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Chong KC, Jia KM. Accelerate the elimination of rubella through supplementary immunisation activities in China. THE LANCET. INFECTIOUS DISEASES 2021; 21:899-900. [PMID: 33515509 DOI: 10.1016/s1473-3099(20)30715-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 08/24/2020] [Indexed: 11/24/2022]
Affiliation(s)
- Ka Chun Chong
- Centre for Health Systems and Policy Research, School of Public Health and Primary Care and Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
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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.
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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
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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.
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Urabe CT, Tanaka G, Oshima T, Maruyama A, Misaki T, Okabe N, Aihara K. Comparing catch-up vaccination programs based on analysis of 2012-13 rubella outbreak in Kawasaki City, Japan. PLoS One 2020; 15:e0237312. [PMID: 32797060 PMCID: PMC7428070 DOI: 10.1371/journal.pone.0237312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 07/26/2020] [Indexed: 11/28/2022] Open
Abstract
During the 2012–13 rubella outbreak in Japan, local governments implemented subsidy programs for catch-up vaccination to mitigate the rubella outbreak and prevent congenital rubella syndrome (CRS). In most local governments, to prevent CRS, eligible persons of the subsidy program were women who were planning to have a child and men who were partners of pregnant women. On the other hand, in Kawasaki City, unimmunized men aged 23–39 years were additionally included in the eligible persons, because they were included in an unimmunized men group resulting from the historical transition of the national routine vaccination in Japan. The number of rubella cases in the city decreased earlier than that in the whole Japan. First, in order to estimate the effect of the catch-up vaccination campaign in Kawasaki City on the epidemic outcome, we performed numerical simulations with a Susceptible-Vaccinated-Exposed-Infectious-Recovered (SVEIR) model incorporating real data. The result indicated that the catch-up vaccination campaign showed a beneficial impact on the early decay of the rubella cases. Second, we numerically compared several different implementation strategies of catch-up vaccinations under a fixed amount of total vaccinations. As a result, we found that early and intensive vaccinations are vital for significant reduction in the number of rubella cases and CRS occurrences. Our study suggests that mathematical models with epidemiological and social data can contribute to identifying the most effective vaccination strategy.
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Affiliation(s)
- Chiyori T. Urabe
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
| | - Gouhei Tanaka
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
- Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | | | - Aya Maruyama
- Kawasaki City Institute for Public Health, Kawasaki, Japan
| | - Takako Misaki
- Kawasaki City Institute for Public Health, Kawasaki, Japan
| | - Nobuhiko Okabe
- Kawasaki City Institute for Public Health, Kawasaki, Japan
| | - Kazuyuki Aihara
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
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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.
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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
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Ding Y, Chen W, Lei Y, Mao N, Gao Z, Xu W, Zhang Y. Evaluating the population measles susceptibility in Tianjin, China. Vaccine 2020; 38:4829-4836. [PMID: 32482462 DOI: 10.1016/j.vaccine.2020.05.053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/09/2020] [Accepted: 05/17/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Measles is a highly infectious illness requiring herd immunity of 95% to interrupt transmission. China has not reached elimination goals despite high vaccination coverage. We estimated the population susceptibility against measles in Tianjin, China and to tailor awareness raising activities in the measles elimination plan. METHODS Age-specific measles seroprevalence was evaluated by Enzyme-Linked Immunosorbent Assay (ELISA) on 12,164 individual aged 0-44 years in 2009-2018. Measles IgG avidity testing was performed to confirm the relationship of the waning immunity after vaccination and secondary vaccination failures (SVF) on 324 confirmed measles cases in 2013-2018. RESULTS 11,108 samples (91.32%) tested positive for measles IgG, 239 (1.96%) tested as equivocal and 817 (6.72%) were negative. The age distribution of measles cases in Tianjin followed a U-shaped curve and was highest for those at <8 months and again at 20-39 years which correlated closely with the age distribution of measles susceptibility based on measles IgG antibody status (r = 0.72, P < 0.001). The seropositivity rate and antibody geometric mean concentration (GMC) for the 2018 study population were significantly lower (χ2 = 7.45, P = 0.006 and t = 12.01, P < 0.001) compared to 2009. The multivariate stepwise logistic regression analysis showed that age and region were the risk factors for both measles seropositivity rate and GMC after vaccination. The proportion of high avidity cases increased with age, being significantly higher in 75.31% of cases in patients aged 30-34 years (χ2 = 18.04, P = 0.003). CONCLUSIONS High immunization coverage in children alone will not be adequate to realizing sufficient levels of population herd immunity, particularly given that the potential susceptibility window in adult. Implementation of supplemental immunization activity (SIA) targeted to appropriate group aged 30-34 years is recommended.
