Publications by authors named "Ngoi J"

The respiratory tract harbours microorganisms of the normal host microbiota which are also capable of causing invasive disease. Among these, Neisseria meningitidis a commensal bacterium of the oropharynx can cause meningitis, a disease with epidemic potential. The oral microbiome plays a crucial role in maintaining respiratory health.

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The patterns of spread of influenza A viruses in local populations in tropical and sub-tropical regions are unclear due to sparsity of representative spatiotemporal sequence data. We sequenced and analyzed 58 influenza A(H3N2) virus genomes sampled between December 2015 and December 2016 from nine health facilities within the Kilifi Health and Demographic Surveillance System (KHDSS), a predominantly rural region, covering approximately 891 km along the Kenyan coastline. The genomes were compared with 1571 contemporaneous global sequences from 75 countries.

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Purpose: Breast cancer is a major cause of cancer-related mortality among African women. The adoption of molecular genomic technologies in the management of cancer cases is limited in Africa. To provide much-needed insights on the feasibility and utility of such precision medicine paradigms in Africa, we conducted a prospective, non-interventional study involving combined tissue and plasma Next-generation sequencing (NGS)-based testing in cancer patients in Ghana.

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Introduction: The oropharyngeal microbiome plays an important role in protection against infectious agents when in balance. Despite use of vaccines and antibiotic therapy to prevent respiratory tract infections, they remain one of the major causes of mortality and morbidity in Low- and middle-income countries. Hence the need to explore other approaches to prevention by identifying microbial biomarkers that could be leveraged to modify the microbiota in order to enhance protection against pathogenic bacteria.

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The SARS-CoV-2 genome occupies a unique place in infection biology - it is the most highly sequenced genome on earth (making up over 20% of public sequencing datasets) with fine scale information on sampling date and geography, and has been subject to unprecedented intense analysis. As a result, these phylogenetic data are an incredibly valuable resource for science and public health. However, the vast majority of the data was sequenced by tiling amplicons across the full genome, with amplicon schemes that changed over the pandemic as mutations in the viral genome interacted with primer binding sites.

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Background: Breast cancer (BC) metastases to the abdomen and pelvis affect the liver, mesentery, retroperitoneum, peritoneum, bladder, kidney, ovary, and uterus. The study documented the radiological pattern and features of the chest, bone, abdominal and pelvic (AP) metastases among advanced BC patients.

Aim: The aim is to document the radiological pattern and features of breast cancer metastasis in the chest, abdomen, pelvis and bones.

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Malaria results in over 600,000 deaths annually, with the highest burden of deaths in young children living in sub-Saharan Africa. Molecular surveillance can provide important information for malaria control policies, including detection of antimalarial drug resistance. However, genome sequencing capacity in malaria-endemic countries is limited.

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Natural killer (NK) cells are potent immune effectors that can be activated via antibody-mediated Fc receptor engagement. Using multiparameter flow cytometry, we found that NK cells degranulate and release IFN-γ upon stimulation with antibody-opsonized merozoites. Antibody-dependent NK (Ab-NK) activity was largely strain transcending and enhanced invasion inhibition into erythrocytes.

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Article Synopsis
  • A lot of money has been spent on studying the COVID-19 virus in Africa, leading to over 100,000 virus samples being analyzed to understand the spread of the disease.
  • *More countries in Africa are now able to do these studies themselves, which helps them get results faster and keep a close watch on the virus.
  • *To keep fighting COVID and other diseases, more funding and support for testing and research in Africa is really important for the future.
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Background: High levels of genetic diversity are common characteristics of Plasmodium falciparum parasite populations in high malaria transmission regions. There has been a decline in malaria transmission intensity over 12 years of surveillance in the community in Kilifi, Kenya. This study sought to investigate whether there was a corresponding reduction in P.

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The COVID-19 pandemic is one of the fastest evolving pandemics in recent history. As such, the SARS-CoV-2 viral evolution needs to be continuously tracked. This study sequenced 1123 SARS-CoV-2 genomes from patient isolates (121 from arriving travellers and 1002 from communities) to track the molecular evolution and spatio-temporal dynamics of the SARS-CoV-2 variants in Ghana.

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Background: Environmental Enteric Dysfunction (EED) is a chronic intestinal inflammatory disorder of unclear aetiology prevalent amongst children in low-income settings and associated with stunting. We aimed to characterise development of EED and its putative risk factors amongst rural Kenyan infants.

