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Cave R, Kalizang'oma A, Chaguza C, Mwalukomo TS, Kamng'ona A, Brown C, Msefula J, Bonomali F, Nyirenda R, Swarthout TD, Kwambana-Adams B, French N, Heyderman RS. Expansion of pneumococcal serotype 23F and 14 lineages with genotypic changes in capsule polysaccharide locus and virulence gene profiles post introduction of pneumococcal conjugate vaccine in Blantyre, Malawi. Microb Genom 2024; 10. [PMID: 38896467 DOI: 10.1099/mgen.0.001264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
Since the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) in Malawi in 2011, there has been persistent carriage of vaccine serotype (VT) Streptococcus pneumoniae, despite high vaccine coverage. To determine if there has been a genetic change within the VT capsule polysaccharide (cps) loci since the vaccine's introduction, we compared 1022 whole-genome-sequenced VT isolates from 1998 to 2019. We identified the clonal expansion of a multidrug-resistant, penicillin non-susceptible serotype 23F GPSC14-ST2059 lineage, a serotype 14 GPSC9-ST782 lineage and a novel serotype 14 sequence type GPSC9-ST18728 lineage. Serotype 23F GPSC14-ST2059 had an I253T mutation within the capsule oligosaccharide repeat unit polymerase Wzy protein, which is predicted in silico to alter the protein pocket cavity. Moreover, serotype 23F GPSC14-ST2059 had SNPs in the DNA binding sites for the cps transcriptional repressors CspR and SpxR. Serotype 14 GPSC9-ST782 harbours a non-truncated version of the large repetitive protein (Lrp), containing a Cna protein B-type domain which is also present in proteins associated with infection and colonisation. These emergent lineages also harboured genes associated with antibiotic resistance, and the promotion of colonisation and infection which were absent in other lineages of the same serotype. Together these data suggest that in addition to serotype replacement, modifications of the capsule locus associated with changes in virulence factor expression and antibiotic resistance may promote vaccine escape. In summary, the study highlights that the persistence of vaccine serotype carriage despite high vaccine coverage in Malawi may be partly caused by expansion of VT lineages post-PCV13 rollout.
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Affiliation(s)
- Rory Cave
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, UK
| | - Akuzike Kalizang'oma
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, UK
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
| | - Chrispin Chaguza
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, CT, USA
| | | | | | - Comfort Brown
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
| | | | | | | | - Todd D Swarthout
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, UK
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
- Julius Center for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Brenda Kwambana-Adams
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, UK
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
| | - Neil French
- Clinical Infection, Microbiology and Immunology, Institute of Infection Veterinary & Ecological Science, University of Liverpool, Liverpool, UK
| | - Robert S Heyderman
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, UK
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
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Kirolos A, Swarthout TD, Mataya AA, Bonomali F, Brown C, Msefula J, Bar-Zeev N, Iroh Tam PY, Alaerts M, Bilima S, Heyderman RS, French N. Invasiveness potential of pneumococcal serotypes in children after introduction of PCV13 in Blantyre, Malawi. BMC Infect Dis 2023; 23:56. [PMID: 36703117 PMCID: PMC9881369 DOI: 10.1186/s12879-023-08022-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 01/20/2023] [Indexed: 01/28/2023] Open
Abstract
INTRODUCTION The introduction of PCV13 to the Malawi infant immunization schedule in 2011 has been associated with reduced disease from Streptococcus pneumoniae. Improved understanding of serotypes with high invasive potential can guide future vaccination interventions. We aimed to estimate pneumococcal serotypes associated with acute respiratory infection (ARI) and invasive pneumococcal disease (IPD) in hospitalized children in Blantyre, Malawi. METHODS We analysed data from healthy children under 5 years in the community in Blantyre and children admitted to Queen Elizabeth Central Hospital with ARI between 2015 and 2018. Nasopharyngeal swabs from children were tested for S. pneumoniae and serotyped by latex agglutination if positive. We analysed culture-positive blood and cerebrospinal fluid samples from admitted children between 2012 and 2018 to identify cases of IPD after the introduction of PCV13. We calculated the age-adjusted odds ratio (OR) of carriage for S. pneumoniae vaccine serotypes (VT) comparing those with ARI to healthy children. We also calculated age-adjusted ORs comparing serotypes causing IPD to carriage in the community with OR > 1 indicating high invasive potential. RESULTS Serotypes 5 (OR 24.73 [95% CI 7.90-78.56] p < 0.001), 1 (OR 23.38 [95% CI 9.75-56.06] p < 0.001), and 6B (OR 4.73 [95% CI 1.66-11.64] p = 0.001) had high invasive potential. Serotype 6B was no longer significant (OR 1.34 [95% CI 0.07-6.87] p = 0.777) in a sensitivity analysis accounting for year of recruitment. The prevalence of S. pneumoniae carriage in the community was 72.6% [95% CI 71.3-74.0] (3078/4238) and 23.4% (719/3078) of positive community samples were VT. The carriage prevalence in those hospitalised with ARI was 45.5% [95% CI 42.1-48.9] (389/855) and 43.8% of hospital attendees reported antibiotic use prior to admission. We did not identify significant associations with carriage of any serotypes in those with ARI. CONCLUSIONS Pneumococcal serotypes 5 and 1 are associated with high invasive potential. Despite high community pneumococcal carriage, pre-hospital antibiotic usage likely reduces pneumococcal detection among children admitted in this setting and further research is needed to investigate serotypes associated with ARI. Data from this study can guide future preventative vaccination strategies in Malawi.