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Affiliation(s)
- Yaxing Ding
- Department of Expanded Program Immunization, Tianjin Center for Disease Control and Prevention, 6 Hua Yue Street, Hedong District, Tianjin 300011, China.
| | - Wei Chen
- Department of Expanded Program Immunization, Tianjin Center for Disease Control and Prevention, 6 Hua Yue Street, Hedong District, Tianjin 300011, China
| | - Yue Lei
- Department of Viral Laboratory, Tianjin Center for Disease Control and Prevention, 6 Hua Yue Street, Hedong District, Tianjin 300011, China
| | - Naiying Mao
- NHC Key Laboratory of Medical Virology and Viral Diseases and WHO WPRO Regional Reference Measles/Rubella Laboratory, National Institute for Viral Disease Control and Prevention, Chinese Center for Diseases Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Zhigang Gao
- Department of Expanded Program Immunization, Tianjin Center for Disease Control and Prevention, 6 Hua Yue Street, Hedong District, Tianjin 300011, China
| | - Wenbo Xu
- National Institute for Viral Disease Control and Prevention, Chinese Center for Diseases Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
| | - Ying Zhang
- Institute for Infectious Diseases Control and Prevention, Tianjin Center for Disease Control and Prevention, 6 Hua Yue Street, Hedong District, Tianjin 300011, China
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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.
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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.
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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.
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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.)
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Chong KC, Hu P, Chan SY, Liang W, Mohammad KN, Sun R, Wang MH, Zee BCY, Shi D, Zheng H. Were infections in migrants associated with the resurgence of measles epidemic during 2013-2014 in southern China? A retrospective data analysis. Int J Infect Dis 2019; 90:77-83. [PMID: 31634615 DOI: 10.1016/j.ijid.2019.10.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/03/2019] [Accepted: 10/13/2019] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVE The 2009 province-wide and 2010 nationwide supplementary immunization activities (SIAs) greatly reduced measles prevalence in Guangdong, a province in southern China with the largest migrant population. However, during 2013-2014, Guangdong experienced a resurgence of the measles epidemic. This study was performed to examine the association between infections in migrants and the resurgence of the measles epidemic. METHODS The records of 22 362 clinically and laboratory-confirmed measles cases from the years 2009 to 2014 were extracted from the National Infectious Disease Monitoring Information System. The epidemiological characteristics of infections in migrants during 2009-2012 were compared to those during 2013-2014. RESULTS Infections in migrants were not significantly associated with the resurgence of the measles epidemic in 2013-2014 (p=0.98). Nevertheless, for infections among locals and migrants during 2009-2012 and 2013-2014, substantial increases in the proportion of infection were detected among children aged <8 months and the unvaccinated population (p<0.01). CONCLUSIONS The study findings suggest that infections in migrants might not have been the major cause of the epidemic resurgence of measles. Instead, the resurgence was likely due to infections among children aged <8 months and the unvaccinated. Thus, officials are advised to give higher priority to appropriate populations when formulating control measures, and to strengthen routine surveillance of vaccination coverage among them.
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Affiliation(s)
- Ka Chun Chong
- 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, Hong Kong, China
| | - Pei Hu
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
| | - See Yeung Chan
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Wenjia Liang
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
| | - Kirran N Mohammad
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Riyang Sun
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Maggie Haitian Wang
- 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, Hong Kong, China
| | - Benny Chung Ying Zee
- 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, Hong Kong, China
| | - Duorui Shi
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.
| | - Huizhen Zheng
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China.
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Wu JN, Zhou Y. Factors associated with and screening models of national immunization programme vaccine series completion among preschool children in Fujian Province, south-eastern China. J Infect Public Health 2018; 12:236-241. [PMID: 30442526 DOI: 10.1016/j.jiph.2018.10.011] [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: 05/25/2018] [Revised: 10/21/2018] [Accepted: 10/23/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND An effective method for the rapid identification of vulnerable preschool children at risk of not completing the national immunization programme (NIP) vaccine series in China is still lacking. METHODS A cross-sectional study involving 772 preschool children born between September 1 2009 and August 31, 2011 was conducted in 2015 in Fujian Province, south-eastern China. The data were collected by face-to-face interviews with the parents or guardians of the children using a standard questionnaire. RESULTS Children who received the first dose of a hepatitis B vaccine (HepB) less than 24h after birth and those who received one or more doses of surrogate for-fee vaccines (SFVs) were more likely to complete the NIP vaccine series with adjusted odds ratios (ORs) of 3.12 (95% confidence interval [CI]: 1.19-8.23) and 4.74 (1.41-15.90), respectively. The cut-off value of the prediction score for the completion of the NIP vaccine series was 92.5%, and the sensitivity, specificity, and positive and negative predictive values were 87.5%, 47.1%, 11.4% and 98.0%, respectively. CONCLUSIONS The receipt of a timely first dose of HepB and one or more doses of SFVs were associated with and good predictors of NIP vaccine series completion by preschool children in Fujian, China.
