1
|
Tran DM, Ong T, Cao TV, Pham QT, Do H, Phan PH, Choisy M, Pham NTH. Hospital-acquired infections and unvaccinated children due to chronic diseases: an investigation of the 2017-2019 measles outbreak in the northern region of Vietnam. BMC Infect Dis 2024; 24:948. [PMID: 39256671 PMCID: PMC11384796 DOI: 10.1186/s12879-024-09816-w] [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] [Received: 05/02/2024] [Accepted: 08/27/2024] [Indexed: 09/12/2024] Open
Abstract
BACKGROUND Measles remains a major public health burden worldwide. Parents often hesitate to vaccinate children with chronic diseases. We investigated the association between the percentage of vaccination and chronic diseases and explore hospital infections' role in the 2017-2019 measles outbreak across northern Vietnam provinces. METHODS A total of 2,064 children aged 0-15 years old admitted for measles to the National Children's Hospital during the outbreak were included in the study. Demographic information, clinical characteristics, vaccination statuses and laboratory examination were extracted from electronic medical records, vaccination records, or interviews with parents when other sources were unavailable. RESULTS The incidence rate that provincial hospitals sent to the National Children's Hospital was proportional to the population density of their provinces of residence. Early nosocomial transmission of measles was observed before community-acquired cases emerged in many provinces. Among patients aged over 18 months, those with chronic diseases had a proportion of vaccination of 9.4%, lower than patients without chronic diseases at 32.4%. Unvaccinated patients had a higher proportion of hospital-acquired infections with aOR = 2.42 (1.65-3.65), p < 0.001 relative to vaccinated patients. The proportion of hospital-acquired infections was higher among children with chronic diseases compared to those without, with aOR = 3.81 (2.90-5.02), p < 0.001. CONCLUSION Measles spread in healthcare settings prior to community cases that occurred in several provinces. We recommend enhancing hospital infection control by increasing staff training and improving early detection and isolation during non-outbreak periods. Measles patients with chronic diseases exhibited lower proportions of vaccination and faced a higher risk of hospital-acquired infections. It is crucial to establish comprehensive vaccination guidelines and enhance parental awareness regarding the significance and safety of measles vaccination to protect these vulnerable individuals.
Collapse
Affiliation(s)
- Dien M Tran
- Director of the Vietnam National Children's Hospital, Hanoi, Vietnam
- Pediatric Department, School of Medicine and Pharmacy, Vietnam National University, Hanoi, Vietnam
| | - Thinh Ong
- Mathematical Modelling Group, Oxford University Clinical Research Unit, Ho Chi Minh City, 70000, Vietnam
| | - Tung V Cao
- Surgical Cadiac Intensive Care Unit, Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Quang Thai Pham
- Vice head of Department (Communicable Disease Control), National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Hien Do
- Health Emergencies Programme, WHO Viet Nam, Hanoi, Vietnam
| | - Phuc H Phan
- Pediatric Intensive Care Unit, Vietnam National Children's Hospital, Hanoi, Vietnam
| | - Marc Choisy
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, 70000, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Nhung T H Pham
- Research Institute for Child Health, Field Epidemiology Training Program - Ministry of Health, Vietnam National Children's Hospital, Hanoi, Vietnam.
- Field Epidemiology Training Program - Ministry of Health, Hanoi, Vietnam.
| |
Collapse
|
2
|
A Multi-Age-Group Interrupted Time-Series Study for Evaluating the Effectiveness of National Expanded Program on Immunization on Mumps. Vaccines (Basel) 2022; 10:vaccines10101587. [PMID: 36298452 PMCID: PMC9610758 DOI: 10.3390/vaccines10101587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 11/16/2022] Open
Abstract
The national Expanded Program on Immunization (EPI) in China has covered vaccines for measles, mumps, and rubella, among children aged 18–24 months since September 2008. However, no previous studies have quantified the effectiveness of the EPI on mumps incidence. There are methodological challenges in assessing the effect of an intervention that targets a subpopulation but finally influences the whole population. In this study, monthly data on mumps incidence were collected in Guangzhou, China, during 2005–2019. We proposed a multi-age-group interrupted time-series design, setting the starting time of exerting effect separately for 14 different age groups. A mixed-effects quasi-Poisson regression was applied to analyze the effectiveness of the EPI on mumps incidence, after controlling for long-term and seasonal trends, and meteorological factors. The model also accounted for the first-order autocorrelation within each age group. Between-age-group correlations were expressed using the contact matrix of age groups. We found that 70,682 mumps cases were reported during 2005–2019, with an annual incidence rate of 37.91 cases per 100,000 population. The effect of EPI strengthened over time, resulting in a decrease in the incidence of mumps by 16.6% (EPI-associated excess risk% = −16.6%, 95% CI: −27.0% to −4.7%) in September 2009 to 40.1% (EPI-associated excess risk% = −40.1%, 95% CI: −46.1% to −33.3%) in September 2019. A reverse U-shape pattern was found in age-specific effect estimates, with the largest reduction of 129 cases per 100,000 population (95% CI: 14 to 1173) in those aged 4–5 years. The EPI is effective in reducing the mumps incidence in Guangzhou. The proposed modeling strategy can be applied for simultaneous assessment of the effectiveness of public health interventions across different age groups, with adequate adjustment for within- and between-group correlations.
