Shinje Moon

Emerging Pathogens and Vehicles of Food- and Water-borne Disease Outbreaks in Korea, 2007–2012

Objectives Food- and water-borne disease outbreaks (FBDOs) are an important public health problem worldwide. This study investigated the trends in FBDOs in Korea and established emerging causal pathogens and causal vehicles. Methods We analyzed FBDOs in Korea by year, location, causal pathogens, and causal vehicles from 2007 to 2012. Information was collected from the FBDOs database in the Korean Centers for Disease Control and Prevention. Results During 2007–2012, a total of 1794 FBDOs and 48,897 patients were reported. After 2007, FBDOs and patient numbers steadily decreased over the next 2 years and then plateaued until 2011. However, in 2012, FBDOs increased slightly accompanied by a large increase in the number of affected patients. Our results highlight the emergence of norovirus and pathogenic Escherichia coli other than enterohemorrhagic E. coli (EHEC) in schools in 2012. We found that pickled vegetables is an emerging causal vehicle responsible for this problem. Conclusion On the basis of this study we recommend intensified inspections of pickled vegetable manufacturers and the strengthening of laboratory surveillance of relevant pathogens.

Autochthonous Lyme Borreliosis in Humans and Ticks in Korea

Objective: This study aimed at finding epidemiological and clinical features of autochthonous Lyme borreliosis in humans through epidemiological investigations and identifying its vectors and pathogens through analysis of ticks. Method: Epidemiological investigations, including review of the retrospective medical records and patient interviews, were conducted in two cases that occurred in 2012. To identify the vectors and pathogens, ticks were collected between September 23 and October 6, 2012 from the area where the tick bite in the first patient occurred. The ticks were classified, and polymerase chain reaction (PCR) tests and cultures were performed. Results: The first patient, a 46-year-old female, visited a forest in Gangwon province, which was 900 m above sea level, where the tick bite occurred. Two weeks after the tick bite, erythema migrans (12 × 6 cm2 in size) appeared on the site of tick bite, along with fever, chill, fatigue, myalgia, and arthralgia on shoulders, knees, and hips. The second patient, a 44-year-old male, visited a mountain in Gangwon province, which was 1200 m above sea level, where a tick bite occurred. One month after the tick bite, erythema migrans appeared at the site of the tick bite, along with fatigue, myalgia, and arthralgia on the right shoulder and temporomandibular joint. Indirect fluorescent antibody testing and Western blotting were carried out in these two cases for diagnosis, and positive findings were obtained. As a result, Lyme borreliosis could be confirmed. To estimate the pathogens and vectors, the ticks were collected. A total of 122 ticks were collected and only two species, Haemaphysalis japonica and Haemaphysalis flava, were identified. PCR and culture were performed on ticks. However, Borrelia burgdo rferi sensu lato was not isolated from any collected ticks. Conclusions: This study is significant to confirm Lyme borreliosis officially at first by the national surveillance system, although identification of the mites and pathogens failed.

Hepatitis A in Korea from 2011 to 2013: Current Epidemiologic Status and Regional Distribution

The hepatitis A virus (HAV) has been the leading cause of viral hepatitis in Korea since the 2000s. We aimed to describe the current status and regional differences in hepatitis A incidence. We studied the total number of hepatitis A cases reported to the Korea Centers for Disease Control and Prevention through the National Infectious Diseases Surveillance System between 2011 and 2013. Additionally, National Health Insurance Review and Assessment Service data and national population data from Statistics Korea were used. In total, 7,585 hepatitis A cases were reported; 5,521 (10.9 cases per 100,000 populations), 1,197 (2.3 cases per 100,000 populations), and 867 (1.7 cases per 100,000 populations) in 2011, 2012, and 2013, respectively. Fifty-eight patients were infected outside of the country and 7,527 patients represented autochthonous HAV infection cases. Autochthonous HAV infection occurred more frequently among men than women (4,619 cases, 6.1 cases per 100,000 population vs. 2,908 cases, 3.9 cases per 100,000 population). The incidence rate was higher in the 20-29 yr-old group (2,309 cases, 11.6 cases per 100,000 populations) and 30-39 yr-old group (3,306 cases, 13.6 cases per 100,000 populations). The majority of cases were reported from March to June (53.6%, 4,038/7,527). Geographic analyses revealed a consistently high relative risk (RR) of HAV infection in mid-western regions (2011, RR, 1.25, P=0.019; 2012, RR, 2.53, P<0.001; 2013, RR, 1.86, P<0.001). In summary, we report that hepatitis A incidence has been decreasing gradually from 2011 to 2013 and that some regions show the highest prevalence rates of HAV infection in Korea.

