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Howie SRC, Schellenberg J, Chimah O, Ideh RC, Ebruke BE, Oluwalana C, Mackenzie G, Jallow M, Njie M, Donkor S, Dionisio KL, Goldberg G, Fornace K, Bottomley C, Hill PC, Grant CC, Corrah T, Prentice AM, Ezzati M, Greenwood BM, Smith PG, Adegbola RA, Mulholland K. Childhood pneumonia and crowding, bed-sharing and nutrition: a case-control study from The Gambia. Int J Tuberc Lung Dis 2016; 20:1405-1415. [PMID: 27725055 PMCID: PMC5019143 DOI: 10.5588/ijtld.15.0993] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 05/19/2016] [Indexed: 12/03/2022] Open
Abstract
SETTING Greater Banjul and Upper River Regions, The Gambia. OBJECTIVE To investigate tractable social, environmental and nutritional risk factors for childhood pneumonia. DESIGN A case-control study examining the association of crowding, household air pollution (HAP) and nutritional factors with pneumonia was undertaken in children aged 2-59 months: 458 children with severe pneumonia, defined according to the modified WHO criteria, were compared with 322 children with non-severe pneumonia, and these groups were compared to 801 neighbourhood controls. Controls were matched by age, sex, area and season. RESULTS Strong evidence was found of an association between bed-sharing with someone with a cough and severe pneumonia (adjusted OR [aOR] 5.1, 95%CI 3.2-8.2, P < 0.001) and non-severe pneumonia (aOR 7.3, 95%CI 4.1-13.1, P < 0.001), with 18% of severe cases estimated to be attributable to this risk factor. Malnutrition and pneumonia had clear evidence of association, which was strongest between severe malnutrition and severe pneumonia (aOR 8.7, 95%CI 4.2-17.8, P < 0.001). No association was found between pneumonia and individual carbon monoxide exposure as a measure of HAP. CONCLUSION Bed-sharing with someone with a cough is an important risk factor for severe pneumonia, and potentially tractable to intervention, while malnutrition remains an important tractable determinant.
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Affiliation(s)
- S R C Howie
- Medical Research Council Unit, Fajara, The Gambia; Department of Paediatrics: Child & Youth Health, University of Auckland, Auckland, Centre for International Health, University of Otago, Dunedin, New Zealand
| | - J Schellenberg
- London School of Hygiene & Tropical Medicine, London, UK
| | - O Chimah
- Medical Research Council Unit, Fajara, The Gambia
| | - R C Ideh
- Medical Research Council Unit, Fajara, The Gambia; Child Health Department, University of Benin, Teaching Hospital, Benin City, Nigeria
| | - B E Ebruke
- Medical Research Council Unit, Fajara, The Gambia
| | - C Oluwalana
- Medical Research Council Unit, Fajara, The Gambia
| | - G Mackenzie
- Medical Research Council Unit, Fajara, The Gambia
| | - M Jallow
- Ministry of Health and Social Welfare, Banjul, The Gambia
| | - M Njie
- Ministry of Health and Social Welfare, Banjul, The Gambia
| | - S Donkor
- Medical Research Council Unit, Fajara, The Gambia
| | - K L Dionisio
- Harvard School of Public Health, Department of Global Health and Population, Boston, and Harvard School of Public Health, Department of Environmental Health, Boston, Massachusetts, USA; National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - G Goldberg
- MRC-Public Health England Centre for Environment and Health, Imperial College London, London, UK
| | - K Fornace
- Medical Research Council Unit, Fajara, The Gambia, London School of Hygiene & Tropical Medicine, London, UK
| | - C Bottomley
- London School of Hygiene & Tropical Medicine, London, UK
| | - P C Hill
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - C C Grant
- Department of Paediatrics: Child & Youth Health, University of Auckland, Auckland, New Zealand
| | - T Corrah
- Medical Research Council Unit, Fajara, The Gambia
| | - A M Prentice
- Medical Research Council Unit, Fajara, The Gambia, London School of Hygiene & Tropical Medicine, London, UK
| | - M Ezzati
- Medical Research Council (MRC) Human Nutrition Research, Cambridge, UK
| | - B M Greenwood
- London School of Hygiene & Tropical Medicine, London, UK
| | - P G Smith
- London School of Hygiene & Tropical Medicine, London, UK
| | - R A Adegbola
- Medical Research Council Unit, Fajara, The Gambia, GlaxoSmithKline Vaccines, Wavre, Belgium
| | - K Mulholland
- London School of Hygiene & Tropical Medicine, London, UK, Harvard School of Public Health, Department of Global Health and Population, Boston, and Harvard School of Public Health, Department of Environmental Health, Boston, Massachusetts, USA
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2