Collapse
|
3
|
Tang XY, Cheng M, Geater A, Deng QY, Zhong G, Lin YD, Chen N, Lan T, Jiang LY, Zhu MT, Li Q. Multi-level determinants of failure to receive timely and complete measles vaccinations in Southwest China: a mixed methods study. Infect Dis Poverty 2021; 10:102. [PMID: 34294157 PMCID: PMC8296749 DOI: 10.1186/s40249-021-00885-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/12/2021] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Measles outbreaks re-emerged in 2013-2014 in Guangxi Zhuang Autonomous Region of China, where measles immunisation coverage is high. The discrepancy between the vaccination coverage and outbreaks indicates that timeliness is crucial, yet there is limited knowledge on the health system barriers to timely vaccination. Using integrated evidence at the household, village clinic, and township hospital levels, this study aimed to identify the determinants of failure in receiving timely measles vaccinations among children in rural Guangxi. METHODS A multi-stage stratified cluster sampling survey with a nested qualitative study was conducted among children aged 18-54 months in Longan, Zhaoping, Wuxuan, and Longlin counties of Guangxi from June to August 2015. The status of timely vaccinations for the first dose of measles-containing vaccine (MCV1) and the second dose of measles-containing vaccine (MCV2) was verified via vaccination certificates. Data on household-level factors were collected using structured questionnaires, whereas data on village and township-level factors were obtained through in-depth interviews and focus group discussions. Determinants of untimely measles vaccinations were identified using multilevel logistic regression models. RESULTS A total of 1216 target children at the household level, 120 villages, and 20 township hospitals were sampled. Children were more likely to have untimely vaccination when their primary guardian had poor vaccination knowledge [MCV1, odds ratio (OR) = 1.72; MCV2, OR = 1.51], had weak confidence in vaccines (MCV1, OR = 1.28-4.58; MCV2, OR = 1.42-3.12), had few practices towards vaccination (MCV1, OR = 12.5; MCV2, OR = 3.70), or had low satisfaction with vaccination service (MCV1, OR = 2.04; MCV2, OR = 2.08). This trend was also observed in children whose village doctor was not involved in routine vaccination service (MCV1, OR = 1.85; MCV2, OR = 2.11) or whose township hospital did not provide vaccination notices (MCV1, OR = 1.64; MCV2, OR = 2.05), vaccination appointment services (MCV1, OR = 2.96; MCV2, OR = 2.74), sufficient and uniformly distributed sessions for routine vaccination (MCV1, OR = 1.28; MCV2, OR = 1.17; MCV1, OR = 2.08), or vaccination service on local market days (MCV1, OR = 2.48). CONCLUSIONS Guardians with poor knowledge, weak beliefs, and little practice towards vaccination; non-involvement of village doctors in routine vaccinations; and inconvenient vaccination services in township hospitals may affect timely measles vaccinations among children in rural China.
Collapse
Affiliation(s)
- Xian-Yan Tang
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China.
| | - Man Cheng
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China
| | - Alan Geater
- Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
| | - Qiu-Yun Deng
- Institute of Vaccination, Guangxi Centre for Disease Control and Prevention, Nanning, Guangxi Zhuang Autonomous Region, China
| | - Ge Zhong
- Institute of Vaccination, Guangxi Centre for Disease Control and Prevention, Nanning, Guangxi Zhuang Autonomous Region, China
| | - Yue-Dong Lin
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China
| | - Ning Chen
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China
| | - Tao Lan
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China
| | - Long-Yan Jiang
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China
| | - Man-Tong Zhu
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China
| | - Qiao Li
- Department of Epidemiology and Biostatistics, School of Public Health, Guangxi Medical University, China. No. 22nd, Shuangyong Road, Nanning, Guangxi Zhuang Autonomous Region, 530021, People's Republic of China.
