24 results on '"Shebe M"'
Search Results
2. Characterisation of metabolic acidosis in Kenyan children admitted to hospital for acute non-surgical conditions
- Author
-
Sasi, P., English, M., Berkley, J., Lowe, B., Shebe, M., Mwakesi, R., and Kokwaro, G.
- Published
- 2006
- Full Text
- View/download PDF
3. The epidemiology of sickle cell disease in Kilifi, Kenya: A prospective cohort study of children recruited in infancy
- Author
-
Uyoga, S, Macharia, AW, Mochamah, G, Ndila, CM, Nyutu, G, Makale, J, Tendwa, M, Nyatichi, E, Ojal, J, Otiende, M, Shebe, M, Awuondo, KO, Mturi, N, Peshu, N, Tsofa, B, Maitland, K, Scott, JAG, Williams, T, and Wellcome Trust
- Subjects
hemic and lymphatic diseases ,sickle cell disease - Abstract
Background Sickle cell disease (SCD) is the commonest severe monogenic disorder of humans. In Africa, 50-90% of children born with SCD die before they reach their fifth birthday. Through the current study, we aimed to describe the comparative incidence of a range of specific clinical outcomes among children aged 3 months-5 years with and without SCD who were resident within the Kilifi area of Kenya. Methods We conducted a prospective study among a cohort of children on the coast of Kenya. Members were typed for SCD and followed for survival status and disease-specific admission to Kilifi County Hospital by passive surveillance. Children with SCD were offered confirmatory testing and care at a dedicated outpatient clinic. Findings Of 15,702 infants recruited to the study one-hundred-and-twenty-eight (0.8%) had SCD of whom 70 (54.7%) enrolled at the clinic. Mortality was higher in children with SCD than in those without [58 versus 2.4/1000PYO; adjusted Incidence Rate Ratio (aIRR) 23.1, 95% CI 15.1-35.3]. Among SCD children, mortality was lower in those who enrolled at the clinic (aIRR 0.26; 0.11-0.62) and in those with higher levels of Haemoglobin F (HbF) (aIRR 0.40; 0.17-0.94). The incidence of admission to hospital was also higher in children with than without SCD (210 versus 43/1000PYO; aIRR 4.80; 3.84-6.15). The most common reason for admission among those with SCD was severe anaemia (a haemoglobin concentration of
- Published
- 2019
4. The clinical epidemiology of sickle cell anemia In Africa
- Author
-
Macharia, AW, Mochamah, G, Uyoga, S, Ndila, CM, Nyutu, G, Makale, J, Tendwa, M, Nyatichi, E, Ojal, J, Shebe, M, Awuondo, KO, Mturi, N, Peshu, N, Tsofa, B, Scott, JAG, Maitland, K, and Williams, TN
- Subjects
parasitic diseases - Abstract
Sickle cell anemia (SCA) is the commonest severe monogenic disorders of humans. The disease has been highly characterized in high-income countries but not in sub-Saharan Africa where SCA is most prevalent. We conducted a retrospective cohort study of all children 0-13 years admitted from within a defined study area to Kilifi County Hospital in Kenya over a five-year period. Children were genotyped for SCA retrospectively and incidence rates calculated with reference to population data. Overall, 576 of 18,873 (3.1%) admissions had SCA of whom the majority (399; 69.3%) were previously undiagnosed. The incidence of all-cause hospital admission was 57.2/100 person years of observation (PYO; 95%CI 52.6-62.1) in children with SCA and 3.7/100 PYO (95%CI 3.7-3.8) in those without SCA (IRR 15.3; 95%CI 14.1-16.6). Rates were higher for the majority of syndromic diagnoses at all ages beyond the neonatal period, being especially high for severe anemia (hemoglobin < 50 g/L; IRR 58.8; 95%CI 50.3-68.7), stroke (IRR 486; 95%CI 68.4-3,450), bacteremia (IRR 23.4; 95%CI 17.4-31.4), and for bone (IRR 607; 95%CI 284-1,300), and joint (IRR 80.9; 95%CI 18.1-362) infections. The use of an algorithm based on just five clinical features would have identified approximately half of all SCA cases among hospital-admitted children with a number needed to test to identify each affected patient of only fourteen. Our study illustrates the clinical epidemiology of SCA in a malaria-endemic environment without specific interventions. The targeted testing of hospital-admitted children using the Kilifi Algorithm provides a pragmatic approach to early diagnosis in high-prevalence countries where newborn screening is unavailable.