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Howie SRC, Morris GAJ, Tokarz R, Ebruke BE, Machuka EM, Ideh RC, Chimah O, Secka O, Townend J, Dione M, Oluwalana C, Njie M, Jallow M, Hill PC, Antonio M, Greenwood B, Briese T, Mulholland K, Corrah T, Lipkin WI, Adegbola RA. Etiology of severe childhood pneumonia in the Gambia, West Africa, determined by conventional and molecular microbiological analyses of lung and pleural aspirate samples. Clin Infect Dis 2014; 59:682-5. [PMID: 24867789 PMCID: PMC4130311 DOI: 10.1093/cid/ciu384] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Molecular analyses of lung aspirates from Gambian children with severe pneumonia detected pathogens more frequently than did culture and showed a predominance of bacteria, principally Streptococcuspneumoniae, >75% being of serotypes covered by current pneumococcal conjugate vaccines. Multiple pathogens were detected frequently, notably Haemophilus influenzae (mostly nontypeable) together with S. pneumoniae.
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Affiliation(s)
| | | | - Rafal Tokarz
- Center for Infection and Immunity, Columbia University, New York, New York
| | | | | | - Readon C Ideh
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | - Osaretin Chimah
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | - Ousman Secka
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | - John Townend
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | - Michel Dione
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | | | - Malick Njie
- Ministry of Health and Social Welfare, Banjul, Republic of The Gambia
| | - Mariatou Jallow
- Ministry of Health and Social Welfare, Banjul, Republic of The Gambia
| | - Philip C Hill
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Martin Antonio
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | - Brian Greenwood
- London School of Hygiene and Tropical Medicine, United Kingdom
| | - Thomas Briese
- Center for Infection and Immunity, Columbia University, New York, New York
| | - Kim Mulholland
- London School of Hygiene and Tropical Medicine, United Kingdom
| | - Tumani Corrah
- Medical Research Council Unit, Fajara, Republic of The Gambia
| | - W Ian Lipkin
- Center for Infection and Immunity, Columbia University, New York, New York
| | - Richard A Adegbola
- Medical Research Council Unit, Fajara, Republic of The Gambia GlaxoSmithKline Vaccines, Wavre, Belgium
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3
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James A, Darboe S, Ceesay B, Jallow M. A new perspective to invasive bacterial infections in The Gambia: Surveillance of etiological agents responsible for admission of patients in the clinic. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.1000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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4
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Jallow M, Casals-Pascual C, Ackerman H, Walther B, Walther M, Pinder M, Sisay-Joof F, Usen S, Jallow M, Abubakar I, Olaosebikan R, Jobarteh A, Conway DJ, Bojang K, Kwiatkowski D. Clinical features of severe malaria associated with death: a 13-year observational study in the Gambia. PLoS One 2012; 7:e45645. [PMID: 23029157 PMCID: PMC3460946 DOI: 10.1371/journal.pone.0045645] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/21/2012] [Indexed: 11/18/2022] Open
Abstract
Background Severe malaria (SM) is a major cause of death in sub-Saharan Africa. Identification of both specific and sensitive clinical features to predict death is needed to improve clinical management. Methods A 13-year observational study was conducted from 1997 through 2009 of 2,901 children with SM enrolled at the Royal Victoria Teaching Hospital in The Gambia to identify sensitive and specific predictors of poor outcome in Gambian children with severe malaria between the ages 4 months to 14 years. We have measured the sensitivity and specificity of clinical features that predict death or development of neurological sequelae. Findings Impaired consciousness (odds ratio {OR} 4.4 [95% confidence interval {CI}, 2.7–7.3]), respiratory distress (OR 2.4 [95%CI, 1.7–3.2]), hypoglycemia (OR 1.7 [95%CI, 1.2–2.3]), jaundice (OR 1.9 [95%CI, 1.2–2.9]) and renal failure (OR 11.1 [95%CI, 3.3–36.5]) were independently associated with death in children with SM. The clinical features that showed the highest sensitivity and specificity to predict death were respiratory distress (area under the curve 0.63 [95%CI, 0.60–0.65]) and impaired consciousness (AUC 0.61[95%CI, 0.59–0.63]), which were comparable to the ability of hyperlactatemia (blood lactate>5 mM) to predict death (AUC 0.64 [95%CI, 0.55–0.72]). A Blantyre coma score (BCS) of 2 or less had a sensitivity of 74% and specificity of 67% to predict death (AUC 0.70 [95% C.I. 0.68–0.72]), and sensitivity and specificity of 74% and 69%, respectively to predict development of neurological sequelae (AUC 0.72 [95% CI, 0.67–0.76]).The specificity of this BCS threshold to identify children at risk of dying improved in children less than 3 years of age (AUC 0.74, [95% C.I 0.71–0.76]). Conclusion The BCS is a quantitative predictor of death. A BCS of 2 or less is the most sensitive and specific clinical feature to predict death or development of neurological sequelae in children with SM.