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Affiliation(s)
- Amir Kirolos
- grid.10025.360000 0004 1936 8470Department of Women’s and Children’s Health, Faculty of Health and Life Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK ,Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Todd D. Swarthout
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi ,grid.83440.3b0000000121901201NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, Research Department of Infection, University College London, London, UK
| | | | | | - Comfort Brown
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi
| | - Jacquline Msefula
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi ,grid.7177.60000000084992262Faculty of Medicine, University of Amsterdam, Amsterdam, Netherlands
| | - Naor Bar-Zeev
- grid.21107.350000 0001 2171 9311International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD USA
| | - Pui-Ying Iroh Tam
- Malawi-Liverpool-Wellcome Research Programme, Blantyre, Malawi ,grid.48004.380000 0004 1936 9764Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Maaike Alaerts
- grid.5284.b0000 0001 0790 3681Cardiogenetics Research Group, Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | | | - Robert S. Heyderman
- grid.83440.3b0000000121901201NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, Research Department of Infection, University College London, London, UK
| | - Neil French
- grid.10025.360000 0004 1936 8470Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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van de Beek D, Brouwer MC, Koedel U, Wall EC. Community-acquired bacterial meningitis. Lancet 2021; 398:1171-1183. [PMID: 34303412 DOI: 10.1016/s0140-6736(21)00883-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/25/2021] [Accepted: 04/07/2021] [Indexed: 12/19/2022]
Abstract
Progress has been made in the prevention and treatment of community-acquired bacterial meningitis during the past three decades but the burden of the disease remains high globally. Conjugate vaccines against the three most common causative pathogens (Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae) have reduced the incidence of disease, but with the replacement by non-vaccine pneumococcal serotypes and the emergence of bacterial strains with reduced susceptibility to antimicrobial treatment, meningitis continues to pose a major health challenge worldwide. In patients presenting with bacterial meningitis, typical clinical characteristics (such as the classic triad of neck stiffness, fever, and an altered mental status) might be absent and cerebrospinal fluid examination for biochemistry, microscopy, culture, and PCR to identify bacterial DNA are essential for the diagnosis. Multiplex PCR point-of-care panels in cerebrospinal fluid show promise in accelerating the diagnosis, but diagnostic accuracy studies to justify routine implementation are scarce and randomised, controlled studies are absent. Early administration of antimicrobial treatment (within 1 hour of presentation) improves outcomes and needs to be adjusted according to local emergence of drug resistance. Adjunctive dexamethasone treatment has proven efficacy beyond the neonatal age but only in patients from high-income countries. Further progress can be expected from implementing preventive measures, especially the development of new vaccines, implementation of hospital protocols aimed at early treatment, and new treatments targeting checkpoints of the inflammatory cascade.
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Affiliation(s)
- Diederik van de Beek
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Meibergdreef, Amsterdam, Netherlands.
| | - Matthijs C Brouwer
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Meibergdreef, Amsterdam, Netherlands
| | - Uwe Koedel
- Department of Neurology, Ludwig-Maximilians-University, Munich, Germany
| | - Emma C Wall
- Research Department of Infection, University College London, London, UK; Francis Crick Institute, London, UK
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Yamba K, Mpabalwani E, Nakazwe R, Mulendele E, Weldegebriel G, Mwenda JM, Katsande R, de Gouveia L, Chizema-Kawesha E, Chanda R, Matapo B, Mwansa JCL, Lukwesa-Musyani C. The Burden of Invasive Bacterial Disease and the Impact of 10-Valent Pneumococcal Conjugate Vaccine in Children <5 years hospitalized for Meningitis in Lusaka, Zambia, 2010-2019. J Infect Dis 2021; 224:S275-S284. [PMID: 34469553 PMCID: PMC8409534 DOI: 10.1093/infdis/jiab193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Despite the availability of vaccines, invasive bacterial diseases remain a public health concern and cause childhood morbidity and mortality. We investigated the characteristics of etiological agents causing bacterial meningitis in children <5 years in the years pre- (2010-2012) and post- (2014-2019) 10-valent pneumococcal conjugate vaccine (PCV10) introduction in Zambia. METHODS Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hi), and Neisseria meningitidis (Nm) from cerebrospinal fluid (CSF) were identified by microbiological culture and/or real-time polymerase chain reaction. RESULTS During the surveillance period, a total of 3811 children were admitted with suspected meningitis, 16% (598 of 3811) of which were probable cases. Bacterial meningitis was confirmed in 37% (221 of 598) of the probable cases. Spn pneumoniae, Hi, and Nm accounted for 67% (148 of 221), 14% (31 of 221), and 19% (42 of 221) of confirmed cases, respectively. Thirty-six percent of pneumococcal meningitis was caused by 10-valent pneumococcal conjugate vaccine (PCV10) serotypes, 16% 13-valent pneumococcal conjugate vaccine and 39% by nonvaccine serotype (NVS). There was an association between the introduction of PCV10 vaccination and a decrease in both Spn meningitis and the proportion of PVC10 serotypes in the postvaccination period. Antimicrobial susceptibility of 47 Spn isolates revealed 34% (16 of 47) penicillin resistance. The 31 serotyped Hi accounted for 74% type b (Hib) and 10% type a (Hia). All 42 serogrouped Nm belonged to serogroup W. CONCLUSIONS There was a decline in pneumococcal meningitis and proportion of PCV10 serotypes in the postvaccination period. However, the serotype replacement with non-PCV10 serotypes and penicillin resistance warrant continued surveillance to inform policy.