- Published
- 2018
5. Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study
- Author
-
Ndila, CM, Uyoga, S, Macharia, AW, Nyutu, G, Peshu, N, Ojal, J, Shebe, M, Awuondo, KO, Mturi, N, Tsofa, B, Sepulveda, N, Clark, TG, Band, G, Clarke, G, Rowlands, K, Hubbart, C, Jeffreys, A, Kariuki, S, Marsh, K, Mackinnon, M, Maitland, K, Kwiatkowski, DP, Rockett, KA, Williams, TN, Ndila, CM, Uyoga, S, Macharia, AW, Nyutu, G, Peshu, N, Ojal, J, Shebe, M, Awuondo, KO, Mturi, N, Tsofa, B, Sepulveda, N, Clark, TG, Band, G, Clarke, G, Rowlands, K, Hubbart, C, Jeffreys, A, Kariuki, S, Marsh, K, Mackinnon, M, Maitland, K, Kwiatkowski, DP, Rockett, KA, and Williams, TN
- Abstract
BACKGROUND: Human genetic factors are important determinants of malaria risk. We investigated associations between multiple candidate polymorphisms-many related to the structure or function of red blood cells-and risk for severe Plasmodium falciparum malaria and its specific phenotypes, including cerebral malaria, severe malaria anaemia, and respiratory distress. METHODS: We did a case-control study in Kilifi County, Kenya. We recruited as cases children presenting with severe malaria to the high-dependency ward of Kilifi County Hospital. We included as controls infants born in the local community between Aug 1, 2006, and Sept 30, 2010, who were part of a genetics study. We tested for associations between a range of candidate malaria-protective genes and risk for severe malaria and its specific phenotypes. We used a permutation approach to account for multiple comparisons between polymorphisms and severe malaria. We judged p values less than 0·005 significant for the primary analysis of the association between candidate genes and severe malaria. FINDINGS: Between June 11, 1995, and June 12, 2008, 2244 children with severe malaria were recruited to the study, and 3949 infants were included as controls. Overall, 263 (12%) of 2244 children with severe malaria died in hospital, including 196 (16%) of 1233 with cerebral malaria. We investigated 121 polymorphisms in 70 candidate severe malaria-associated genes. We found significant associations between risk for severe malaria overall and polymorphisms in 15 genes or locations, of which most were related to red blood cells: ABO, ATP2B4, ARL14, CD40LG, FREM3, INPP4B, G6PD, HBA (both HBA1 and HBA2), HBB, IL10, LPHN2 (also known as ADGRL2), LOC727982, RPS6KL1, CAND1, and GNAS. Combined, these genetic associations accounted for 5·2% of the variance in risk for developing severe malaria among individuals in the general population. We confirmed established associations between severe malaria and sickle-cell trait (odds ratio [OR
- Published
- 2018
6. Malaria hospitalisation in East Africa: age, phenotype and transmission intensity
- Author
-
Alice Kamau, Robert S. Paton, Samuel Akech, Arthur Mpimbaza, Cynthia Khazenzi, Morris Ogero, Eda Mumo, Victor A. Alegana, Ambrose Agweyu, Neema Mturi, Shebe Mohammed, Godfrey Bigogo, Allan Audi, James Kapisi, Asadu Sserwanga, Jane F. Namuganga, Simon Kariuki, Nancy A. Otieno, Bryan O. Nyawanda, Ally Olotu, Nahya Salim, Thabit Athuman, Salim Abdulla, Amina F. Mohamed, George Mtove, Hugh Reyburn, Sunetra Gupta, José Lourenço, Philip Bejon, and Robert W. Snow
- Subjects
Malaria ,Age pattern ,Parasite prevalence ,Severe malaria ,Anaemia ,Cerebral malaria ,Medicine - Abstract
Abstract Background Understanding the age patterns of disease is necessary to target interventions to maximise cost-effective impact. New malaria chemoprevention and vaccine initiatives target young children attending routine immunisation services. Here we explore the relationships between age and severity of malaria hospitalisation versus malaria transmission intensity. Methods Clinical data from 21 surveillance hospitals in East Africa were reviewed. Malaria admissions aged 1 month to 14 years from discrete administrative areas since 2006 were identified. Each site-time period was matched to a model estimated community-based age-corrected parasite prevalence to provide predictions of prevalence in childhood (PfPR2–10). Admission with all-cause malaria, severe malaria anaemia (SMA), respiratory distress (RD) and cerebral malaria (CM) were analysed as means and predicted probabilities from Bayesian generalised mixed models. Results 52,684 malaria admissions aged 1 month to 14 years were described at 21 hospitals from 49 site-time locations where PfPR2–10 varied from
- Published
- 2022
- Full Text
- View/download PDF
7. BIRC6 modifies risk of invasive bacterial infection in Kenyan children
- Author
-
James J Gilchrist, Silvia N Kariuki, James A Watson, Gavin Band, Sophie Uyoga, Carolyne M Ndila, Neema Mturi, Salim Mwarumba, Shebe Mohammed, Moses Mosobo, Kaur Alasoo, Kirk A Rockett, Alexander J Mentzer, Dominic P Kwiatkowski, Adrian VS Hill, Kathryn Maitland, J Anthony G Scott, and Thomas N Williams
- Subjects
bacteraemia ,GWAS ,malaria ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Invasive bacterial disease is a major cause of morbidity and mortality in African children. Despite being caused by diverse pathogens, children with sepsis are clinically indistinguishable from one another. In spite of this, most genetic susceptibility loci for invasive infection that have been discovered to date are pathogen specific and are not therefore suggestive of a shared genetic architecture of bacterial sepsis. Here, we utilise probabilistic diagnostic models to identify children with a high probability of invasive bacterial disease among critically unwell Kenyan children with Plasmodium falciparum parasitaemia. We construct a joint dataset including 1445 bacteraemia cases and 1143 severe malaria cases, and population controls, among critically unwell Kenyan children that have previously been genotyped for human genetic variation. Using these data, we perform a cross-trait genome-wide association study of invasive bacterial infection, weighting cases according to their probability of bacterial disease. In doing so, we identify and validate a novel risk locus for invasive infection secondary to multiple bacterial pathogens, that has no apparent effect on malaria risk. The locus identified modifies splicing of BIRC6 in stimulated monocytes, implicating regulation of apoptosis and autophagy in the pathogenesis of sepsis in Kenyan children.
