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.

Early Changes in the Serotype Distribution of Invasive Pneumococcal Isolates from Children after the Introduction of Extended-valent Pneumococcal Conjugate Vaccines in Korea, 2011-2013

This study was performed to measure early changes in the serotype distribution of pneumococci isolated from children with invasive disease during the 3-year period following the introduction of 10- and 13-valent pneumococcal conjugate vaccines (PCVs) in Korea. From January 2011 to December 2013 at 25 hospitals located throughout Korea, pneumococci were isolated among children who had invasive pneumococcal disease (IPD). Serotypes were determined using the Quellung reaction, and the change in serotype distribution was analyzed. Seventy-five cases of IPD were included. Eighty percent of patients were aged 3-59 months, and 32% had a comorbidity that increased the risk of pneumococcal infection. The most common serotypes were 19A (32.0%), 10A (8.0%), and 15C (6.7%). The PCV7 serotypes (4, 6B, 9V, 14, 18C, 19F, 23F, and 6A) accounted for 14.7% of the total isolates and the PCV13 minus PCV7 types (1, 3, 5, 7F and 19A) accounted for 32.0% of the total isolates. Serotype 19A was the only serotype in the PCV13 minus PCV7 group. The proportion of serotype 19A showed decreasing tendency from 37.5% in 2011 to 22.2% in 2013 (P = 0.309), while the proportion of non-PCV13 types showed increasing tendency from 45.8% in 2011 to 72.2% in 2013 (P = 0.108). Shortly after the introduction of extended-valent PCVs in Korea, serotype 19A continued to be the most common serotype causing IPD in children. Subsequently, the proportion of 19A decreased, and non-vaccine serotypes emerged as an important cause of IPD. The impact of extended-valent vaccines must be continuously monitored.

Laboratory-acquired dengue virus infection by needlestick injury: a case report, South Korea, 2014

BACKGROUND: Dengue fever is one of the most dominant vector-borne diseases, putting approximately 3.9 billion people at risk worldwide. While it is generally vector-borne, other routes of transmission such as needlestick injury are possible. Laboratory workers can be exposed to dengue virus transcutaneously by needlestick injury. This is the first case, to our knowledge, of dengue virus infection by needlestick injury in a laboratory environment. This paper evaluates the risk and related health concerns of laboratory workers exposed to dengue virus. CASE PRESENTATION: We evaluated a 30-year-old female laboratory worker exposed to the dengue virus by needlestick injury while conducting virus filtering. During admission, she showed symptoms of fever, nausea, myalgia, and a characteristic maculopapular rash with elevated aspartate aminotransferase (AST) of 235 IU/L and alanine aminotransferase (ALT) of 269 IU/L. She had been diagnosed by a positive nonstructural protein 1 (NS1) antigen (Ag) rapid test one day prior to symptom onset along with positive immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) on the ninth day of symptom onset. Reverse transcription polymerase chain reaction (RT-PCR), also conducted on the ninth day, was negative. After proper symptomatic treatment, she recovered without any sequelae. As a result of thorough epidemiologic investigation, it was determined that she had tried to recap the needle during the virus filtering procedure and a subsequent needlestick injury occurred. CONCLUSIONS: In the context of health promotion of laboratory workers, we suggest that the laboratory biosafety manual be revised and reinforced, and related prevention measures be implemented. Furthermore, health authorities and health care providers in Korea should be fully informed of proper dengue fever management.

Management of vaccine safety in Korea

Although vaccination is regarded as one of the most effective public health measure to prevent and control infectious diseases, no vaccine is perfectly safe. Therefore, safety management is an essential component in running National Immunization Program. Here, we review the current issues and suggest future perspectives of Korean vaccine safety management system.