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Affiliation(s)
- Kaunda Yamba
- University Teaching Hospitals, Pathology & Microbiology Laboratory, Lusaka, Zambia
| | - Evans Mpabalwani
- University of Zambia, School of Medicine, Department of Paediatrics & Child Health, Lusaka, Zambia.,University Teaching Hospitals, Children's Hospital, Lusaka, Zambia
| | - Ruth Nakazwe
- University Teaching Hospitals, Pathology & Microbiology Laboratory, Lusaka, Zambia
| | - Evans Mulendele
- University Teaching Hospitals, Children's Hospital, Lusaka, Zambia
| | - Goitom Weldegebriel
- World Health Organisation, Regional Office for Africa, Brazzaville, Republic of Congo
| | - Jason M Mwenda
- World Health Organisation, Regional Office for Africa, Brazzaville, Republic of Congo
| | - Reggis Katsande
- World Health Organisation, Regional Office for Africa, Brazzaville, Republic of Congo
| | - Linda de Gouveia
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Johannesburg, South Africa
| | | | - Raphael Chanda
- University Teaching Hospitals, Pathology & Microbiology Laboratory, Lusaka, Zambia
| | - Belem Matapo
- World Health Organisation, Regional Office for Africa, Brazzaville, Republic of Congo
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Abstract
Purpose of review Community-acquired bacterial meningitis is a continually changing disease. This review summarises both dynamic epidemiology and emerging data on pathogenesis. Updated clinical guidelines are discussed, new agents undergoing clinical trials intended to reduce secondary brain damage are presented. Recent findings Conjugate vaccines are effective against serotype/serogroup-specific meningitis but vaccine escape variants are rising in prevalence. Meningitis occurs when bacteria evade mucosal and circulating immune responses and invade the brain: directly, or across the blood–brain barrier. Tissue damage is caused when host genetic susceptibility is exploited by bacterial virulence. The classical clinical triad of fever, neck stiffness and headache has poor diagnostic sensitivity, all guidelines reflect the necessity for a low index of suspicion and early Lumbar puncture. Unnecessary cranial imaging causes diagnostic delays. cerebrospinal fluid (CSF) culture and PCR are diagnostic, direct next-generation sequencing of CSF may revolutionise diagnostics. Administration of early antibiotics is essential to improve survival. Dexamethasone partially mitigates central nervous system inflammation in high-income settings. New agents in clinical trials include C5 inhibitors and daptomycin, data are expected in 2025. Summary Clinicians must remain vigilant for bacterial meningitis. Constantly changing epidemiology and emerging pathogenesis data are increasing the understanding of meningitis. Prospects for better treatments are forthcoming.
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Lower Density and Shorter Duration of Nasopharyngeal Carriage by Pneumococcal Serotype 1 (ST217) May Explain Its Increased Invasiveness over Other Serotypes. mBio 2020; 11:mBio.00814-20. [PMID: 33293378 PMCID: PMC7733939 DOI: 10.1128/mbio.00814-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pneumoniae is a frequent colonizer of the human nasopharynx and a major cause of life-threating invasive infections such as pneumonia, meningitis and sepsis. Over 1 million people die every year due to invasive pneumococcal disease (IPD), mainly in developing countries. Serotype 1 is a common cause of IPD; however, unlike other serotypes, it is rarely found in the carrier state in the nasopharynx, which is often considered a prerequisite for disease. The aim of this study was to understand this dichotomy. We used murine models of carriage and IPD to characterize the pathogenesis of African serotype 1 (sequence type 217) pneumococcal strains obtained from the Queen Elizabeth Central Hospital in Blantyre, Malawi. We found that ST217 pneumococcal strains were highly virulent in a mouse model of invasive pneumonia, but in contrast to the generally accepted assumption, can also successfully establish nasopharyngeal carriage. Interestingly, we found that cocolonizing serotypes may proliferate in the presence of serotype 1, suggesting that acquisition of serotype 1 carriage could increase the risk of developing IPD by other serotypes. RNA sequencing analysis confirmed that key virulence genes associated with inflammation and tissue invasiveness were upregulated in serotype 1. These data reveal important new insights into serotype 1 pathogenesis, with implications for carriage potential and risk of invasive disease through interactions with other cocolonizing serotypes, an often-overlooked factor in transmission and disease progression.IMPORTANCE The pneumococcus causes serious diseases such as pneumonia, sepsis, and meningitis and is a major cause of morbidity and mortality worldwide. Serotype 1 accounts for the majority of invasive pneumococcal disease cases in sub-Saharan Africa but is rarely found during nasopharyngeal carriage. Understanding the mechanisms leading to nasopharyngeal carriage and invasive disease by this serotype can help reduce its burden on health care systems worldwide. In this study, we also uncovered the potential impact of serotype 1 on disease progression of other coinfecting serotypes, which can have important implications for vaccine efficacy. Understanding the interactions between different serotypes during nasopharyngeal carriage may lead to improved intervention methods and therapies to reduce pneumococcal invasive disease levels.
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7
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Nyazika TK, Law A, Swarthout TD, Sibale L, Ter Braake D, French N, Heyderman RS, Everett D, Kadioglu A, Jambo KC, Neill DR. Influenza-like illness is associated with high pneumococcal carriage density in Malawian children. J Infect 2020; 81:549-556. [PMID: 32711042 PMCID: PMC7375306 DOI: 10.1016/j.jinf.2020.06.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 01/29/2023]
Abstract
Influenza-like illness (ILI) in children is associated with high pneumococcal carriage density. Children with ILI harboured more viral organisms than asymptomatic healthy children. Children with ILI patients had higher IL-8 levels in nasal aspirates than asymptomatic healthy children.
