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Nguyen DT, Nguyen TL, Olmsted A, Duong TH, Hoang HM, Nguyen LH, Ouattara M, Milucky J, Lessa FC, Vo TTD, Phan VT, Nguyen THA, Pham NMN, Truong HK, Phan TQT, Bui THH, Pham VK, Iijima M, Le B, Kim L, Farrar JL. Epidemiology of pneumococcal meningitis in sentinel hospital surveillance of Viet Nam, 2015-2018. BMC Infect Dis 2024; 24:1179. [PMID: 39425015 PMCID: PMC11490006 DOI: 10.1186/s12879-024-10065-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 10/07/2024] [Indexed: 10/21/2024] Open
Abstract
BACKGROUND Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), and Neisseria meningitidis (N. meningitidis) are leading causes of childhood bacterial meningitis and preventable by vaccines. The aim of this hospital-based sentinel surveillance is to describe the epidemiological characteristics of pneumococcal meningitis, including disease burden, and to provide baseline data on pneumococcal serotype distribution to support decision making for pneumococcal conjugate vaccine (PCV) introduction in Vietnam. METHODS Surveillance for probable bacterial meningitis in children 1-59 months of age is conducted in three tertiary level pediatric hospitals: one in Hanoi and two in Ho Chi Minh City. Cerebrospinal fluid (CSF) specimens were collected via lumbar puncture from children with suspected meningitis. Specimens were transferred immediately to the laboratory department of the respective hospital for cytology, biochemistry, and microbiology testing, including culture. PCR testing was conducted on CSF specimens for bacterial detection (S. pneumoniae, H. influenzae, and N. meningitidis) and pneumococcal serotyping. RESULTS During 2015-2018, a total of 1,803 children with probable bacterial meningitis were detected; 1,780 had CSF specimens available for testing. Of 245 laboratory-confirmed positive cases, the majority were caused by S. pneumoniae (229,93.5%). Of those with S. pneumoniae detected, over 70% were caused by serotypes included in currently available PCV products; serotypes 6 A/6B (27.1%), 14 (19.7%), and 23 F (16.2%) were the most common serotypes. Children with laboratory-confirmed pneumococcal meningitis were more likely to live in Hanoi (p < 0.0001) and children 12-23 months of age were at greater odds (OR = 1.65, 95% CI: 1.11, 2.43; p = 0.006) of having confirmed pneumococcal meningitis compared to children < 12 months of age when compared to those without laboratory-confirmed bacterial meningitis. Additionally, children with confirmed pneumococcal meningitis were more likely to exhibit signs and symptoms consistent with clinical meningitis compared to negative laboratory-confirmed meningitis cases (p < 0.0001) and had a greater odds of death (OR = 6.18, 95% CI: 2.98, 12.86; p < 0.0001). CONCLUSIONS Pneumococcal meningitis contributes to a large burden of bacterial meningitis in Vietnamese children. A large proportion are caused by serotypes covered by PCVs currently available. Introduction of PCV into the routine immunization program could reduce the burden of pneumococcal meningitis in Viet Nam.
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Affiliation(s)
| | - Thi Loan Nguyen
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | - Allison Olmsted
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Thi Hong Duong
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | - Hong Mai Hoang
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | | | | | | | | | | | - Van Thanh Phan
- Pasteur Institute in Ho Chi Minh City, Ho Chi Minh, Viet Nam
| | | | | | - Huu Khanh Truong
- Ho Chi Minh City Children Hospital No.1, Ho Chi Minh City, Viet Nam
| | | | | | - Van Khang Pham
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | | | - Binh Le
- Centers for Disease Control and Prevention, Hanoi, Viet Nam
| | - Lindsay Kim
- Centers for Disease Control and Prevention, Hanoi, Viet Nam
- US Public Health Service, Rockville, MD, USA
| | - Jennifer Loo Farrar
- Centers for Disease Control and Prevention, Atlanta, GA, USA.
- , 1600 Clifton Road NE, Atlanta, GA, 30329, USA.
