Epidemiological characteristics of the first water-borne outbreak of cryptosporidiosis in Seoul, Korea.

The first case of human cryptosporidiosis was reported in Korea in 1995; however, an outbreak of Cryptosporidium has not been reported in Korea until now. This paper describes the first outbreak of cryptosporidiosis in Korea. On May 24, 2012, a local public health center filed a report on 126 residents with gastrointestinal symptoms in an old apartment complex in Seoul. Epidemiological investigations were implemented on 125 of the 126 patients. The patients were reported continuously over a period of 22 days. Diarrhea was the most common clinical symptom, and lasted for 5 days on average. The tap water was the only common exposure of the patients. During the environmental investigation it was discovered that the water and septic tanks were situated closely and that the waste water pipes were corroded where they passed over the water pipes. Cryptosporidium parvum was detected in 3 of the 7 stool specimens by PCR-RFLP. A number of Cryptosporidium oocysts were also detected in the water specimens from the water tank. In conclusion, Cryptosporidium parvum was the key causal pathogen of this outbreak. It is presumed that the tap water was contaminated by a sewage leak from the aged pipelines.

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

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 characteristics of serologically confirmed q Fever cases in South Korea, 2006-2011.

OBJECTIVES: Q fever has been reported worldwide; however, there was almost no official report of Q fever in Korea. In this study, we describe the current status of human Q fever occurrence in Korea. METHODS: Demographic data of Q fever patients were collected from the National Notifiable Diseases Surveillance System from 2006 to 2011. Case investigation reports from regional public health departments were used for additional information, like risk factors and clinical manifestation, of the patients since 2008. RESULTS: There were 65 serologically confirmed cases during the study period. The annual notification rate of Q fever was 0.22 cases per million persons. The majority of cases were men (87.7%), adults (98.5%), and urban inhabitants (67.7%). Relevant exposures to risk factors were identified in 45.7% of patients. The most common symptoms of acute Q fever were fever (89.3%), myalgia (67.9%) and asthenia (53.6%). Two cases with endocarditis were identified in chronic Q fever. CONCLUSION: This study suggests that Q fever has a low endemicity in Korea. However, management and research at national level is required for prevention of a future epidemic.

Trends in water- and foodborne disease outbreaks in Korea, 2007-2009.

OBJECTIVES: In Korea, every outbreak of acute gastroenteritis in two or more patients who are epidemiologically related is investigated by local public health centres to determine causative agents and control the outbreak with the support of the Korean Centers for Disease Control and Prevention. The findings and conclusions of each outbreak investigation have been summarized annually since 2007 to make reports and statistics of water- and foodborne disease outbreaks. METHODS: All outbreaks reported to Korean Centers for Disease Control and Prevention from 2007 to 2009 were included in the study. We analysed the trends and epidemiologic aspects of outbreaks by month, year, and location. RESULTS: The total number of outbreaks decreased steadily each year for the period the study covered, whereas the number of patients per outbreak continued to increase resulting from a dramatic increase in the number of patients per outbreak in food service establishments. The outbreaks occurred in the period of June to September, when temperature and humidity are relatively high, which accounted for 44.3% of total outbreaks. The monthly number of outbreaks decreased steadily until November after peaking in May 2009. The most common causative agent was norovirus (16.5%) followed by pathogenic Escherichia coli. The rate of causative agent identification was 60.1%, with higher identification rates in larger outbreaks. CONCLUSIONS: Although a decreasing trend of outbreaks by year was observed in the study, the food services in schools and companies require more attention to hygiene and sanitation to prevent large outbreaks. The ability to establish the cause of an outbreak should be further improved.