Background High pneumococcal carriage density is a risk factor for invasive pneumococcal disease (IPD) and transmission, but factors that increase pneumococcal carriage density are still unclear. Methods We undertook a cross-sectional study to evaluate the microbial composition, cytokine levels and pneumococcal carriage densities in samples from children presenting with an influenza-like illness (ILI) and asymptomatic healthy controls (HC). Results The proportion of children harbouring viral organisms (Relative risk (RR) 1.4, p = 0.0222) or ≥ 4 microbes at a time (RR 1.9, p < 0.0001), was higher in ILI patients than HC. ILI patients had higher IL-8 levels in nasal aspirates than HC (median [IQR], 265.7 [0 – 452.3] vs. 0 [0 – 127.3] pg/ml; p = 0.0154). Having an ILI was associated with higher pneumococcal carriage densities compared to HC (RR 4.2, p < 0.0001). Conclusion These findings suggest that children with an ILI have an increased propensity for high pneumococcal carriage density. This could in part contribute to increased susceptibility to IPD and transmission in the community.
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Affiliation(s)
- Tinashe K Nyazika
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; Department of Pathology, College of Health Sciences, University of Malawi, Blantyre, Malawi.
| | - Alice Law
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Todd D Swarthout
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi; Division of Infection and Immunity, NIHR Global Health Research Unit on Mucosal Pathogens, University College London, London, United Kingdom
| | - Lusako Sibale
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Danielle Ter Braake
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom; Department of Biomolecular Health Sciences, Division of Infectious Diseases & Immunology, Faculty of Veterinary Medicine, Utrecht, the Netherlands
| | - Neil French
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Robert S Heyderman
- Division of Infection and Immunity, NIHR Global Health Research Unit on Mucosal Pathogens, University College London, London, United Kingdom
| | - Dean Everett
- The Queens Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Aras Kadioglu
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Kondwani C Jambo
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi; Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
| | - Daniel R Neill
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
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Iroh Tam PY, Sadoh AE, Obaro SK. A meta-analysis of antimicrobial susceptibility profiles for pneumococcal pneumonia in sub-Saharan Africa. Paediatr Int Child Health 2018; 38:7-15. [PMID: 28453405 DOI: 10.1080/20469047.2017.1298700] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Pneumonia causes an enormous burden of childhood disease globally, particularly in low- and middle-income countries. Pneumococcus is the most common bacterial aetiology of pneumonia; however, antimicrobials are limited and may not adequately address the local epidemiology of the region. AIM To undertake a review and meta-analysis of pneumonia studies in sub-Saharan Africa to evaluate antimicrobial susceptibility patterns in childhood pneumonia. METHODS Articles published in PubMed and Google between 2006 and 2016 which evaluated antimicrobial susceptibility profiles of pneumococcal pneumonia in children in sub-Saharan Africa were identified. The source of specimens, pathogens and antimicrobial susceptibility data were extracted. Pooled analysis of susceptible isolates was conducted using random effects models. RESULTS Children from 15 studies and 1634 isolates were included in the meta-analysis. In cases of childhood pneumonia, the mean overall proportion of penicillin susceptibility from invasive specimens of Streptococcus pneumoniae was 85.7% (95% CI 80.1-91.3), and of trimethoprim-sulfamethoxazole was 21.0% (95% CI 5.1-36.9). Compared with all S. pneumoniae specimens, penicillin susceptibility was 68.6% (95% CI 59.6-77.5) and that of trimethoprim-sulfamethoxazole was 26.3% (95% CI 14.1-38.6). CONCLUSIONS A high level of heterogeneity was detected, reflecting the paucity of data available. The establishment of national and regional diagnostic platforms to monitor antimicrobial susceptibility profiles for pneumonia as well as other invasive diseases will provide data with which to assess the relevance and adaptation of antimicrobial prescribing recommendations.
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Affiliation(s)
- Pui-Ying Iroh Tam
- a Department of Pediatrics , University of Minnesota , Minneapolis , MN , USA
| | - Ayebo E Sadoh
- b Department of Pediatrics , University of Nebraska , Omaha , NE , USA
| | - Stephen K Obaro
- b Department of Pediatrics , University of Nebraska , Omaha , NE , USA
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Chaguza C, Cornick JE, Andam CP, Gladstone RA, Alaerts M, Musicha P, Peno C, Bar-Zeev N, Kamng'ona AW, Kiran AM, Msefula CL, McGee L, Breiman RF, Kadioglu A, French N, Heyderman RS, Hanage WP, Bentley SD, Everett DB. Population genetic structure, antibiotic resistance, capsule switching and evolution of invasive pneumococci before conjugate vaccination in Malawi. Vaccine 2017; 35:4594-4602. [PMID: 28711389 PMCID: PMC5571440 DOI: 10.1016/j.vaccine.2017.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/23/2017] [Accepted: 07/03/2017] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Pneumococcal infections cause a high death toll in Sub Saharan Africa (SSA) but the recently rolled out pneumococcal conjugate vaccines (PCV) will reduce the disease burden. To better understand the population impact of these vaccines, comprehensive analysis of large collections of pneumococcal isolates sampled prior to vaccination is required. Here we present a population genomic study of the invasive pneumococcal isolates sampled before the implementation of PCV13 in Malawi. MATERIALS AND METHODS We retrospectively sampled and whole genome sequenced 585 invasive isolates from 2004 to 2010. We determine the pneumococcal population genetic structure and assessed serotype prevalence, antibiotic resistance rates, and the occurrence of serotype switching. RESULTS Population structure analysis revealed 22 genetically distinct sequence clusters (SCs), which consisted of closely related isolates. Serotype 1 (ST217), a vaccine-associated serotype in clade SC2, showed highest prevalence (19.3%), and was associated with the highest MDR rate (81.9%) followed by serotype 12F, a non-vaccine serotype in clade SC10 with an MDR rate of 57.9%. Prevalence of serotypes was stable prior to vaccination although there was an increase in the PMEN19 clone, serotype 5 ST289, in clade SC1 in 2010 suggesting a potential undetected local outbreak. Coalescent analysis revealed recent emergence of the SCs and there was evidence of natural capsule switching in the absence of vaccine induced selection pressure. Furthermore, majority of the highly prevalent capsule-switched isolates were associated with acquisition of vaccine-targeted capsules. CONCLUSIONS This study provides descriptions of capsule-switched serotypes and serotypes with potential to cause serotype replacement post-vaccination such as 12F. Continued surveillance is critical to monitor these serotypes and antibiotic resistance in order to design better infection prevention and control measures such as inclusion of emerging replacement serotypes in future conjugate vaccines.
