Corrigendum to “Epidemiological Characterization of Imported Systemic Mycoses Occurred in Korea” Osong Public Health Res Perspect 2018;9(5):255–60

The authors want to update the existing affiliation for one of the authors Keun-Dol Yook. Correct affiliation for the author should be Department of Clinical Laboratory Science, Daejeon Health Institute of Technology, Daejeon, Korea.

Epidemiological Characterization of Imported Systemic Mycoses Occurred in Korea

OBJECTIVES: Imported systemic mycoses is a severe fungal infection that can cause diseases in healthy people. However, there is a serious lack of epidemiological data about imported systemic mycoses. Therefore, an epidemiological characterization of imported systemic mycoses in Korea was performed. METHODS: We collected health insurance data between 2008 and 2012 from the Health Insurance Corporation and analyzed the data to determine the prevalence and treatment management of imported systemic mycoses. RESULTS: The prevalence of imported systemic mycoses between 2008 and 2012 increased slowly by 0.49/100,000 to 0.53/100,000 persons. The prevalence of coccidioidomycosis increased from 0.28/100,000 in 2008 to 0.36/100,000 persons in 2012. A mean of 229.6 cases occurred each year. Children and the elderly showed higher prevalence than adults in the 20- to 59-year-old age group. The rate of infection according to region ranged from 0.18/100,000 persons in Ulsan, to 0.59/100,000 persons in Gyeonggi. The prevalence in females was higher than that in males. Inpatient treatment was 3.3% (38 cases), with 96.7% treated as outpatients. Hospitalizations cost 272.7 million won and outpatient treatments cost 111.7 million won. The treatment cost for coccidioidomycosis from 2008 to 2012 was 330.9 million won, with personal charges of 79.2 million won and insurance charges of 251.7 million won. Most of the expenses for the coccidioidomycosis treatment were for inpatient treatment. CONCLUSION: The results in this study may be a useful resource for determining the changes in the trend of imported systemic mycoses.

Characterization of Clostridium difficile Strains Isolated from Patients with C. difficile-associated Disease in Korea

OBJECTIVES: Studies on Clostridium difficile are rare in Korea. We investigated the epidemiological characteristics of C. difficile isolates from patients with C. difficile-associated disease (CDAD) in Korea. METHODS: Multiplex polymerase chain reaction was performed to detect the presence of tcdA and tcdB toxin genes. Antimicrobial susceptibility test was carried out by the disk-dilution method. C. difficile strains were subtyped by automated repetitive-element palindromic PCR (rep-PCR). RESULTS: Among patients with CDAD, 73 (25.8%), 32 (11.3%), 32 (11.3%), and 26 (9.2%) suffered from pneumonia, cancer or neoplasm, diabetes, and colitis, respectively. Of all stool samples, 43 samples (15.2%) were positive for C. difficile strains. We observed two expression patterns of toxin genes: tcdA+/tcdB+ (86% isolates) and tcdA−/tcdB+ (14% isolates), with all isolates expressing tcdB. Furthermore, some isolates were resistant to clindamycin (65%), ampicillin (56%), and cefazolin (40%), but all were susceptible to vancomycin and metronidazole. The tested samples were classified into diverse clusters using automated rep-PCR. CONCLUSION: Our findings revealed the characteristics and antibiotic resistance of C. difficile isolates from patients in Korea. The epidemiological data may provide valuable insight into development of treatment strategies for C. difficile infections in Korea.

A Case of a Shiga Toxin Producing Escherichia Coli

We encountered a patient with hemolytic uremic syndrome (HUS) with persistent isolation of shiga toxin-producing Escherichia coli (STEC) for 3 weeks despite of having no clinical symptoms. STEC has been recognized as an important food-borne pathogen that causes severe diseases such as HUS. We characterized this STEC strain via a polymerase chain reaction, reverse-passive latex agglutination and the slide agglutination method. In this STEC strain, stx2 (shiga toxin), eaeA, tir, iha (adherence genes), espADB (type III secretion genes), and hlyA, ehxA, clyA (hemolysin genes) were present. The O antigen of the strain was non-typable.