| |
Collapse
|
4
|
Chong KC, Cheng W, Zhao S, Ling F, Mohammad KN, Wang M, Zee BCY, Wei L, Xiong X, Liu H, Wang J, Chen E. Transmissibility of coronavirus disease 2019 in Chinese cities with different dynamics of imported cases. PeerJ 2020; 8:e10350. [PMID: 33194456 PMCID: PMC7651459 DOI: 10.7717/peerj.10350] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/21/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Monitoring the reproduction number (Rt ) of the disease could help determine whether there is sustained transmission in a population, but areas with similar epidemic trends could have different transmission dynamics given the risk from imported cases varied across regions. In this study, we examined the Rt of coronavirus disease 2019 (COVID-19) by taking different dynamics of imported cases into account and compared the transmissibility of COVID-19 at different intervention periods in Hangzhou and Shenzhen. METHODS We obtained the daily aggregated counts of laboratory-confirmed imported and local cases of COVID-19 infections in Hangzhou and Shenzhen from January 1 to March 13, 2020. Daily Rt and piecewise Rt before and after Wuhan lockdown were estimated, accounting for imported cases. RESULTS Since the epidemic of COVID-19 in Shenzhen was dominated by imported cases, Rt was around 0.1 to 0.7 before the Wuhan lockdown. After the lockdown of Wuhan and the initialization of measures in response to the outbreak, local transmission was well-controlled as indicated by a low estimated value of piecewise Rt , 0.15 (95% CI [0.09-0.21]). On the contrary, Rt obtained for Hangzhou ranged from 1.2 to 4.9 with a piecewise Rt of 2.55 (95% CI [2.13-2.97]) before the lockdown of Wuhan due to the surge in local cases. Because of the Wuhan lockdown and other outbreak response measures, Rt dropped below unity in mid-February. CONCLUSIONS Even though Shenzhen had more cases than Hangzhou, local transmission did not sustain probably due to limited transmission from imported cases owing to the reduction in local susceptibles as residents left the city during Chunyun. The lockdown measures and local outbreak responses helped reduce the local transmissibility.
Collapse
Affiliation(s)
- Ka Chun Chong
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Wei Cheng
- Zhejiang Province Centre for Disease Control and Prevention, Hangzhou, China
| | - Shi Zhao
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Feng Ling
- Zhejiang Province Centre for Disease Control and Prevention, Hangzhou, China
| | - Kirran N. Mohammad
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Maggie Wang
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Benny CY Zee
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Lai Wei
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Xi Xiong
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Hengyan Liu
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Jingxuan Wang
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Enfu Chen
- Zhejiang Province Centre for Disease Control and Prevention, Hangzhou, China
| |
Collapse
|
5
|
Changes in Measles Seroprevalence in China After the Launch of Two Provincial Supplementary Immunization Activities During 2009 to 2013. Pediatr Infect Dis J 2020; 39:867-871. [PMID: 32404783 DOI: 10.1097/inf.0000000000002731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Supplementary immunization activities (SIAs) have been demonstrated being effective in reducing measles incidence within a short period of time in China, but the effects are short-lived if there is no follow-up SIA with high routine immunization coverage. OBJECTIVES To assess the change in measles seroprevalence from 2009 to 2013 after the launch of 2 large-scale SIAs within the period. METHODS Three population-based cross-sectional serologic surveys of measles antibodies were conducted in 2009, 2011 and 2013 in Zhejiang, a province in eastern China, with serologic samples collected from 1541, 896 and 1474 subjects, respectively. The serum levels of immunoglobulin G antibodies were measured by enzyme-linked immunosorbent assay. RESULTS We found that the seropositivity rate among infants 0-7 months of age, a group having no vaccination benefit, was below 80% throughout the study period. In addition, the seropositivity rate among adults 30-49 years of age decreased significantly from 96.0% (95% confidence interval: 93.7%-98.3%) in 2011 to 88.5% (95% confidence interval: 84.3%-92.8%) in 2013. CONCLUSION We showed that large-scale SIAs were effective, but their effects were not long lasting. Given the drop in seropositivity among adults, their susceptibility should be carefully monitored. While older individuals could benefit from the immunization activities, children who were too young to be vaccinated still have a weak seropositivity profile and the optimal age for the administration of the first dose of vaccine should be reconsidered.