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Affiliation(s)
- Chrispin Chaguza
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Jennifer E Cornick
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Cheryl P Andam
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Maaike Alaerts
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Patrick Musicha
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Biomedical Sciences, University of Malawi College of Medicine, Blantyre, Malawi
| | - Chikondi Peno
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Naor Bar-Zeev
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Arox W Kamng'ona
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Biomedical Sciences, University of Malawi College of Medicine, Blantyre, Malawi
| | - Anmol M Kiran
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Chisomo L Msefula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Biomedical Sciences, University of Malawi College of Medicine, Blantyre, Malawi
| | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, USA
| | - Robert F Breiman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, USA
| | - Aras Kadioglu
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Neil French
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Robert S Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Division of Infection and Immunity, University College London, London, UK
| | - William P Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Stephen D Bentley
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Dean B Everett
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
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10
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Elshafie S, Taj-Aldeen SJ. Emerging resistant serotypes of invasive Streptococcus pneumoniae. Infect Drug Resist 2016; 9:153-60. [PMID: 27418844 PMCID: PMC4935045 DOI: 10.2147/idr.s102410] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7). METHODS A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005. RESULTS The most common serotypes for all age groups were 3 (12.70%), 14 (11.90%), 1 (11.90%), 19A (9.00%), 9V (5.20%), 23F (5.20%), and 19F (4.50%). Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10), and the 13-valent conjugated vaccine (PCV-13) were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2-5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6-64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46%) were multidrug resistant (MDR) and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in cefotaxime nonsusceptible strains from 3.55% to 16.66%. CONCLUSION Invasive pneumococcal strains and the emergence of MDR serotypes is a global burden that must be addressed through multiple strategies, including vaccination, antibiotic stewardship, and continuous surveillance.
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Affiliation(s)
- Sittana Elshafie
- Qatar Orthopedic and Sports Medicine Hospital, Aspetar, Doha, Qatar
- Weill Cornell Medicine-Qatar
| | - Saad J Taj-Aldeen
- Weill Cornell Medicine-Qatar
- Department of Laboratory Medicine and Pathology, Microbiology Division, Hamad Medical Corporation, Doha, Qatar
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11
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DeAntonio R, Yarzabal JP, Cruz JP, Schmidt JE, Kleijnen J. Epidemiology of community-acquired pneumonia and implications for vaccination of children living in developing and newly industrialized countries: A systematic literature review. Hum Vaccin Immunother 2016; 12:2422-40. [PMID: 27269963 PMCID: PMC5027706 DOI: 10.1080/21645515.2016.1174356] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
This systematic review evaluated the epidemiology of community-acquired pneumonia in children <6 y of age within 90 developing and newly industrialized countries. Literature searches (1990–2011), based on MEDLINE, EMBASE, Cochrane, CAB Global Health, WHO, UNICEF, country-specific websites, conferences, health-technology-assessment agencies, and the reference lists of included studies, yielded 8,734 records; 62 of 340 studies were included in this review. The highest incidence rate among included studies was 0.51 episodes/child-year, for children <5 y of age in Bangladesh. The highest prevalence was in Chinese children <6 months of age (37.88%). The main bacterial pathogens were Streptococcus pneumoniae, Haemophilus influenzae and Mycoplasma pneumoniae and the main viral pathogens were respiratory syncytial virus, adenovirus and rhinovirus. Community-acquired pneumonia remains associated with high rates of morbidity and mortality. Improved and efficient surveillance and documentation of the epidemiology and burden of community-acquired pneumonia across various geographical regions is warranted.
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Affiliation(s)
| | | | | | | | - Jos Kleijnen
- d School for Public Health and Primary Care (CAPHRI), Maastricht University , Maastricht , The Netherlands.,e Kleijnen Systematic Reviews Ltd , York , United Kingdom
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12
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Immunogenicity and safety of the 13-valent pneumococcal conjugate vaccine in HIV-infected individuals naive to pneumococcal vaccination. AIDS 2015; 29:1345-54. [PMID: 25888646 PMCID: PMC4521829 DOI: 10.1097/qad.0000000000000689] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Supplemental Digital Content is available in the text Objective: Immunocompromised individuals are at an increased risk of pneumococcal disease. Vaccination is recommended as an important strategy to reduce risk of pneumococcal disease in HIV-infected individuals. This study evaluated the safety and immunogenicity of three 13-valent pneumococcal conjugate vaccine (PCV13) doses followed by one dose of 23-valent pneumococcal polysaccharide vaccine (PPSV23) at 1-month intervals in pneumococcal vaccine-naive, HIV-infected individuals. Design: This was a phase 3, open-label, single-arm study. Methods: Pneumococcal vaccine-naive, HIV-infected individuals at least 6 years of age with CD4+ T-cell count at least 200 cells/μl and viral load less than 50 000 copies/ml received three doses of PCV13 followed by one dose of PPSV23 at 1-month intervals. Serotype-specific antipneumococcal immune responses were assessed by IgG geometric mean concentrations (GMCs) and opsonophagocytic activity (OPA) assay geometric mean titres (GMTs) after each dose. Local reactions at the PCV13 injection site, systemic and other adverse events were collected. Results: Three hundred and one individuals were enrolled and vaccinated; 279 completed the study. Statistically significant increases in IgG GMCs and OPA GMTs were observed for all serotypes after dose 1 of PCV13 compared with prevaccine levels. GMCs and GMTs were comparable or only modestly increased for all serotypes after PCV13 doses 2 and 3 and after PPSV23. The majority of local reactions and systemic events were mild to moderate in severity. Conclusion: A three-dose regimen of PCV13 was well tolerated in pneumococcal vaccine-naive, HIV-infected individuals. Significant immune responses to all serotypes were observed following the first dose of PCV13, with only modest increases in antibody titres following subsequent PCV13 or PPSV23 administration.
