9 results on '"Alfred Mwanzu"'
Search Results
2. The epidemiology of fecal carriage of nontyphoidal Salmonella among healthy children and adults in three sites in Kenya.
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Esther M Muthumbi, Alfred Mwanzu, Cecilia Mbae, Godfrey Bigogo, Angela Karani, Salim Mwarumba, Jennifer R Verani, Samuel Kariuki, and J Anthony G Scott
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Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundDespite the importance of non-Typhoidal Salmonella (NTS) disease in Africa, epidemiologic data on carriage and transmission are few. These data are important to understand the transmission of NTS in Africa and to design control strategies.MethodTo estimate the prevalence of stool carriage of NTS in Kenya, we conducted a cross-sectional study in Kilifi, Nairobi, and Siaya, sites with a low, moderate and high incidence of invasive NTS disease, respectively. At each site, we randomly selected 100 participants in each age-group of 0-11 months, 12-59 months, 5-14 years, 15-54 years and ≥55 years. We collected stool, venous blood (for hemoglobin and malaria rapid tests), anthropometric measurements, and administered a questionnaire on Water Access Sanitation and Hygiene (WASH) practices. Stool samples were cultured on selective agar for Salmonella; suspect isolates underwent serotyping and antimicrobial susceptibility testing.ResultOverall, 53 (3.5%) isolates of NTS were cultured from 1497 samples. Age-adjusted prevalence was 13.1% (95%CI 8.8-17.4) in Kilifi, 0.4% (95%CI 0-1.3) in Nairobi, and 0.9% (95%CI 0-2.0) in Siaya. Prevalence was highest among those aged 15-54 years (6.2%). Of 53 isolates; 5 were S. Enteritidis, 1 was S. Typhimurium. No S. Typhi was isolated. None of the risk factors were associated with carriage of NTS. All isolates were susceptible to all antibiotics tested, including ampicillin, chloramphenicol, ciprofloxacin and co-trimoxazole.ConclusionPrevalence of fecal carriage was high in Kilifi, an area of low incidence of invasive NTS disease and was low in areas of higher incidence in Nairobi and Siaya. The age-prevalence, risk factors, geographical and serotype distribution of NTS in carriage differs from invasive disease.
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- 2023
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3. Complementary measurement of nontyphoidal Salmonella-specific IgG and IgA antibodies in oral fluid and serum
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Sean C. Elias, Esther Muthumbi, Alfred Mwanzu, Perpetual Wanjiku, Agnes Mutiso, Raphael Simon, and Calman A. MacLennan
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Nontyphoidal ,Oral fluid ,IgG ,IgA ,O-Antigen ,Flagellin ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Objectives: Immuno-epidemiological studies of orally acquired, enteric pathogens such as nontyphoidal Salmonella (NTS) often focus on serological measures of immunity, ignoring potentially relevant oral mucosal responses. In this study we sought to assess the levels and detectability of both oral fluid and serum IgG and IgA to NTS antigens, in endemic and non-endemic populations. Methods: IgG and IgA antibodies specific for Salmonella Typhimurium and Salmonella Enteritidis O antigen and phase 1 flagellin were assessed using Enzyme Linked Immunosorbent Assay (ELISA). Paired oral fluid and serum samples were collected from groups of 50 UK adults, Kenyan adults and Kenyan infants. Additionally, oral fluid alone was collected from 304 Kenyan individuals across a range of ages. Results: Antigen-specific IgG and IgA was detectable in the oral fluid of both adults and infants. Oral fluid antibody increased with age, peaking in adulthood for both IgG and IgA but a separate peak was also observed for IgA in infants. Oral fluid and serum responses correlated for IgG but not IgA. Despite standardised collection the relationship between oral fluid volume and antibody levels varied with age and country of origin. Conclusions: Measurement of NTS-specific oral fluid antibody can be used to complement measurement of serum antibody. For IgA in particular, oral fluid may offer insights into how protective immunity to NTS changes as individuals transition with age, from maternal to acquired systemic and mucosal immunity. This may prove useful in helping to guide future vaccine design.