Collapse
|
6
|
Lai CKC, Ng RWY, Wong MCS, Chong KC, Yeoh YK, Chen Z, Chan PKS. Epidemiological characteristics of the first 100 cases of coronavirus disease 2019 (COVID-19) in Hong Kong Special Administrative Region, China, a city with a stringent containment policy. Int J Epidemiol 2020; 49:1096-1105. [PMID: 32601677 PMCID: PMC7337784 DOI: 10.1093/ije/dyaa106] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Hong Kong (HK) is a densely populated city near the epicentre of the coronavirus disease 2019 (COVID-19) outbreak. Stringent border control together with aggressive case finding, contact tracing, social distancing and quarantine measures were implemented to halt the importation and spread of the virus. METHODS We performed an epidemiological study using government information covering the first 100 confirmed cases to examine the epidemic curve, incidence, clusters, reproduction number (Rt), incubation period and time to containment. RESULTS A total of 93 of the 100 cases were HK residents (6 infected in Mainland China, 10 on the Diamond Princess Cruise). Seven were visitors infected in Mainland China before entering HK. The majority (76%) were aged ≥45 years, and the incidence increased with age (P < 0.001). Escalation of border control measures correlated with a decrease in the proportion (62.5% to 0%) of cases imported from Mainland China, and a reduction in Rt (1.07 to 0.75). The median incubation period was 4.2 days [95% confidence interval (CI), 4.0-4.5; 5th and 95th percentiles: 1.3 and 14.0). Most clusters with identifiable epidemiological links were households involving 2-4 people. Three medium-spreading events were identified: two from New Year gatherings (6-11 people), and another from environmental contamination of a worship hall (12 people). Despite intensified contact tracing, containment was delayed in 78.9% of cases (mean = 5.96 days, range = 0-24 days). An unusual transmission in a multi-storey building via faulty toilet plumbing was suspected with >100 residents evacuated overnight. Our analysis indicated that faulty plumbing was unlikely to be the source of this transmission. CONCLUSION Timely stringent containment policies minimized the importation and transmission of COVID-19 in HK.
Collapse
Affiliation(s)
- Christopher K C Lai
- Department of Microbiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Rita W Y Ng
- Department of Microbiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Martin C S Wong
- JC School of Public Health and Primary Care, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Ka Chun Chong
- JC School of Public Health and Primary Care, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
- Centre for Health System and Policy Research, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Yun Kit Yeoh
- Department of Microbiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Zigui Chen
- Department of Microbiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Paul K S Chan
- Department of Microbiology, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| |
Collapse
|
7
|
Zheng H, Jia KM, Sun R, Hu P, Wang MH, Zee BCY, Liang W, Chong KC. Epidemiological changes in measles infections in southern China between 2009 and 2016: a retrospective database analysis. BMC Infect Dis 2020; 20:197. [PMID: 32138688 PMCID: PMC7059666 DOI: 10.1186/s12879-020-4919-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 02/26/2020] [Indexed: 11/15/2022] Open
Abstract
Background The incidence rate of measles in China reached a nadir in 2012 after 2 supplementary immunization activities (SIAs) were undertaken in 2009 and 2010. However, the disease began re-emerging in 2013, with a high prevalence rate observed in 2013–2014 in the southern province of Guangdong. In this study, we assessed the changes that occurred in measles epidemiology during 2009–2016, particularly between 2009 and 2011 (when the influence of the SIAs were in full effect) and between 2012 and 2016 (when this influence subsided). Methods Data from 22,362 patients with measles diagnosed between 2009 and 2016, and whose diagnoses were confirmed clinically and/or with laboratory testing, were extracted from the National Infectious Disease Monitoring Information System. Descriptive analyses were performed, and changes in epidemiological characteristics between 2009 and 2011 and 2012–2016 were compared. Results There was a substantial surge in 0–8-month-old patients after 2012; the incidence rate increased from 4.0 per 100,000 population in 2011 (10.3% of the total) to 280 per 100,000 population in 2013 (32.8% of the total). Patients aged 0–6 years represented 73.4% of the total increase between 2011 and 2013. Compared with 2009–2011, adults aged ≥25 years accounted for a higher proportion of patients in 2013 and after (p < 0.01), and were highest in 2016 (31% of the patient total). Conclusion Despite the remarkable results achieved by SIAs in terms of providing herd immunity, the 2013 resurgence of measles revealed insufficient immunization coverage among children. Therefore routine immunization programs should be strengthened, and supplementary vaccinations targeting adults should also be contemplated.