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Affiliation(s)
- Jiang-Nan Wu
- Department of Clinical Epidemiology, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China.
| | - Yong Zhou
- Fujian Provincial Centers for Disease Control and Prevention, Fuzhou, 350000, China.
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Targeting Adults for Supplementary Immunization Activities of Measles Control in Central China: A Mathematical Modelling Study. Sci Rep 2018; 8:16124. [PMID: 30382120 PMCID: PMC6208397 DOI: 10.1038/s41598-018-34461-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 10/18/2018] [Indexed: 11/17/2022] Open
Abstract
Routine immunizations and supplementary immunization activities (SIAs) have significantly improved measles control over the past two decades in China. Progress towards eliminating measles currently faces multiple challenges as the infection age increases, and adult-targeted SIA strategies are being considered. This study developed an age-stratified susceptible-exposed-infectious-recovered model using a recently published contact matrix to depict measles transmissions between individuals in seven age groups. Hubei, a high measles-incidence province in central China, was the selected setting. The baseline scenario was calibrated by fitting with the 2012–2015 age-stratified incidence data. SIAs targeting multiple age groups were simulated. Adult-targeted (>29 years) two-year SIA cycles produced the greatest annual incidence rate decrease, reducing incidences by half over a long timespan with 90% coverage levels. Incidences could remain below 10/100,000 until 2030 if SIAs were provided to individuals ≥6 years old with at least 50% coverage. These findings will help officials prioritize supplementary vaccination strategies. Public health officials in China should consider adult-to-adult transmissions and provide adult-targeted SIAs. Although officials have reported approximately 90% SIA coverage in the past, SIAs for the adult population should be provided on shorter intervals, particularly for the aging population with decreased immunity.
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Chong KC, Hu P, Lau S, Jia KM, Liang W, Wang MH, Zee BCY, Sun R, Zheng H. Monitoring the age-specificity of measles transmissions during 2009-2016 in Southern China. PLoS One 2018; 13:e0205339. [PMID: 30296273 PMCID: PMC6175510 DOI: 10.1371/journal.pone.0205339] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 09/24/2018] [Indexed: 12/19/2022] Open
Abstract
Background Despite several immunization efforts, China saw a resurgence of measles in 2012. Monitoring of transmissions of individuals from different age groups could offer information that would be valuable for planning adequate disease control strategies. We compared the age-specific effective reproductive numbers (R) of measles during 2009–2016 in Guangdong, China. Methods We estimated the age-specific R values for 7 age groups: 0–8 months, 9–18 months, 19 months to 6 years, 7–15 years, 16–25 years, 26–45 years, and ≥46 years adapting the contact matrix of China. The daily numbers of laboratory and clinically confirmed cases reported to the Center for Disease Control and Prevention of Guangdong were used. Results The peak R values of the entire population were above unity from 2012 to 2016, indicating the persistence of measles in the population. In general, children aged 0–6 years and adults aged 26–45 years had larger values of R when comparing with other age groups after 2012. While the peaks of R values for children aged 0–6 years dropped steadily after 2013, the peaks of R values for adults aged 26–45 years kept at a high range every year. Conclusions Although the provincial supplementary immunization activities (SIAs) conducted in 2009 and 2010 were able to reduce the transmissions from 2009 to 2011, larger values of R for children aged 0–6 years were observed after 2012, indicating that the benefits of the SIAs were short-lived. In addition, the transmissions from adults aged between 26 and 45 years increased over time. Disease control strategies should target children and adult groups that carry high potential for measles transmission.
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Affiliation(s)
- Ka Chun Chong
- JC 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, Hong Kong, China
| | - Pei Hu
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
| | - Steven Lau
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Katherine Min Jia
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
| | - Wenjia Liang
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
| | - Maggie Haitian Wang
- JC 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, Hong Kong, China
| | - Benny Chung Ying Zee
- JC 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, Hong Kong, China
| | - Riyang Sun
- JC School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China
- * E-mail: (HZ); (RS)
| | - Huizhen Zheng
- Center for Disease Control and Prevention of Guangdong Province, Guangzhou, China
- * E-mail: (HZ); (RS)
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