Infection Status of Hospitalized Diarrheal Patients with Gastrointestinal Protozoa, Bacteria, and Viruses in the Republic of Korea

To understand protozoan, viral, and bacterial infections in diarrheal patients, we analyzed positivity and mixed-infection status with 3 protozoans, 4 viruses, and 10 bacteria in hospitalized diarrheal patients during 2004-2006 in the Republic of Korea. A total of 76,652 stool samples were collected from 96 hospitals across the nation. The positivity for protozoa, viruses, and bacteria was 129, 1,759, and 1,797 per 10,000 persons, respectively. Especially, Cryptosporidium parvum was highly mixed-infected with rotavirus among pediatric diarrheal patients (29.5 per 100 C. parvum positive cases), and Entamoeba histolytica was mixed-infected with Clostridium perfringens (10.3 per 100 E. histolytica positive cases) in protozoan-diarrheal patients. Those infected with rotavirus and C. perfringens constituted relatively high proportions among mixed infection cases from January to April. The positivity for rotavirus among viral infection for those aged or = 50 years. The information for association of viral and bacterial infections with enteropathogenic protozoa in diarrheal patients may contribute to improvement of care for diarrhea as well as development of control strategies for diarrheal diseases in Korea.

Surveillance of Stool Samples for the Presence of Enterobacter sakazakii among Korean People

PURPOSE: Enterobacter sakazakii (E. sakazakii) infections are an important cause of life-threatening meningitis, septicemia, and necrotizing enterocolitis in infants. Dried infant formula milk is an important vehicle for E. sakazakii infection. E. sakazakii was isolated in Korea from dried infant formula milk. Although E. sakazakii infection of infants may occur in Korea, its prevalence has not yet been documented. Therefore, we determined the prevalence of E. sakazakii and documented symptoms. MATERIALS AND METHODS: Between March and October 2006, 1,146 stool samples were collected from patients at Uijeongbu St. Mary's Hospital. Each fecal swab was dissolved in 10mL of buffered peptone solution, and enriched culture was streaked onto Druggan-Forsythe-Iversen (DFI) agar. Presumptive E. sakazakii colonies that exhibited a blue-green color during culture on DFI medium were selected. The identity of colonies that developed yellow pigment during culture on TSA was determined using the Vitek system and PCR. RESULTS: We isolated 4 E. sakazakii strains whose 16S rRNA sequence alignments had a similarity of 99% with those of 3 E. sakazakii ATCC strains. CONCLUSION: This is the first report on isolation of E. sakazakii from stool samples and to document the symptoms of Korean patients.

Enterotoxigenic Escherichia coli Outbreak in a High School / 감염과화학요법

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) has been well known pathogen as a cause of travelers' diarrhea. Nowadays, however, ETEC is also increasingly recognized as the cause of foodborne or waterborne outbreaks. We investigated an outbreak of a high school in Gwangju metropolitan city to trace the source of infection and the mode of transmission of ETEC. MATERIALS AND METHODS: All symptomatic persons were interviewed and filled out the questionnaires. We surveyed their clinical symptoms and the foods that they ate. We checked the facilities of the school, dinning room and water supply system. Microbiologic examination were carried out on above symptomatic persons and many environmental specimens. All gathered samples were examined in Gwangju city Health & Environment Research Institute. ETEC isolates were submitted to Korea Center for Disease Control and Prevention (KCDC) for Pulsed-field gel electrophoresis (PFGE). We also requested water quality analysis of water samples to Waterworks Research Institute. RESULTS: The 39 students and one sibling who visited and ate school meal showed symptoms. All staffs and cooks showed no symptom. Among 51 stool specimens, ETEC was isolated from 19 (18: students, 1:cook). ETEC was also isolated from specimens from a purifier and a water tap of the dinning room and water tank (underground water). In PFGE test, isolates from 18 persons showed identical pattern, but the PFGE patterns from water were different. Isolates of water samples showed different PFGE patterns even within the same sample. Investigation of the water distribution system revealed that contaminated underground water had been supplied to the dinning room and students of the school were exposed to it. CONCLUSION: This is the outbreak of ETEC infection occurred in a high school. Besides students, ETEC was also isolated from water samples. Considering some epidemiologic features, we suspect the mode of transmission may be waterborne despite the inconsistent PFGE results.

