Browsing by Author "Ouma, Collins"
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Association between Fcγ receptor IIA, IIIA and IIIB genetic polymorphisms and susceptibility to severe malaria anemia in children in western Kenya
Munde, Elly O.; Okeyo, Winnie A.; Raballah, Evans; Anyona, Samuel B.; Were, Tom; Ong’echa, John M.; Perkins, Douglas J.; Ouma, Collins (BMC Infectious Diseases, 2017-04-20)Background Naturally-acquired immunity to Plasmodium falciparum malaria develops after several episodes of infection. Fc gamma receptors (FcγRs) bind to immunoglobulin G (IgG) antibodies and mediate phagocytosis of opsonized ... -
Changes in the frequencies of Plasmodium falciparum dhps and dhfr drug-resistant mutations in children from Western Kenya from 2005 to 2018: the rise of Pfdhps S436H
Pacheco, M. Andreína; Schneider, Kristan A.; Cheng, Qiuying; Munde, Elly O.; Ndege, Caroline; Onyango, Clinton; Raballah, Evans; Anyona, Samuel B.; Ouma, Collins; Perkins, Douglas J.; Escalante, Ananias A. (Malaria Journal, 2020-10-22)Background Sulfadoxine-pyrimethamine (SP) is the only anti-malarial drug formulation approved for intermittent preventive treatment in pregnancy (IPTp). However, mutations in the Plasmodium falciparum dhfr (Pfdhfr) and ... -
Changes in the frequencies of Plasmodium falciparum dhps and dhfr drug-resistant mutations in children from Western Kenya from 2005 to 2018: the rise of Pfdhps S436H
Pacheco, M. Andreína; Schneider, Kristan A.; Cheng, Qiuying; Munde, Elly O.; Ndege, Caroline; Onyango, Clinton; Raballah, Evans; Anyona, Samuel B.; Ouma, Collins; Perkins, Douglas J.; Escalante, Ananias A. (Malaria Journal, 2020-10-22)Background Sulfadoxine-pyrimethamine (SP) is the only anti-malarial drug formulation approved for intermittent preventive treatment in pregnancy (IPTp). However, mutations in the Plasmodium falciparum dhfr (Pfdhfr) and ... -
Clinical chemistry profiles in injection heroin users from Coastal Region, Kenya
Were, Tom; Wesongah, Jesca O; Munde, Elly; Ouma, Collins; Kahiga, Titus M; Owuor, Francisca Ongecha; Kiarie, James N; Ahmed, Aabid A; Makokha, Ernest P; Budambula, Valentine (BMC Clin Pathol, 2014-07-09)Background: Although the co-burden of injection drug use and HIV is increasing in Africa, little is known about the laboratory markers of injection drug use and anti-retroviral treatment (ART) in Kenyan injection drug ... -
Comparative genomic and phenotypic characterization of invasive non-typhoidal Salmonella isolates from Siaya, Kenya
Kubicek-Sutherland, Jessica Z.; Xie, Gary; Shakya, Migun; Dighe, Priya K.; Jacobs, Lindsey L.; Daligault, Hajnalka; Davenport, Karen; Stromberg, Loreen R.; Stromberg, Zachary R.; Cheng, Qiuying; Kempaiah, Prakasha; Ong’echa, John Michael; Otieno, Vincent; Raballah, Evans; Anyona, Samuel; Ouma, Collins; Chain, Patrick S. G.; Perkins, Douglas J.; Mukundan, Harshini; McMahon, Benjamin H.; Doggett, Norman A. (PLOS ONE, 2021-01-01)Non-typhoidal Salmonella (NTS) is a major global health concern that often causes bloodstream infections in areas of the world affected by malnutrition and comorbidities such as HIV and malaria. Developing a strategy to ... -
Complement component 3 mutations alter the longitudinal risk of pediatric malaria and severe malarial anemia
Raballah, Evans; Anyona, Samuel B; Cheng, Qiuying; Munde, Elly O; Hurwitz, Ivy-Foo; Onyango, Clinton; Ndege, Caroline; Hengartner, Nicolas W; Pacheco, Maria Andreína; Escalante, Ananias A; Lambert, Christophe G; Ouma, Collins; Obama, Henri C Jr T; Schneider, Kristan A; Seidenberg, Philip D; McMahon, Benjamin H; Perkins, Douglas J (Experimental Biology and Medicine, 2021-11-19)Severe malarial anemia (SMA) is a leading cause of childhood morbidity and mortality in holoendemic Plasmodium falciparum transmission regions. To gain enhanced understanding of predisposing factors for SMA, we explored ... -
Cyclooxygenase-2 haplotypes influence the longitudinal risk of malaria and severe malarial anemia in Kenyan children from a holoendemic transmission region.