- Published
- 2022
- Full Text
- View/download PDF
8. Malaria infection, disease and mortality among children and adults on the coast of Kenya
- Author
-
Alice Kamau, Grace Mtanje, Christine Mataza, Gabriel Mwambingu, Neema Mturi, Shebe Mohammed, Gerald Ong’ayo, Gideon Nyutu, Amek Nyaguara, Philip Bejon, and Robert W. Snow
- Subjects
Malaria ,Age-pattern ,Adults ,Immunity ,Infection ,Mortality ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Malaria transmission has recently fallen in many parts of Africa, but systematic descriptions of infection and disease across all age groups are rare. Here, an epidemiological investigation of parasite prevalence, the incidence of fevers associated with infection, severe hospitalized disease and mortality among children older than 6 months and adults on the Kenyan coast is presented. Methods A prospective fever surveillance was undertaken at 6 out-patients (OPD) health-facilities between March 2018 and February 2019. Four community-based, cross sectional surveys of fever history and infection prevalence were completed among randomly selected homestead members from the same communities. Paediatric and adult malaria at Kilifi county hospital was obtained for the 12 months period. Rapid Diagnostic Tests (CareStart™ RDT) to detect HRP2-specific to Plasmodium falciparum was used in the community and the OPD, and microscopy in the hospital. Crude and age-specific incidence rates were computed using Poisson regression. Results Parasite prevalence gradually increased from childhood, reaching 12% by 9 years of age then declining through adolescence into adulthood. The incidence rate of RDT positivity in the OPD followed a similar trend to that of infection prevalence in the community. The incidence of hospitalized malaria from the same community was concentrated among children aged 6 months to 4 years (i.e. 64% and 70% of all hospitalized and severe malaria during the 12 months of surveillance, respectively). Only 3.7% (12/316) of deaths were directly attributable to malaria. Malaria mortality was highest among children aged 6 months–4 years at 0.57 per 1000 person-years (95% CI 0.2, 1.2). Severe malaria and death from malaria was negligible above 15 years of age. Conclusion Under conditions of low transmission intensity, immunity to disease and the fatal consequences of infection appear to continue to be acquired in childhood and faster than anti-parasitic immunity. There was no evidence of an emerging significant burden of severe malaria or malaria mortality among adults. This is contrary to current modelled approaches to disease burden estimation in Africa and has important implications for the targeting of infection prevention strategies based on chemoprevention or vector control.
- Published
- 2020
- Full Text
- View/download PDF
9. Using GIS in the Management of Health Infrastructure within Kaduna Metropolis, Nigeria
- Author
-
Aliyu, Y. A., primary and Shebe, M. W, additional
- Published
- 2013
- Full Text
- View/download PDF
10. Hepcidin regulation in Kenyan children with severe malaria and non-typhoidal Salmonella bacteremia
- Author
-
Kelvin M. Abuga, John Muthii Muriuki, Sophie M. Uyoga, Kennedy Mwai, Johnstone Makale, Reagan M. Mogire, Alex W. Macharia, Shebe Mohammed, Esther Muthumbi, Salim Mwarumba, Neema Mturi, Philip Bejon, J. Anthony G. Scott, Manfred Nairz, Thomas N. Williams, and Sarah H. Atkinson
- Subjects
Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Malaria and invasive non-typhoidal Salmonella (NTS) are life-threatening infections that often co-exist in African children. The iron-regulatory hormone hepcidin is highly upregulated during malaria and controls the availability of iron, a critical nutrient for bacterial growth. We investigated the relationship between Plasmodium falciparum malaria and NTS bacteremia in all pediatric admissions aged
- Published
- 2021
- Full Text
- View/download PDF
11. A randomized control trial of phototherapy and 20% albumin versus phototherapy and saline in Kilifi, Kenya
- Author
-
Dorcas N. Magai, Michael Mwaniki, Amina Abubakar, Shebe Mohammed, Anne L. Gordon, Raphael Kalu, Paul Mwangi, Hans M. Koot, and Charles R. Newton
- Subjects
Albumin ,Saline ,Neonates ,Neonatal jaundice ,Sub-Saharan Africa ,Medicine ,Biology (General) ,QH301-705.5 ,Science (General) ,Q1-390 - Abstract
Abstract Objective The study evaluated the efficacy of phototherapy and 20% albumin infusion to reduce total serum bilirubin (TSB) in neonates with severe hyperbilirubinemia. The primary outcome was a reduction of TSB at the end of treatment. The secondary outcomes were the need for exchange transfusion, inpatient mortality, neurological outcomes at discharge, and development outcomes at 12-months follow-up. Results One hundred and eighteen neonates were randomly assigned to phototherapy and 20% albumin (n = 59) and phototherapy and saline (n = 69). The median age at admission was 5 (interquartile range (IQR) 3–6) days, and the median gestation was 36 (IQR 36–38) weeks. No significant differences were found in the change in TSB (Mann–Whitney U =609, p = 0.98) and rate of change in TSB per hour after treatment (Mann–Whitney U = 540, p = 0.39) between the two groups. There were no significant differences between the two groups in the proportion of participants who required exchange transfusion (χ2 (2) = 0.36, p = 0.546); repeat phototherapy (χ2 (2) = 2.37, p = 0.123); and those who died (χ2 (2) = 0.92, p = 0.337). Trial registration The trial was registered in the International Standardized Randomized Controlled Trial Number (ISRCTN); trial registration number ISRCTN89732754.