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13
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Kamng'ona AW, Hinds J, Bar-Zeev N, Gould KA, Chaguza C, Msefula C, Cornick JE, Kulohoma BW, Gray K, Bentley SD, French N, Heyderman RS, Everett DB. High multiple carriage and emergence of Streptococcus pneumoniae vaccine serotype variants in Malawian children. BMC Infect Dis 2015; 15:234. [PMID: 26088623 PMCID: PMC4474563 DOI: 10.1186/s12879-015-0980-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 06/08/2015] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Carriage of either single or multiple pneumococcal serotypes (multiple carriage) is a prerequisite for developing invasive pneumococcal disease. However, despite the reported high rates of pneumococcal carriage in Malawi, no data on carriage of multiple serotypes has been reported previously. Our study provides the first description of the prevalence of multiple pneumococcal carriage in Malawi. METHODS The study was conducted in Blantyre and Karonga districts in Malawi, from 2008 to 2012. We recruited 116 children aged 0-13 years. These children were either HIV-infected (N = 44) or uninfected (N = 72). Nasopharyngeal samples were collected using sterile swabs. Pneumococcal serotypes in the samples were identified by microarray. Strains that could not be typed by microarray were sequenced to characterise possible genetic alterations within the capsular polysaccharide (CPS) locus. RESULTS The microarray identified 179 pneumococcal strains (from 116 subjects), encompassing 43 distinct serotypes and non-typeable (NT) strains. Forty per cent (46/116) of children carried multiple serotypes. Carriage of vaccine type (VT) strains was higher (p = 0.028) in younger (0-2 years) children (71 %, 40/56) compared to older (3-13 years) children (50 %, 30/60). Genetic variations within the CPS locus of known serotypes were observed in 19 % (34/179) of the strains identified. The variants included 13-valent pneumococcal conjugate vaccine (PCV13) serotypes 6B and 19A, and the polysaccharide vaccine serotype 20. Serotype 6B variants were the most frequently isolated (47 %, 16/34). Unlike the wild type, the CPS locus of the 6B variants contained an insertion of the licD-family phosphotransferase gene. The CPS locus of 19A- and 20-variants contained an inversion in the sugar-biosynthesis (rmlD) gene and a 717 bp deletion within the transferase (whaF) gene, respectively. CONCLUSIONS The high multiple carriage in Malawian children provides opportunities for genetic exchange through horizontal gene transfer. This may potentially lead to CPS locus variants and vaccine escape. Variants reported here occurred naturally, however, PCV13 introduction could exacerbate the CPS genetic variations. Further studies are therefore recommended to assess the invasive potential of these variants and establish whether PCV13 would offer cross-protection. We have shown that younger children (0-2 years) are a reservoir of VT serotypes, which makes them an ideal target for vaccination.
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Affiliation(s)
- Arox W Kamng'ona
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Biochemistry Department, University of Malawi, College of Medicine, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
| | - Jason Hinds
- Division of Clinical Sciences, St George's, University of London, London, UK.
| | - Naor Bar-Zeev
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
| | - Katherine A Gould
- Division of Clinical Sciences, St George's, University of London, London, UK.
| | - Chrispin Chaguza
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
| | - Chisomo Msefula
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Microbiology Department, University of Malawi, College of Medicine, Blantyre, Malawi.
| | - Jennifer E Cornick
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
| | - Benard W Kulohoma
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK. .,International Centre for Insect Physiology and Ecology, Nairobi, Kenya.
| | - Katherine Gray
- Biochemistry Department, University of Malawi, College of Medicine, Blantyre, Malawi.
| | - Stephen D Bentley
- Pathogen Genomics, Wellcome Trust Sanger Institute, Cambridge, UK. .,Department of Medicine, University of Cambridge, Cambridge, UK.
| | - Neil French
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK. .,Malawi Epidemiology and Intervention Research Unit (MEIRU), Karonga, Malawi.
| | - Robert S Heyderman
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Dean B Everett
- Microbes, Immunity and Vaccines, Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi. .,Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.