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Affiliation(s)
- Muminatou Jallow
- Malaria Programme, MRC Laboratories, Banjul, The Gambia
- Royal Victoria Teaching Hospital, Banjul, The Gambia
| | | | - Hans Ackerman
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | | | - Michael Walther
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, Maryland, United States of America
| | | | | | - Stanley Usen
- Malaria Programme, MRC Laboratories, Banjul, The Gambia
| | | | | | | | | | - David J. Conway
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kalifa Bojang
- Malaria Programme, MRC Laboratories, Banjul, The Gambia
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5
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Yindom LM, Forbes R, Aka P, Janha O, Jeffries D, Jallow M, Conway DJ, Walther M. Killer-cell immunoglobulin-like receptors and malaria caused by Plasmodium falciparum in The Gambia. ACTA ACUST UNITED AC 2012; 79:104-13. [PMID: 22220719 PMCID: PMC3320664 DOI: 10.1111/j.1399-0039.2011.01818.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The relevance of innate immune responses to Plasmodium falciparum infection, in particular the central role of natural killer (NK) cell-derived interferon gamma (IFN-γ), is becoming increasingly recognised. Recently, it has been shown that IFN-γ production in response to P. falciparum antigens is in part regulated by killer-cell immunoglobulin-like receptor (KIR) genes, and a study from malaria-exposed Melanesians suggested an association between KIR genotypes and susceptibility to infection. This prompted us to determine and compare the frequencies of 15 KIR genes in Gambian children presenting with either severe malaria (n = 133) or uncomplicated malaria (n = 188) and in cord-blood population control samples (n = 314) collected from the same area. While no significant differences were observed between severe and uncomplicated cases, proportions of individuals with KIR2DS2+C1 and KIR2DL2+C1 were significantly higher among malaria cases overall than in population control samples. In an exploratory analysis, activating KIR genes KIR2DS2, KIR3DS1 and KIR2DS5 were slightly higher in children in disease subgroups associated with the highest mortality. In addition, our data suggest that homozygosity for KIR genotype A might be associated with different malaria outcomes including protection from infection and higher blood parasitaemia levels in those that do get infected. These findings are consistent with a probable role of KIR genes in determining susceptibility to malaria, and further studies are warranted in different populations.
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Affiliation(s)
- L-M Yindom
- Medical Research Council Laboratories, Fajara, Banjul, The Gambia.