- Published
- 2019
- Full Text
- View/download PDF
12. Observational study: 27 years of severe malaria surveillance in Kilifi, Kenya
- Author
-
Patricia Njuguna, Kathryn Maitland, Amek Nyaguara, Daniel Mwanga, Polycarp Mogeni, Neema Mturi, Shebe Mohammed, Gabriel Mwambingu, Caroline Ngetsa, Kenedy Awuondo, Brett Lowe, Ifedayo Adetifa, J. Anthony G. Scott, Thomas N. Williams, Sarah Atkinson, Faith Osier, Robert W. Snow, Kevin Marsh, Benjamin Tsofa, Norbert Peshu, Mainga Hamaluba, James A. Berkley, Charles R. J. Newton, John Fondo, Anisa Omar, and Philip Bejon
- Subjects
Severe malaria ,Secular trend ,Mortality ,Africa ,Longitudinal surveillance ,Medicine - Abstract
Abstract Background Many parts of Africa have witnessed reductions in Plasmodium falciparum transmission over the last 15 years. Since immunity to malaria is acquired more rapidly at higher transmission, the slower acquisition of immunity at lower transmission may partially offset the benefits of reductions in transmission. We examined the clinical spectrum of disease and predictors of mortality after sustained changes in transmission intensity, using data collected from 1989 to 2016. Methods We conducted a temporal observational analysis of 18,000 children, aged 14 days to 14 years old, who were admitted to Kilifi County Hospital, Kenya, from 1989 to 2016 with malaria. We describe the trends over time of the clinical and laboratory criteria for severe malaria and associated risk of mortality. Results During the time periods 1989–2003, 2004–2008, and 2009–2016, Kilifi County Hospital admitted averages of 657, 310, and 174 cases of severe malaria per year including averages of 48, 14, and 12 malaria-associated deaths per year, respectively. The median ages in years of children admitted with cerebral malaria, severe anaemia, and malaria-associated mortality were 3.0 (95% confidence interval (CI) 2.2–3.9), 1.1 (95% CI 0.9–1.4), and 1.1 (95% CI 0.3–2.2) in the year 1989, rising to 4.9 (95% CI 3.9–5.9), 3.8 (95% CI 2.5–7.1), and 5 (95% CI 3.3–6.3) in the year 2016. The ratio of children with cerebral malaria to severe anaemia rose from 1:2 before 2004 to 3:2 after 2009. Hyperparasitaemia was a risk factor for death after 2009 but not in earlier time periods. Conclusion Despite the evidence of slower acquisition of immunity, continued reductions in the numbers of cases of severe malaria resulted in lower overall mortality. Our temporal data are limited to a single site, albeit potentially applicable to a secular trend present in many parts of Africa.
- Published
- 2019
- Full Text
- View/download PDF
13. Improving statistical power in severe malaria genetic association studies by augmenting phenotypic precision
- Author
-
James A Watson, Carolyne M Ndila, Sophie Uyoga, Alexander Macharia, Gideon Nyutu, Shebe Mohammed, Caroline Ngetsa, Neema Mturi, Norbert Peshu, Benjamin Tsofa, Kirk Rockett, Stije Leopold, Hugh Kingston, Elizabeth C George, Kathryn Maitland, Nicholas PJ Day, Arjen M Dondorp, Philip Bejon, Thomas N Williams, Chris C Holmes, and Nicholas J White
- Subjects
severe malaria ,GWAS ,diagnosis ,complete blood count ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Severe falciparum malaria has substantially affected human evolution. Genetic association studies of patients with clinically defined severe malaria and matched population controls have helped characterise human genetic susceptibility to severe malaria, but phenotypic imprecision compromises discovered associations. In areas of high malaria transmission, the diagnosis of severe malaria in young children and, in particular, the distinction from bacterial sepsis are imprecise. We developed a probabilistic diagnostic model of severe malaria using platelet and white count data. Under this model, we re-analysed clinical and genetic data from 2220 Kenyan children with clinically defined severe malaria and 3940 population controls, adjusting for phenotype mis-labelling. Our model, validated by the distribution of sickle trait, estimated that approximately one-third of cases did not have severe malaria. We propose a data-tilting approach for case-control studies with phenotype mis-labelling and show that this reduces false discovery rates and improves statistical power in genome-wide association studies.
- Published
- 2021
- Full Text
- View/download PDF
14. Near Real Time Processing of Differential GPS Observation using Internet Technology.
- Author
-
Isioye, O. A., Enebeli, I., Shebe, M. W., and Mefe, M.
- Subjects
GLOBAL Positioning System ,DATA transmission systems ,INFORMATION & communication technologies ,COMPUTER systems ,INTERNET - Abstract
The study is focused on transmitting GPS observed data via the internet for near real-time post-processing solution. It exploits possible and available technology in integrating the basic concept of real-time GPS survey and post-processing technique to achieve a near real-time post-processing result. This was achieved by exploring the internet as a means of communication and transmission of GPS data for a near real-time post- processing solution. The base and rover stations were equipped with wireless mobile internet modems and portable mobile computer systems to provide the internet accessibility required for online transfer of downloaded observed GPS data in near real time. The research work with a view to saving the time required for post-processing of GPS data, process the observed base and rover data as fast as possible on-site as soon as the reference station data is received. This allow for check and correction of any observed error or anomaly on site. Based on the evaluated methodology, the positions of some points were determined. An independent web interface was also designed and tested using PHP ('Hypertext Pre -Processor', a server side HTML scripting/programming language) for practical assessment and validation of the concept. [ABSTRACT FROM AUTHOR]
- Published
- 2011
15. Should first-line empiric treatment strategies cover coagulase-negative staphylococcal infections in severely malnourished or HIV-infected children in Kenya?
- Author
-
Christina W Obiero, Anna C Seale, Kelsey Jones, Moses Ngari, Charlotte L Bendon, Susan Morpeth, Shebe Mohammed, Neema Mturi, Greg Fegan, and James A Berkley
- Subjects
Medicine ,Science - Abstract
Bloodstream infection is a common cause of morbidity in children aged
- Published
- 2017
- Full Text
- View/download PDF
16. Non-O ABO blood group genotypes differ in their associations with Plasmodium falciparum rosetting and severe malaria.
