• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.197-206
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• 2006

In March 2003, classical swine fever (CSF) infection was reported in a piggery located at Iksan city, Jeollabuk-do in Korea. Subsequently, a total of 72 infected farms were confirmed between March and December, 2003. Based on epidemiological investigation of the earlier confirmed infected farms, the source of infection was shown to be from a breeding farm. Targeted surveillance of 82 piggeries that had acquired pigs from this breeding farm showed 44 piggeries were infected with CSF virus. CSF virus was introduced into this breeding farm by movement of selected breeder pigs from its 12 contracted farms which were located in areas that had been affected by CSF epidemic in late 2002. CSF had then spread through out the country mainly by direct transmission through the sale and movement of pigs from this breeding farm. Consequently, 47 (62%) among 72 CSF affected farms were associated, directly and indirectly, with this breeding farm. This study showed that inadequate control for breeding farms and transport restriction in CSF outbreak areas resulted in the nationwide spread of CSF and the failure of the eradication campaign that has been underway for several years by the Korean animal hygiene authority as well as the fanners. Improvements of control policy through further research of the 2003 CSF epidemic will be needed to reestablish the Korean CSF eradication program in the future.

• Tuberculosis and Respiratory Diseases
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• v.83 no.3
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• pp.211-217
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• 2020

The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on false-positive cultures of M. tuberculosis. Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, false-positive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.132-138
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• 2013

Acinetobacter baumannii is gram-negative bacilli that can be widely found in environments. Recently, A. baumannii emerged as a serious nosocomial infection. A total of 92 A. baumannii were isolated from hospitalized patients in Seoul, Korea, between December 2010 and April 2011. Antimicrobial susceptibility testing was investigated using CLSI agar dilution methods. Tigecycline non-susceptible A. baumannii isolates were investigated by repetitive extragenic palindromic sequence-based PCR (rep-PCR). Pulsed-field gel electrophoresis was performed to determine the epidemiological relationships. All clinical isolates showed high-level resistance to the most commonly used antibiotics: Ciprofloxacin (87.0%), Ampicillin/sulbactam (82.6%), Cefotaxime (81.5%), Ceftazidime (80.4%). Moreover, 50.0% of these isolates were non-susceptible to tigecycline. When evaluated by RAPD analysis, generated distinct band ranging in size from 1kb to 8k band varying from 4 to 10 bands. Stricter surveillance and more rapid detection are essential to prevent the spread of multi drug resistant A. baumannii.

• Journal of Microbiology
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• v.45 no.4
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• pp.358-363
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• 2007

Multi-drug resistant Pseudomonas aeruginosa has been implicated in a variety of serious therapeutic problems in clinical environments. Among the 968 P. aeruginosa isolates obtained from two hospitals in Daegu, Korea, we acquired 17 isolates that were resistant to all available tested antimicrobial agents, with the exception of colistin (colistin-only sensitive). We characterized the antimicrobial susceptibilities, $metallo-{\beta}-lactamases$, and epidemiological relatedness among the colistin-only sensitive P. aeruginosa isolates. All colistin-only sensitive isolates were positive in the modified Hodge test and imipenem-EDTA synergy test, thereby indicating the production of $metallo-{\beta}-lactamases$. 11 isolates from the secondary hospital and six isolates from the tertiary teaching hospital harbored $bla_{VIM-2}$ and $bla_{IMP-1}$, respectively. The pulsed-field gel electrophoretic analysis of the SpeI-digested DNA from P. aeruginosa isolates indicated that two different clones of colistin-only sensitive P. aeruginosa originated from each hospital, and had spread within the hospital environment. Overall, colistin-only sensitive P. aeruginosa was detected in Korea for the first time, but no pan-drug resistant bacteria were identified. Nationwide surveillance is required in order to monitor the emergence of colistin-only sensitive or pan-drug resistant bacteria.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.327-338
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• 2022