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6
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Howie SRC, Hill S, Ebonyi A, Krishnan G, Njie O, Sanneh M, Jallow M, Stevens W, Taylor K, Weber MW, Njai PC, Tapgun M, Corrah T, Mulholland K, Peel D, Njie M, Hill PC, Adegbola RA. Meeting oxygen needs in Africa: an options analysis from the Gambia. Bull World Health Organ 2011; 87:763-71. [PMID: 19876543 DOI: 10.2471/blt.08.058370] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Accepted: 04/06/2009] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To compare oxygen supply options for health facilities in the Gambia and develop a decision-making algorithm for choosing oxygen delivery systems in Africa and the rest of the developing world. METHODS Oxygen cylinders and concentrators were compared in terms of functionality and cost. Interviews with key informants using locally developed and adapted WHO instruments, operational assessments, cost-modelling and cost measurements were undertaken to determine whether oxygen cylinders or concentrators were the better choice. An algorithm and a software tool to guide the choice of oxygen delivery system were constructed. FINDINGS In the Gambia, oxygen concentrators have significant advantages compared to cylinders where power is reliable; in other settings, cylinders are preferable as long as transporting them is feasible. Cylinder costs are greatly influenced by leakage, which is common, whereas concentrator costs are affected by the cost of power far more than by capital costs. Only two of 12 facilities in the Gambia were found suitable for concentrators; at the remaining 10 facilities, cylinders were the better option. CONCLUSION Neither concentrators nor cylinders are well suited to every situation, but a simple options assessment can determine which is better in each setting. Nationally this would result in improved supply and lower costs by comparison with conventional cylinders alone, although ensuring a reliable supply would remain a challenge. The decision algorithm and software tool designed for the Gambia could be applied in other developing countries.
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Affiliation(s)
- Stephen R C Howie
- Bacterial Diseases Programme, Medical Research Council Laboratories, Banjul, Gambia.
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7
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Hill SE, Njie O, Sanneh M, Jallow M, Peel D, Njie M, Weber M, Hill PC, Adegbola RA, Howie SRC. Oxygen for treatment of severe pneumonia in The Gambia, West Africa: a situational analysis. Int J Tuberc Lung Dis 2009; 13:587-593. [PMID: 19383191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
SETTING Health facilities in The Gambia, West Africa. OBJECTIVES Oxygen treatment is vital in pneumonia, the leading cause of death in children globally. There are shortages of oxygen in developing countries, but little information is available on the extent of the problem. We assessed national oxygen availability and use in The Gambia, a sub-Saharan African country. METHODS A government-led team visited 12 health facilities in The Gambia. A modified World Health Organization assessment tool was used to determine oxygen requirements, current provision and capacity to support effective oxygen use. RESULTS Eleven of the 12 facilities managed severe pneumonia. Oxygen was reliable in three facilities. Requirement and supply were often mismatched. Both oxygen concentrators and oxygen cylinders were used. Suboptimal electricity and maintenance made using concentrators difficult, while logistical problems and cost hampered cylinder use. Children were usually triaged by trained nurses who reported lack of training in oxygen use. Oxygen was given typically by nasal prongs; pulse oximetry was available in two facilities. CONCLUSIONS National data showed that oxygen availability did not meet needs in most Gambian health facilities. Remedial options must be carefully assessed for real costs, reliability and site-by-site usability. Training is needed to support oxygen use and equipment maintenance.
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Affiliation(s)
- S E Hill
- Department of Public Health, University of Otago, Wellington, New Zealand
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8
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Fry AE, Auburn S, Diakite M, Green A, Richardson A, Wilson J, Jallow M, Sisay-Joof F, Pinder M, Griffiths MJ, Peshu N, Williams TN, Marsh K, Molyneux ME, Taylor TE, Rockett KA, Kwiatkowski DP. Variation in the ICAM1 gene is not associated with severe malaria phenotypes. Genes Immun 2008; 9:462-9. [PMID: 18528404 DOI: 10.1038/gene.2008.38] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Evidence from autopsy and in vitro binding studies suggests that adhesion of erythrocytes infected with Plasmodium falciparum to the human host intercellular adhesion molecule (ICAM)-1 receptor is important in the pathogenesis of severe malaria. Previous association studies between polymorphisms in the ICAM1 gene and susceptibility to severe malarial phenotypes have been inconclusive and often contradictory. We performed genetic association studies with 15 single nucleotide polymorphisms (SNPs) around the ICAM1 locus. All SNPs were screened in a family study of 1071 trios from The Gambia, Malawi and Kenya. Two key non-synonymous SNPs with previously reported associations, rs5491 (K56M or 'ICAM-1(Kilifi)') and rs5498 (K469E), were tested in an additional 708 Gambian trios and a case-control study of 4058 individuals. None of the polymorphisms were associated with severe malaria phenotypes. Pooled results across our studies for ICAM-1(Kilifi) were, in severe malaria, odds ratio (OR) 1.02, 95% confidence interval (CI) 0.96-1.09, P=0.54, and cerebral malaria OR 1.07, CI 0.97-1.17, P=0.17. We assess the available epidemiological, population genetic and functional evidence that links ICAM-1(Kilifi) to severe malaria susceptibility.
