• Journal of Preventive Medicine and Public Health
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• v.33 no.1
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• pp.10-16
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• 2000

Objectives : This study was carried out to investigate the sources of infection and modes of transmission of an outbreak of shigellosis that occurred among students of B middle and high school in Bonghwa, Korea from May 1 to 21, 1999. Methods : We conducted questionnaires to 468 students, 38 stalls and 9 food handlers twice times (May 6, May 21) for follow up and secondary attack rate. Personal details and history of illness and exposure to particular foods were sought. And we conducted rectal swab for culture to 243 students, 33 staffs and 9 food handlers. Bacteriological examinations of water in the school were done. Cases were identified as subjects who had diarrhea (two or more loose stools in a 24-hour periods) on or after May 1. Results : A total of 307 cases (attack rate: 59.6%) of 515 subject were identified, including 50 confirmed (46 students and 4 staffs) by S. sonnei. All 9 food handlers denied illness and were had rectal swab for culture at May 6 that were negative for S. sonnei. 146 of 307 reported fever, 156 had tenesmus, 44 reported vomiting, and only 5 of 307 reported blood in the stool. The median duration of diarrhea was 4 days (range: 1-18 days). The mean incubation period until onset of diarrhea was 63 hours (range: 46-144 hours) and the secondary attack rate was 2.8% (43 cases of 1,561 family members). Risk for illness was higher among students who had eaten watered kimchi at March 30 than among those who did not [301(72.7%) of 417 versus 5(9.6%) of 52; RR=7.51;95% CI=3.26-17.31]. Conclusion : The source of infection was estimated to be contaminated watered kimchi by ore or two food hardier who is presumed to be carrier.

• Journal of agricultural medicine and community health
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• v.34 no.1
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• pp.24-33
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• 2009

Objectives: In September 2008, an outbreak of diarrhea occurred among students attending Y school in Yeongcheon-si. Shigella sonnei was cultured from some of the rectal swabs. An epidemiological investigation was carried out to determine the source of the infection and the mode of transmission of the shigellosis outbreak. Methods: The index case lived in the D rehabilitation facility in Gyeongsan-si and an additional epidemiological investigation was carried out there. The cases could not be questioned due to their mental handicaps. The teachers were interviewed instead. A patient case was defined as a resident with diarrhea more than one time a day from September 18 to September 26, 2008 or a resident with confirmed Shigella sonnei at the Y school or the D rehabilitation facility. Results: The attack rate was 1.2% (8 persons) among 659 persons in the Y school and D rehabilitation facility. Five persons were microbiologically confirmed to have the infection and three persons were diagnosed on the basis of symptoms. Shigella sonnei was cultured from five of the 659 rectal swabs. However, 80 environmental specimens including drinking water, preserved foods, and cooking utensils were negative. All eight patients were Y school students and had been living in group boarding and lodging. Six of them lived in the D rehabilitation facility and two lived in the dormitory at the Y school. Five cases showed pulsed-field gel electrophoresis patterns that were identical for Shigella sonnei. Conclusions: The results of this study showed that the infection source of the shigellosis outbreak, in the two places, were identical. It is likely that the infections initially spread from a teacher or volunteer and then among the students.

• Journal of Microbiology
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• v.45 no.2
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• pp.168-170
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• 2007

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

• BMB Reports
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• v.32 no.5
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• pp.436-439
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• 1999

Shigella sonnei is an important cause of human enteric infections. S. sonnei KNIH104S was previously reported to be isolated from Korean shigellosis patients. We cloned a 2.8-kb KpnI fragment containing the recA gene encoding a recombinase from the chromosomal DNA of S. sonnei KNIH104S. This recombinant plasmid was named pRAK28. E. coli HB101, a recA mutant, cannot grow on Luria-Bertani medium in the presence of the alkylating agent methylmethane sulfonate, however, E. coli HB101 harboring pRAK28 was found to grow on this medium. As far as we know, we are the first to sequence the recA gene from S. sonnei. This gene is composed of 1062 base pairs with an ATG initiation codon and a TAA termination codon. Nucleotide sequence comparison of the S. sonnei recA gene exhibited 99.7% and 99.5% identity with those of S. flexneri and E. coli, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.610-615
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• 2002

This study is to evaluate the risk perception of noise of the ground-crews in the Korean airbases who exposed to noise of jet plane. 1148 ground-crews and 231 pilots of 2 airbases participated in this study. The questionnaires of risk perception with visual analogue scale were completed by the participants. For comparison, the perception of other risks such as beef contaminated with dioxin, AIDS, lung cancer, otitis media, shigellosis, driving, drinking, and smoking were also included in the questionnaire of risk perception. The results of this study suggested the necessity of risk communication about noise and activation of effective hearing conservation program in the Korean air-force.