Current status of measles in the Republic of Korea: an overview of case-based and seroepidemiological surveillance scheme / 소아과

Following the Five Year Measles Elimination Program, measles has been declared eliminated from the Republic of Korea since 2006. However, there remain challenges related to the surveillance of measles in the postelimination phase. Even though the routine surveillance system has revealed a gradual decrease in the number of reported cases since 2002, 4 resurgences have occurred, notably due to outbreaks. Because vaccine-modified measles is becoming widespread due to high vaccination coverage, conducting laboratory confirmation in each case becomes important. Moreover, susceptible individuals with measles have been identified through seroprevalence studies. Lastly, the efforts to improve the timeliness of measles reporting have led to the establishment of an active laboratory-based surveillance network, which has shortened the interval between diagnosis and notification. In these circumstances, searching for more sensitive and effective surveillance measures is important for maintaining the elimination status and preventing future outbreaks of measles in Korea.

Socioeconomic burden of the polycystic ovary syndrome / 대한산부인과학회지

OBJECTIVE: The objective of the study was to estimate socioeconomic burden of polycystic ovary syndrome (PCOS) during the reproductive life span using current definitions and prevalence or incidence data. METHODS: Questionnaires were given to 8,588 reproductive women reviewed at Ewha Womans University Mokdong hospital. The PCOS affected approximately 10.4% of reproductive-aged women (11 million women in Korea, prevalence rate according to 1990 National Institutes of Health PCOS diagnosis criteria). We tied general societal cost data for the different health consequences to reproductive-age PCOS costs, using prevalence data. RESULTS: We estimated the mean annual cost of the initial evaluation to be 76 hundred million won, that of hormonally treating menstrual dysfunction, providing infertility care, diagnosis/treatment of endometrial hyperplasia, GDM, type 2 DM, and hypertension to be 280 billion won. The total annual socioeconomic cost of evaluating and providing care to reproductive-aged PCOS women in Korea is 350 billion won. CONCLUSION: Because the cost of the diagnostic evaluation accounted for a relatively minor part of the total socioeconomic costs, more widespread screening for PCOS appears be a cost-effective strategy, leading to earlier diagnosis and intervention and possibly the amelioration and prevention of serious sequelae.

Seroprevalence of measles and mumps antibody among preschool children in Korea, according to their vaccination history / 한국역학회지

PURPOSE: To maintain measles elimination status, we evaluated the seropositivity of measles and mumps according to time interval since the first or second dose of MMR in children aged 4 to 6 years, who are starting communal life. MATERIALS AND METHOD: 2,447 children aged 4 to 6 years were enrolled at 251 public health centers over the period of March to May 2007. Subjects were verified their date of MMR vaccination and then their blood was sampled for serologic test. Measles and mumps IgG antibody was tested by ELISA at Korea CDC. RESULTS: Vaccination coverage was 99.9% in the first dose, 64.9% in the second dose regardless of gender. Seropositivity of measles and mumps was 95.7%, 85.5% in the first dose and 98.7%, 98.1% in the second dose, respectively. The seropositivity of measles was 88.1% in 6-year-olds who did not receive the second dose of MMR. As time since receipt, seropositivity of measles tended to decrease over time and was 93.3% in vaccinees over 48 months after the first dose. CONCLUSION: A first dose MMR at 12-15 months cannot lead to herd immunity. More public information is needed to encourage second dose vaccination before admission to day-care center or kindergarten.

Prevalence and Risk Factors of Fibromyalgia Syndrome and Chronic Widespread Pain in Two Communities in Korea-First Report in Korean / 대한류마티스학회지