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Affiliation(s)
- A E Fry
- The Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, UK.
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9
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Wilson JN, Rockett K, Keating B, Jallow M, Pinder M, Sisay-Joof F, Newport M, Kwiatkowski D. A hallmark of balancing selection is present at the promoter region of interleukin 10. Genes Immun 2006; 7:680-3. [PMID: 16943796 DOI: 10.1038/sj.gene.6364336] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
As an anti-inflammatory mediator IL10 is beneficial in certain contexts and deleterious in others. As increased production of IL10 favours protection against inflammatory disease, whereas low production promotes elimination of foreign pathogens by the host, we investigated the possible influence of balancing selection at this locus. We began by resequencing 48 European and 48 African chromosomes across 2.2 kb of the IL10 promoter region, and compared this with four neighbouring gene regions: MK2, IL19, IL20 and IL24. Analysis of nucleotide diversity showed a positive Tajima's D-test for IL10 in Europeans, of borderline statistical significance (1.89, P=0.05). Analysis of F(st) values showed significant population divergence at MK2, IL19, IL20 and IL24 (P<0.01) but not at IL10. Taken together, these findings are consistent with the hypothesis that balancing selection has played a role in the evolution of polymorphisms in the IL10 promoter region.
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Affiliation(s)
- J N Wilson
- Wellcome Trust Centre for Human Genetics, Oxford, UK.
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10
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Luoni G, Forton J, Jallow M, Sadighi Akha E, Sisay-Joof F, Pinder M, Hanchard N, Herbert M, Kimber M, Mott R, Hull J, Rockett K, Kwiatkowski D. Population-specific patterns of linkage disequilibrium in the human 5q31 region. Genes Immun 2006; 6:723-7. [PMID: 16052173 DOI: 10.1038/sj.gene.6364250] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Linkage disequilibrium across the human genome is generally lower in West Africans than Europeans. However in the 5q31 region, which is rich in immune genes, we find significantly more examples of apparent nonrecombination between distant marker pairs in West Africans. Much of this effect is due to SNPs that are absent in Europeans, possibly reflecting recent positive selection in the West African population.
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Affiliation(s)
- G Luoni
- University Department of Paediatrics, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, Oxon OX3 7BN, UK
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11
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Ackerman H, Usen S, Jallow M, Sisay-Joof F, Pinder M, Kwiatkowski DP. A comparison of case-control and family-based association methods: the example of sickle-cell and malaria. Ann Hum Genet 2005; 69:559-65. [PMID: 16138914 DOI: 10.1111/j.1529-8817.2005.00180.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There has been much debate about the relative merits of population- and family-based strategies for testing genetic association, yet there is little empirical data that directly compare the two approaches. Here we compare case-control and transmission/disequilibrium test (TDT) study designs using a well-established genetic association, the protective effect of the sickle-cell trait against severe malaria. We find that the two methods give similar estimates of the level of protection (case-control odds ratio = 0.10, 95% confidence interval 0.03-0.23; family-based estimate of the odds ratio = 0.11, 95% confidence interval 0.04-0.25) and similar statistical significance of the result (case-control: chi2= 41.26, p= 10(-10), TDT: chi2= 39.06, p= 10(-10)) when 315 TDT cases are compared to 583 controls. We propose a family plus population control study design, which allows both case-control and TDT analysis of the cases. This combination is robust against the respective weaknesses of the case-control and TDT study designs, namely population structure and segregation distortion. The combined study design is especially cost-effective when cases are difficult to ascertain and, when the case-control and TDT results agree, offers greater confidence in the result.
