Strategies to Improve Smoking Cessation for Participants in Lung Cancer Screening Program: Analysis of Factors Associated with Smoking Cessation in Korean Lung Cancer Screening Project (K-LUCAS).

PURPOSE: Smoking cessation intervention is one of the key components of successful lung cancer screening program. We investigated the effectiveness and related factors of smoking cessation services provided to the participants in a population-based lung cancer screening trial. MATERIALS AND METHODS: The Korean Lung Cancer Screening Project (K-LUCAS) is a nationwide, multi-center lung cancer screening trial that evaluates the feasibility of implementing population-based lung cancer screening. All 5,144 current smokers who participated in the K-LUCAS received a mandatory smoking cessation counseling. Changes in smoking status were followed up using a telephone survey in 6 months after lung cancer screening participation. The lung cancer screening's impact on smoking cessation is analyzed by variations in the smoking cessation interventions provided in screening units. RESULTS: Among 4,136 survey responders, participant's motivation to quit smoking increased by 9.4% on average after lung cancer screening. After 6 months from the initial screening, 24.3% of participants stopped smoking, and 10.6% of participants had not smoked continuously for at least 6 months after screening. Over 80% of quitters stated that participation in lung cancer screening motivated them to quit smoking. Low-cost public smoking cessation program combined with lung cancer screening increased the abstinence rates. The smokers were three times more likely to quit smoking when the smoking cessation counseling was provided simultaneously with low-dose computed tomography screening results than when provided separately. CONCLUSION: A mandatory smoking cessation intervention integrated with screening result counselling by a physician after participation in lung cancer screening could be effective for increasing smoking cessation attempts.

Feasibility of implementing a national lung cancer screening program: Interim results from the Korean Lung Cancer Screening Project (K-LUCAS).

BACKGROUND: Lung cancer screening conducted in high-risk group using low-dose computer tomography (LDCT) has been reported as an effective method to reduce lung cancer mortality in two large randomized-control trials. However, the effectiveness is uncertain when lung cancer screening is expanded to a nationwide population-based program. METHODS: The Korean Lung Cancer Screening Project (K-LUCAS) is a single-arm cohort study that was conducted from February 2017 to evaluate the feasibility of implementing an organized national lung cancer screening program in Korea. High-risk population aged 55-74 years with more than a 30-pack-year smoking history was recruited. Smoking history was obtained from administering questionnaires at national health screening programs or public smoking cessation programs which are already established programs in Korea. The screening results were reported using the Lung Imaging Reporting and Data System (Lung-RADS), suggested by the American College of Radiology. K-LUCAS was performed by a network-based diagnosis supporting system using a computer-aided detection (CAD) program to maintain screening quality. Current smokers were provided with mandatory smoking counseling. RESULTS: Among 71,829 participants aged 50 years or older in the national health screening program, 5,975 (8.3%) were eligible for lung cancer screening. Among them, 1,062 (17.8%) refused to participate in K-LUCAS. Additionally, 779 participants were recruited in the smoking cessation program. Thus, a total of 5,692 eligible high-risk participants were recruited in this study. Among them, 865 (15.2%) had positive screening results, which requires a further examination; 529 (9.3%) had Lung-RADS category 3 (indeterminate), and 336 (5.9%) had category 4 (suspicious of lung cancer); 42 (0.7%) had confirmed lung cancer. Approximately 66.7% had early-stage lung cancer: 24 (57.1%), stage I and 4 (9.5%), stage II. Six (1.1%) patients developed complications at the time of diagnosis, including one death. The anxiety level related to cancer screening was low. Participation in screening encouraged motivation to quit smoking. CONCLUSIONS: K-LUCAS provided promising evidence supporting the implementation of a national lung cancer screening program to detect early stage lung cancer and promote smoking cessation for participants in Asian population.

Radiotherapy can increase the risk of ischemic cerebrovascular disease in head and neck cancer patients: A Korean population-based cohort study.