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- 2023
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4. Maintaining laboratory quality assurance and safety in a pandemic: Experiences from the KEMRI-Wellcome Trust Research Programme laboratory’s COVID-19 response [version 2; peer review: 2 approved]
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Shadrack Mutua, Brian Bartilol, Debra Riako, Lydia Nyamako, Angela Karani, Daisy Mugo, Brian Tawa, Michael Opiyo, Wesley Cheruiyot, Metrine Tendwa, Oscar Kai, Caroline Ngetsa, Yiakon Sein, Nelson Ouma, Arnold W. Lambisia, Bonface M. Gichuki, Boniface Karia, John M. Morobe, Shaban Mwangi, Benjamin Tsofa, Philip Bejon, Alfred Mwakubia, Fredrick Mitsanze, Kelly Ominde, Patience Kiyuka, Martin Rono, Johnstone Makale, Agnes Mutiso, Perpetual Wanjiku, Victor Osoti, John N. Gitonga, Alfred Mwanzu, Calleb Odundo, Martin Mutunga, Salim Mwarumba, Donwilliams O. Omuoyo, Amek Nyaguara, Clement Lewa, Elijah Gicheru, Wilson Gumbi, Jennifer Musyoki, Susan Njuguna, Moses Mosobo, Lynette Isabella Ochola-Oyier, Horace Gumba, Wilfred Nyamu, Khadija Said Mohammed, Janet Thoya, Edward Otieno, Domtila Kimani, Jedidah Mwacharo, David Amadi, Charles N. Agoti, Zaydah R. de Laurent, and Robinson Cheruiyot
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Quality management system ,laboratory pandemic response ,quality assurance ,coronavirus disease ,COVID-19 testing ,COVID-19 pandemic ,eng ,Medicine ,Science - Abstract
Laboratory diagnosis plays a critical role in the containment of a pandemic. Strong laboratory quality management systems (QMS) are essential for laboratory diagnostic services. However, low laboratory capacities in resource-limited countries has made the maintenance of laboratory quality assurance, especially during a pandemic, a daunting task. In this paper, we describe our experience of how we went about providing diagnostic testing services for SARS-CoV-2 through laboratory reorganization, redefining of the laboratory workflow, and training and development of COVID-19 documented procedures, all while maintaining the quality assurance processes during the COVID-19 pandemic at the Kenya Medical Research Institute (KEMRI) Wellcome Trust Research Programme (KWTRP) laboratory. The KWTRP laboratory managed to respond to the COVID-19 outbreak in Kenya by providing diagnostic testing for the coastal region of the country, while maintaining its research standard quality assurance processes. A COVID-19 team comprising of seven sub-teams with assigned specific responsibilities and an organizational chart with established reporting lines were developed. Additionally, a total of four training sessions were conducted for county Rapid Response Teams (RRTs) and laboratory personnel. A total of 11 documented procedures were developed to support the COVID-19 testing processes, with three for the pre-analytical phases, seven for the analytical phase, and one for the post-analytical phase. With the workflow re-organization, the development of appropriate standard operating procedures, and training, research laboratories can effectively respond to pandemic outbreaks while maintaining research standard QMS procedures.
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- 2022
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5. Implementing a quality management system using good clinical laboratory practice guidelines at KEMRI-CMR to support medical research [version 2; peer review: 2 approved]
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Horace Gumba, Joseph Waichungo, Brett Lowe, Alfred Mwanzu, Robert Musyimi, Johnstone Thitiri, Caroline Tigoi, Martin Kamui, James A. Berkley, Ronald Ngetich, Susan Kavai, and Samuel Kariuki
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Medicine ,Science - Abstract
Background: Good Clinical Laboratory Practice (GCLP) is a standard that helps ensure the quality and reliability of research data through principles of Good Laboratory Practice (GLP) and Good Clinical Practice (GCP). The implementation of GCLP includes careful documentation of procedures, competencies and safety measures. Implementation of GCLP is influenced by existing resources and quality systems, thus laboratories in low- and middle-income countries may face additional challenges. Methods: This paper describes implementation of GCLP at the Kenya Medical Research Institute-Center for Microbiology Research (KEMRI-CMR) as part of a quality system to support medical research. This study employed assessment, twinning (institutional mentorship) model, conducting relevant training workshops and Kaizen 5S approaches to implement an effective quality management system using GCLP standard. This was achieved through a collaboration between the KEMRI/Wellcome Trust Research Programme (KWTRP) and KEMRI-CMR. The aim was compliance and continuous monitoring to meet international GCLP standards in a way that could be replicated in other research organizations. Results: Following a baseline assessment in March 2017, training, mentorship and a cycle of quality audit and corrective action using a Kaizen 5S approach (sorting, setting in order, shining, standardizing and sustaining) was established. Laboratory personnel were trained in writing standard operating procedures and analytical plans, microbiological techniques, and good documentation practice. Mid-term and exit assessments demonstrated significant declines in non-conformances across all GCLP elements. KEMRI-CMR achieved GCLP accreditation in May 2018 by Qualogy Ltd (UK). Conclusions: Involving all the laboratory personnel in implementation of quality management system processes is critical to success. An institutional mentorship (twinning) approach shows potential for future collaborations between accredited and non-accredited organizations to accelerate the implementation of high-quality management systems and continuous improvement.