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Affiliation(s)
- H Ackerman
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, OX3 7BN, UK
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12
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Wilson JN, Rockett K, Jallow M, Pinder M, Sisay-Joof F, Newport M, Newton J, Kwiatkowski D. Analysis of IL10 haplotypic associations with severe malaria. Genes Immun 2005; 6:462-6. [PMID: 15933743 DOI: 10.1038/sj.gene.6364227] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We investigated the association between severe malaria and genetic variation of IL10 in Gambian children, as several lines of evidence indicate that IL10 is protective against severe malaria and that IL10 production is genetically determined. We began by identifying five informative SNPs in the Gambian population that were genotyped in a combined case-control and intrafamilial study including 654 cases of severe malaria, 579 sets of parents and 459 ethnically matched controls. No significant associations were identified with individual SNPs. One haplotype of frequency 0.11 was strongly associated with protection against severe malaria in the case-control analysis (odds ratio 0.52, P=0.00002), but the transmission disequilibrium test in families showed no significant effect. These findings raise the question of whether IL10 associations with severe malaria might be confounded by foetal survival rates or other sources of transmission bias.
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Affiliation(s)
- J N Wilson
- Wellcome Trust Centre for Human Genetics, Oxford, UK.
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13
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Koch O, Rockett K, Jallow M, Pinder M, Sisay-Joof F, Kwiatkowski D. Investigation of malaria susceptibility determinants in the IFNG/IL26/IL22 genomic region. Genes Immun 2005; 6:312-8. [PMID: 15858598 DOI: 10.1038/sj.gene.6364214] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interferon-gamma, encoded by IFNG, is a key immunological mediator that is believed to play both a protective and a pathological role in malaria. Here, we investigate the relationship between IFNG variation and susceptibility to malaria. We began by analysing West African and European haplotype structure and patterns of linkage disequilibrium across a 100 kb genomic region encompassing IFNG and its immediate neighbours IL22 and IL26. A large case-control study of severe malaria in a West Africa population identified several weak associations with individual single-nucleotide polymorphisms in the IFNG and IL22 genes, and defined two IL22 haplotypes that are, respectively, associated with resistance and susceptibility. These data provide a starting point for functional and genetic analysis of the IFNG genomic region in malaria and other infectious and inflammatory conditions affecting African populations.
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Affiliation(s)
- O Koch
- Wellcome Trust Centre for Human Genetics, Oxford, UK
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14
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Ackerman HC, Ribas G, Jallow M, Mott R, Neville M, Sisay-Joof F, Pinder M, Campbell RD, Kwiatkowski DP. Complex haplotypic structure of the central MHC region flanking TNF in a West African population. Genes Immun 2004; 4:476-86. [PMID: 14551600 DOI: 10.1038/sj.gene.6364008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
TNF polymorphisms have been associated with susceptibility to malaria and other infectious and inflammatory conditions. We investigated a sample of 150 West African chromosomes to determine linkage disequilibrium (LD) between 25 SNP markers located in an 80 kb segment of the MHC Class III region encompassing TNF and eight neighbouring genes. We observed 45 haplotypes, and 22 of them comprise 80% of the sample. The pattern of LD is remarkably patchy, such that many markers show no LD with adjacent markers but high LD with markers that are much further away. We introduce a method of examining the implications of LD data for disease association studies based on sample size considerations: this shows that certain TNF polymorphisms would be likely to yield positive associations if the true disease allele resided in LTA or BAT1. We conclude that detailed marker maps are needed to resolve the causal origin of disease associations observed at the TNF locus.
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Affiliation(s)
- H C Ackerman
- Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, UK.
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Sabeti P, Usen S, Farhadian S, Jallow M, Doherty T, Newport M, Pinder M, Ward R, Kwiatkowski D. CD40L association with protection from severe malaria. Genes Immun 2002; 3:286-91. [PMID: 12140747 DOI: 10.1038/sj.gene.6363877] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2001] [Revised: 02/19/2002] [Accepted: 02/19/2002] [Indexed: 11/09/2022]
Abstract
CD40 ligand (CD40L), a glycoprotein involved in B cell proliferation, antigen presenting cell activation, and Ig class switching, is important in the immune response to infection. Rare coding mutations in CD40L can lead to life-threatening immunodeficiency but the potential for common variants to alter disease susceptibility remains to be explored. To identify polymorphisms in CD40L, we sequenced 2.3 kb of the 5' flanking region and the first exon of the gene in DNA samples from 36 Gambian females and one chimpanzee. Diversity was lower than the average reported for other areas of the X chromosome, and only two polymorphisms were identified. The polymorphisms were genotyped in DNA samples from 957 Gambian individuals, cases and controls from a study of severe malaria. A significant reduction in risk for severe malaria (OR = 0.52, P = 0.002) was associated with males hemizygous for the CD40L-726C. Analysis by transmission disequilibrium test of 371 cases, for whom DNA from both parents was also available, confirmed the result was not due to stratification (P = 0.04). A similar but non-significant trend was found in females. This preliminary association of a common variant in CD40L with a malaria resistance phenotype encourages further genetic characterization of the role of CD40L in infectious disease.