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van Ettekoven CN, Liechti FD, Brouwer MC, Bijlsma MW, van de Beek D. Global Case Fatality of Bacterial Meningitis During an 80-Year Period: A Systematic Review and Meta-Analysis. JAMA Netw Open 2024; 7:e2424802. [PMID: 39093565 PMCID: PMC11297475 DOI: 10.1001/jamanetworkopen.2024.24802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/16/2024] [Indexed: 08/04/2024] Open
Abstract
Importance The impact of vaccination, antibiotics, and anti-inflammatory treatment on pathogen distribution and outcome of bacterial meningitis over the past century is uncertain. Objective To describe worldwide pathogen distribution and case fatality ratios of community-acquired bacterial meningitis. Data Sources Google Scholar and MEDLINE were searched in January 2022 using the search terms bacterial meningitis and mortality. Study Selection Included studies reported at least 10 patients with bacterial meningitis and survival status. Studies that selected participants by a specific risk factor, had a mean observation period before 1940, or had more than 10% of patients with health care-associated meningitis, tuberculous meningitis, or missing outcome were excluded. Data Extraction and Synthesis Data were extracted by 1 author and verified by a second author. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Random-effects models stratified by age (ie, neonates, children, adults), Human Development Index (ie, low-income or high-income countries), and decade and meta-regression using the study period's year as an estimator variable were used. Main Outcome and Measure Case fatality ratios of bacterial meningitis. Results This review included 371 studies performed in 108 countries from January 1, 1935, to December 31, 2019, describing 157 656 episodes. Of the 33 295 episodes for which the patients' sex was reported, 13 452 (40%) occurred in females. Causative pathogens were reported in 104 598 episodes with Neisseria meningitidis in 26 344 (25%) episodes, Streptococcus pneumoniae in 26 035 (25%) episodes, Haemophilus influenzae in 22 722 (22%), other bacteria in 19 161 (18%) episodes, and unidentified pathogen in 10 336 (10%) episodes. The overall case fatality ratio was 18% (95% CI, 16%-19%), decreasing from 32% (95% CI, 24%-40%) before 1961 to 15% (95% CI, 12%-19%) after 2010. It was highest in meningitis caused by Listeria monocytogenes at 27% (95% CI, 24%-31%) and pneumococci at 24% (95% CI, 22%-26%), compared with meningitis caused by meningococci at 9% (95% CI, 8%-10%) or H influenzae at 11% (95% CI, 10%-13%). Meta-regression showed decreasing case fatality ratios overall and stratified by S pneumoniae, Escherichia coli, or Streptococcus agalactiae (P < .001). Conclusions and Relevance In this meta-analysis with meta-regression, declining case fatality ratios of community-acquired bacterial meningitis throughout the last century were observed, but a high burden of disease remained.
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Affiliation(s)
- Cornelis N. van Ettekoven
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Neurology, HagaZiekenhuis, The Hague, the Netherlands
| | - Fabian D. Liechti
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Matthijs C. Brouwer
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Merijn W. Bijlsma
- Department of Pediatrics, Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - Diederik van de Beek
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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Park JJ, Narayanan S, Tiefenbach J, Lukšić I, Ale BM, Adeloye D, Rudan I. Estimating the global and regional burden of meningitis in children caused by Haemophilus influenzae type b: A systematic review and meta-analysis. J Glob Health 2022; 12:04014. [PMID: 35265327 PMCID: PMC8893283 DOI: 10.7189/jogh.12.04014] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Haemophilus influenzae Type B (Hib) meningitis caused significant public health concern for children. Recent assessment in 2015 suggests vaccination has virtually eliminated invasive Hib diseases. However, many countries launched their programs after 2010, and few are yet to establish routine Hib immunisations. We therefore aimed to update the most recent global burden of Hib meningitis before the impact of COVID-19 pandemic, from 2010 to 2020, in order to aid future public health policies on disease management and prevention. Methods Epidemiological data regarding Hib meningitis in children <5 years old were systematically searched and evaluated from PubMed and Scopus in August, 2020. We included studies published between 2010 and 2019 that reported incidence, prevalence, mortality, or case-fatality-ratio (CFR), and confirmation of meningitis by cerebrospinal fluid culture, with a minimum one year study period and ten cases. Each data was stratified by one study-year. Median study-year was used if information was not available. Quality of all studies were assessed using our adapted assessment criteria from Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Study Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from National Heart, Lung and Blood Institute (NHLBI). We constructed and visually inspected a funnel plot of standard error by the incidence rate and performed an Egger’s regression test to statistically assess publication bias. To ascertain incidence and CFR, we performed generalised linear mixed models on crude individual study estimates. Heterogeneity was assessed using I-squared statistics whilst further exploring heterogeneity by performing subgroup analysis. Results 33 studies were identified. Pooled incidence of global Hib meningitis in children was 1.13 per 100 000-child-years (95% confidence interval (CI) = 0.80-1.59). Southeast Asian Region (SEAR) of World Health Organisation (WHO) region reported the highest incidence, and European Region (EUR) the lowest. Considering regions with three or more data, Western Pacific Region (WPR) had the highest incidence rate of 5.22 (95% CI = 3.12-8.72). Post-vaccination incidence (0.67 cases per 100 000-child-years, 95% CI = 0.48-0.94) was dramatically lower than Pre-vaccination incidence (4.84 cases per 100 000-child-years, 95% CI = 2.95-7.96). Pooled CFR in our meta-analysis was 11.21% (95% CI = 7.01-17.45). Eastern Mediterranean Region (EMR) had the highest CFR (26.92, 95% CI = 13.41-46.71) while EUR had the lowest (4.13, 95% CI = 1.73-9.54). However, considering regions with three or more data, African Region (AFR) had the highest CFR at 21.79% (95% CI = 13.65-32.92). Before the coronavirus disease 2019 (COVID-19) impact, the estimation for global Hib meningitis cases in 2020 is 7645 and 857 deaths. Conclusions Global burden of Hib meningitis has markedly decreased, and most regions have implemented vaccination programs. Extrapolating population-at-risk from studies has possibly led to an underestimation. Continuous surveillance is necessary to monitor vaccination impact, resurgence, vaccine failures, strain variance, COVID-19 impact, and to track improvement of regional and global Hib meningitis mortality.
