Charles Owuora Obonyo

Prof. Charles Owuora Obonyo

KEMRI Centre for Global Health Research
+1
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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28 January 2014 in Malaria Journal
Verified
Journal Article
Open access
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BOBernhards R Ogutu
Bernhards R Ogutu
KOKevin O Onyango
Kevin O Onyango
NKNelly Koskei
Nelly Koskei
EOEdgar K Omondi
Edgar K Omondi
JOJohn M Ongecha
John M Ongecha
EJElizabeth Juma
Elizabeth Juma
This open-label, randomized study evaluated efficacy and safety of artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP) in treatment of uncomplicated falciparum malaria in children below five years of age, to build evidence on use of AL as first-line treatment and DP as second-line treatment in Kenya. A total of 454 children aged six to 59 months with uncomplicated falciparum malaria were randomized (1:1) to receive AL dispersible or DP paediatric tablets and followed up for 42 days. Primary efficacy variable was corrected adequate clinical and parasitological response (ACPR) rate on day 28. Secondary variables included corrected (day 14, 28 and 42), uncorrected (day 3, 14, 28 and 42) cure rates, parasitological failure at days 3, 14 and 42. Acceptability and tolerability of both drugs were assessed by caregiver questionnaire. On day 28, corrected ACPR rates for AL dispersible and DP paediatric were 97.8% (95% CI: 94.9-99.3) and 99.1% (95% CI: 96.8-99.9), respectively, in intention-to-treat population, with no significant treatment differences noted between AL dispersible and DP paediatric arms. Additionally, no significant differences were observed for PCR corrected cure rates on days 14 and ACPR on day 42 for AL dispersible (100%; 96.8%) and DP paediatric (100%; 98.7%). Similarly, for PCR uncorrected cure rates, no significant differences were seen on days 3, 14, 28, and 42 for AL dispersible (99.1%; 98.7%; 81.1%; 67.8%) and DP paediatric (100%; 100%; 87.7%; 70.5%). Parasite clearance was rapid, with approximately 90% clearance achieved in 40 hours in both treatment arms. Incidence of adverse events was related to underlying disease; malaria being reported in both treatment arms. One serious adverse event was noted in AL dispersible (0.42%) arm, not related to study drug. Adherence to treatment regimen was higher for children treated with AL dispersible (93.6%) compared to DP paediatric (85.6%). Acceptability of AL dispersible regimen was assessed as being significantly better than DP paediatric. AL and DP were both efficacious and well tolerated, and had similar effects at day 42 on risk of recurrent malaria. No signs of Plasmodium falciparum tolerance to artemisinins were noted. PACTR201111000316370 .

4 January 2012 in Malaria Journal
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Journal Article
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Charles Owuora ObonyoCharles Owuora Obonyo
Charles Owuora Obonyo
EJElizabeth A Juma
Elizabeth A Juma
Artemisinin-based combinations are recommended for treatment of uncomplicated falciparum malaria, but are costly and in limited supply. Clindamycin plus quinine is an alternative non-artemisinin-based combination recommended by World Health Organization. The efficacy and safety of clindamycin plus quinine is not known. This systematic review aims to assess the efficacy of clindamycin plus quinine versus other anti-malarial drugs in the treatment of uncomplicated falciparum malaria.

12 October 2015 in Tropical Medicine & International Health
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Journal Article
Closed access
JAJanet Agaya
Janet Agaya
CNChimeremma D. Nnadi
Chimeremma D. Nnadi
JOJoseph Odhiambo
Joseph Odhiambo
Charles Owuora ObonyoCharles Owuora Obonyo
Charles Owuora Obonyo
VOVincent Obiero
Vincent Obiero
JOJohn E. Oeltmann
John E. Oeltmann

1 September 2020 in Global Health Action
Verified
Journal Article
Open access
TOTolu Oni
Tolu Oni
LMLisa Micklesfield
Lisa Micklesfield
PWPamela Wadende
Pamela Wadende
Charles Owuora ObonyoCharles Owuora Obonyo
Charles Owuora Obonyo
JWJames Woodcock
James Woodcock
NWNicholas J. Wareham
Nicholas J. Wareham
At the time of writing, it is unclear how the COVID-19 pandemic will play out in rapidly urbanising regions of the world. In these regions, the realities of large overcrowded informal settlements, a high burden of infectious and non-communicable diseases, as well as malnutrition and precarity of livelihoods, have raised added concerns about the potential impact of the COVID-19 pandemic in these contexts. COVID-19 infection control measures have been shown to have some effects in slowing down the progress of the pandemic, effectively buying time to prepare the healthcare system. However, there has been less of a focus on the indirect impacts of these measures on health behaviours and the consequent health risks, particularly in the most vulnerable. In this current debate piece, focusing on two of the four risk factors that contribute to >80% of the NCD burden, we consider the possible ways that the restrictions put in place to control the pandemic, have the potential to impact on dietary and physical activity behaviours and their determinants. By considering mitigation responses implemented by governments in several LMIC cities, we identify key lessons that highlight the potential of economic, political, food and built environment sectors, mobilised during the pandemic, to retain health as a priority beyond the context of pandemic response. Such whole-of society approaches are feasible and necessary to support equitable healthy eating and active living required to address other epidemics and to lower the baseline need for healthcare in the long term.