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Pneumonia Prevention during a Humanitarian Emergency: Cost-effectiveness of Haemophilus Influenzae Type B Conjugate Vaccine and Pneumococcal Conjugate Vaccine in Somalia. Prehosp Disaster Med 2015; 30:402-11. [PMID: 26061190 DOI: 10.1017/s1049023x15004781] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Pneumonia is a leading cause of death among children less than five years old during humanitarian emergencies. Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae are the leading causes of bacterial pneumonia. Vaccines for both of these pathogens are available to prevent pneumonia. Problem This study describes an economic analysis from a publicly funded health care system perspective performed on a birth cohort in Somalia, a country that has experienced a protracted humanitarian emergency. METHODS An impact and cost-effectiveness analysis was performed comparing: no vaccine, Hib vaccine only, pneumococcal conjugate vaccine 10 (PCV10) only, and both together administered through supplemental immunization activities (SIAs). The main summary measure was the incremental cost per disability-adjusted life-years (DALYs) averted. One-way sensitivity analysis was conducted for uncertainty in parameter values. RESULTS Each SIA would avert a substantial number of cases and deaths. Compared with no vaccine, the DALYs averted by two SIAs for two doses of Hib vaccine was US $202.93 (lower and upper limits: $121.80-$623.52), two doses of PCV10 was US $161.51 ($107.24-$227.21), and two doses of both vaccines was US $152.42 ($101.20-$214.42). Variables that influenced the cost-effectiveness for each strategy most substantially were vaccine effectiveness, case fatality rates (CFRs), and disease burden. CONCLUSIONS The World Health Organization (WHO) defines a cost-effective intervention as costing one to three times the per capita gross domestic product (GDP; in 2011, for Somalia=US $112). Based on the presented model, Hib vaccine alone, PCV10 alone, or Hib vaccine and PCV10 given together in SIAs are cost-effective interventions in Somalia. The WHO/Strategic Advisory Group of Experts decision-making factors for vaccine deployment appear to have all been met: the disease burden is large, the vaccine-related risk is low, prevention in this setting is more feasible than treatment, the vaccine duration probably is sufficient for the vulnerable period of the child's life, cost is reasonable, and herd immunity is possible.
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15
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Leopold SJ, van Leth F, Tarekegn H, Schultsz C. Antimicrobial drug resistance among clinically relevant bacterial isolates in sub-Saharan Africa: a systematic review. J Antimicrob Chemother 2014; 69:2337-53. [PMID: 24879668 DOI: 10.1093/jac/dku176] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Little is known about the prevalence of antimicrobial resistance (AMR) amongst bacterial pathogens in sub-Saharan Africa (sSA), despite calls for continent-wide surveillance to inform empirical treatment guidelines. METHODS We searched PubMed and additional databases for susceptibility data of key pathogens for surveillance, published between 1990 and 2013. Extracted data were standardized to a prevalence of resistance in populations of isolates and reported by clinical syndrome, microorganism, relevant antimicrobial drugs and region. RESULTS We identified 2005 publications, of which 190 were analysed. Studies predominantly originated from east sSA (61%), were hospital based (60%), were from an urban setting (73%) and reported on isolates from patients with a febrile illness (42%). Quality procedures for susceptibility testing were described in <50% of studies. Median prevalence (MP) of resistance to chloramphenicol in Enterobacteriaceae, isolated from patients with a febrile illness, ranged between 31.0% and 94.2%, whilst MP of resistance to third-generation cephalosporins ranged between 0.0% and 46.5%. MP of resistance to nalidixic acid in Salmonella enterica Typhi ranged between 15.4% and 43.2%. The limited number of studies providing prevalence data on AMR in Gram-positive pathogens or in pathogens isolated from patients with a respiratory tract infection, meningitis, urinary tract infection or hospital-acquired infection suggested high prevalence of resistance to chloramphenicol, trimethoprim/sulfamethoxazole and tetracycline and low prevalence to third-generation cephalosporins and fluoroquinolones. CONCLUSIONS Our results indicate high prevalence of AMR in clinical bacterial isolates to antimicrobial drugs commonly used in sSA. Enhanced approaches for AMR surveillance are needed to support empirical therapy in sSA.
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Affiliation(s)
- Stije J Leopold
- Department of Global Health, Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Frank van Leth
- Department of Global Health, Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Hayalnesh Tarekegn
- Department of Global Health, Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Constance Schultsz
- Department of Global Health, Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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16
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Wall EC, Cartwright K, Scarborough M, Ajdukiewicz KM, Goodson P, Mwambene J, Zijlstra EE, Gordon SB, French N, Faragher B, Heyderman RS, Lalloo DG. High mortality amongst adolescents and adults with bacterial meningitis in sub-Saharan Africa: an analysis of 715 cases from Malawi. PLoS One 2013; 8:e69783. [PMID: 23894538 PMCID: PMC3716691 DOI: 10.1371/journal.pone.0069783] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 06/13/2013] [Indexed: 01/09/2023] Open
Abstract
Mortality from bacterial meningitis in African adults is significantly higher than those in better resourced settings and adjunctive therapeutic interventions such as dexamethasone and glycerol have been shown to be ineffective. We conducted a study analysing data from clinical trials of bacterial meningitis in Blantyre, Malawi to investigate the clinical parameters associated with this high mortality. Methods We searched for all clinical trials undertaken in Blantyre investigating bacterial meningitis from 1990 to the current time and combined the data from all included trial datasets into one database. We used logistic regression to relate individual clinical parameters to mortality. Adults with community acquired bacterial meningitis were included if the CSF culture isolate was consistent with meningitis or if the CSF white cell count was >100 cells/mm3 (>50% neutrophils) in HIV negative participants and >5 cells/mm3 in HIV positive participants. Outcome was measured by mortality at discharge from hospital (after 10 days of antibiotic therapy) and community follow up (day 40). Results Seven hundred and fifteen episodes of bacterial meningitis were evaluated. The mortality rate was 45% at day 10 and 54% at day 40. The most common pathogens were S.pneumoniae (84% of positive CSF isolates) and N.meningitidis (4%). 607/694 (87%) participants tested were HIV antibody positive. Treatment delays within the hospital system were marked. The median presenting GCS was 12/15, 17% had GCS<8 and 44.9% had a seizure during the illness. Coma, seizures, tachycardia and anaemia were all significantly associated with mortality on multivariate analysis. HIV status and pneumococcal culture positivity in the CSF were not associated with mortality. Adults with community acquired bacterial meningitis in Malawi present with a severe clinical phenotype. Predictors of high mortality are different to those seen in Western settings. Optimising in-hospital care and minimising treatment delays presents an opportunity to improve outcomes considerably.