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Affiliation(s)
- Jay J Park
- Edinburgh Medical School, University of Edinburgh, 49 Little France Crescent, Edinburgh, UK
| | - Sandhya Narayanan
- School of Biological Sciences, University of Edinburgh, Grant Institute Kings Buildings, W Mains Rd, Edinburgh, UK
| | - Jakov Tiefenbach
- Edinburgh Medical School, University of Edinburgh, 49 Little France Crescent, Edinburgh, UK
| | - Ivana Lukšić
- Department of Microbiology, Teaching Institute of Public Health “Dr Andrija Štampar”, Zagreb, Croatia
| | | | - Davies Adeloye
- Centre for Global Health, Edinburgh Medical School, Usher Institute, University of Edinburgh, Edinburgh, Scotland, UK
| | - Igor Rudan
- Centre for Global Health, Edinburgh Medical School, Usher Institute, University of Edinburgh, Edinburgh, Scotland, UK
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Xi Y, Wang H, Wang S, Wu X, Wang Z. A study of various factors affecting satellitism tests of Haemophilus influenzae and Haemophilus parainfluenzae using Staphylococcus aureus as the source of NAD. METHODS IN MICROBIOLOGY 2022; 193:106417. [PMID: 35033634 DOI: 10.1016/j.mimet.2022.106417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 10/19/2022]
Abstract
Many factors affecting satellitism tests are unclear, and it is difficult to avoid misidentification, even if the medium is properly selected. We investigated the factors causing false-positive results for Haemophilus influenzae and false-negative results for Haemophilus parainfluenzae in the satellitism tests using Staphylococcus aureus as the source of nicotinamide adenine dinucleotide (NAD). H. influenzae (four reference strains and 47 clinical isolates), H. parainfluenzae (two reference strains and 67 clinical isolates), four different media, and two strains of S. aureus revived on two different media were used in this study. The type of medium used to revive S. aureus was the most common factor causing false-positive results for H. influenzae, followed by different strains of S. aureus and the type of medium used for the experiment. The production of false-negative results for H. parainfluenzae was only related to the medium used in the experiment. To improve the accuracy of the tests in routine laboratories, using S. aureus as the source of NAD, tryptic soy agar, and S. aureus (ATCC 25923) revived on nutrient agar should be adopted.
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Affiliation(s)
- Yu Xi
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Hexuan Wang
- Zhengzhou No. 47 Middle & High School, Zhengzhou, Henan, China
| | - Shanmei Wang
- Department of Clinical Laboratory, Henan Provincial People's Hospital, Zhengzhou, Henan, China
| | - Xuxiao Wu
- R&D Center, Autobio Diagnostics Co., Ltd, Zhengzhou, Henan, China
| | - Zeyu Wang
- R&D Center, Autobio Diagnostics Co., Ltd, Zhengzhou, Henan, China.