1 January 2020 in Annals of the American Thoracic Society
Verified
Journal Article
Closed access
JCJu-Wei R. Chang
Ju-Wei R. Chang
FAFatai M. Akemokwe
Fatai M. Akemokwe
DMDiana M. Marangu
Diana M. Marangu
BCBlessings Chisunkha
Blessings Chisunkha
EIEshiobo Irekpita
Eshiobo Irekpita
Charles Owuora ObonyoCharles Owuora Obonyo
Charles Owuora Obonyo
Rationale: Obstructive sleep apnea (OSA) is a significant health problem among adults and children globally, resulting in decreased quality of life and increased costs of healthcare. For optimal clinical care, primary care physicians should be familiar with OSA and confident in their ability to screen, diagnose, and manage this condition. Objectives: To assess the knowledge, attitudes, and practices of primary care physicians in Kenya, Nigeria, and South Africa regarding OSA in adults and children. Methods: We conducted a multicenter cross-sectional survey in Kenya (Nairobi), Nigeria (Edo State), and South Africa (Cape Town) between April 2016 and July 2017. At least 40 participants were randomly selected from a register of primary care physicians at each site. Potential participants were contacted to receive online/paper-based, validated OSA Knowledge and Attitudes (OSAKA) and OSAKA in Children (OSAKA-KIDS) questionnaires related to adults and children, respectively. The median percentage knowledge scores and proportions of favorable attitude were computed and current diagnostic and referral practices were documented. Results: The median OSAKA knowledge scores were 83.3% (interquartile range [IQR], 77.8–88.9), 66.7% (IQR, 55.6–77.8), and 61.1% (IQR, 55.6–77.8) among South African, Kenyan, and Nigerian physicians, respectively. For OSAKA-KIDS, the median knowledge scores were 61.1% (IQR, 50.0–72.2), 64.2% (IQR, 35.3–93.2), and 58.3% (IQR, 44.4–66.7) among South African, Kenyan, and Nigerian physicians, respectively. Most physicians (90–94%) considered adult and pediatric OSA very/extremely important. Fewer physicians agreed/strongly agreed that they were confident about OSA diagnosis (55%), management (25%), and continuous positive airway pressure (18%) use in adults. Even fewer physicians agreed/strongly agreed that they were confident about pediatric OSA diagnosis (35%), management (21%), and continuous positive airway pressure use (18%). South African physicians mainly prescribed polysomnography (51%) and overnight oximetry (22%), whereas 49% of Nigerian physicians and 65% of Kenyan physicians commonly requested lateral cervical radiography. Conclusions: Primary care physicians in South Africa, Nigeria, and Kenya considered OSA to be important but had modest knowledge about OSA in adults and children, and had a low perceived confidence in adult and pediatric management. Focused educational interventions during undergraduate training and continuing professional development programs may improve primary physicians’ knowledge about OSA and its diagnosis and management.

9 April 2022 in International Journal for Equity in Health
Verified
Journal Article
Open access
PDF file
VWVincent Omondi Were
Vincent Omondi Were
LFLouise Foley
Louise Foley
ETEleanor Turner-Moss
Eleanor Turner-Moss
EMEbele Mogo
Ebele Mogo
PWPamela Wadende
Pamela Wadende
Charles Owuora ObonyoCharles Owuora Obonyo
Charles Owuora Obonyo
Introduction: Low household socioeconomic status is associated with unhealthy behaviours including poor diet and adverse health outcomes. Different methods leading to variations in SES classification has the potential to generate spurious research findings or misinform policy. In low and middle-income countries, there are additional complexities in defining household SES, a need for fieldwork to be conducted efficiently, and a dearth of information on how classification could impact estimation of disease risk. Methods: Using cross-sectional data from 200 households in Kisumu County, Western Kenya, we compared three approaches of classifying households into low, middle, or high SES: fieldworkers (FWs), Community Health Volunteers (CHVs), and a Multiple Correspondence Analysis econometric model (MCA). We estimated the sensitivity, specificity, inter-rater reliability and misclassification of the three methods using MCA as a comparator. We applied an unadjusted generalized linear model to determine prevalence ratios to assess the association of household SES status with a self-reported diagnosis of diabetes or hypertension for one household member. Results: Compared with MCA, FWs successfully classified 21.7% (95%CI = 14.4%-31.4%) of low SES households, 32.8% (95%CI = 23.2–44.3) of middle SES households, and no high SES households. CHVs successfully classified 22.5% (95%CI = 14.5%-33.1%) of low SES households, 32.8% (95%CI = 23.2%-44.3%) of middle SES households, and no high SES households. The level of agreement in SES classification was similar between FWs and CHVs but poor compared to MCA, particularly for high SES. None of the three methods differed in estimating the risk of hypertension or diabetes. Conclusions: FW and CHV assessments are community-driven methods for SES classification. Compared to MCA, these approaches appeared biased towards low or middle SES households and not sensitive to high household SES. The three methods did not differ in risk estimation for diabetes and hypertension. A mix of approaches and further evaluation to refine SES classification methodology is recommended.