Epidemic intelligence service officers and field epidemiology training program in Korea.

Abstract Korea has adopted Epidemic Intelligence Service (EIS) officers through the Field Epidemiology Training Program (FETP) since 1999 for systematic control of emerging and re-emerging infectious diseases. Graduates of medical schools in Korea are selected and serve as public health doctors (PHDs) for their mandatory military service. The duration of service is 3 years and PHDs comprise general practitioners and specialists. Some PHDs are selected as EIS officers with 3 weeks basic FETP training and work for central and provincial public health authorities to conduct epidemiological investigations. The total number of EIS officers is 31 as of 2012. The Korea Centers for Disease Control and Prevention (KCDC) has 12 specialists, whereas specialists and each province has one or two EIS officers to administer local epidemiological investigations in 253 public health centers. The Korean EIS officers have successfully responded and prevented infectious diseases, but there is a unique limitation: the number of PHDs in Korea is decreasing and PHDs are not allowed to stay outside Korea, which makes it difficult to cope with overseas infectious diseases. Furthermore, after 3 years service, they quit and their experiences are not accumulated. KCDC has hired full-time EIS officers since 2012 to overcome this limitation.

Epidemiological Features and Clinical Manifestations of Lyme Borreliosis in Korea during the Period 2005–2012

Lyme borreliosis is one of the most common tick-borne infections in the northern hemisphere. However, the epidemiological features and clinical manifestations of this disease in Korea are unknown. The present study is the first to investigate the characteristics of Lyme borreliosis in Korea. We traced suspected cases of Lyme borreliosis during the period 2005-2012. Of the 16 identified patients with the disease, 11 had acquired autochthonous infection within Korea, while 5 patients were infected outside Korea. The history of past exposure was investigated in 8 of the 11 patients with autochthonous infection; 5 of these 8 patients (62.5%) were suspected to have acquired the infection in the northeastern alpine region. Clinically, of 11 patients with autochthonous infection, 6 (54.5%) showed early skin manifestations, 4 (36.4%) showed neurological manifestations, and 1 (9.1%) showed acrodermatitis chronica atrophicans. In conclusion, Lyme borreliosis could be endemic in the northeastern alpine region of Korea, and neurological and early skin manifestations are likely to be the major clinical characteristics of autochthonous Lyme borreliosis in Korea.

Factors associated with severe neurologic complications in patients with either hand-foot-mouth disease or herpangina: A nationwide observational study in South Korea, 2009-2014

Background In 2009, a nationwide sentinel surveillance for hand-foot-mouth disease (HFMD) and herpangina (HA) with neurologic complications was initiated in South Korea. We used this surveillance system to investigate the clinical characteristics of patients with either HFMD or HA with neurologic complications, with the aim of determining risk factors for severe neurologic complications. Methods A retrospective review of medical records was conducted on all cases of HFMD and HA with neurologic complications that were reported in the national system between April 1, 2009 and December 31, 2014. A severe case was defined as having HFMD or HA with encephalitis, polio-like syndrome, or cardiopulmonary failure, and less-severe cases were defined as having HFMD or HA with aseptic meningitis. Results A total of 138 cases (less-severe: 90/138, 65.2%; severe: 48/138, 24.8%) were included from 28 hospitals; 28 ineligible cases were excluded. Of 48 severe cases, 27 (56.2%) had encephalitis; 14 (29.2%) had polio-like syndrome; and seven (14.6%) had cardiopulmonary syndrome. The median patient age was 36 months (IQR: 18–60) and 63 (45.7%) patients were female. Most patients completely recovered, except for seven cases that were fatal or resulted in long-term symptoms (5.1%, 3 patients with neurologic sequelae and 4 deaths). In a multivariable logistic regression analysis, lethargy (OR = 4.67, 95% CI: 1.37–15.96, P = 0.014), female sex (OR = 3.51, 95% CI: 1.17–10.50, P = 0.025), and enterovirus A71 (OR = 3.55, 95% CI: 1.09–11.57, P = 0.035) were significantly associated with severe neurologic complications in HFMD and HA patients. Conclusion In patients with HFMD and HA, lethargy, female, and enterovirus A71 may predict severe neurologic complications.