• Proceedings of the PSK Conference
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• 2005.11a
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• pp.231-232
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• 2005

Bacteria of Shigella spp. are responsible for shigellosis in humans, a disease characterized by destruction of the colonic epithelium that is induced by the inflammatory response elicited by invasive bacteria. They use a type III secretion system injecting effector proteins into host cells to induce their entry into epithelial cells and triggers apoptosis in macrophages. We present evidence that the effector OspG is a protein kinase that binds various ubiquitinylated ubiquitin-conjugating enzymes (E2s) and blocks degradation of phospho-$I{\kappa}B{\alpha}$ induced upon entry of bacteria into epithelial cells. Transfection experiments confirmed that OspG interferes with the $NF-{\kappa}B$ activation patway by preventing phospho-$I{\kappa}B{\alpha}$ degradation, suggesting that OspG inactivates a component of the $SCF^{{\beta}-TrCP}$ ubiquitin ligase complex (E3) involved in phospho-$I{\kappa}B{\alpha}$ ubiquitination. Upon infection of ileal loops in rabbits, the ospG mutant induced a stronger inflammatory response compared with the wild-type strain, indicating that OspG down-regulates the host innate response induced by invasive bacteria.

• Journal of Preventive Medicine and Public Health
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• v.33 no.1
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• pp.1-9
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• 2000

Objectives : This study was carried out to investigate the sources of infection and modes of transmission of an outbreak of shigellosis that occurred among pupils of 'M' primary school and residents near the school in Kyongju from Sept. 24 to Oct. 24, 1998. Methods : The subjects who completed a questionnaire and a rectal swab for microbiologic examinations were 1,534 persons (781 males, 753 females), including 469 pupils of 'M' primary school (268 males, 201 females). Bacteriological examinations of underground water and simple piped water were done. Results : The attack rate of diarrhea was 28.7% in the subjects from Sept.24 to Oct. 24, 1958. There was no difference in attack rate of diarrhea by gender, but it was significantly higher in the pupils of 'M' primary school than others (p<0.01). The attack rate of diarrhea by resident areas was no different to the pupils of 'M' primary school, but was significantly higher in the residents of Mohwa 2 Ri except pupils that 'M' primary school is located in (p<0.01). The distribution of date of onset revealed the exposure date to be Sept, 22 and 23 in consideration of incubation periods and common source outbreak followed propagative spread in the epidemic curve. The major characteristics of diarrhea were watery (89.1%) in nature, $1\sim3$ days (72.5%) in duration, $2\sim3$ times (63.9%) in frequency. The clinical symptoms among the diarrheal cases included abdominal pain (74.1%), fever (56.4%), headache (55.9%), chill (40.4%) and tenesmus (31.4%). Conclusions : The source of infection was estimated to be contaminated underground water and simple piped water caused by leakage from the cess pool. It is highly necessary that the management of drinking water and cess fools should be done thoroughly.

• Journal of agricultural medicine and community health
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• v.34 no.3
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• pp.368-374
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• 2009

Objectives: A group consisted of 32 Korean rural people had been travelled to Cambodia and Vietnam. During their travel for 7 days, first diarrheal case had occurred on 3rd day of travel and overall 8 people had diarrhea during travel. So we investigated the case for determination of the cause and route of infection. Methods: We interviewed all 32 people by visiting or telephone and took 23 stool samples from them, which are examined by Gyeungsangbuk-do Government Public Institute of Health & Environment in Korea. We interviewed travel agency for travel route and schedule. Results: The attack rate was 25.0% (8 cases) among 32 people. Of them, 3 cases were microbiologically confirmed to have the infection of Shigella flexneri (Serotype 3a). The result of this epidemiological investigation showed that the infection of shigellosis was happened in foreign countries. We assumed the water from Angkor-Watt was contaminated by S. flexneri. We could not able to test environmental specimens because of the infection is thought to be occurred in foreign countries. Conclusions: Most common infectious diseases from foreign countries are transmitted by water or food. Travellers to foreign countries must take caution for communicable diseases and must do report and get appropriate treatment when symptoms developed after travel.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.73-95
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• 1986