Collapse
Affiliation(s)
- Huizhen Zheng
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
| | - Katherine Min Jia
- Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.
| | - Riyang Sun
- Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Pui Hu
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
| | - Maggie Haitian Wang
- Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.,Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Benny Chung-Ying Zee
- Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.,Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Wenjia Liang
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China.
| | - Ka Chun Chong
- Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China. .,Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
| |
Collapse
|
8
|
Cutts FT, Dansereau E, Ferrari MJ, Hanson M, McCarthy KA, Metcalf CJE, Takahashi S, Tatem AJ, Thakkar N, Truelove S, Utazi E, Wesolowski A, Winter AK. Using models to shape measles control and elimination strategies in low- and middle-income countries: A review of recent applications. Vaccine 2020; 38:979-992. [PMID: 31787412 PMCID: PMC6996156 DOI: 10.1016/j.vaccine.2019.11.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 01/30/2023]
Abstract
After many decades of vaccination, measles epidemiology varies greatly between and within countries. National immunization programs are therefore encouraged to conduct regular situation analyses and to leverage models to adapt interventions to local needs. Here, we review applications of models to develop locally tailored interventions to support control and elimination efforts. In general, statistical and semi-mechanistic transmission models can be used to synthesize information from vaccination coverage, measles incidence, demographic, and/or serological data, offering a means to estimate the spatial and age-specific distribution of measles susceptibility. These estimates complete the picture provided by vaccination coverage alone, by accounting for natural immunity. Dynamic transmission models can then be used to evaluate the relative impact of candidate interventions for measles control and elimination and the expected future epidemiology. In most countries, models predict substantial numbers of susceptible individuals outside the age range of routine vaccination, which affects outbreak risk and necessitates additional intervention to achieve elimination. More effective use of models to inform both vaccination program planning and evaluation requires the development of training to enhance broader understanding of models and where feasible, building capacity for modelling in-country, pipelines for rapid evaluation of model predictions using surveillance data, and clear protocols for incorporating model results into decision-making.
Collapse
Affiliation(s)
- F T Cutts
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
| | - E Dansereau
- Vaccine Delivery, Global Development, The Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - M J Ferrari
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - M Hanson
- Vaccine Delivery, Global Development, The Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - K A McCarthy
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005, USA
| | - C J E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - S Takahashi
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - A J Tatem
- WorldPop, Department of Geography and Environmental Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - N Thakkar
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005, USA
| | - S Truelove
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - E Utazi
- WorldPop, Department of Geography and Environmental Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - A Wesolowski
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - A K Winter
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
9
|
Lei M, Wang K, Li J, Zhang Y, Wei X, Qi L, Zhou G, Wu Y. Phylogenetic and Epidemiological Analysis of Measles Viruses in Shenzhen, China from January 2015 to July 2019. Med Sci Monit 2019; 25:9245-9254. [PMID: 31800568 PMCID: PMC6911309 DOI: 10.12659/msm.920614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background Measles morbidity and mortality were significantly reduced after the measles vaccine was introduced in China in 1965. However, measles outbreaks easily occur in densely populated areas, especially where there is no universal vaccination. The outbreak that occurred in Shenzhen, the Chinese city with the largest internal immigration, provides a lesson in measles virus mutation and measles prevention. The present study is a phylogenetic analysis of measles viruses and comparison of clinical signs between individuals with and without vaccination. Material/Methods We performed phylogenetic analysis of the nucleoprotein (N) genes of measles virus from 129 measles patients in Shenzhen from January 2015 to July 2019. Phylogenetic trees were constructed using the neighbor-joining method. Results The phylogenetic analysis showed all viruses were classified into genotype H1. In addition, there is often a seasonal measles outbreak in July each year. The clinical data showed that patients who were unvaccinated were more likely to have coughing, chronic bronchitis, conjunctivitis, catarrh, Koplik spots, and diarrhea. Children of migrant workers and those living in mountainous and rural districts accounted for most measles cases. Conclusions Our results showed there was a seasonal measles outbreak in Shenzhen Children’s Hospital. All the measles virus from 129 measles patients were H1 viruses. The clinical signs also showed a difference between unvaccinated and vaccinated patients. Moreover, most of the unvaccinated patients came from migrant worker families. We suggest there is a need for increased health promotion and vaccination programs for migrant workers and people living in remote villages.