BACKGROUND AND PURPOSE: Several reports suggested that radiotherapy (RT) was related to an increased risk of cerebrovascular disease (CVD) in head and neck cancer (HNC) patients, but other risk factors of CVD were not properly considered in estimating the risk of RT. The purpose of this study is to analyze the effect of RT on the risk of CVD in HNC patients. MATERIALS AND METHODS: The Korean Central Cancer Registry data and Korean National Health Insurance Service data were used. A total of 5570 patients with newly diagnosed HNC between the years 2003-2005 was included in our study cohort. We analyzed the effect of treatment modality and other socioeconomic variables on ischemic CVD incidence using the Cox proportional hazard regression model both in the entire cohort (n = 5570) and in the propensity score matching (PSM) cohort (n = 3310). RESULTS: RT increased the CVD risk by 40.8% (aHR: 1.408, p = 0.006) in the entire cohort and by 44.3% (aHR: 1.443, p = 0.047) in the PSM cohort, respectively. CONCLUSION: The risk of ischemic CVD increased by RT after adjusting for other socioeconomic and clinical risk factors. Regular follow up and appropriate screening for CVD are required for HNC patients who received RT, and focus should be on advanced-age patients with a low socioeconomic status and known clinical risk factors of CVD.

Development of Protocol for Korean Lung Cancer Screening Project (K-LUCAS) to Evaluate Effectiveness and Feasibility to Implement National Cancer Screening Program.

PURPOSE: To reduce lung cancer mortality, lung cancer screening was recommended using low-dose computed tomography (LDCT) to high-risk population. A protocol for multicenter lung cancer screening pilot project was developed to evaluate the effectiveness and feasibility of lung cancer screening to implement National Cancer Screening Program in Korea. MATERIALS AND METHODS: Multidisciplinary expert committee was comprised to develop a standardized protocol for Korean Lung Cancer Screening Project (K-LUCAS). K-LUCAS is a population-based single arm trial that targets high-risk population aged 55-74 years with at least 30 pack-year smoking history. LDCT results are reported by Lung-RADS suggested by American Radiology Society. Network-based system using computer-aided detection program is prepared to assist reducing diagnostic errors. Smoking cessation counselling is provided to all currently smoking participants. A small pilot test was conducted to check the feasibility and compliance of the protocols for K-LUCAS. RESULTS: In pilot test, 256 were participated. The average age of participants was 63.2 years and only three participants (1.2%) were female. The participants had a smoking history of 40.5 pack-year on average and 53.9% were current smokers. Among them, 86.3% had willing to participate in lung cancer screening again. The average willingness to quit smoking among current smokers was 12.7% higher than before screening. In Lung-RADS reports, 10 (3.9%) were grade 3 and nine (3.5%) were grade 4. One participant was diagnosed as lung cancer. CONCLUSION: The protocol developed by this study is assessed to be feasible to perform K-LUCAS in multicenter nationwide scale.

Geographical Variations and Trends in Major Cancer Incidences throughout Korea during 1999-2013.

PURPOSE: We aimed to describe the temporal trends and district-level geographical variations in cancer incidences throughout Korea during 1999-2013. MATERIALS AND METHODS: Data were obtained from the Korean National Cancer Incidence Database. We calculated the age-standardized cumulative cancerincidences according to sex and geographicalregion (metropolitan cities, provinces, and districts) for three 5-year periods (1999-2003, 2004- 2008, and 2009-2013). Each quintile interval contained the same number of regions. Disease maps were created to visualize regional differences in the cancer incidences. RESULTS: Substantial differences in cancer incidences were observed according to district and cancer type. The largest variations between geographical regions were found for thyroid cancer among both men and women. There was little variation in the incidences of stomach, colorectal, and lung cancer according to geographical region. Substantially elevated incidences of specific cancers were observed in Jeollanam-do (thyroid); Daejeon (colorectum); Jeollanam-do, Gyeongsangbuk-do, and Chungcheongbuk-do (lung); Seocho-gu, Gangnam-gu and Seongnam, Bundang-gu (breast and prostate); Chungcheong and Gyeongsang provinces (stomach); Ulleung-gun and the southern districts of Gyeongsangnam-do and Jeollanam-do (liver); and along the Nakdonggang River (gallbladder and biliary tract). CONCLUSION: Mapping regional cancer incidences in Korea allowed us to compare the results according to geographical region. Our results may facilitate the development of infrastructure for systematic cancerincidence monitoring,which could promote the planning and implementation of region-specific cancer management programs.