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- 2019
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6. Implementing a quality management system using good clinical laboratory practice guidelines at KEMRI-CMR to support medical research [version 1; referees: 2 approved]
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Horace Gumba, Joseph Waichungo, Brett Lowe, Alfred Mwanzu, Robert Musyimi, Johnstone Thitiri, Caroline Tigoi, Martin Kamui, James A. Berkley, Ronald Ngetich, Susan Kavai, and Samuel Kariuki
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Medicine ,Science - Abstract
Background: Good Clinical Laboratory Practice (GCLP) is a standard that helps ensure the quality and reliability of research data through principles of Good Laboratory Practice (GLP) and Good Clinical Practice (GCP). The implementation of GCLP includes careful documentation of procedures, competencies and safety measures. Implementation of GCLP is influenced by existing resources and quality systems, thus laboratories in low- and middle-income countries may face additional challenges. Methods: This paper describes implementation of Good Clinical Laboratory Practice (GCLP) at the Kenya Medical Research Institute-Center for Microbiology Research (KEMRI-CMR) as part of a quality system to support medical research. This study employed assessment, twinning (institutional mentorship) model, conducting relevant training workshops and Kaizen 5S approaches to implement an effective quality management system using GCLP standard. This was achieved through a collaboration between the KEMRI/Wellcome Trust Research Programme (KWTRP) and KEMRI-CMR. The aim was compliance and continuous monitoring to meet international GCLP standards in a way that could be replicated in other research organizations. Results: Following a baseline assessment in March 2017, training, mentorship and a cycle of quality audit and corrective action using a Kaizen 5S approach (sorting, setting in order, shining, standardizing and sustaining) was established. Laboratory personnel were trained in writing standard operating procedures and analytical plans, microbiological techniques, and good documentation practice. Mid-term and exit assessments demonstrated significant declines in non-conformances across all GCLP elements. KEMRI-CMR achieved GCLP accreditation in May 2018 by Qualogy Ltd (UK). Conclusions: Involving all the laboratory personnel in implementation of quality management system processes is critical to success. An institutional mentorship (twinning) approach shows potential for future collaborations between accredited and non-accredited organizations to accelerate the implementation of high-quality management systems and continuous improvement.
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- 2018
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7. Measuring Non-Typhoidal Salmonella Specific Antibodies in Oral Fluid as a Non-Invasive Alternative to Serum
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Sean Christopher Elias, Esther Muthumbi, Alfred Mwanzu, Perpetual Wanjiku, Agnes Mutiso, Raphael Simon, and Calman MacLennan
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2022
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8. Implementing a quality management system using good clinical laboratory practice guidelines at KEMRI-CMR to support medical research
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Johnstone Thitiri, Susan Kavai, James A. Berkley, Joseph Waichungo, Robert Musyimi, Alfred Mwanzu, Ronald Ngetich, Martin Kamui, Brett Lowe, Samuel Kariuki, Horace Gumba, and Caroline Tigoi
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Kaizen ,Computer science ,business.industry ,Quality system ,030231 tropical medicine ,Medicine (miscellaneous) ,Articles ,medical research ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Quality audit ,Engineering management ,0302 clinical medicine ,Quality management system ,quality management system ,Good clinical practice ,Good Clinical Laboratory Practice ,030212 general & internal medicine ,Good clinical laboratory practice ,Quality Assurance ,business ,Good laboratory practice ,Quality assurance ,Research Article ,Accreditation - Abstract
Background: Good Clinical Laboratory Practice (GCLP) is a standard that helps ensure the quality and reliability of research data through principles of Good Laboratory Practice (GLP) and Good Clinical Practice (GCP). The implementation of GCLP includes careful documentation of procedures, competencies and safety measures. Implementation of GCLP is influenced by existing resources and quality systems, thus laboratories in low- and middle-income countries may face additional challenges. Methods: This paper describes implementation of Good Clinical Laboratory Practice (GCLP) at the Kenya Medical Research Institute-Center for Microbiology Research (KEMRI-CMR) as part of a quality system to support medical research. This study employed assessment, twinning (institutional mentorship) model, conducting relevant training workshops and Kaizen 5S approaches to implement an effective quality management system using GCLP standard. This was achieved through a collaboration between the KEMRI/Wellcome Trust Research Programme (KWTRP) and KEMRI-CMR. The aim was compliance and continuous monitoring to meet international GCLP standards in a way that could be replicated in other research organizations. Results: Following a baseline assessment in March 2017, training, mentorship and a cycle of quality audit and corrective action using a Kaizen 5S approach (sorting, setting in order, shining, standardizing and sustaining) was established. Laboratory personnel were trained in writing standard operating procedures and analytical plans, microbiological techniques, and good documentation practice. Mid-term and exit assessments demonstrated significant declines in non-conformances across all GCLP elements. KEMRI-CMR achieved GCLP accreditation in May 2018 by Qualogy Ltd (UK). Conclusions: Involving all the laboratory personnel in implementation of quality management system processes is critical to success. An institutional mentorship (twinning) approach shows potential for future collaborations between accredited and non-accredited organizations to accelerate the implementation of high-quality management systems and continuous improvement.
