Karen I Barnes

Prof. Dr. Karen I Barnes

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

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

Representative Publications

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1 March 2008 in Trends in Parasitology
Verified
Journal Article
Closed access
KBKaren I Barnes
Karen I Barnes
WWWilliam M. Watkins
William M. Watkins
NWNicholas J. White
Nicholas J. White

12 October 2009 in Malaria Journal
Verified
Journal Article
Open access
PDF file
KBKaren I Barnes
Karen I Barnes
PCPascalina Chanda
Pascalina Chanda
GBGebre Ab Barnabas
Gebre Ab Barnabas
Malaria is one of the most significant causes of morbidity and mortality worldwide. Every year, nearly one million deaths result from malaria infection. Malaria can be controlled in endemic countries by using artemisinin-based combination therapy (ACT) in combination with indoor residual spraying (IRS) and insecticide-treated nets (ITNs). At least 40 malaria-endemic countries in sub-Saharan Africa now recommend the use of ACT as first-line treatment for uncomplicated falciparum malaria as a cornerstone of their malaria case management. The scaling up of malaria control strategies in Zambia has dramatically reduced the burden of malaria. Zambia was the first African country to adopt artemether/lumefantrine (AL; Coartem®) as first-line therapy in national malaria treatment guidelines in 2002. Further, the vector control with IRS and ITNs was also scaled up. By 2008, the rates of in-patient malaria cases and deaths decreased by 61% and 66%, respectively, compared with the 2001-2002 reference period.

29 October 2018 in BMC Medicine
Verified
Journal Article
Open access
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DDD Das
D Das
RGRebecca F Grais
Rebecca F Grais
EOE A Okiro
E A Okiro
KSK Stepniewska
K Stepniewska
RMR Mansoor
R Mansoor
PGP J Guerin
P J Guerin
Despite substantial improvement in the control of malaria and decreased prevalence of malnutrition over the past two decades, both conditions remain heavy burdens that cause hundreds of thousands of deaths in children in resource-poor countries every year. Better understanding of the complex interactions between malaria and malnutrition is crucial for optimally targeting interventions where both conditions co-exist. This systematic review aimed to assess the evidence of the interplay between malaria and malnutrition. Database searches were conducted in PubMed, Global Health and Cochrane Libraries and articles published in English, French or Spanish between Jan 1980 and Feb 2018 were accessed and screened. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale and the risk of bias across studies was assessed using the GRADE approach. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guideline were followed. Of 2945 articles screened from databases, a total of 33 articles were identified looking at the association between malnutrition and risk of malaria and/or the impact of malnutrition in antimalarial treatment efficacy. Large methodological heterogeneity of studies precluded conducting meaningful aggregated data meta-analysis. Divergent results were reported on the effect of malnutrition on malaria risk. While no consistent association between risk of malaria and acute malnutrition was found, chronic malnutrition was relatively consistently associated with severity of malaria such as high-density parasitemia and anaemia. Furthermore, there is little information on the effect of malnutrition on therapeutic responses to artemisinin combination therapies (ACTs) and their pharmacokinetic properties in malnourished children in published literature. The evidence on the effect of malnutrition on malaria risk remains inconclusive. Further analyses using individual patient data could provide an important opportunity to better understand the variability observed in publications by standardising both malaria and nutritional metrics. Our findings highlight the need to improve our understanding of the pharmacodynamics and pharmacokinetics of ACTs in malnourished children. Further clarification on malaria-malnutrition interactions would also serve as a basis for designing future trials and provide an opportunity to optimise antimalarial treatment for this large, vulnerable and neglected population. PROSPERO CRD42017056934 .

16 April 2008 in European Journal of Clinical Pharmacology
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Journal Article
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COCatherine Orrell
Catherine Orrell
FLFrancesca Little
Francesca Little
PSPeter Smith
Peter Smith
PFPeter Folb
Peter Folb
WTWalter Taylor
Walter Taylor
KBKaren I Barnes
Karen I Barnes
The WHO recommends artemisinin-based combination therapies for treatment of uncomplicated falciparum malaria. At least 15 African countries have adopted artesunate plus amodiaquine as treatment policy. As no pharmacokinetic data on this combination have been published to date, we investigated its pharmacokinetic interactions and tolerability in healthy volunteers in Africa.

9 December 2014 in Malaria Journal
Verified
Journal Article
Open access
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NWNicholas J White
Nicholas J White
EAElizabeth Ashley
Elizabeth Ashley
JRJudith Recht
Judith Recht
MDMichael J Delves
Michael J Delves
ARAndrea Ruecker
Andrea Ruecker
FNFrancois H Nosten
Francois H Nosten
Indirect clinical measures assessing anti-malarial drug transmission-blocking activity in falciparum malaria include measurement of the duration of gametocytaemia, the rate of gametocyte clearance or the area under the gametocytaemia-time curve (AUC). These may provide useful comparative information, but they underestimate dose-response relationships for transmission-blocking activity. Following 8-aminoquinoline administration P. falciparum gametocytes are sterilized within hours, whereas clearance from blood takes days. Gametocytaemia AUC and clearance times are determined predominantly by the more numerous female gametocytes, which are generally less drug sensitive than the minority male gametocytes, whereas transmission-blocking activity and thus infectivity is determined by the more sensitive male forms. In choosing doses of transmission-blocking drugs there is no substitute yet for mosquito-feeding studies.

24 March 2020 in Antimicrobial Agents and Chemotherapy
Verified
Journal Article
Open access
PDF file
PSPhumla Sinxadi
Phumla Sinxadi
CDCristina Donini
Cristina Donini
HJHilary Johnstone
Hilary Johnstone
GLGrant Langdon
Grant Langdon
LWLubbe Wiesner
Lubbe Wiesner
KBKaren I Barnes
Karen I Barnes
MMV390048 is a novel antimalarial compound that inhibits Plasmodium phosphatidylinositol-4-kinase. The safety, tolerability, pharmacokinetic profile, and antimalarial activity of MMV390048 were determined in healthy volunteers in three separate studies. A first-in-human, double-blind, randomized, placebo-controlled, single-ascending-dose study was performed. Additionally, a volunteer infection study investigated the antimalarial activity of MMV390048 using the Plasmodium falciparum induced blood-stage malaria (IBSM) model.