- Author
-
Opi DH, Ndila CM, Uyoga S, Macharia AW, Fennell C, Ochola LB, Nyutu G, Siddondo BR, Ojal J, Shebe M, Awuondo KO, Mturi N, Peshu N, Tsofa B, Band G, Maitland K, Kwiatkowski DP, Rockett KA, Williams TN, and Rowe JA
- Subjects
- Child, Humans, ABO Blood-Group System genetics, Plasmodium falciparum genetics, Case-Control Studies, Kenya, Genotype, Malaria, Malaria, Falciparum genetics
- Abstract
Blood group O is associated with protection against severe malaria and reduced size and stability of P. falciparum-host red blood cell (RBC) rosettes compared to non-O blood groups. Whether the non-O blood groups encoded by the specific ABO genotypes AO, BO, AA, BB and AB differ in their associations with severe malaria and rosetting is unknown. The A and B antigens are host RBC receptors for rosetting, hence we hypothesized that the higher levels of A and/or B antigen on RBCs from AA, BB and AB genotypes compared to AO/BO genotypes could lead to larger rosettes, increased microvascular obstruction and higher risk of malaria pathology. We used a case-control study of Kenyan children and in vitro adhesion assays to test the hypothesis that "double dose" non-O genotypes (AA, BB, AB) are associated with increased risk of severe malaria and larger rosettes than "single dose" heterozygotes (AO, BO). In the case-control study, compared to OO, the double dose genotypes consistently had higher odds ratios (OR) for severe malaria than single dose genotypes, with AB (OR 1.93) and AO (OR 1.27) showing most marked difference (p = 0.02, Wald test). In vitro experiments with blood group A-preferring P. falciparum parasites showed that significantly larger rosettes were formed with AA and AB host RBCs compared to OO, whereas AO and BO genotypes rosettes were indistinguishable from OO. Overall, the data show that ABO genotype influences P. falciparum rosetting and support the hypothesis that double dose non-O genotypes confer a greater risk of severe malaria than AO/BO heterozygosity., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Opi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
- Full Text
- View/download PDF
17. Plasma Plasmodium falciparum Histidine-rich Protein 2 Concentrations in Children With Malaria Infections of Differing Severity in Kilifi, Kenya.
- Author
-
Uyoga S, Wanjiku P, Rop JC, Makale J, Macharia AW, Nyutu GM, Shebe M, Awuondo KA, Mturi N, Woodrow CJ, Dondorp AM, Maitland K, and Williams TN
- Subjects
- Child, Humans, Kenya epidemiology, Parasite Load, Plasmodium falciparum, Antigens, Protozoan blood, Malaria, Falciparum epidemiology, Protozoan Proteins blood
- Abstract
Background: Most previous studies support a direct link between total parasite load and the clinical severity of Plasmodium falciparum malaria infections., Methods: We estimated P. falciparum parasite loads in 3 groups of children with malaria infections of differing severity: (1) children with World Health Organization-defined severe malaria (n = 1544), (2) children admitted with malaria but without features of severity (n = 200), and (3) children in the community with asymptomatic parasitemia (n = 33)., Results: Peripheral parasitemias were highest in those with uncomplicated malaria (geometric mean [GM] parasite count, 111 064/μL; 95% confidence interval, CI, 86 798-141 819/μL), almost 3 times higher than in those with severe malaria (39 588/μL; 34 990-44 791/μL) and >100 times higher than in those with asymptomatic malaria (1092/μL; 523-2280/μL). However, the GM P. falciparum histidine-rich protein 2 (PfHRP2) values (95% CI) increased with severity, being 7 (4-12) ng/mL in asymptomatic malaria, 843 (655-1084) ng/mL in uncomplicated malaria, and 1369 (1244-1506) ng/mL in severe malaria. PfHRP2 concentrations were markedly lower in the subgroup of patients with severe malaria and concomitant invasive bacterial infections of blood or cerebrospinal fluid (GM concentration, 312 ng/mL; 95% CI, 175-557 ng/mL; P < .001) than in those without such infections (1439 ng/mL; 1307-1584; P < .001)., Conclusions: The clinical severity of malaria infections related strongly to the total burden of P. falciparum parasites. A quantitative test for plasma concentrations of PfHRP2 could be useful in identifying children at the greatest clinical risk and identifying critically ill children in whom malaria is not the primary cause., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.)
- Published
- 2021
- Full Text
- View/download PDF
18. The Etiology of Pneumonia in HIV-uninfected Children in Kilifi, Kenya: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study.
- Author
-
Awori JO, Kamau A, Morpeth S, Kazungu S, Silaba M, Sande J, Karani A, Nyongesa S, Mwarumba S, Musyimi R, Bett A, Wande S, Shebe M, Ngama M, Munywoki PK, Muturi N, Nokes DJ, Feikin DR, Murdoch DR, Prosperi C, O'Brien KL, Deloria Knoll M, Hammitt LL, and Scott JAG
- Subjects
- Bayes Theorem, Case-Control Studies, Child Health, Child, Preschool, Developing Countries, Female, HIV Infections, Haemophilus Vaccines, Hospitalization, Humans, Infant, Kenya epidemiology, Male, Patient Acuity, Pneumococcal Vaccines, Pneumonia diagnosis, Pneumonia epidemiology, Pneumonia prevention & control, Risk Factors, Pneumonia etiology
- Abstract
Background: In the 1980s, Streptococcus pneumoniae and Haemophilus influenzae were identified as the principal causes of severe pneumonia in children. We investigated the etiology of severe childhood pneumonia in Kenya after introduction of conjugate vaccines against H. influenzae type b, in 2001, and S. pneumoniae, in 2011., Methods: We conducted a case-control study between August 2011 and November 2013 among residents of the Kilifi Health and Demographic Surveillance System 28 days to 59 months of age. Cases were hospitalized at Kilifi County Hospital with severe or very severe pneumonia according to the 2005 World Health Organization definition. Controls were randomly selected from the community and frequency matched to cases on age and season. We tested nasal and oropharyngeal samples, sputum, pleural fluid, and blood specimens and used the Pneumonia Etiology Research for Child Health Integrated Analysis, combining latent class analysis and Bayesian methods, to attribute etiology., Results: We enrolled 630 and 863 HIV-uninfected cases and controls, respectively. Among the cases, 282 (44%) had abnormal chest radiographs (CXR positive), 33 (5%) died in hospital, and 177 (28%) had diagnoses other than pneumonia at discharge. Among CXR-positive pneumonia cases, viruses and bacteria accounted for 77% (95% CrI: 67%-85%) and 16% (95% CrI: 10%-26%) of pneumonia attribution, respectively. Respiratory syncytial virus, S. pneumoniae and H. influenza, accounted for 37% (95% CrI: 31%-44%), 5% (95% CrI: 3%-9%), and 6% (95% CrI: 2%-11%), respectively., Conclusions: Respiratory syncytial virus was the main cause of CXR-positive pneumonia. The small contribution of H. influenzae type b and pneumococcus to pneumonia may reflect the impact of vaccine introductions in this population., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)