OBJECTIVE: To estimate the prevalence and risk factors of fibromyalgia syndrome (FMS) and chronic widespread pain (CWP) in Korean. METHODS: Those who participated chronic pain field study in Uljin and Pohang, Kyongsangbuk-do in 2004 were evaluated for the prevalence of FMS and CWP. Diagnosis of FMS and CWP were made using American College of Rheumatology criteria. All 1,028 were interviewed based on a detailed questionnaire and 144 CWP patients were examined for tender points. RESULTS: Among the 1,028 participants (mean age+/-SD, 63.3+/-12.7 years), 676 participants were female (mean age+/-SD, 62.1+/-13.5 years) and 352 participants were male (mean age+/-SD, 65.7+/-10.5 years). There were 23 cases of FMS (2.2%), which consisted of 21 female cases and 2 cases of male. Prevalence of FMS was significantly higher in female compared to male (3.1% vs 0.6%, p<0.01). Prevalence of FMS showed increasing trend in the ascending order of age in decade (p<0.001). CWP was detected in 144 cases (14.0%), which consisted of 130 female cases and 14 cases of male. Prevalence of CWP was also significantly higher in female compared to male (19.2% vs 4.0%, p<0.001). Prevalence of CWP also showed increasing trend in the ascending order of age in decade (p<0.001). Except for age and sex, hating vegetables is an associated factor for the development of FMS in CWP [OR 18.7 (95% CI 2.4, 145.3)] and diabetes is a risk factor for the development of FMS in normal population [OR 3.7 (95% CI 1.1, 11.9)] on multivariate analyses. CONCLUSION: The prevalence of FMS and CWP were 2.2% and 14.0% in Korean, respectively. The prevalence of FMS and CWP were significantly higher in female and aged individuals. Aging, female sex, hating vegetables and diabetes are prognostic factors for the development of FMS.

Outbreak of Measles among School Ages in Yeongju in 2000 / 한국역학회지

BACKGROUND: The outbreak of measles from 2000 to 2001 was the biggest epidemic since measles vaccination was introduced in Korea. Outbreak of measles in Yeongju was one of the earliest milestones of the nationwide outbreak in the year 2000. The authors investigated epidemiologic characteristics of the outbreak in this area. METHODS: The authors estimated attack rate through the investigation of all the school age cases of measles reported to local health authority between March and May, 2000. Case investigation was done to trace the source of the outbreak. One hundred seventy two cases were examined with medical examination, with interview on their clinical manifestations, and with serologic examination on the anti-measles IgM and IgG antibody. RESULTS: Overall attack rate among the school children was 4.3%, with highest attack rate in middle school students (8.5%). The outbreak began in March in middle schools, which spread to elementary and high schools. IgG was positive in 160(93.0%) cases and IgM was positive in 94(54.6%) cases, among which 90 cases (95.7%) were also positive for IgG. IgM positive cases had higher prevalence of rash (91.5%) compared to those without IgM (70.5%). Diagnostic criteria based on the clinical manifestation and contact history showed the highest sensitivity (92.6%) compared to conventional diagnostic criteria in outbreak (40.4-44.7%) CONCLUSIONS: High proportion of susceptible children in the population due to primary or secondary vaccine failure played a key role in this outbreak. Clinical manifestation was milder than classical measles and adjustment of diagnostic criteria can be helpful in the management of outbreak.

Status on Influenza Vaccination in Some Community Health Centers / 한국역학회지

PURPOSE: This study was conducted to improve the Korean influenza management system and to determine the status of influenza vaccination in some community health centers through a survey of the officers in charge of influenza vaccination. METHODS: The authors conducted a questionnaire survey by e-mail for the officers in charge of influenza vaccination of 8 community health centers in Daegu-si, 5 community health centers in Ulsan-si and 25 community health centers in Gyeongsangbuk-do. The authors developed a questionnaire including selection methods of the influenza vaccination objects, results of influenza vaccination in 2002, problems of influenza vaccination, the population within the respondents`jurisdiction and so on. RESULTS: The proportion of influenza vaccination at community health centers among all residents in the 2002-2003 influenza season was 3.8% in Daegu-si, 14.8% in Ulsan-si, 15.1% in urban Gyeongsangbuk-do and 24.9% in rural Gyeongsangbuk-do. The proportion of influenza vaccination at community health centers among priority cases for vaccination was 12.9% in Daegu-si, 43.1% in Ulsan-si, 39.3% in urban Gyeongsangbuk and 41.6% in rural Gyeongsangbuk-do. The officers in charge of influenza vaccination stated that the problems of influenza vaccination were deficiencies in preparatory examination such as manpower shortage. Twenty-five persons stated as a problem that influenza vaccinations conducted in the hospitals were hardly reported, and fifteen of these clarified that this was due to hospital indifference. CONCLUSIONS: The authors examined all community health centers of Daegu-si, Ulsan-si, and Gyeongsangbuk-do, and investigated the vaccination states and problems that health officers were dealing with. Therefore, this study is meaningful with its basic data for the management of domestic influenza vaccination.