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Ho NT, Thompson C, Nhan LNT, Van HMT, Dung NT, Tran My P, Quang VM, Minh NNQ, Tuan TA, Hung NT, Tuan HM, Vinh Chau NV, Wolbers M, Thwaites GE, Choisy M, Baker S. Retrospective analysis assessing the spatial and temporal distribution of paediatric acute respiratory tract infections in Ho Chi Minh City, Vietnam. BMJ Open 2018; 8:e016349. [PMID: 29358416 PMCID: PMC5780701 DOI: 10.1136/bmjopen-2017-016349] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Acute respiratory tract infections (ARIs) are the leading cause of morbidity and mortality in young children in low/middle-income countries. Using routine hospital data, we aimed to examine the spatial distribution, temporal trends and climatic risk factors of paediatric ARIs in Vietnam. METHODS Data from hospitalised paediatric (<16 years) patients with ARIs residing in Ho Chi Minh City (HCMC) between 2005 and 2010 were retrieved from the two main Children's Hospitals and the Hospital for Tropical Diseases in HCMC. Spatial mapping and time series analysis were performed after disaggregating data into upper respiratory tract infections (URIs) and lower respiratory tract infections (LRIs). RESULTS Over the study period, there were 155 999 paediatric patients admitted with ARIs (33% of all hospital admissions). There were 68 120 URIs (14%) and 87 879 LRIs (19%). The most common diagnoses were acute pharyngitis (28% of all ARI), pneumonia (21%), bronchitis (18%) and bronchiolitis (16%). A significant increasing trend over time was found for both URIs (mean weekly incidence per 1000 population, I=3.12), incidence rate ratio for 1-week increase in time (RR 1.0, 95% CI 1.02 to 1.17) for URI and (I=4.02, RR 1.08 (95% CI 1.006 to 1.16)) for LRI. The weekly URI incidence peaked in May-June and was significantly associated with lags in weekly URI incidence and the average humidity, rainfall and water level. The weekly LRI incidence exhibited significant seasonality (P<0.0001), with an annual peak in September-October and was significantly associated with lags in weekly LRI incidence and lags in weekly average temperature, rainfall and water level. CONCLUSIONS ARIs are a leading cause of childhood hospitalisation in HCMC, Vietnam. The incidence of ARIs was higher in the wet season and in specific HCMC districts. These results may guide health authorities in where and when to effectively allocate resources for the prevention and control of ARIs.
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Affiliation(s)
- Nhan Thi Ho
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Program, Ho Chi Minh City, Vietnam
- Pediatrics, Columbia UniversityMedical Center, New York, New York, United States
| | - Corinne Thompson
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Program, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Infection Biology, The London School of Hygiene & Tropical Medicine, London, UK
| | | | | | - Nguyen Thanh Dung
- General planning, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Phuc Tran My
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Program, Ho Chi Minh City, Vietnam
| | - Vo Minh Quang
- General planning, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Tran Anh Tuan
- General medicine, Children’s Hospital 1, Ho Chi Minh City, Vietnam
| | | | - Ha Manh Tuan
- General medicine, Children’s Hospital 2, Ho Chi Minh City, Vietnam
| | | | - Marcel Wolbers
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Program, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Program, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Marc Choisy
- Institute of Research and Development, Ho Chi Minh City, Vietnam
| | - Stephen Baker
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Program, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
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Le P, Griffiths UK, Anh DD, Franzini L, Chan W, Swint JM. Cost-effectiveness of Haemophilus influenzae type b vaccine in Vietnam. Vaccine 2015; 33:4639-46. [PMID: 26044493 PMCID: PMC4547866 DOI: 10.1016/j.vaccine.2015.05.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/14/2015] [Accepted: 05/20/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND With GAVI support, Vietnam introduced Haemophilus influenzae type b (Hib) vaccine in 2010 without evidence on cost-effectiveness. We aimed to analyze the cost-effectiveness of Hib vaccine from societal and governmental perspectives. METHOD We constructed a decision-tree cohort model to estimate the costs and effectiveness of Hib vaccine versus no Hib vaccine for the 2011 birth cohort. The disease burden was estimated from local epidemiologic data and literature. Vaccine delivery costs were calculated from governmental reports and 2013 vaccine prices. A prospective cost-of-illness study was conducted to estimate treatment costs. The human capital approach was employed to estimate productivity loss. The incremental costs of Hib vaccine were divided by cases, deaths, and disability-adjusted life years (DALY) averted. We used the WHO recommended cost-effectiveness thresholds of an intervention being highly cost-effective if incremental costs per DALY were below GDP per capita. RESULT From the societal perspective, incremental costs per discounted case, death and DALY averted were US$ 6252, US$ 26,476 and US$ 1231, respectively; the break-even vaccine price was US$ 0.69/dose. From the governmental perspective, the results were US$ 6954, US$ 29,449, and US$ 1373, respectively; the break-even vaccine price was US$ 0.48/dose. Vietnam's GDP per capita was US$ 1911 in 2013. In deterministic sensitivity analysis, morbidity and mortality parameters were among the most influential factors. In probabilistic sensitivity analysis, Hib vaccine had an 84% and 78% probability to be highly cost-effective from the societal and governmental perspectives, respectively. CONCLUSION Hib vaccine was highly cost-effective from both societal and governmental perspectives. However, with GAVI support ending in 2016, the government will face a six-fold increase in its vaccine budget at the 2013 vaccine price. The variability of vaccine market prices adds an element of uncertainty. Increased government commitment and improved resource allocation decision making will be necessary to retain Hib vaccine.