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Affiliation(s)
- P Sabeti
- Wellcome Trust Centre for Human Genetics, Oxford, UK
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Weber MW, Milligan P, Sanneh M, Awemoyi A, Dakour R, Schneider G, Palmer A, Jallow M, Oparaogu A, Whittle H, Mulholland EK, Greenwood BM. An epidemiological study of RSV infection in the Gambia. Bull World Health Organ 2002; 80:562-8. [PMID: 12163920 PMCID: PMC2567560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Abstract
OBJECTIVE To describe the epidemiology of respiratory syncytial virus (RSV) infection in a developing country. METHODS The work was carried out in three hospitals for primary cases and in the community for secondary cases in the western region of the Gambia, West Africa. RSV infection was diagnosed by immunofluorescence of nasopharyngeal aspirate samples in children younger than two years admitted to hospital with acute lower respiratory infection (ALRI). Routine records of all children with ALRI were analysed, and the incidence rates of ALRI, severe RSV-associated respiratory illness and hypoxaemic RSV infections were compared. A community-based study was undertaken to identify secondary cases and to obtain information about spread of the virus. FINDINGS 4799 children with ALRI who were younger than two years and lived in the study area were admitted to the study hospitals: 421 had severe RSV-associated respiratory illness; 55 of these were hypoxaemic. Between 1994 and 1996, the observed incidence rate for ALRI in 100 children younger than one year living close to hospital was 9.6 cases per year; for severe RSV-associated respiratory illness 0.83; and for hypoxaemic RSV-associated respiratory illness 0.089. The proportion of all ALRI admissions due to RSV was 19%. Overall, 41% of children younger than five years in compounds in which cases lived and 42% in control compounds had evidence of RSV infection during the surveillance period. CONCLUSION RSV is an important cause of ALRI leading to hospital admission in the Gambia. Morbidity is considerable and efforts at prevention are worthwhile.
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Affiliation(s)
- Martin W Weber
- Medical Research Council Laboratories, Fajara, The Gambia.
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Deming MS, Jaiteh KO, Otten MW, Flagg EW, Jallow M, Cham M, Brogan D, N'jie H. Epidemic poliomyelitis in The Gambia following the control of poliomyelitis as an endemic disease. II. Clinical efficacy of trivalent oral polio vaccine. Am J Epidemiol 1992; 135:393-408. [PMID: 1550091 DOI: 10.1093/oxfordjournals.aje.a116300] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An epidemic of poliomyelitis caused by poliovirus type 1 occurred in The Gambia from May to November 1986. Descriptive findings and vaccination coverage levels are reported in part I. This article (part II) describes a case-control study to estimate the clinical efficacy of three or more doses of trivalent oral polio vaccine compared with zero doses. "Cases" were 1- to 7-year-old children paralyzed during the epidemic who were diagnosed as having poliomyelitis by designated referral physicians. They were identified by reports from referral physicians during the epidemic and by a nationwide village-to-village search after the epidemic. Up to five controls were randomly selected for each case from among children of the same age and sex living in neighboring households. In a matched analysis of 195 cases and 839 controls, the efficacy of three or more doses of trivalent oral polio vaccine was 72% (95% confidence interval 57-82) when children without vaccination cards were considered unvaccinated. The efficacy of three or more doses in 1- to 2-year-old children, in whom the determination of vaccination status was considered to be more accurate than in older children, was 81% (95% confidence interval 66-90). Vaccine failure was not associated with short intervals between doses. Higher levels of vaccination coverage and efficacy than those achieved in The Gambia may be needed in African countries to prevent the return of poliomyelitis as an epidemic disease after it has been controlled as an endemic disease.
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Affiliation(s)
- M S Deming
- International Health Program Office, Centers for Disease Control, Atlanta, GA 30333
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