Marianne Mureithi

Dr. Marianne Mureithi

University of Nairobi
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 April 2019 in BMC Research Notes
Verified
Journal Article
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DMDaniel Munyambu Mutonga
Daniel Munyambu Mutonga
Marianne MureithiMarianne Mureithi
Marianne Mureithi
NNNancy N. Ngugi
Nancy N. Ngugi
FOFredrick C. F. Otieno
Fredrick C. F. Otieno
Diabetic foot ulcers (DFUs) often lead to hospital admissions, amputations and deaths; however, there is no up-to-date information on microbial isolates from DFUs and no mention of utilization of molecular techniques in Sub-Saharan Africa. We conducted a cross-sectional study among 83 adult patients at a tertiary hospital in Kenya over 12 months. The study aimed to isolate, identify bacteria, their antibiotic susceptibility patterns in active DFUs, and to compare standard microbiological methods versus a real-time PCR commercial kit in the detection of Staphylococcus aureus DNA and methicillin-resistant S. aureus (MRSA) DNA. Eighty swabs (94%) were culture-positive; 29% were Gram-positive and 65% were Gram-negative. The main organisms isolated were S. aureus (16%), Escherichia coli (15%), Proteus mirabilis (11%), Klebsiella pneumoniae (7%) and Pseudomonas aeruginosa (7%). The bacterial isolates showed resistance to commonly used antibiotics such as ampicillin, amoxicillin, cefepime, ceftazidime, cefuroxime, clindamycin, erythromycin, piperacillin–tazobactam, tetracycline and trimethoprim–sulphamethoxazole (TMPSMX). Thirty-one percent of the S. aureus isolated and 40% of the Gram-negatives were multi-drug resistant organisms (MDROs). There was a high prevalence of nosocomial bacteria. MRSA were not identified using culture methods but were identified using PCR. PCR was more sensitive but less specific than culture-based methods to identify S. aureus.

23 January 2020 in Viruses
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Journal Article
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JOJoseph Michael Ochieng Oduor
Joseph Michael Ochieng Oduor
EKErmir Kadija
Ermir Kadija
ANAtunga Nyachieo
Atunga Nyachieo
Marianne MureithiMarianne Mureithi
Marianne Mureithi
Mikael SkurnikMikael Skurnik
Mikael Skurnik
Emergence of antibiotic-resistant bacteria is a serious threat to the public health. This is also true for Staphylococcus aureus and other staphylococci. Staphylococcus phages Stab20, Stab21, Stab22, and Stab23, were isolated in Albania. Based on genomic and phylogenetic analysis, they were classified to genus Kayvirus of the subfamily Twortvirinae. In this work, we describe the in-depth characterization of the phages that electron microscopy confirmed to be myoviruses. These phages showed tolerance to pH range of 5.4 to 9.4, to maximum UV radiation energy of 25 µJ/cm2, to temperatures up to 45 °C, and to ethanol concentrations up to 25%, and complete resistance to chloroform. The adsorption rate constants of the phages ranged between 1.0 × 10−9 mL/min and 4.7 × 10−9 mL/min, and the burst size was from 42 to 130 plaque-forming units. The phages Stab20, 21, 22, and 23, originally isolated using Staphylococcus xylosus as a host, demonstrated varied host ranges among different Staphylococcus strains suggesting that they could be included in cocktail formulations for therapeutic or bio-control purpose. Phage particle proteomes, consisting on average of ca 60–70 gene products, revealed, in addition to straight-forward structural proteins, also the presence of enzymes such DNA polymerase, helicases, recombinases, exonucleases, and RNA ligase polymer. They are likely to be injected into the bacteria along with the genomic DNA to take over the host metabolism as soon as possible after infection.

24 May 2024 in Circulation Research
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Journal Article
Closed access
JHJonathan A. Hudson
Jonathan A. Hudson
RFRashida Abbas Ferrand
Rashida Abbas Ferrand
SGSamuel N. Gitau
Samuel N. Gitau
Marianne MureithiMarianne Mureithi
Marianne Mureithi
PMPasquale Maffia
Pasquale Maffia
ASAnoop S.V. Shah
Anoop S.V. Shah
Cardiac abnormalities were identified early in the epidemic of AIDS, predating the isolation and characterization of the etiologic agent, HIV. Several decades later, the causation and pathogenesis of cardiovascular disease (CVD) linked to HIV infection continue to be the focus of intense speculation. Before the widespread use of antiretroviral therapy, HIV-associated CVD was primarily characterized by HIV-associated cardiomyopathy linked to profound immunodeficiency. With increasing antiretroviral therapy use, viral load suppression, and establishment of immune competency, the effects of HIV on the cardiovascular system are more subtle. Yet, people living with HIV still face an increased incidence of cardiovascular pathology. Advances in cardiac imaging modalities and immunology have deepened our understanding of the pathogenesis of HIV-associated CVD. This review provides an overview of the pathogenesis of HIV-associated CVD integrating data from imaging and immunologic studies with particular relevance to the HIV population originating from high-endemic regions, such as sub-Saharan Africa. The review highlights key evidence gaps in the field and suggests future directions for research to better understand the complex HIV-CVD interactions.