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- 2019
9. Invasive Salmonellosis in Kilifi, Kenya
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Michael Ooko, Samuel Kariuki, Esther Muthumbi, James A. Berkley, Alfred Mwanzu, Thomas N. Williams, Neema Mturi, Susan C. Morpeth, J. Anthony G. Scott, Anthony Etyang, Salim Mwarumba, and Wellcome Trust
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Male ,Salmonella typhimurium ,Salmonella ,Bacteremia ,HIV Infections ,Salmonella infection ,Salmonella typhi ,medicine.disease_cause ,0302 clinical medicine ,Risk Factors ,Drug Resistance, Multiple, Bacterial ,Case fatality rate ,030212 general & internal medicine ,Child ,11 Medical and Health Sciences ,0303 health sciences ,education.field_of_study ,Incidence ,Incidence (epidemiology) ,Salmonella enterica ,Middle Aged ,3. Good health ,Infectious Diseases ,Child, Preschool ,Salmonella Infections ,Female ,Adult ,Microbiology (medical) ,Typhi ,Population ,Microbiology ,Typhoid fever ,Young Adult ,03 medical and health sciences ,Environmental health ,parasitic diseases ,medicine ,Humans ,Typhoid Fever ,education ,030306 microbiology ,business.industry ,Malnutrition ,Infant, Newborn ,Infant ,06 Biological Sciences ,medicine.disease ,Kenya ,Virology ,Malaria ,Salmonella enteritidis ,nontyphoidal ,Invasive SALMONELLA Disease in Africa ,business - Abstract
Estimates of the burden of invasive Salmonella infections in sub-Saharan Africa are limited by the scarcity of regional data. The global burden of typhoid fever was estimated at 26.9 million cases in 2010 [1], but only Egypt and South Africa contributed to this estimate for the African continent. Within Africa, surveillance from Kenya, Tanzania, Malawi, and South Africa has shown marked regional variation in the incidence and age-specific patterns of typhoid fever [2–4]. Typhoid fever is caused by Salmonella enterica serovar Typhi, whereas nontyphoidal Salmonella (NTS) disease refers to infections caused by Salmonella enterica serovars other than Typhi and Paratyphi A. The burden of NTS disease in Africa is even less well understood. In high-income countries, NTS causes a self-limiting gastroenteritis and is transmitted though contaminated food. In contrast, infection with NTS in Africa is usually invasive, causing severe life-threatening sepsis. In fact, NTS is a common cause of bacteremia in both children and adults [5, 6]. In a study of community-acquired bloodstream infections across Africa, NTS was the most common pathogenic isolate in adults; in children, it was the second most common, after Streptococcus pneumoniae [6]. Risk factors for invasive NTS (iNTS) disease include malaria infection, human immunodeficiency virus (HIV), and malnutrition [5, 7], all of which have a high prevalence in Africa. Existing estimates of the incidence of iNTS are derived mainly from children and high-risk groups [5, 8–10]. Population-based studies are few and thus incidence estimates are extremely limited. Modeled estimates of iNTS infection, based on extrapolations from these studies, adjusting for the effects of HIV and malaria, suggest an incidence in Africa of 227 cases per 100 000 per year across all age groups, with a case fatality rate of 20% [11]. Although incidence estimates are scarce, NTS repeatedly rank near the top in series of invasive pathogenic bacteria on the continent, suggesting that they are a cause of considerable morbidity and mortality. Vaccines are available to protect against Salmonella Typhi infections and are in development to prevent NTS. The case for vaccine development, and the proper evaluation and deployment of such vaccines in Africa, depends upon a sound understanding of the epidemiology of the disease in different parts of the continent. This study describes the incidence, clinical characteristics, and antimicrobial susceptibility patterns of invasive salmonellosis among children and adults admitted to Kilifi County Hospital in Coastal Kenya.
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- 2015
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