Joint Symposium of Korean Cancer Association & UICC-ARO-Cross-boundary cancer studies: cancer and Universal Health Coverage (UHC) in Asia.

On 16 June 2016, the Korean Cancer Association (KCA) and Union for International Cancer Control-Asia Regional Office (UICC-ARO) organized a joint symposium as part of the official program of the 42nd Annual Meeting of the Korean Cancer Association to discuss the topic 'Cross-boundary Cancer Studies: Cancer and Universal Health Coverage (UHC) in Asia.' Universal Health Coverage is included in the Sustainable Development Goals adopted by the United Nations as part of the 2030 Agenda for Sustainable Development. The objectives of UHC are to ensure that all people can receive high-quality medical services, are protected from public health risks, and are prevented from falling into poverty due to medical costs or loss of income arising from illness. The participants discussed the growing cost of cancer in the Asian region and the challenges that this poses to the establishment and deployment of UHC in the countries of Asia, all of which face budgetary and other systemic constraints in controlling cancer in the region. Representatives from Korea, Japan and Indonesia reported on the status of UHC in their countries and the challenges that are being faced, many of which are common to other countries in Asia. In addition to country-specific presentations about the progress of and challenges facing UHC, there were also presentations from WHO Kobe Centre concerning advancing UHC in non-communicable diseases and prospects for further collaboration and research on UHC. A presentation from the University of Tokyo also highlighted the need to focus on multidisciplinary studies in an age of globalization and digitization.

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2014.

PURPOSE: This study presents the 2014 nationwide cancer statistics in Korea, including cancer incidence, survival, prevalence, and mortality. MATERIALS AND METHODS: Cancer incidence data from 1999 to 2014 was obtained from the Korea National Cancer Incidence Database and followed until December 31, 2015. Mortality data from 1983 to 2014 were obtained from Statistics Korea. The prevalence was defined as the number of cancer patients alive on January 1, 2015, among all cancer patients diagnosed since 1999. Crude and age-standardized rates (ASRs) for incidence, mortality, prevalence, and 5-year relative survivals were also calculated. RESULTS: In 2014, 217,057 and 76,611 Koreans were newly diagnosed and died from cancer respectively. The ASRs for cancer incidence and mortality in 2014 were 270.7 and 85.1 per 100,000, respectively. The all-cancer incidence rate has increased significantly by 3.4% annually from 1999 to 2012, and started to decrease after 2012 (2012-2014; annual percent change, -6.6%). However, overall cancer mortality has decreased 2.7% annually since 2002. The 5-year relative survival rate for patients diagnosed with cancer between 2010 and 2014 was 70.3%, an improvement from the 41.2% for patients diagnosed between 1993 and 1995. CONCLUSION: Age-standardized cancer incidence rates have decreased since 2012 and mortality rates have also declined since 2002, while 5-year survival rates have improved remarkably from 1993-1995 to 2010-2014 in Korea.

Prediction of Cancer Incidence and Mortality in Korea, 2017.

PURPOSE: This study aimed to report on cancer incidence and mortality for the year 2017 in Korea in order to estimate the nation's current cancer burden. MATERIALS AND METHODS: Cancer incidence data from 1999 to 2014 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2015 were acquired from Statistics Korea. Cancer incidence and mortality were projected by fitting a linear regression model to observe age-specific cancer rates against observed years, and then multiplying the projected age-specific rates by the age-specific population. The Joinpoint regression model was used to determine at which year the linear trend changed significantly; we only used data of the latest trend. RESULTS: A total of 221,143 new cancer cases and 80,268 cancer deaths are expected to occur in Korea in 2017. The most common cancer sites are the colorectum, stomach, lung, thyroid, and breast. These five cancers represent half of the overall burden of cancer in Korea. For mortality, the most common sites are the lung, liver, colorectal, stomach, and pancreas. CONCLUSION: The incidence rate of all cancers in Korea appears to have decreased mainly because of a decrease in thyroid cancer. These up-to-date estimates of the cancer burden in Korea could be an important resource for planning and evaluation of cancer-control programs.