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Affiliation(s)
- Phuc Le
- University of Texas School of Public Health, United States.
| | | | - Dang Duc Anh
- Vietnam National Institute of Hygiene and Epidemiology, Viet Nam
| | - Luisa Franzini
- University of Texas School of Public Health, United States
| | - Wenyaw Chan
- University of Texas School of Public Health, United States
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Flasche S, Takahashi K, Vu DT, Suzuki M, Nguyen THA, Le H, Hashizume M, Dang DA, Edmond K, Ariyoshi K, Mulholland EK, Edmunds WJ, Yoshida LM. Early indication for a reduced burden of radiologically confirmed pneumonia in children following the introduction of routine vaccination against Haemophilus influenzae type b in Nha Trang, Vietnam. Vaccine 2014; 32:6963-6970. [PMID: 25444823 PMCID: PMC7125610 DOI: 10.1016/j.vaccine.2014.10.055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 10/06/2014] [Accepted: 10/20/2014] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Despite the global success of Hib vaccination in reducing disease and mortality, uncertainty about the disease burden and the potential impact of Hib vaccination in Southeast Asia has delayed the introduction of vaccination in some countries in the region. Hib vaccination was introduced throughout Vietnam in July 2010 without catch-up. In an observational, population based surveillance study we estimated the impact of routine Hib vaccination on all cause radiologically confirmed childhood pneumonia in Nha Trang, Vietnam. MATERIALS AND METHODS In 2007 active hospital based surveillance was established in Khanh Hoa General Hospital, the only hospital in Nha Trang, Khanh Hoa province. Nasopharyngeal samples and chest radiographs are taken routinely from all children diagnosed with acute respiratory illness on admission. For admissions between 02/2007 and 03/2012 chest radiographs were interpreted for the presence of WHO primary endpoint pneumonia and nasopharyngeal swabs were analysed by PCR for the presence of Influenza A or B, RSV and rhinovirus. We employed Poisson regression to estimate the impact of Hib vaccination on radiologically confirmed pneumonia (RCP) while statistically accounting for potential differences in viral circulation in the post vaccination era which could have biased the estimate. RESULTS Of 3151 cases admitted during the study period, 166 had RCP and major viruses were detected in 1601. The adjusted annual incidence of RCP in children younger than 5 years declined by 39% (12-58%) after introduction of Hib vaccination. This decline was most pronounced in children less than 2 years old, adjusted IRR: 0.52 (0.33-0.81), and no significant impact was observed in the 2-4 years old who were not eligible for vaccination, adjusted IRR: 0.96 (0.52-1.72). DISCUSSION We present early evidence that the burden of Hib associated RCP in Nha Trang before vaccination was substantial and that shortly after introduction to the routine childhood immunisation scheme vaccination has substantially reduced that burden.
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Affiliation(s)
- Stefan Flasche
- London School of Hygiene and Tropical Medicine, London, UK.
| | - Kensuke Takahashi
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Dinh Thiem Vu
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | - Motoi Suzuki
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | | | - HuuTho Le
- Khanh Hoa Health Service Department, Nha Trang, Viet Nam
| | | | - Duc Anh Dang
- National Institute of Hygiene and Epidemiology, Hanoi, Viet Nam
| | - Karen Edmond
- Menzies School of Health Research, Darwin, Australia
| | - Koya Ariyoshi
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - E Kim Mulholland
- London School of Hygiene and Tropical Medicine, London, UK; Menzies School of Health Research, Darwin, Australia
| | - W John Edmunds
- London School of Hygiene and Tropical Medicine, London, UK
| | - Lay-Myint Yoshida
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
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Thoon KC, Tee NWS, Chew L, Chong CY. Near disappearance of childhood invasive Haemophilus influenzae type b disease in Singapore. Vaccine 2014; 32:5862-5. [DOI: 10.1016/j.vaccine.2014.08.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 08/11/2014] [Accepted: 08/15/2014] [Indexed: 11/27/2022]
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