- Published
- 2021
- Full Text
- View/download PDF
19. Glucose-6-phosphate dehydrogenase deficiency and susceptibility to childhood diseases in Kilifi, Kenya.
- Author
-
Uyoga S, Macharia AW, Ndila CM, Nyutu G, Shebe M, Awuondo KO, Mturi N, Peshu N, Tsofa B, Scott JAG, Maitland K, and Williams TN
- Subjects
- Case-Control Studies, Child, Female, Genotype, Glucosephosphate Dehydrogenase genetics, Humans, Infant, Newborn, Kenya epidemiology, Glucosephosphate Dehydrogenase Deficiency epidemiology, Glucosephosphate Dehydrogenase Deficiency genetics
- Abstract
Few previous studies have reported the effects of glucose-6-phosphate dehydrogenase (G6PD)-deficiency on child health in Africa. We conducted a case-control study in which cases (n = 6829) were children admitted, for any reason, to Kilifi County Hospital, Kenya, while controls (n = 10 179) were recruited from the surrounding community. Cases were subclassified based on their clinical and laboratory findings at admission. We calculated the prevalence of specific diseases by G6PD c.202 genotype, the only significant cause of G6PD-deficiency in this area, then estimated the association between genotype and admission with specific conditions using logistic regression. Among neonates, the prevalence of jaundice was higher in both G6PD c.202T heterozygotes (40/88; 45.5%; P = .004) and homo/hemizygotes (81/134; 60.5%; P < .0001) than in wild-type homozygotes (157/526; 29.9%). Median bilirubin levels also increased across the groups, being highest (239 mmol/L; interquartile range 96-390 mmol/L) in G6PD c.202T homo/hemizygotes. No differences were seen in admission hemoglobin concentrations or the prevalence of anemia or severe anemia by G6PD c.202 genotype. On case control analysis, G6PD heterozygosity was negatively associated with all-cause hospital admission (odds ratio 0.81; 95% confidence interval 0.73-0.90; P < .0001) and, specifically, admission with either pneumonia or Plasmodium falciparum parasitemia; while, conversely, it was positively associated with Gram-positive bacteremia. G6PD c.202T homo/heterozygosity was positively associated with neonatal jaundice, severe pneumonia, the receipt of a transfusion, and in-patient death. Our study supports the conclusion that G6PD c.202T is a balanced polymorphism in which a selective advantage afforded to heterozygous females against malaria is counterbalanced by increased risks of neonatal jaundice, invasive bacterial infections, and anemia., (© 2020 by The American Society of Hematology.)
- Published
- 2020
- Full Text
- View/download PDF
20. The epidemiology of sickle cell disease in children recruited in infancy in Kilifi, Kenya: a prospective cohort study.
- Author
-
Uyoga S, Macharia AW, Mochamah G, Ndila CM, Nyutu G, Makale J, Tendwa M, Nyatichi E, Ojal J, Otiende M, Shebe M, Awuondo KO, Mturi N, Peshu N, Tsofa B, Maitland K, Scott JAG, and Williams TN
- Subjects
- Child, Preschool, Humans, Incidence, Infant, Infant, Newborn, Kenya epidemiology, Prospective Studies, Anemia, Sickle Cell epidemiology
- Abstract
Background: Sickle cell disease is the most common severe monogenic disorder in humans. In Africa, 50-90% of children born with sickle cell disease die before they reach their fifth birthday. In this study, we aimed to describe the comparative incidence of specific clinical outcomes among children aged between birth and 5 years with and without sickle cell disease, who were resident within the Kilifi area of Kenya., Methods: This prospective cohort study was done on members of the Kilifi Genetic Birth Cohort Study (KGBCS) on the Indian Ocean coast of Kenya. Recruitment to the study was facilitated through the Kilifi Health and Demographic Surveillance System (KHDSS), which covers a resident population of 260 000 people, and was undertaken between Jan 1, 2006, and April 30, 2011. All children who were born within the KHDSS area and who were aged 3-12 months during the recruitment period were eligible for inclusion. Participants were tested for sickle cell disease and followed up for survival status and disease-specific admission to Kilifi County Hospital by passive surveillance until their fifth birthday. Children with sickle cell disease were offered confirmatory testing and care at a dedicated outpatient clinic., Findings: 15 737 infants were recruited successfully to the KGBCS, and 128 (0·8%) of these infants had sickle cell disease, of whom 70 (54·7%) enrolled at the outpatient clinic within 12 months of recruitment. Mortality was higher in children with sickle cell disease (58 per 1000 person-years of observation, 95% CI 40-86) than in those without sickle cell disease (2·4 per 1000 person-years of observation, 2·0-2·8; adjusted incidence rate ratio [IRR] 23·1, 95% CI 15·1-35·3). Among children with sickle cell disease, mortality was lower in those who enrolled at the clinic (adjusted IRR 0·26, 95% CI 0·11-0·62) and in those with higher levels of haemoglobin F (HbF; adjusted IRR 0·40, 0·17-0·94). The incidence of admission to hospital was also higher in children with sickle cell disease than in children without sickle cell disease (210 per 1000 person-years of observation, 95% CI 174-253, vs 43 per 1000 person-years of observation, 42-45; adjusted IRR 4·80, 95% CI 3·84-6·15). The most common reason for admission to hospital among those with sickle cell disease was severe anaemia (incidence 48 per 1000 person-years of observation, 95% CI 32-71). Admission to hospital was lower in those with a recruitment HbF level above the median (IRR 0·43, 95% CI 0·24-0·78; p=0·005) and those who were homozygous for α-thalassaemia (0·07, 0·01-0·83; p=0·035)., Interpretation: Although morbidity and mortality were high in young children with sickle cell disease in this Kenyan cohort, both were reduced by early diagnosis and supportive care. The emphasis must now move towards early detection and prevention of long-term complications of sickle cell disease., Funding: Wellcome Trust., (Copyright © 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