Methods: In a birth cohort study in Junju, rural coastal Kenya, between August 2015 and January 2017, 100 infants were each followed for nine months.

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After decades of research, our understanding of when and why individuals infected with  develop clinical malaria is still limited. Correlates of immune protection are often sought through prospective cohort studies, where measured host factors are correlated against the incidence of clinical disease over a set period of time. However, robustly inferring individual-level protection from these population-level findings has proved difficult due to small effect sizes and high levels of variance underlying such data.

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Studies of long-term malaria cohorts have provided essential insights into how interacts with humans, and influences the development of antimalarial immunity. Immunity to malaria is acquired gradually after multiple infections, some of which present with clinical symptoms. However, there is considerable variation in the number of clinical episodes experienced by children of the same age within the same cohort.

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Article Synopsis
  • The SARS-CoV-2 pandemic in Africa has varied significantly across countries, and its overall impact remains unclear.
  • An analysis of 8,746 genomes from 33 African countries indicated that most outbreaks originated from Europe before international travel restrictions took effect.
  • As the pandemic continued, increased movement and local transmission led to the emergence of several variants within Africa, emphasizing the need for a strong pandemic response on the continent to prevent becoming a source of new variants.
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BACKGROUNDNaturally acquired immunity to malaria is incompletely understood. We used controlled human malaria infection (CHMI) to study the impact of past exposure on malaria in Kenyan adults in relation to infection with a non-Kenyan parasite strain.METHODSWe administered 3.

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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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Article Synopsis
  • The case fatality rate for COVID-19 in Ghana has decreased from 2% in March 2020 to below 1% since May 2020, indicating improvements in managing the virus.
  • Researchers sequenced 46 whole genomes of SARS-CoV-2 in Ghana from different time periods, identifying various clades, with notable clustering into five clades for early samples and three for later samples.
  • Most analyzed genomes closely mirrored the original Wuhan strain, suggesting that the genetic diversity in Ghana is low, which aligns with the lower transmission rates of the virus in the country.
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Article Synopsis
  • - Respiratory syncytial virus (RSV) is a major cause of respiratory illness in young children and has seasonal outbreaks, but there's limited genomic data on its transmission and evolution.
  • - An analysis of 295 RSV group B genomes from Kilifi, Kenya, revealed multiple introductions of the virus, the co-circulation of different genetic clusters, and a link between genetic diversity and seasonal incidence.
  • - A unique cluster from the 2016/17 epidemic showed distinct genetic changes, including a potential new variant in the Fusion protein, which may affect future prevention strategies currently in development.
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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: Although the significance of the human vaginal microbiome for health and disease is increasingly acknowledged, there is paucity of data on the differences in the composition of the vaginal microbiome upon infection with different sexually transmitted pathogens.

Method: The composition of the vaginal bacterial community of women with Trichomonas vaginalis (TV, N = 18) was compared to that of women with Chlamydia trachomatis (CT, N = 14), and to that of controls (N = 21) (women negative for TV, CT and bacterial vaginosis). The vaginal bacterial composition was determined using high throughput sequencing with the Ion 16S metagenomics kit of the variable regions 2, 4 and 8 of the bacterial 16S ribosomal RNA gene from the vaginal swab DNA extract of the women.

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Background: There are over 200 million reported cases of malaria each year, and most children living in endemic areas will experience multiple episodes of clinical disease before puberty. We set out to understand how frequent clinical malaria, which elicits a strong inflammatory response, affects the immune system and whether these modifications are observable in the absence of detectable parasitaemia.

Methods: We used a multi-dimensional approach comprising whole blood transcriptomic, cellular and plasma cytokine analyses on a cohort of children living with endemic malaria, but uninfected at sampling, who had been under active surveillance for malaria for 8 years.

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Dengue infection remains poorly characterized in Africa and little is known regarding its associated viral genetic diversity. Here, we report dengue virus type 2 (DENV-2) sequence data from 10 clinical samples, including 5 complete genome sequences of the cosmopolitan genotype, obtained from febrile adults seeking outpatient care in coastal Kenya.

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Background: Gut microbiota were recently shown to impact malaria disease progression and outcome, and prior studies have shown that Plasmodium infections increase the likelihood of enteric bacteria causing systemic infections. Currently, it is not known whether Plasmodium infection impacts human gut microbiota as a prelude to bacteremia or whether antimalarials affect gut microbiota. Our goal was to determine to what degree Plasmodium infections and antimalarial treatment affect human gut microbiota.

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