A total of 5,462 isolates suspicious of Salmonella, Shigella and E. coli which were isolated during 1983 to 1985 by 12 City Hygine Laboratories and General Hospital Laboratories were received and identified at the National Salmonella Center, Seoul, Korea. The result of identification of these strains were summarized as follows: 1. It was confirmed that the total organisms broke down into 2,014 strains of Salmonella 1,294 of which were S. typhi, 887 strains of Shigella and 2,561 strains of E. coli. 2. For seasonal distribution of enteric pathogens, July was the month with the highest out breaks of salmonellosis, May was the month of Shigellosis, and April was of the highest month it in the case of E. coli. 3. Salmonella typhi with the highest incidence of isolation was shown to belong to various phage types, especially with the strains detected in Seoul. M1 type was widely distributed all over the country, but the majority was E1 type in 1983. 4. For age distribution of patients, the 20-29 age group had the highest incidence of salmonellosis whileas the 1 to 9 age group had the highest incidence of Shigellosis. 5. For sexuly distribution of Salmonella and Shigella infections seemed to be relatively higher in the female than in the male. However, E. coli. had no relationship to both sex. 6. The antibiotic sensitivity patterns of S. typhi cultures showed a tendancy to be resistant to colistin, gentamycin, neomycin, tetracycline and streptomycin. 7. The isolates of S. paratyphi-A, S. typhimurium and S. enteritidis seemed to have a tendency of multiple drug resistance. 8. 93.9 percent of 1,568 E. coli strains showed negative reactions to the antisera of enteropathogenic E. coli and 15.6 percent of them produced a heat-labile enterotoxin, but positive reaction to the antisera was 6.1 percent and 11.6 percent of them producled the enterotoxin.

• Journal of the Korean Geographical Society
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• v.34 no.5
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• pp.473-491
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• 1999

세균성 이질은 국내 제1종 법정 전염병으로 분류되어 관리되고 있는 질환으로서 1998년 이후 그 발병 사례가 급속히 증가하고 있다. 본 연구는 1999년 3월 부산시 사상구에서 집단 발병한 세균성 이질을 대상으로 하여, 각 환자들의 발병 시점과 장소의 분포패턴에 대한 지리학적 고찰을 목적으로 한다. 환자분포의 특징적 공간패턴과 그들의 시계열적 확산 양상 등을 탐색하기 위한 방법론은 보건지리학과 지도학 및 공간통계학에 기반을 둔 공간분석기법을 중심으로 설정하였다. 분석자료는 해당 지역의 수치지형도, 지적도, 인구 센서스 자료를 포함한 GIS 데이터베이스로 구축되었다. 인구분포를 감안한 밀도구분도를 바탕으로 개별환자의 위치자료와 동 단위로 집계된 자료를 자료의 형태에 따라 분석기법을 달리하였으며, 환자 발생 밀도, 상대적 위험지수 등을 지도화하여 역학자료의 시각적 통계적 분석을 수행하였다. 환자분포의 공간적 중심위치와 분산의 변화 등 기술적 통계분석과 함께 제1차 공간속성을 커널추정법으로 찾아보았다. 이와 더불어 ‘공간적 의존성’과 관련된 제2차 공간속성은 K-함수와 시뮬레이션을 통해 분석하여 군집성 등이 통계적으로 확인되었다. 본 연구를 통해 역학조사시 GIS의 활용사례가 제시되었으며, 모집단 인구를 고려한 확률지도 작성 기법과 다양한 데이터 가시화 방법, 그리고 시계열별 발생 환자들의 지리적 변이를 분석 하는데 따르는 문제들이 논의되었다.