21. The indirect health effects of malaria estimated from health advantages of the sickle cell trait.
- Author
-
Uyoga S, Macharia AW, Ndila CM, Nyutu G, Shebe M, Awuondo KO, Mturi N, Peshu N, Tsofa B, Scott JAG, Maitland K, and Williams TN
- Subjects
- Bacteremia immunology, Case-Control Studies, Child, Preschool, Genotype, Hemoglobin, Sickle genetics, Humans, Infant, Malaria, Falciparum parasitology, Malnutrition immunology, Odds Ratio, Patient Admission statistics & numerical data, Plasmodium falciparum immunology, Plasmodium falciparum physiology, Sickle Cell Trait genetics, Disease Resistance immunology, Hemoglobin, Sickle immunology, Malaria, Falciparum immunology, Sickle Cell Trait immunology
- Abstract
Most estimates of the burden of malaria are based on its direct impacts; however, its true burden is likely to be greater because of its wider effects on overall health. Here we estimate the indirect impact of malaria on children's health in a case-control study, using the sickle cell trait (HbAS), a condition associated with a high degree of specific malaria resistance, as a proxy indicator for an effective intervention. We estimate the odds ratios for HbAS among cases (all children admitted to Kilifi County Hospital during 2000-2004) versus community controls. As expected, HbAS protects strongly against malaria admissions (aOR 0.26; 95%CI 0.22-0.31), but it also protects against other syndromes, including neonatal conditions (aOR 0.79; 0.67-0.93), bacteraemia (aOR 0.69; 0.54-0.88) and severe malnutrition (aOR 0.67; 0.55-0.83). The wider health impacts of malaria should be considered when estimating the potential added benefits of effective malaria interventions.
- Published
- 2019
- Full Text
- View/download PDF
22. Human candidate gene polymorphisms and risk of severe malaria in children in Kilifi, Kenya: a case-control association study.
- Author
-
Ndila CM, Uyoga S, Macharia AW, Nyutu G, Peshu N, Ojal J, Shebe M, Awuondo KO, Mturi N, Tsofa B, Sepúlveda N, Clark TG, Band G, Clarke G, Rowlands K, Hubbart C, Jeffreys A, Kariuki S, Marsh K, Mackinnon M, Maitland K, Kwiatkowski DP, Rockett KA, and Williams TN
- Subjects
- Case-Control Studies, Child, Child, Preschool, Female, Gene Frequency, Humans, Kenya, Male, Genetic Predisposition to Disease genetics, Malaria genetics, Polymorphism, Genetic
- Abstract
Background: Human genetic factors are important determinants of malaria risk. We investigated associations between multiple candidate polymorphisms-many related to the structure or function of red blood cells-and risk for severe Plasmodium falciparum malaria and its specific phenotypes, including cerebral malaria, severe malaria anaemia, and respiratory distress., Methods: We did a case-control study in Kilifi County, Kenya. We recruited as cases children presenting with severe malaria to the high-dependency ward of Kilifi County Hospital. We included as controls infants born in the local community between Aug 1, 2006, and Sept 30, 2010, who were part of a genetics study. We tested for associations between a range of candidate malaria-protective genes and risk for severe malaria and its specific phenotypes. We used a permutation approach to account for multiple comparisons between polymorphisms and severe malaria. We judged p values less than 0·005 significant for the primary analysis of the association between candidate genes and severe malaria., Findings: Between June 11, 1995, and June 12, 2008, 2244 children with severe malaria were recruited to the study, and 3949 infants were included as controls. Overall, 263 (12%) of 2244 children with severe malaria died in hospital, including 196 (16%) of 1233 with cerebral malaria. We investigated 121 polymorphisms in 70 candidate severe malaria-associated genes. We found significant associations between risk for severe malaria overall and polymorphisms in 15 genes or locations, of which most were related to red blood cells: ABO, ATP2B4, ARL14, CD40LG, FREM3, INPP4B, G6PD, HBA (both HBA1 and HBA2), HBB, IL10, LPHN2 (also known as ADGRL2), LOC727982, RPS6KL1, CAND1, and GNAS. Combined, these genetic associations accounted for 5·2% of the variance in risk for developing severe malaria among individuals in the general population. We confirmed established associations between severe malaria and sickle-cell trait (odds ratio [OR] 0·15, 95% CI 0·11-0·20; p=2·61 × 10
-58 ), blood group O (0·74, 0·66-0·82; p=6·26 × 10-8 ), and -α3·7 -thalassaemia (0·83, 0·76-0·90; p=2·06 × 10-6 ). We also found strong associations between overall risk of severe malaria and polymorphisms in both ATP2B4 (OR 0·76, 95% CI 0·63-0·92; p=0·001) and FREM3 (0·64, 0·53-0·79; p=3·18 × 10-14 ). The association with FREM3 could be accounted for by linkage disequilibrium with a complex structural mutation within the glycophorin gene region (comprising GYPA, GYPB, and GYPE) that encodes for the rare Dantu blood group antigen. Heterozygosity for Dantu was associated with risk for severe malaria (OR 0·57, 95% CI 0·49-0·68; p=3·22 × 10-11 ), as was homozygosity (0·26, 0·11-0·62; p=0·002)., Interpretation: Both ATP2B4 and the Dantu blood group antigen are associated with the structure and function of red blood cells. ATP2B4 codes for plasma membrane calcium-transporting ATPase 4 (the major calcium pump on red blood cells) and the glycophorins are ligands for parasites to invade red blood cells. Future work should aim at uncovering the mechanisms by which these polymorphisms can result in severe malaria protection and investigate the implications of these associations for wider health., Funding: Wellcome Trust, UK Medical Research Council, European Union, and Foundation for the National Institutes of Health as part of the Bill & Melinda Gates Grand Challenges in Global Health Initiative., (Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