A Case of Intermediate Syndrome of Organophosphate Poisoning after Dermal Exposure / 대한산업의학회지

BACKGROUND: Organophosphate poisoning is one of the most common toxicologic emergencies in Korea. Acute organophosphate poisoning and delayed polyneuropathy by ingestion are well published. There have been several reports about intermediate syndrome in organophosphate poisoning by ingestion but few about intermediate syndrome via dermal route. CASE REPORT: We observed a 59-years-old male who had weakness of proximal limb muscles and respiratory muscles 2 days after dermal exposure by unidentified pesticide. The paralytic symptoms lasted up to 20 days but the delayed polyneuropathy did not develop. The patient needed mechanical ventilatory support for 2 weeks and had completely recovered from IMS 6 weeks later. Electrophysiological study was characterized by an axonal polyneuropathy pattern on the proximal limb muscles. Serum acetylcholinesterase level was below half of normal level. Clinical manifestations and electrophysiological study support the clinical diagnosis of intermediate syndrome. CONCLUSION: Intermediate syndrome is commonly developed by ingestion of organophosphate but, as in this case, dermal absorption can also lead to intermediate syndrome. More detailed history taking and close observation is needed for about 3 or more days after intoxication because of the risk of respiratory failure.

Cause of Enterohemorrhagic Escherichia coli Infection in Ulju County, Korea / 예방의학회지

OBJECTIVES: Two related cases of Hemolytic-Uremic Syndrome (HUS) were reported to the Korea National Institute of Health in May, 2001. Shiga toxin 2 genes were detected in both stool samples. We suspected an enterohemorrhagic Escherichia coli (EHEC) infection as the cause of the HUS, and conducted an investigation to find the source of the infection and its route of transmission. METHODS: We performed case investigations on these two related HUS cases, and obtained interviews and rectal swabs form the family members and other close contacts. Additionally, we performed rectal swabs on the cattle raised by the household of the index patient. RESULTS: We found a 20 month old index patient and a 6 year-old cousin had developed HUS, where there had been a 2 day history of contact with the index, and bacteriological examinations for these two patients revealed, indistinguishably, the same E. coli O171. The grandmother of the index patient was found to be asymptomatic, but E. coli O26 was isolated. We also found a probable case in the mother of the cousin. She reported a history of contact with the index, and developed bloody diarrhea of 3 days duration. The test results for the cattle revealed E. coli O26 in one cow, and E. coli O26 and O55 in another. E. coli O26, which was isolated in both cows and the grandmother of the index, were indistinguishably the same. CONCLUSIONS: We found that the E. coli O26 in the grandmother had originated from the cows, and that the E. coli O171 found in the index patient had been transmitted to the cousin through person-to-person contact.

Outbreak of Salmonellosis Misdiagnosed with Amebiasis in Gumi City and Chilgok County, Korea / 한국역학회지

PURPOSES: In May 29, 1999, the health department in Gumi city received a report from a local pediatrician that three children who attended a kindergarten were diagnosed with amebic dysentery. By May 31, fifteen more children from the same kindergarten were diagnosed with amebic dysentery. We conducted an investigation in order to verify the diagnosis, and to implement appropriate control measures. METHODS: We conducted a questionnaire survey on 264 children in 3 kindergarten in Gumi city. Furthermore, 726 children in 4 kindergarten and 13 academies in Chilgok county whose lunch is supplied by the same unlicensed catering company were monitored for diarrheal symptoms. RESULTS: Of 264 children in Gumi city, 74 children fitted the case definition (attack rate, 28%). Of 726 children in Chilgok county, 50 children were reported to have diarrheal symptoms. The clinical picture was dominated by the following symptoms; abdominal pain (85.1%), fever (83.8%), headache (50.0%), chilling (45.9%), vomiting (28.4%). The median duration of diarrhea was 2 days, and the median frequency of diarrhea was 3 times/day. Salmonella Typhimurium of the same antibiogram pattern were isolated from fifteen cases. However, no evidence of amebiasis was found from laboratory results or epidemiologic pattern. CONCLUSIONS : This epidemic was caused by Salmonella Typhimurium, which were present in lunch supplied by the unlicensed catering company. Improvement of the diagnostic ability in local health centers as well as public health centers and reinforcement of strict protocols regarding appropriate management of catering services should be emphasized

