in coastal Kenya, HCoV-NL63 was found in a small percentage (1.3%) of child pneumonia cases, and research identified two genotypes circulating between 2008 and 2014.
  • The findings suggest that HCoV-NL63 has low genetic diversity and that previous infections do not provide strong immune protection, as repeat infections showed no significant changes in the virus genotype.
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Background: Direct immuno-fluorescence test (IFAT) and multiplex real-time RT-PCR have been central to RSV diagnosis in Kilifi, Kenya. Recently, these two methods showed discrepancies with an increasing number of PCR undetectable RSV-B viruses.

Objectives: Establish if mismatches in the primer and probe binding sites could have reduced real-time RT-PCR sensitivity.

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