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Affiliation(s)
- Emma C Wall
- Clinical group, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
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Collard JM, Alio Sanda AK, Jusot JF. Determination of pneumococcal serotypes in meningitis cases in Niger, 2003-2011. PLoS One 2013; 8:e60432. [PMID: 23555971 PMCID: PMC3610823 DOI: 10.1371/journal.pone.0060432] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 02/26/2013] [Indexed: 11/19/2022] Open
Abstract
Background The epidemiology of pneumococcal meningitis in the African ‘meningitis belt’ is poorly studied. In order to ensure an effective vaccination strategy and post-vaccination surveillance, we examined the serotype distribution patterns of pneumococcal meningitis in Niger over the period 2003–2011. Methods Cerebrospinal fluid (CSF) samples were collected from different health facilities throughout Niger in the frame of the national microbiological surveillance of meningitis. Determination of the serotype of CSF positive for pneumococci was performed using a sequential multiplex PCR method (SM-PCR) adapted with a national algorithm in which 32 different serotypes were covered and grouped into eight consecutive PCR. Results The SM-PCR assay could predict the Sp serotype for 779 CSF (88.7%), 98 CSF (11.3%) were not-typeable in our national-adapted algorithm. In total, 26 different serotypes were identified. Serotype 1 (n = 393) was the most prevalent and accounted for 45.3% of infections, followed by serogroups/serotypes 12F/(12A)/(44)/(46) (7.3%), 6/(6A/6B/6C/6D) (5.4%), 14 (5.2%), 5 (4.6%), 23F (4.2%), 45 (3.6%), 2 (3.1%), 18/(18A/18B/18C/18F) (2.9%) and 17 others serotypes with a prevalence of less than 2%. The proportion of serotype 1 in infants(<2 years old) represented only 4.3% of the cases affected by this serotype. In contrast, serotypes 5, 6, 14, 19A and 23F were only detected in very young children. Conclusions The proportion of serotype 1 in the pneumococcal meningitis cases and the theoretical vaccine coverage across all age groups advocates for the introduction of a conjugate vaccine (PCV10 or 13) into the Expanded Programme on Immunization (EPI) in Niger. Post-vaccine introduction surveillance supported by molecular approaches will be essential to provide a comprehensive picture of the impact of the vaccine on the burden reduction of pneumococcal meningitis and on pneumococcal serotype distribution.
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McCormick DW, Wilson ML, Mankhambo L, Phiri A, Chimalizeni Y, Kawaza K, Denis B, Carrol ED, Molyneux EM. Risk factors for death and severe sequelae in Malawian children with bacterial meningitis, 1997-2010. Pediatr Infect Dis J 2013; 32:e54-61. [PMID: 22914560 PMCID: PMC3671939 DOI: 10.1097/inf.0b013e31826faf5a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Acute bacterial meningitis (ABM) causes significant death and disability in children worldwide, with HIV recognized as an established risk factor for infection and negative outcomes. However, additional major risk factors for death and disability in pediatric ABM remain unclear. METHODS We conducted a retrospective analysis of case data from 3 departmental studies of ABM involving 1784 children <15 years old who attended Queen Elizabeth Central Hospital in Blantyre, Malawi during 1997 to 2010. Univariate and multivariate logistic regression models were used to estimate the effects of HIV seropositivity, impaired consciousness and causative organism on death and severe sequelae. RESULTS Impaired consciousness or coma at the time of admission was strongly associated with death (coma: odds ratio [OR] = 14.4, 95% confidence interval [CI]: 9.42, 22.1) and severe sequelae (Coma: OR = 3.27, 95% CI: 2.02, 5.29) in multivariate logistic regression models. HIV seropositivity was significantly associated with increased odds of death (OR = 1.65, 95% CI: 1.20, 2.26) but not with developing severe sequelae (OR = 0.88, 95% CI: 0.56, 1.38). After adjustment, infection with Salmonella spp. was associated with increased odds of death (OR = 2.11, 95% CI: 1.06, 4.08) and pneumococcal meningitis was associated with increased odds of severe sequelae (OR = 1.84, 95% CI: 1.03, 3.29). CONCLUSIONS Impaired consciousness and HIV infection increased the odds of death from ABM in Malawian children. Use of pneumococcal conjugate vaccine could greatly reduce the burden of ABM in Malawi.
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Affiliation(s)
- David W McCormick
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
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Pittet LF, Posfay-Barbe KM. Pneumococcal vaccines for children: a global public health priority. Clin Microbiol Infect 2012; 18 Suppl 5:25-36. [PMID: 22862432 DOI: 10.1111/j.1469-0691.2012.03938.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pneumococcal conjugated vaccines have been recommended in children for over a decade in many countries worldwide. Here we review the development of pneumococcal vaccines with a focus on the two types currently available for children and their safety record. We discuss also the effect of vaccines, including the 13-valent pneumococcal conjugate vaccine, on invasive pneumococcal diseases in children, particularly bacteraemia, pneumonia and meningitis, as well as on mucosal disease and carriage. In regions where immunization was implemented in young children, the number of invasive pneumococcal diseases decreased significantly, not only in the target age group, but also in younger and much older subjects. Challenges and future perspectives regarding the development of new 'universal' vaccines, which could bypass the current problem of serotype-specific protection in a context of serotype replacement, are also discussed.
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Affiliation(s)
- L F Pittet
- Department of Paediatrics, Geneva University Hospitals and University of Geneva Medical School, Geneva, Switzerland
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