Duk-Hyoung Lee

Linezolid for Treatment of Chronic Extensively Drug-Resistant Tuberculosis

BACKGROUND Linezolid has antimycobacterial activity in vitro and is increasingly used for patients with highly drug-resistant tuberculosis. METHODS We enrolled 41 patients who had sputum-culture-positive extensively drug-resistant (XDR) tuberculosis and who had not had a response to any available chemotherapeutic option during the previous 6 months. Patients were randomly assigned to linezolid therapy that started immediately or after 2 months, at a dose of 600 mg per day, without a change in their background regimen. The primary end point was the time to sputum-culture conversion on solid medium, with data censored 4 months after study entry. After confirmed sputum-smear conversion or 4 months (whichever came first), patients underwent a second randomization to continued linezolid therapy at a dose of 600 mg per day or 300 mg per day for at least an additional 18 months, with careful toxicity monitoring. RESULTS By 4 months, 15 of the 19 patients (79%) in the immediate-start group and 7 of the 20 (35%) in the delayed-start group had culture conversion (P=0.001). Most patients (34 of 39 [87%]) had a negative sputum culture within 6 months after linezolid had been added to their drug regimen. Of the 38 patients with exposure to linezolid, 31 (82%) had clinically significant adverse events that were possibly or probably related to linezolid, including 3 patients who discontinued therapy. Patients who received 300 mg per day after the second randomization had fewer adverse events than those who continued taking 600 mg per day. Thirteen patients completed therapy and have not had a relapse. Four cases of acquired resistance to linezolid have been observed. CONCLUSIONS Linezolid is effective at achieving culture conversion among patients with treatment-refractory XDR pulmonary tuberculosis, but patients must be monitored carefully for adverse events. (Funded by the National Institute of Allergy and Infectious Diseases and the Ministry of Health and Welfare, South Korea; ClinicalTrials.gov number, NCT00727844.).

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.

Alcohol consumption and persistent infection of high-risk human papillomavirus

Alcohol consumption is a possible co-factor of high-risk human papillomavirus (HR-HPV) persistence, a major step in cervical carcinogenesis, but the association between alcohol and continuous HPV infection remains unclear. This prospective study identified the association between alcohol consumption and HR-HPV persistence. Overall, 9230 women who underwent screening during 2002-2011 at the National Cancer Center, Korea were analysed in multivariate logistic regression. Current drinkers [odds ratio (OR) 2·49, 95% confidence interval (CI) 1·32-4·71] and drinkers for ⩾5 years (OR 2·33, 95% CI 1·17-4·63) had a higher risk of 2-year HR-HPV persistence (HPV positivity for 3 consecutive years) than non-drinkers and drinkers for <5 years, respectively (vs. HPV negativity for 3 consecutive years). A high drinking frequency (⩾twice/week) and a high beer intake (⩾3 glasses/occasion) had higher risks of 1-year (OR 1·80, 95% CI 1·01-3·36) HPV positivity for 2 consecutive years) and 2-year HR-HPV persistence (OR 3·62, 95% CI 1·35-9·75) than non-drinkers. Of the HPV-positive subjects enrolled, drinking habit (OR 2·68, 95% CI 1·10-6·51) and high consumption of beer or soju (⩾2 glasses/occasion; OR 2·90, 95% CI 1·06-7·98) increased the risk of 2-year consecutive or alternate HR-HPV positivity (vs. consecutive HPV negativity). These findings suggest that alcohol consumption might increase the risk of cervical HR-HPV persistence in Korean women.

The Incidence of Tuberculosis after a Measles Outbreak

Among 53,974 cases of measles that occurred during the 2000-2001 outbreak in Korea, the incidence of tuberculosis following measles was 47 cases per 214,949.6 person-years, which was significantly lower than that in the general population (standardized incidence ratio, 0.73; 95% confidence interval, 0.54-0.96). In conclusion, we did not find a positive relationship between measles and tuberculosis.

Mycobacterium massiliense outbreak after intramuscular injection, South Korea

SUMMARY We conducted an epidemic investigation to discover the route of transmission and the host factors of an outbreak of post-injection abscesses. Of the 2984 patients who visited a single clinic, 77 cases were identified and 208 age- and sex-matched controls were selected for analysis. Injected medications per se were not found to be responsible, and a deviation from safe injection practice suggested the likelihood of diluent contamination. Therefore the injected medications were classified according to whether there was a need for a diluent, and two medications showed a statistically significant association, i.e. injection with pheniramine [adjusted odds ratios (aOR) 5·93, 95% confidence interval (CI) 2·97-11·87] and ribostamycin (aOR 47·95, 95% CI 11·08-207·53). However, when considered concurrently, pheniramine lost statistical significance (aOR 8·71, 95% CI 0·44-171·61) suggesting that normal saline was the causative agent of this outbreak. Epidemiological evidence strongly suggested that this post-injection outbreak was caused by saline contaminated with Mycobacterium massiliense without direct microbiological evidence.

Tuberculosis prevention and care in Korea: Evolution of policy and practice

Tuberculosis (TB) in Korea remains a serious health problem with an estimated 77 per 100,000 incidence rate for 2016. This makes Korea as the only OECD country with high incidence of TB. The government has increased budgets and strengthened patient management policies since 2011. The management of latent tuberculosis was added to the response with strengthened and extensive contact investigations in the five-year tuberculosis control plan (2013–2017) and implementation was established in 2013. Due to these efforts Korea has achieved an average 5.2% reduction annually in tuberculosis incidence rate between 2011 and 2016. To further expedite the reduction of the TB burden the government has introduced additional measures including mandatory screening of latent tuberculosis infection for community workers in congregate settings including daycare centers for children, kindergarten, and teachers in schools and health care workers in clinics and hospitals to solve the problems identified through contact investigations in 2017. Providing high quality free diagnosis and treatment of active TB including for multidrug resistant TB combined with active contact investigations is the mainstay of the current programmatic response in Korea. However, the limitation of existing tools for LTBI pose challenge including absence of best mechanism for effective communication with professionals and the public, the need for at least 3 months of treatment and the risk of side effects. Developing effective tools will help to overcome these challenges.

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.

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.