Investigation of Health Hazards in the Underground Storage Facilities of Ginger Roots / 예방의학회지

OBJECTIVES: To evaluate the health hazards in the underground storage facilities of ginger roots. METHODS: The authors reviewed the emergency rescue records from the Seosan fire department over the period Jan 1, 1996 to Aug 31, 1999. The atmospheres in 3 different underground storage locations were analyzed for O2, CO2, CO, H2S and NH4. RESULTS: From the emergency records, we were able to identify 20 individuals that had been exposed to occupational hazards in the underground storage facilities. Among these 20 cases, 13 were due to asphyxiation (resulting in 7 deaths) and 7 were due to falls. In the first atmospheric tests, performed on Feb 25, 1998, the O2 level inside the underground storage facility, located about 5~6 meters below the surface, was 20.6% and the CO2 level was about 1,000 ppm. CO, H2S and NH4 were not detected. In the second tests on Jul 6, 1999, measurements of the O2 level at 3 meters below the surface in two different storage locations were 15.3 and 15.1%. And the O2 levels inside the storage facilities were 12.2 and 12.1%. The CO2 level was above 5,000 ppm (beyond upper limits of measurement). CO, H2S and NH4 were not detected. CONCLUSIONS: We conclude that asphyxiation in the underground storage facilities for ginger roots was not due to the presence of toxic gases such as CO, H2S and NH4, but rather the exclusion of oxygen by carbon dioxide was responsible for causing casualties. For the development of a hazard free working environment, safety education as well as improvements in storage methods are needed.

Survey on the Epidemiological Characteristics of Measles Incidence between 1980 and 1999 Year in Korea / 감염

BACKGROUND: This study reports the incidences of measles in Koea and the epidemiologic characteristics for the incidence reported for the period 1980~1999. It provides the epidemeologic adta for measles before implementing the catch-up campaign in 2001. METHODS: We obtained information for the survey from the data for the incidence reported from health centers. Incidences per 100,000 population were calculated for the 1963~1999. And the following variables were studied: seasonal or regional distribution for the 1980~1999. RESULTS: The incidence rate of measles declined after the systemic immunization in 1990, the outbreak of measles occurred periodically and incidences per 100,000 population increased from 8.4 cases in 1990 to 17.7 in 1994. In 1990 and 1994, measles cases centered around the 5~6th month. On the other hand, in non-epidemic year measles cases were scattered around the year. The incidence rates of measles by the province were greatly defferent whenever the outbreak of measles occurred. CONCLUSION: In 1990s, the outbreak of measles occurred periodically at the interval of 4 years until 1994. The seasonal distribution may be caused by Iimitation of transmission due to the increased measles immunity in outbreak region. Our results showed that the measles outbreak did not occur in the specific province, but it occurred nationwide whenever measles outbreak occurred, even though the incidence rates of the provinces were different.