Prediction of Cancer Incidence and Mortality in Korea, 2016.

PURPOSE: To estimate of Korea's current cancer burden, this study aimed to report on projected cancer incidence and mortality rates for the year 2016. MATERIALS AND METHODS: Cancer incidence data from 1999 to 2013 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2014 were acquired from Statistics Korea. Cancer incidence in 2016 was projected by fitting a linear regression model to observed age-specific cancer incidence rates against observed years, then multiplying the projected age-specific rates by the age-specific population. The Joinpoint regression model was used to determine at which year the linear trend changed significantly. RESULTS: A total of 254,962 new cancer cases and 75,172 cancer deaths are expected to occur in Korea in 2016. The five leading primary cancer incident sites in 2016 were estimated colorectal, stomach, lung, liver and thyroid cancer in men; thyroid, breast, colorectal, stomach, and lung cancer in women. CONCLUSION: Currently cancer is one of the foremost public health concerns in Korea. Although cancer rates are anticipated to decrease the nation's cancer burden will continue to increase as the population ages.

Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2013.

PURPOSE: This study described the 2013 nationwide cancer statistics in Korea, including cancer incidence, survival, prevalence, and mortality. MATERIALS AND METHODS: Cancer incidence data from 1999-2013 were obtained from Korea National Cancer Incidence Database and followed until December 31, 2014. Mortality data from 1983-2013 were obtained from Statistics Korea. The prevalence was defined as the number of cancer patients alive on January 1, 2014 among all cancer patients diagnosed since 1999. Crude, and age-standardized and 5-year relative survival rates were also calculated. RESULTS: In 2013, a total of 225,343 and 75,334 Koreans were newly diagnosed and died from cancer, respectively. The age-standardized rates for cancer incidence and mortality in 2013 were 290.5 and 87.9 per 100,000, respectively. The age-standardized cancer incidence rate increased 3.1% annually between 1999 and 2013. However, the overall cancer incidence rates have decreased slightly in recent years (2011 to 2013). The age-standardized rate for all-cancer mortality has decreased 2.7% annually since 2002. Overall, the 5-year relative survival rate for people diagnosed with cancer between 2009 and 2013 was 69.4%, which represents an improved survival rate as compared with 41.2% for people diagnosed between 1993 and 1995. CONCLUSION: Age-standardized cancer incidence rates have decreased between 2011 and 2013; mortality rates have also declined since 2002, while 5-year survival rates have improved remarkably from 1993-1995 to 2009-2013 in Korea.

Trends in Cancer Screening Rates among Korean Men and Women: Results of the Korean National Cancer Screening Survey, 2004-2013.

PURPOSE: The Korean National Cancer Screening Survey (KNCSS), a nationwide cross-sectional survey, has been conducted annually since 2004. The current study was conducted to report on the trends in screening rates among Korean men and women, and to evaluate policies regarding cancer screening programs implemented to reduce the burden of cancer. MATERIALS AND METHODS: The current study used KNCSS data. The eligible study population included men aged 40-74 years and women aged 30-74 years with no cancer history. The lifetime screening rate, screening rate with recommendation, and changes in annual rates were calculated for five major cancers (i.e., stomach, liver, colorectal, breast, and cervix uteri). RESULTS: The screening rates with recommendation increased by 4.2% (95% confidence interval [CI], 3.7% to 4.8%) annually for stomach cancer, 1.2% (95% CI, 0.1% to 2.4%) for liver cancer, 3.0% (95% CI, 1.8% to 4.1%) for colorectal cancer, 3.7% (95% CI, 2.7% to 4.8%) for breast cancer, and 1.3% (95% CI, 0.8% to 1.8%) for cervical cancer. In 2013, the screening rates with recommendation for stomach, liver, colorectal, breast, and cervical cancers were 73.6%, 33.6%, 55.6%, 59.7%, and 67.0%, respectively. CONCLUSION: Both the lifetime screening rates and screening rates with recommendation for the five above-mentioned cancers increased annually from 2004 to 2013.