Enterotoxigenic Escherichia coli Outbreak in a High School / 감염과화학요법

BACKGROUND: Enterotoxigenic Escherichia coli (ETEC) has been well known pathogen as a cause of travelers' diarrhea. Nowadays, however, ETEC is also increasingly recognized as the cause of foodborne or waterborne outbreaks. We investigated an outbreak of a high school in Gwangju metropolitan city to trace the source of infection and the mode of transmission of ETEC. MATERIALS AND METHODS: All symptomatic persons were interviewed and filled out the questionnaires. We surveyed their clinical symptoms and the foods that they ate. We checked the facilities of the school, dinning room and water supply system. Microbiologic examination were carried out on above symptomatic persons and many environmental specimens. All gathered samples were examined in Gwangju city Health & Environment Research Institute. ETEC isolates were submitted to Korea Center for Disease Control and Prevention (KCDC) for Pulsed-field gel electrophoresis (PFGE). We also requested water quality analysis of water samples to Waterworks Research Institute. RESULTS: The 39 students and one sibling who visited and ate school meal showed symptoms. All staffs and cooks showed no symptom. Among 51 stool specimens, ETEC was isolated from 19 (18: students, 1:cook). ETEC was also isolated from specimens from a purifier and a water tap of the dinning room and water tank (underground water). In PFGE test, isolates from 18 persons showed identical pattern, but the PFGE patterns from water were different. Isolates of water samples showed different PFGE patterns even within the same sample. Investigation of the water distribution system revealed that contaminated underground water had been supplied to the dinning room and students of the school were exposed to it. CONCLUSION: This is the outbreak of ETEC infection occurred in a high school. Besides students, ETEC was also isolated from water samples. Considering some epidemiologic features, we suspect the mode of transmission may be waterborne despite the inconsistent PFGE results.

An outbreak of inapparent non-O157 enterohemorrhagic escherichia coli infection / 대한내과학회지

BACKGROUND: No outbreak of Enterohemorrhagic Escherichia coli (EHEC) infection has occurred as a group in Korea. On July 2004, an outbreak of EHEC infection occurred in an elementary school in Gwangju metropolitan city. Epidemic investigation was undertaken to track the source of infection and the mode of transmission of EHEC. METHODS: All students and staffs of the elementary school were interviewed and completed questionnaires. We surveyed their clinical symptoms and the foods that they ate. Microbiologic examinations were also carried out on the above school-related persons and many environmental specimens. We also investigated the facilities of the school, some suppliers of food materials, and other associated institutions. All the EHEC-positive persons were isolated in 5 hospitals and tested everyday for verotoxin until they turned out to be negative twice in succession, and their family were also interviewed and tested for EHEC. Pulsed-field gel electrophoresis (PFGE) was performed to find out the genetic relationship between isolates. RESULTS: Of the 1,643 school-related persons, 77 persons (4.7%) were positive for EHEC. Most of them were asymptomatic. All the isolated strains were non-O157 EHEC. Serotype O91 was the most frequent serotype (68 isolates), and the isolates revealing O91 serotypes showed identical PFGE patterns. The school meal was significantly associated with this outbreak (relative risk=13.29, p=0.00). CONCLUSIONS: This is the first EHEC outbreak occurred as a group in Korea, All the isolated strains were non-O157 serotypes and the mode of transmission was most likely by school meal.