Anyona, Samuel B; Hengartner, Nicolas W; Raballah, Evans; Ong'echa, John Michael; Lauve, Nick; Cheng, Qiuying; Fenimore, Paul W; Ouma, Collins; Lambert, Christophe G; McMahon, Benjamin H; Perkins, Douglas J (Journal of Human Genetics, 2019-10-29)Cyclooxygenase-2 [(COX-2) or prostaglandin endoperoxide H2 synthase-2 (PTGS-2)] induces the production of prostaglandins as part of the host-immune response to infections. Although a number of studies have demonstrated the ... -
The diagnostic accuracy of Th1 (IFN-γ, TNF-α, and IL-2) and Th2 (IL-4, IL-6 and IL-10) cytokines response in AFB microscopy smear negative PTB- HIV co-infected patients
Kisuya, Job; Chemtai, Alex; Raballah, Evans; Keter, Alfred; Ouma, Collins (Microbiology Resource Announcements, 2019-04)Acid Fast Bacilli (AFB) microscopy smear remains the most widely used laboratory diagnostic technique for Pulmonary Tuberculosis (PTB) in low-and-middle income countries. Although it is highly specific, the sensitivity ... -
Differential Gene Expression in Host Ubiquitination Processes in Childhood Malarial Anemia
Anyona, Samuel B.; Raballah, Evans; Cheng, Qiuying; Hurwitz, Ivy; Ndege, Caroline; Munde, Elly; Otieno, Walter; Seidenberg, Philip D.; Schneider, Kristan A.; Lambert, Christophe G.; McMahon, Benjamin H.; Ouma, Collins; Perkins, Douglas J. (Frontiers in Genetics, 2021-11-22)Background: Malaria remains one of the leading global causes of childhood morbidity and mortality. In holoendemic Plasmodium falciparum transmission regions, such as western Kenya, severe malarial anemia [SMA, hemoglobin ... -
Direct detection of bacteremia by exploiting host-pathogen interactions of lipoteichoic acid and lipopolysaccharide
Kubicek-Sutherland, Jessica Z.; Vu, Dung M.; Aneesa, Noormohamed; Mendez, Heather M.; Stromberg, Loreen R.; Pedersen, Christine A.; Hengartner, Astrid C.; Klosterman, Katja E.; Haley, A. Bridgewater; Otieno, Vincent; Cheng, Qiuying; Anyona, Samuel B.; Ouma, Collins; Raballah, Evans; Perkins, Douglas J.; McMahon, Benjamin H.; Mukundan, Harshini (Scientific Reports, 2019-04-17)Bacteremia is a leading cause of death in sub-Saharan Africa where childhood mortality rates are the highest in the world. The early diagnosis of bacteremia and initiation of treatment saves lives, especially in high-disease ... -
Entire Expressed Peripheral Blood Transcriptome in Pediatric Severe Malarial Anemia
Anyona, Samuel; Cheng, Qiuying; Guo, Yan; Raballah, Evans; Hurwitz, Ivy; Onyango, Clinton; Seidenberg, Philip; Schneider, Kristan; Lambert, Christophe; McMahon, Benjamin; Ouma, Collins; Perkins, Douglas (Research Square, 2023-06-19)This study on severe malarial anemia (SMA: Hb < 6.0 g/dL), a leading global cause of childhood morbidity and mortality, analyzed the entire expressed transcriptome in whole blood from children with non-SMA (Hb ≥ 6.0 g/dL, ... -
Erratum to: Hepatitis B virus sero-profiles and genotypes in HIV-1 infected and uninfected injection and Non-injection drug users from coastal Kenya
Webale, Mark K.; Budambula, Valentine; Lihana, Raphael; Musumba, Francis O.; Nyamache, Anthony K.; Budambula, Nancy L. M.; Ahmed, Aabid A.; Ouma, Collins; Were, Tom (BMC Infectious Diseases, 2015-09-03)Erratum After publication of [1] it came to the authors’ attention that Mark K. Webale’s name was displayed incorrectly. The correct spelling of their name has been updated in the original article and is included in this erratum. -
Factors associated with non-adherence to Artemisinin-based combination therapy (ACT) to malaria in a rural population from holoendemic region of western Kenya
Onyango, Elizabeth O; Ayodo, George; Watsierah, Carren A; Were, Tom; Okumu, Wilson; Anyona, Samuel B; Raballah, Evans; Okoth, John M; Gumo, Sussy; Orinda, George O; Ouma, Collins (National Library of Medicine, 2012-06-24)Background: Over the years, reports implicate improper anti-malarial use as a major contributor of morbidity and mortality amongst millions of residents in malaria endemic areas, Kenya included. However, there are limited ... -