This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP) infected populations using data from the Health Insurance Review & Assessment Service (HIRA) and the Korea Disease Control and Prevention Agency (KDCA). SaTScan and Join-point were used for statistical analyses. Non-HIV-PcP cases showed an upward trend during the study period from 2010 to 2021, with the largest number in 2021 (551 cases). The upward trend was similar until 2020 after adjusting for the population. Seoul had the highest number of cases (1,597) in the non-HIV-PcP group, which was the same after adjusting for the population (162 cases/1,000,000). It was followed by Jeju-do (89 cases/1,000,000). The most likely cluster (MLC) for the non-HIV-PCP group was Seoul (Relative Risk (RR)=4.59, Log Likelihood Ratio (LLR)=825.531), followed by Jeju-do (RR=1.59, LLR=5.431). An upward trend was observed among the non-HIV-PcP group in the Jeju-do/Jeollanam-do/Jeollabuk-do/Gyeongsangnam-do/Busan/Daejeon/Daegu/Ulsan joint cluster (29.02%, LLR=11.638, P<0.001) located in the southern part of Korea. Both women and men in the non-HIV groups showed an overall upward trend of PcP during the study period. Men in the 60-69 age group had the highest annual percentage change (APC 41.8) during 2014-2019. In contrast, the HIV groups showed a falling trend of PcP recently. Men in the 60-69 age group had the most decrease (APC -17.6) during 2018-2021. This study provides an analytic basis for health measures and a nationwide epidemiological surveillance system for the management of PcP.

• BMB Reports
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• v.55 no.11
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• pp.571-576
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• 2022

Advancements in the field of proteomics have provided opportunities to develop diagnostic and therapeutic strategies against various diseases. About half of the world's population remains at risk of malaria. Caused by protozoan parasites of the genus Plasmodium, malaria is one of the oldest and largest risk factors responsible for the global burden of infectious diseases with an estimated 3.2 billion persons at risk of infection. For epidemiological surveillance and appropriate treatment of individuals infected with Plasmodium spp., timely detection is critical. In this study, we used combinations of depletion of abundant plasma proteins, 2-dimensional gel electrophoresis (2-DE), image analysis, LC-MS/MS and western blot analysis on the plasma of healthy donors (100 individuals) and vivax and falciparum malaria patients (100 vivax malaria patients and 8 falciparum malaria patients). These analyses revealed that α1-antichymotrypsin (AACT) protein levels were elevated in vivax malaria patient plasma samples (mean fold-change ± standard error: 2.83 ± 0.11, based on band intensities), but not in plasma from patients with other mosquito-borne infectious diseases. The results of AACT immunoblot analyses showed that AACT protein was significantly elevated in vivax and falciparum malaria patient plasma samples (≥ 2-fold) compared to healthy control donor plasma samples, which has not been previously reported.

• Journal of Medicine and Life Science
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• v.20 no.2
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• pp.67-72
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• 2023

Carbapenem-resistant Enterobacteriaceae (CRE) infections have increased rapidly over the past decade and are recognized as a severe health threat in Korea and worldwide. This study aimed to identify the status and characteristics of CRE infection in Jeju province and provide important basic data for the prevention and management of CRE infection. A descriptive epidemiological analysis was performed on reported cases of CRE infection in Jeju Province between 2018 and 2021 using the integrated management system for disease, an infectious disease reporting system from the Korea Disease Control and Prevention Agency. The annual difference and distribution trends of CRE infection were analyzed using CRE isolates, carbapenemase-producing CREs (CP-CRE) and their genotypes, and the type of medical institution in Jeju Province. CRE infections steadily increased in Jeju from 2018 to 2021, and the proportion of CP-CRE among the CREs also showed a statistically significant increase each year. Among the CRE isolates, Klebsiella pneumoniae (KPC, 62.13%) was the most common, and among the CP-CRE genotypes, KPC (81.62%) showed the highest distribution and increased each year. As the distribution of CP-CRE in have increased over the past 4 years, measures to prevent the spread and outbreak of CRE infections are warranted. The results of this study are expected to be used as basic data for prevention and management of CRE infections in the province.