Prediction of cancer incidence and mortality in Korea, 2015.

PURPOSE: For estimation of Korea's current cancer burden, this study aimed to report on the projected cancer incidence and mortality rates for the year 2015. MATERIALS AND METHODS: Cancer incidence data from 1999 to 2012 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2013 were acquired from Statistics Korea. The cancer incidence in 2015 was projected by fitting a linear regression model to the observed age-specific cancer incidence rates against the observed years and then multiplying the projected age-specific rates by the age-specific population. A similar procedure was used for cancer mortality, except a Joinpoint regression model was used to determine at which year the linear trend changed significantly. RESULTS: A total of 280,556 new cancer cases and 76,698 cancer deaths are expected to occur in Korea in 2015. The crude incidence rate per 100,000 of all sites combined will likely reach 551.6 and the age-standardized incidence rate, 347.6. The estimated five leading primary cancer incidence sites are the stomach, colorectum, lung, prostate, and liver in men; and thyroid, breast, colorectum, stomach, and lung in women. The projected crude mortality rate of all sites combined and age-standardized rate is 150.8 and 82.4, respectively. CONCLUSION: Cancer is currently one of the foremost public health concerns in Korea, and as the population ages, the nation's cancer burden will continue to increase.

Cancer statistics in Korea: incidence, mortality, survival, and prevalence in 2012.

PURPOSE: The aim of this study was to report nationwide cancer statistics in Korea, including incidence, mortality, survival, and prevalence, and their trends. MATERIALS AND METHODS: Incidence data from 1993 to 2012 were obtained from the Korea National Cancer Incidence Database, and vital status was followed through December 31, 2013. Mortality data from 1983 to 2012 were obtained from Statistics Korea. Crude and age-standardized rates for incidence, mortality, and prevalence, and relative survival were calculated. RESULTS: A total of 224,177 cancer cases and 73,759 cancer deaths were reported in 2012, and there were 1,234,879 prevalent cases identified in Korea as of January 1, 2013. Over the past 14 years (1999-2012), overall incidence rates have increased by 3.3% per year. The incidence rates of liver and cervical cancers have decreased, while those of thyroid, breast, prostate, and colorectal cancers have increased. Notably, incidence of thyroid cancer increased by 22.3% per year in both sexes and has been the most common cancer since 2009. The mortality for all cancers combined decreased by 2.7% per year from 2002 to 2012. Five-year relative survival rates of patients diagnosed in the last 5 years (2008-2012) have improved by 26.9% compared with those from 1993 to1995. CONCLUSION: Overall cancer mortality rates have declined since 2002 in Korea, while incidence has increased and survival has improved.

Cancer statistics in Korea: incidence, mortality, survival, and prevalence in 2011.

PURPOSE: This study aimed to report nationwide cancer statistics in Korea, including incidence, mortality, survival, and prevalence, and their trends. MATERIALS AND METHODS: Incidence data from 1993 to 2011 were obtained from the Korea National Cancer Incidence Database, and vital status was followed through December 31, 2012. Mortality data from 1983 to 2011 were obtained from Statistics Korea. Crude and age-standardized rates for incidence, mortality, and prevalence, and relative survival were calculated. RESULTS: A total of 218,017 cancer cases and 71,579 cancer deaths were reported to have occurred in 2011, and there were 1,097,253 prevalent cases identified in Korea as of January 1, 2012. Over the past 13 years (1999-2011), overall incidence rates have increased by 3.4% per year. The incidence rates of liver and cervical cancers have decreased, while those of thyroid, breast, prostate, and colorectal cancers have increased. Notably, thyroid cancer increased by 23.3% per year in both sexes, and became the most common cancer since 2009. The mortality for all cancers combined decreased by 2.7% per year from 2002 to 2011. Five-year relative survival rates of patients diagnosed in the last 5 years (2007-2011) have improved by 25.1% compared with those from 1993 to 1995. CONCLUSION: Overall cancer mortality rates have declined since 2002 in Korea, while incidence has increased rapidly and survival has improved.