Factors associated with non-adherence to Artemisinin-based combination therapy (ACT) to malaria in a rural population from holoendemic region of western Kenya
Onyango, Elizabeth O; Ayodo, George; Watsierah, Carren A; Were, Tom; Okumu, Wilson; Anyona, Samuel B; Raballah, Evans; Okoth, John M; Gumo, Sussy; Orinda, George O; Ouma, Collins (National Library of Medicine, 2012-06-24)Background: Over the years, reports implicate improper anti-malarial use as a major contributor of morbidity and mortality amongst millions of residents in malaria endemic areas, Kenya included. However, there are limited ... -
Factors associated with non-adherence to Artemisinin-based combination therapy (ACT) to malaria in a rural population from holoendemic region of western Kenya
Onyango, Elizabeth O; Ayodo, George; Watsierah, Carren A; Were, Tom; Okumu, Wilson; Anyona, Samuel B; Raballah, Evans; Okoth, John M; Gumo, Sussy; Orinda, George O; Ouma, Collins (National Library of Medicine, 2012-06-24)Background: Over the years, reports implicate improper anti-malarial use as a major contributor of morbidity and mortality amongst millions of residents in malaria endemic areas, Kenya included. However, there are limited ... -
Genetic variation in CSF2 (5q31.1) is associated with longitudinal susceptibility to pediatric malaria, severe malarial anemia, and all-cause mortality in a high-burden malaria and HIV region of Kenya
Kisia, Lily E.; Cheng, Qiuying; Raballah, Evans; Munde, Elly O.; McMahon, Benjamin H.; Hengartner, Nick W.; Ong’echa, John M.; Chelimo, Kiprotich; Lambert, Christophe G.; Ouma, Collins; Kempaiah, Prakasha; Perkins, Douglas J.; Schneider, Kristan A.; Anyona, Samuel B. (Tropical Medicine and Health, 2022-06-25)Plasmodium falciparum infections remain among the leading causes of morbidity and mortality in holoendemic transmission areas. Located within region 5q31.1, the colony-stimulating factor 2 gene (CSF2) encodes granulocyte ... -
Genetic variation in interleukin-7 is associated with a reduced erythropoietic response in Kenyan children infected with Plasmodium falciparum
Kisia, Lily E.; Kempaiah, Prakasha; Anyona, Samuel B.; Munde, Elly O.; Achieng, Angela O.; Ong’echa, John M.; Lambert, Christophe G.; Chelimo, Kiprotich; Ouma, Collins; Perkins, Douglas J; Raballah, Evans (BMC Med Genet., 2019-08-16)Background Severe malarial anemia (SMA) is a leading cause of malaria-related morbidity and mortality in children. The genetic factors that influence development of SMA and inefficient erythropoiesis, a central pathogenic ... -
Haplotype of non-synonymous mutations within IL-23R is associated with susceptibility to severe malaria anemia in a P. falciparum holoendemic transmission area of Kenya
Munde, Elly O.; Raballah, Evans; Okeyo, Winnie A.; Ong’echa, John M.; Perkins, Douglas J.; Ouma, Collins (BMC Infectious Diseases volume, 2017-04-20)Background Improved understanding of the molecular mechanisms involved in pediatric severe malarial anemia (SMA) pathogenesis is a crucial step in the design of novel therapeutics. Identification of host genetic susceptibility ... -
Hemoglobinopathies, merozoite surface protein-2 gene polymorphisms, and acquisition of Epstein Barr virus among infants in Western Kenya
Olewe, Perez K.; Awandu, Shehu Shagari; Munde, Elly O.; Anyona, Samuel B.; Raballah, Evans; Amolo, Asito S.; Ogola, Sidney; Ndenga, Erick; Onyango, Clinton O.; Rochford, Rosemary; Perkins, Douglas J.; Ouma, Collins (BMC Cancer, 2023-06-20)Background Epstein Barr virus (EBV)-associated endemic Burkitt’s Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. ... -
HIV-1 protease inhibitor drug resistance in Kenyan antiretroviral treatment-naive and -experienced injection drug users and non-drug users
Budambula, Valentine; Musumba, Francis O.; Webale, Mark K.; Kahiga, Titus M.; Owuor, Francisca Ongecha; Kiarie, James N.; Sowayi, George A.; Ahmed, Aabid A.; Ouma, Collins; Were, Tom (AIDS Research and Therapy, 2015-08-15)Background Although injection drug use drives antiretroviral drug resistance, the prevalence of protease inhibitor (PI) resistance among Kenyan IDUs remains undetermined. We, therefore, explored PI resistance mutations ...