23. The clinical epidemiology of sickle cell anemia In Africa.
- Author
-
Macharia AW, Mochamah G, Uyoga S, Ndila CM, Nyutu G, Makale J, Tendwa M, Nyatichi E, Ojal J, Shebe M, Awuondo KO, Mturi N, Peshu N, Tsofa B, Scott JAG, Maitland K, and Williams TN
- Subjects
- Adolescent, Anemia, Sickle Cell diagnosis, Bacteremia epidemiology, Child, Child, Preschool, Comorbidity, Delayed Diagnosis prevention & control, Delayed Diagnosis statistics & numerical data, Developing Countries, Diagnostic Tests, Routine, Disease Susceptibility, Early Diagnosis, Female, Humans, Infant, Infant, Newborn, Kenya epidemiology, Malaria epidemiology, Male, Malnutrition epidemiology, Meningitis epidemiology, Patient Admission, Population Surveillance, Retrospective Studies, Stroke epidemiology, Anemia, Sickle Cell epidemiology
- Abstract
Sickle cell anemia (SCA) is the commonest severe monogenic disorders of humans. The disease has been highly characterized in high-income countries but not in sub-Saharan Africa where SCA is most prevalent. We conducted a retrospective cohort study of all children 0-13 years admitted from within a defined study area to Kilifi County Hospital in Kenya over a five-year period. Children were genotyped for SCA retrospectively and incidence rates calculated with reference to population data. Overall, 576 of 18,873 (3.1%) admissions had SCA of whom the majority (399; 69.3%) were previously undiagnosed. The incidence of all-cause hospital admission was 57.2/100 person years of observation (PYO; 95%CI 52.6-62.1) in children with SCA and 3.7/100 PYO (95%CI 3.7-3.8) in those without SCA (IRR 15.3; 95%CI 14.1-16.6). Rates were higher for the majority of syndromic diagnoses at all ages beyond the neonatal period, being especially high for severe anemia (hemoglobin <50 g/L; IRR 58.8; 95%CI 50.3-68.7), stroke (IRR 486; 95%CI 68.4-3,450), bacteremia (IRR 23.4; 95%CI 17.4-31.4), and for bone (IRR 607; 95%CI 284-1,300), and joint (IRR 80.9; 95%CI 18.1-362) infections. The use of an algorithm based on just five clinical features would have identified approximately half of all SCA cases among hospital-admitted children with a number needed to test to identify each affected patient of only fourteen. Our study illustrates the clinical epidemiology of SCA in a malaria-endemic environment without specific interventions. The targeted testing of hospital-admitted children using the Kilifi Algorithm provides a pragmatic approach to early diagnosis in high-prevalence countries where newborn screening is unavailable., (© 2017 The Authors American Journal of Hematology Published by Wiley Periodicals, Inc.)
- Published
- 2018
- Full Text
- View/download PDF
24. Diagnostic criteria for severe acute malnutrition among infants aged under 6 mo.
- Author
-
Mwangome M, Ngari M, Fegan G, Mturi N, Shebe M, Bauni E, and Berkley JA
- Subjects
- Acute Disease, Age Factors, Anthropometry, Body Height, Body Size, Child, Child Nutrition Disorders complications, Child Nutrition Disorders mortality, Female, Growth Disorders etiology, Hospitalization, Humans, Infant, Infant, Newborn, Kenya epidemiology, Male, Malnutrition complications, Malnutrition mortality, Patient Discharge, ROC Curve, Reference Values, Severity of Illness Index, Arm, Body Weight, Child Nutrition Disorders diagnosis, Malnutrition diagnosis, Nutritional Status
- Abstract
Background: There is an increasing recognition of malnutrition among infants under 6 mo of age (U6M). Current diagnosis criteria use weight-for-length z scores (WLZs), but the 2006 WHO standards exclude infants shorter than 45 cm. In older children, midupper arm circumference (MUAC) predicts mortality better than does WLZ. Outcomes may also be influenced by exposure to HIV and size or gestational age at birth. Diagnostic thresholds for WLZ, MUAC, and other indexes have not been fully evaluated against mortality risk among U6M infants. Objective: The aim was to determine the association of anthropometric indexes with risks of inpatient and postdischarge mortality among U6M infants recruited at the time of hospitalization. Design: We analyzed data from a cohort of U6M infants admitted to Kilifi County Hospital (2007-2013), Kenya. The primary outcomes were inpatient death and death during follow-up over 1 y after discharge. We calculated adjusted RRs for inpatient mortality and HRs for postdischarge mortality for different anthropometric measures and thresholds. Discriminatory value was assessed by using receiver operating characteristic curves. Results: A total of 2882 infants were admitted: 140 (4.9%) died in the hospital and 1405 infants were followed up after discharge. Of these, 75 (5.3%) died within 1 y during 1318 child-years of observation. MUAC and weight-for-age z score (WAZ) predicted inpatient and postdischarge mortality better than did WLZ ( P < 0.0001). A single MUAC threshold of <11.0 cm performed similarly to MUAC thresholds that varied with age (all P > 0.05) and performed better than WLZ <-3 for both inpatient and postdischarge mortality (both P < 0.001). Reported small size at birth did not reduce the risk of death associated with anthropometric indexes. Conclusions: U6M infants at the highest risk of death are best targeted by using MUAC or WAZ. Further research into the effectiveness of potential interventions is required.
- Published
- 2017
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.