Prediction of cancer incidence and mortality in Korea, 2014.

PURPOSE: We studied and reported on cancer incidence and mortality rates as projected for the year 2014 in order to estimate Korea's current cancer burden. MATERIALS AND METHODS: Cancer incidence data from 1999 to 2011 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2012 were acquired from Statistics Korea. Cancer incidence in 2014 was projected by fitting a linear regression model to observed age-specific cancer incidence rates against observed years, then multiplying the projected age-specific rates by the age-specific population. For cancer mortality, a similar procedure was employed, except that a Joinpoint regression model was used to determine at which year the linear trend changed significantly. RESULTS: A total of 265,813 new cancer cases and 74,981 cancer deaths are expected to occur in Korea in 2014. Further, the crude incidence rate per 100,000 of all sites combined will likely reach 524.7 and the age-standardized incidence rate, 338.5. Meanwhile, the crude mortality rate of all sites combined and age-standardized rate are projected to be 148.0 and 84.6, respectively. Given the rapid rise in prostate cancer cases, it is anticipated to be the fourth most frequently occurring cancer site in men for the first time. CONCLUSION: Cancer has become the most prominent public health concern in Korea, and as the population ages, the nation's cancer burden will continue to increase.

Revision of the national action plan in response to poliovirus importation in Korea.

The polio outbreak in China in 2011 makes it necessary to revise the 2010 polio National Action Plan (NAP) in Korea. The revised plan was provided after evaluation of the 2010 NAP, literature reviews, and expert advice. It was discussed and confirmed by the Polio National Certificate Committee (NCC). The revised NAP (2012 NAP) has structured the action to take by patient phase and the role of each institution. It also provides the specified classification and management actions on the contacts. It includes a new recommendation of onetime additional immunization for the contacts regardless of the immunization history. The 2012 NAP could provide an effective countermeasure if there are imported poliomyelitis patients in Korea.

Reemergence of measles in South Korea: implications for immunization and surveillance programs.

Following the implementation of the national measles elimination program, the Republic of Korea declared in 2006 that measles had been eliminated. However in 2011, a measles outbreak was reported in Gyeongnam Province in the southeastern part of the country. We conducted active case-based surveillance and analyzed the data of cases reported in 2011 to identify the factors contributing to the reemergence of measles in this province. Of 41 confirmed measles cases reported in Korea, 32 were from within the Gyeongnam Province. Among cases identified in the outbreak, 97% had inadequate history of immunization, 28% were not immunized at the recommended ages, and 22% were infants aged 6-11 months. The outbreak involved transmission in 3 hospitals, 1 kindergarten, 1 day-care center, and 3 households. Molecular analysis of measles virus isolates from 11 cases revealed the same D9 genotype, which was the first to be discovered in Korea. In conclusion, inadequate immunization coverage, non-timely immunization, infants under 12 months of age, nosocomial transmission, and international importation may play important roles in the reemergence of measles in Korea during the attempted sustained elimination of the disease.

No association between influenza A(H1N1)pdm09 vaccination and narcolepsy in South Korea: an ecological study.