Epidemiological Characteristics of Measles Outbreakin 2000~2001, Korea / 감염

BACKGROUND: In 2000~2001 there was a nationwide outbreak of measles in the Republic of Korea. Since supplementary vaccination program was implemented in 2001, the control strategy of this measles outbreak has been stepped up from the control phase to the elimination phase. We here present the result of survey for the epidemiologic characteristics of the nationwide outbreak of measles in 2000~2001. METHODS: Using the data based on the sheet of epidemiologic investigation, incidences rates per 100,000 population and distributions of cases with vaccination history were investigated by the age. The seasonal or regional distribution were also studied with the onset days of cases. RESULTS: In 2000~2001, a measles outbreak occurred with 52,897 reported cases. The incidence rate per 100,000 population of measles was 111.9 cases and that of geopolitical unit (province) was high nationwide, 35.9~386.3 cases. The incidence rates were very high in less than 12 months and 10 years of age, 954.4 and 714.9, respectively. The 1st vaccination rate of measles/mumps/rubella (MMR) in 1~3 years old was 26.3~77.1%, and especially, that of 1 year old showed very low coverage, 26.3%. However, there was no special propensity in the 1st vaccine coverage in the age of 7~15 years, which had 87.7~91.4%. On the other hand, the 2nd MMR vaccination rate of the cases was very low, 17.7% at the age of 7~10 years. From the 21st May, 2001 a mass catch-up campaign with measles/rubella (MR) vaccine was launched, resulting in prominent reduction in the incidence of measles case. CONCLUSION: This survey showed that the measles outbreak in 2000~2001 had a high incidence nationwide from October 2000 to April 2001 and in less than 12 month and 10 years of age. Our results also showed that no routine immunization made the age group under 1 year vulnerable to measles infection. In cases of school-age group after 7 years of age, some cases with vaccination history were also infected. The characteristics of recent outbreaks indicates the need for the introduction of a specific vaccination programme at that age group. This survey was helpful to establish the effective vaccination strategy and it would be used as reference data on survey continuously for the epidemiologic characteristics of measles case for elimination of indigenous measles transmission in Republic of Korea.

A Epidemic Survey of the Shigellosis in Jeju Island during the First Half of Year 2000 / 한국역학회지

PURPOSE: A field investigation was done to evaluate the level of the epidemic of Shigellosis in Jeju Island during the first half of year 2000. METHODS: Confirming the Shigellosis was done by the structured questionnaire and the result of rectal swab for the residents having a diarrhea. RESULTS: As the confirmed patients with Shigella sonnei were 933 from 25 April to 14 August 2000, the crude incidence rate was 174 per 100,000 persons. The highest incidence rate was shown in 5-9 year-old group. Especially the south area of Jeju Island, called as Namjejugun, had the major epidemic occurrence. CONCLUSIONS: The huge and chronic epidemic of Shigellosis was confirmed. The nature of this epidemic suggested that the endemic occurrence had been existed in Jeju Island.

Epidemiologic Investigation of an Outbreak of Shigellosis in Kyongju, Korea / 예방의학회지

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, 1998. 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, 1~3 days (72.5%) in duration, 2~3 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 pools should be done thoroughly.

Epidemiologic Investigation of an Outbreak of Shigella sonnei among Students in Bonghwa, 1999 / 예방의학회지

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 staffs 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 subjects 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: 16-144 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 one or two food handler who is presumed to be carrier.

Occupational Relationship of Cancer Patients Diagnosed in Two University Hospitals / 한국역학회지

OBJECTIVES: This study was performed to evaluate the occupational relationship on 190 cases of cancer selected out of 622 cases of cancer registered in two university hospitals from January 1, 1996 to December 31, 1997. METHODS: The selection criteria was for the patient to be more than 40 years old with lung, liver, urinary bladder, nasal cavity and skin cancer or leukemia. We reviewed the medical records to update the missing data and occupational histories. Telephone interviews were used to obtain complete occupational histories on the subjects. RESULTS: The sites of cancer in the order of relative frequency was lung (51.0%), followed by liver (32.9%), urinary bladder (14.1%) and skin (2.0%) in male, liver (41.5%), followed by lung (31.7%), skin (19.5%) and urinary bladder (7.3%) in female. The occupational histories of 190 cases with suspected cancer-causing occupations were recorded 5.8% on the doctor's medical records and 33.2% on the nursing records. The response rates of the telephone interviews were 87.4%. The distribution of occupation according to the telephone interviews was farmer (47.7%), office worker (16.1%), salesman (12.8%), production worker (6.7%), simple laborer (3.4%) and unknown (13.4%) in male, housewife (63.4%), farmer (17.1%), saleswoman (9.8%) and unknown (9.8%) in female. And there were two cases of suspected occupational relationships in the lung cancer cases. CONCLUSIONS: We could not discover definite cases of occupational cancer but found out two cases of suspected occupational relationships. Occupational cancer is likely to increase in the near future, so the efforts to detect occupational relationships with cancer should be continued.