5 May 2022 in COVID
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CWCAROLYNE NASIMIYU WANYONYI
CAROLYNE NASIMIYU WANYONYI
DMDamaris Matoke-Muhia
Damaris Matoke-Muhia
GKGilbert Kibet-Rono
Gilbert Kibet-Rono
EOEric Osoro
Eric Osoro
DODaniel Ouso
Daniel Ouso
SOSamuel Oyola
Samuel Oyola
Using classical and genomic epidemiology, we tracked the COVID-19 pandemic in Kenya over 23 months to determine the impact of SARS-CoV-2 variants on its progression. SARS-CoV-2 surveillance and testing data were obtained from the Kenya Ministry of Health, collected daily from 306 health facilities. COVID-19-associated fatality data were also obtained from these health facilities and communities. Whole SARS-CoV-2 genome sequencing were carried out on 1241 specimens. Over the pandemic duration (March 2020–January 2022), Kenya experienced five waves characterized by attack rates (AR) of between 65.4 and 137.6 per 100,000 persons, and intra-wave case fatality ratios (CFR) averaging 3.5%, two-fold higher than the national average COVID-19 associated CFR. The first two waves that occurred before emergence of global variants of concerns (VoC) had lower AR (65.4 and 118.2 per 100,000). Waves 3, 4, and 5 that occurred during the second year were each dominated by multiple introductions each, of Alpha (74.9% genomes), Delta (98.7%), and Omicron (87.8%) VoCs, respectively. During this phase, government-imposed restrictions failed to alleviate pandemic progression, resulting in higher attack rates spread across the country. In conclusion, the emergence of Alpha, Delta, and Omicron variants was a turning point that resulted in widespread and higher SARS-CoV-2 infections across the country.

17 January 2025 in Viruses
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Journal Article
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AKAndrew Mramba Karani
Andrew Mramba Karani
COCynthia Ombok
Cynthia Ombok
SSSilvia Situma
Silvia Situma
RBRobert Breiman
Robert Breiman
Marianne MureithiMarianne Mureithi
Marianne Mureithi
INIsaac Ambogo Ngere
Isaac Ambogo Ngere
Human outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) are more common in Middle Eastern and Asian human populations, associated with clades A and B. In Africa, where clade C is dominant in camels, human cases are minimal. We reviewed 16 studies (n = 6198) published across seven African countries between 2012 and 2024 to assess human MERS-CoV cases. We also analyzed data from four cohort studies conducted in camel-keeping communities between 2018 and 2024 involving camel keepers, camel slaughterhouse workers, and hospital patients with acute respiratory illness (ARI). The analysis showed a pooled MERS-CoV prevalence of 2.4% (IQR: 0.6, 11.4) from 16 publications and 1.14% from 4 cohort studies (n = 2353). Symptomatic cases were rarely reported, with most individuals reporting camel contact, and only 12% had travel history to the Middle East. There was one travel-associated reported death, resulting in a mortality rate of 0.013%. The findings suggest a low camel-to-human transmission of clade C MERS-CoV in Africa. Ongoing research focuses on genomic comparisons between clade C and the more virulent clades A and B, alongside the surveillance of viral evolution. This study highlights the need for continuous monitoring but indicates that MERS-CoV clade C currently poses a minimal public health threat in Africa.

14 November 2019 in AAS Open Research
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Journal Article
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Lucy Wanjiku MachariaLucy Wanjiku Macharia
Lucy Wanjiku Macharia
Marianne MureithiMarianne Mureithi
Marianne Mureithi
OAOmu Anzala
Omu Anzala
Background: Cancer in Africa is an emerging health problem. In Kenya it ranks third as a cause of death after infectious and cardiovascular diseases. Nearly 31% of the total cancer burden in sub-Saharan Africa is attributable to infectious agents. Information on cancer burden is scanty in Kenya and this study aimed to provide comprehensive hospital based data to inform policies. Method: A cross-sectional retrospective survey was conducted at Kenyatta National Hospital (KNH) and Moi Teaching and Referral Hospital (MTRH) from January 2008 to December 2012. Data was obtained from the patients files and the study was approved by the KNH/University of Nairobi and MTRH Ethics and Research Committees. Results: In KNH, the top five cancers were: cervical (62, 12.4%), breast (59, 11.8%), colorectal (31, 6.2%), chronic leukemia (27, 5.4%) and stomach cancer (26, 5.2%). Some 154 (30.8%) of these cancers were associated with infectious agents, while an estimated 138 (27.6%) were attributable to infections. Cancers of the cervix (62, 12.4%), stomach (26, 5.2%) and nasopharynx (17, 3.4%) were the commonest infection-associated cancers. In MTRH, the five common types of cancers were Kaposi’s sarcoma (93, 18.6%), breast (77, 15.4%), cervical (41, 8.2%), non-Hodgkin’s lymphoma (37, 7.4%) and colorectal, chronic leukemia and esophageal cancer all with 27 (5.4%). Some 241 (48.2%) of these cancers were associated with infectious agents, while an estimated 222 (44.4%) were attributable to infections. Kaposi’s sarcoma (93, 18.6%), cancer of the cervix (41, 8.2%) and non-Hodgkin’s lymphoma (37, 7.4%) were the commonest infection-associated cancers. Conclusion: Our results suggest that 30.8% and 48.2% of the total cancer cases sampled in KNH and MTRH respectively were associated with infectious agents, while 27.6% and 44.4% were attributable to infections in the two hospitals respectively. Reducing the burden of infection-attributable cancers can translate to a reduction of the overall cancer burden.