BACKGROUND: There is concern about a possible association between influenza A(H1N1)pdm09 vaccination and narcolepsy. In this study, we assessed the incidence and incidence rate of narcolepsy in the South Korean population before and after the implementation of an A(H1N1)pdm09 vaccination campaign to see if vaccination led to a change in the occurrence of narcolepsy. METHODS: We conducted an ecological study, comparing incident cases and incidence rates for newly diagnosed narcolepsy case-patients in South Korea, between July 2006 and June 2011. We used data from the Health Insurance Review Agency and Korea Centers for Disease Control and Prevention, which have limited information on case ascertainment. During vaccination campaign period, South Korea used non-adjuvanted and MF59-adjuvanted A(H1N1)pdm09 vaccines. RESULTS: Generally, incidence rate was highest in prepandemic period. No trend toward increase in the incidence of narcolepsy after pandemic period was found. Observation of incidence by season did not suggest any time pattern for occurrence of narcolepsy. CONCLUSION: No increase in cases or incidence rate for narcolepsy during the A(H1N1)pdm09 vaccination campaign was found in South Korea. Our data do not support the use of MF59-adjuvanted or non-adjuvanted A(H1N1)pdm09 vaccine as a trigger for narcolepsy on a population level.

National pertussis surveillance in South Korea 1955-2011: epidemiological and clinical trends.

BACKGROUND: Although there has been substantial progress in controlling pertussis in South Korea, the reported number of pertussis case-patients has gradually been increasing during the last decade. To address this, we summarized the surveillance data on pertussis collected during the period 1955-2011. Detailed epidemiologic and clinical data were determined, primarily using data from recent years. METHODS: We analyzed data from the national surveillance system to describe the occurrence of pertussis. The annual numbers of reported pertussis case-patients were identified for the period 1955-2000. For 2001-2009, information including limited demographic characteristics and the date of onset of symptoms were identified. For 2010-2011, detailed epidemiologic and clinical information of reported pertussis case-patients were collected. RESULTS: During 1955-2011, the secular trend was characterized by a gradual decrease in the reported number of cases from 1955 to the late 1990s, then a recent increase starting in the early 2000s. In 2009, a large number of reported cases occurred in infants <1 year of age. In 2011, an increase in reported cases among adolescents and adults aged ≥15 years was observed. During 2010-2011, 29.8% of reported cases were not immunized and 11.3% had not been immunized in a timely manner. Of adolescents and adults aged ≥15 years, 91.7% did not have a record of immunization. CONCLUSIONS: During 2010-2011, a shift in age group was observed in pertussis case-patients: 33.8% were young infants <3 months of age and 29.0% were adolescents and adults ≥15 years of age. Considering that infants without timely vaccination may be vulnerable to an increased risk of pertussis infection, steps to provide timely vaccination to infants, to provide Tdap vaccination to adolescents and adults, and to enhance surveillance to capture adult pertussis cases should be taken in South Korea.

Sudden death in the first 2 years of life following immunization in the Republic of Korea.

BACKGROUND: Because the peak age for incidence of sudden deaths in infancy temporally coincides with the age of infant primary immunization, some have raised the question as to whether immunization is a risk factor for sudden death in infancy. Recent occurrence of two sudden deaths in infants in Korea has renewed concerns about the causal association between immunization and sudden deaths in infants. METHODS: We carried out a retrospective review of data from the Korea Centers for Disease Control and Prevention Adverse Events Following Immunization Surveillance System and Vaccine Compensation programs. RESULTS: From 1994 to 2011, a total of 45 cases of sudden deaths in the first 2 years of life following immunization were reported in Korea. The causes of death were classified as follows: infectious diseases (n= 13); accidental injuries (n= 7); congenital abnormalities (n= 2); and malignancy (n= 1). Of 20 sudden deaths in infancy, nine deaths met Brighton Collaboration case definition level I and II, and therefore were classified as possible sudden infant death syndrome cases. Hepatitis B vaccine (n= 13) was the most frequent vaccine with temporal association with sudden deaths in the first 2 years of life. CONCLUSION: Few sudden deaths in the first 2 years of life following immunization have been reported, despite the use of universal immunization in Korea. The majority of deaths in infancy did not meet case definition for sudden infant death syndrome. Encouraging investigators to perform thorough investigation, including postmortem autopsy and death scene examination, may promote data comparability and provide guidance on decision-making in the vaccine-safety monitoring and response system in Korea.