• Journal of Preventive Medicine and Public Health
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• v.56 no.3
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• pp.264-271
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• 2023

Objectives: Hanging is a common method of attempted suicide. This study investigated the epidemiological profile of attempted and completed suicides by hanging in southern Iran. Methods: This cross-sectional study was performed on 1167 suicide attempts by hanging between 2011 and 2019. All data related to suicide attempts by hanging were collected from the Fars Suicide Surveillance System. The trends in suicide cases and the mean age of attempted and completed suicides were plotted. The chi-square test was used to identify suicide-related factors. Crude rates of incidence, mortality, and standardized fatality during the study period were calculated. Finally, logistic regression was used to identify the predictors of death in individuals who attempted suicide. Results: The mean age of those who attempted suicide was 33.21±16.82 years; the majority were male (80.5%). The rate of attempted and completed suicide by hanging were 3.50 and 2.79 per 100 000 people, respectively. The case-fatality rate was calculated as 79.34%. The results of our study indicated an increasing trend in suicide attempts by hanging. The likelihood of death was 2.28 times higher in individuals with a previous history of suicide attempts and 1.85 times higher in those with a psychological disorder. Conclusions: The findings of this study suggest an increasing trend in attempted and completed suicide by hanging, especially among individuals with a history of suicide attempts and psychological disorders. It is necessary to take action to reduce the rate of suicide attempts and identify the underlying causes of suicide attempts by hanging.

• Pediatric Infection and Vaccine
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• v.28 no.2
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• pp.101-109
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• 2021

Purpose: Common human coronaviruses (HCoVs) are relatively understudied due to the mild nature of HCoV infection. Given the lack of local epidemiology data on common HCoVs, we aimed to describe clinical and epidemiological characteristics of common HCoVs in children. Methods: Respiratory viral test results from 9,589 respiratory samples from Seoul National University Children's Hospital were analyzed from January 2015 to December 2019. Viral detection was done by the multiplex reverse transcription polymerase chain reaction. Demographics and clinical diagnosis were collected for previously healthy children tested positive for HCoVs. Results: Of the 9,589 samples tested, 1 or more respiratory viruses were detected from 5,017 (52.3%) samples and 463 (4.8%) samples were positive for HCoVs (OC43 2.8%, NL63 1.4%, 229E 0.7%). All 3 types co-circulated during winter months (November to February) with some variation by type. HCoV-OC43 was the most prevalent every winter season. HCoV-NL63 showed alternate peaks in late winter (January to March) and early winter (November to February). HCoV-229E had smaller peaks every other winter. Forty-one percent of HCoV-positive samples were co-detected with additional viruses; human rhinovirus 13.2%, respiratory syncytial virus 13.0%, influenza virus 4.3%. Common clinical diagnosis was upper respiratory tract infection (60.0%) followed by pneumonia (14.8%), croup (8.1%), and bronchiolitis (6.7%). Croup accounted for 17.0% of HCoV-NL63-positive children. Conclusions: This study described clinical and epidemiological characteristics of common HCoVs (OC43, NL63, 229E) in children. Continuing surveillance, perhaps by adding HKU1 in the diagnostic panel can further elucidate the spectrum of common HCoV infections in children.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.114-118
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• 2014

A total of 122 ESBL-producing intestinal bacteria were collected from regional hospitals in the Chungcheong area. Combination disk test (CDT) was performed for antimaicrobial susceptability using cefotaxime and cefotaxime/clavulanate according to Clinical Laboratory Standard Institute (CLSI). Mutiplex PCR using specific primers was performed for a detection of ESBL-genotypes and enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out for the tracking of molecular epidemiology. In the confirmation test using CDT, 73 out of 76 (96.1%) ESBL-producing Escherichia coli and 43 out of 46 (93.4%) ESBL-producing Klebsiella pnemoniae were positive. In the multiplex PCR, 60.5% of E. coil were positive for CTX-M-2 type gene and 56.5% of K. pneumoniae were positive for VEB -1 type gene. In the ERIC-PCR, E. coil isolates formed 5 clusters and K. pneumoniae isolates were grouped into 4 clusters depending on region. Genotypes of clinical isolates are useful for detection and differentiation of ESBL producing intestinal bacteria. The ERIC-PCR method is thought to be helpful for establishing a regional surveillance system for infection due to its formation of different clusters depending on region.