Collapse
Affiliation(s)
- Min Lei
- Department of Infectious Diseases, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Kai Wang
- Department of Nephrology, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Jing Li
- Department of Respiration, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Yan Zhang
- Department of Clinical Laboratory, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Xuemei Wei
- Department of Infectious Diseases, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Lifeng Qi
- Department of Infectious Diseases, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Gaofeng Zhou
- Department of Infectious Diseases, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| | - Yue Wu
- Department of Pharmacy, Shenzhen Children's Hospital, Shenzhen, Guangdong, China (mainland)
| |
Collapse
|
10
|
Chong KC, Rui Y, Liu Y, Zhou T, Jia K, Wang MH, Mohammad KN, He H. Early Waning of Maternal Measles Antibodies in Infants in Zhejiang Province, China: A Comparison of Two Cross-Sectional Serosurveys. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16234680. [PMID: 31771262 PMCID: PMC6926550 DOI: 10.3390/ijerph16234680] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/14/2019] [Accepted: 11/21/2019] [Indexed: 01/28/2023]
Abstract
In China, children aged <8 months, who were expected to be protected by maternal antibodies before receiving the first dose of measles vaccine, were the age group with the greatest risk of infection in recent years. In this study, we evaluated whether infants yet to be age-eligible for measles vaccine had a sufficient seropositive level of maternal measles antibodies in 2009 and 2013. Blood samples were collected from infants aged <8 months through population-based serological surveys conducted in Zhejiang, China. Serum levels of immunoglobulin G measles antibodies were quantified using enzyme-linked immunosorbent assay. In 2013, the mean geometric mean titres (GMTs) of infants aged 4 to 8 months were below the seropositivity threshold (<200 mIU/mL), decreasing from 118.6 mIU/mL (95% confidence interval [CI] 83.0, 169.3 mIU/mL) at 4 months to 28.6 mIU/mL (95% CI 15.6, 52.3 mIU/mL) at 7 months. Antibody levels were significantly lower in 2013 than in 2009 starting from 5 months of age. In conclusion, infants aged 4 to 8 months are susceptible to measles due to low levels of maternal measles antibodies. It is thus suggested to provide infants with a supplementary dose on top of the routine schedule, and/or launch catch-up vaccination campaigns among young women.
Collapse
Affiliation(s)
- Ka Chun Chong
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; (K.C.C.); (Y.L.); (T.Z.); (K.J.); (M.H.W.)
- Clinical Trials and Biostatistics Laboratory Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Yan Rui
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310058, China;
| | - Yan Liu
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; (K.C.C.); (Y.L.); (T.Z.); (K.J.); (M.H.W.)
| | - Tianyuan Zhou
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; (K.C.C.); (Y.L.); (T.Z.); (K.J.); (M.H.W.)
| | - Katherine Jia
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; (K.C.C.); (Y.L.); (T.Z.); (K.J.); (M.H.W.)
| | - Maggie Haitian Wang
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; (K.C.C.); (Y.L.); (T.Z.); (K.J.); (M.H.W.)
- Clinical Trials and Biostatistics Laboratory Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Kirran N. Mohammad
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; (K.C.C.); (Y.L.); (T.Z.); (K.J.); (M.H.W.)
- Correspondence: (K.N.M.); (H.H.)
| | - Hanqing He
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310058, China;
- Correspondence: (K.N.M.); (H.H.)
| |
Collapse
|
11
|
Measles transmission during a large outbreak in California. Epidemics 2019; 30:100375. [PMID: 31735584 PMCID: PMC7211428 DOI: 10.1016/j.epidem.2019.100375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 10/26/2019] [Accepted: 10/29/2019] [Indexed: 02/07/2023] Open
Abstract
A large measles outbreak in 2014–2015, linked to Disneyland theme parks, attracted international attention, and led to changes in California vaccine policy. We use dates of symptom onset and known epidemic links for California cases in this outbreak to estimate time-varying transmission in the outbreak, and to estimate generation membership of cases probabilistically. We find that transmission declined significantly during the course of the outbreak (p = 0.012), despite also finding that estimates of transmission rate by day or by generation can overestimate temporal decline. We additionally find that the outbreak size and duration alone are sufficient in this case to distinguish temporal decline from time-invariant transmission (p = 0.014). As use of a single large outbreak can lead to underestimates of immunity, however, we urge caution in interpretation of quantities estimated from this outbreak alone. Further research is needed to distinguish causes of temporal decline in transmission rates.
Collapse
|