• Quality Improvement in Health Care
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• v.10 no.2
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• pp.190-203
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• 2003

Background: Dental hygienists are at risk of acquiring infections through exposure to infectious agents. This study explores the frequency of exposure to infectious agents and infection control practices among dental hygienists. Methods: We undertook a cross-sectional survey to examine the exposure to infectious agents and infection control practices among dental hygienists through questionnaire. Data were obtained from 124 dental hygienists attending educational conferences. A multiple logistic regression analysis was conducted to determine the factors that effect infection control practices in relation to age, completion of infection control education, recognition of their own serum hepatitis Ag/Ab status, the number of one day patients, location of clinics, type of clinics, and career years. Result: Of the 124 dental hygienists, 91.7% were exposed to at least one accident such as needle stick injuries during their practices periods. The health screening coverage rate in dental hygienists was 16.5%. The number of one day patients and career years were important in relation to infection control practices among dental hygienists. The adjusted odds ratio estimates for career years were 5.049 times greater(95% Cl 1.238-20.597) for groups with over 4 career years than under 2 career years. That for the number of one day patients were 0.261(95% Cl 0.071-0.955) lower for through 20 up to 30 patients, 0.531(95% Cl 0.102-2.78) lower for through 30 up to 40 patients and 0.498(95% Cl 0.123-2.017) lower for more than 40 patients than under 20 patients. Conclusion: From these results, prevalence of infection control practices among dental hygienists is related to the number of one day patients and career years. Prevention of cross infection and reduction of future transmission should be a priority to dental hygienists for promotion of infection control and further efforts to educate newcomers on infection prevention should be made.

• Parasites, Hosts and Diseases
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• v.47 no.3
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• pp.269-273
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• 2009

A 57-year old man who was admitted to an emergency room of a tertiary hospital with hemoptysis developed malarial fever 19 days later and then died from severe falciparum malaria 2 days later. He had not traveled outside of Korea for over 30 years. Through intensive interviews and epidemiological surveys, we found that a foreign patient with a recent history of travel to Africa was transferred to the same hospital with severe falciparum malaria. We confirmed through molecular genotyping of the MSP-1 gene that Plasmodium falciparum genotypes of the 2 patients were identical. It is suggested that a breach of standard infection control precautions resulted in this P. falciparum transmission between 2 patients in a hospital environment. This is the first report of a nosocomial transmission of falciparum malaria in Korea.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.366-370
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• 2018

Purpose: Tuberculosis (TB) is one of the most important diseases that cause significant mortality and morbidity in young children. Data on TB transmission from an infected child are limited. Herein, we report a case of disseminated TB in a child and conducted a contact investigation among exposed individuals. Methods: A 4-year-old child without Bacille Calmette-$Gu{\acute{e}}rin$ vaccination was diagnosed as having culture-proven disseminated TB. The child initially presented with symptoms of inflammatory bowel disease, and nosocomial and kindergarten exposures were reported. The exposed individuals to the index case were divided into 3 groups, namely household, nosocomial, or kindergarten contacts. Evaluation was performed following the Korean guidelines for TB. Kindergarten contacts were further divided into close or casual contacts. Chest radiography and tuberculin skin test or interferon-gamma-releasing assay were performed for the contacts. Results: We examined 327 individuals (3 household, 10 nosocomial, and 314 kindergarten contacts), of whom 18 (5.5%), the brother of the index patient, and 17 kindergarten children were diagnosed as having latent TB infection (LTBI). LTBI diagnosis was more frequent in the children who had close kindergarten contact with the index case (17.1% vs. 4.4%, P=0.007). None of the cases had active TB. Conclusion: This is the first reported case of TB transmission among young children from a pediatric patient with disseminated TB in Korea. TB should be emphasized as a possible cause of chronic diarrhea and failure to thrive in children. A national TB control policy has been actively applied to identify Korean children with LTBI.

• Journal of Life Science
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• v.33 no.2
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• pp.199-207
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• 2023

To prepare for the threat of a future epidemic in the post-COVID-19 era, research based on the one-health concept (i.e., the health of humans, animals, and the environment as "one") is essential. Cross-species infections are being identified as a result of the high infection rate and viral load of SARS-CoV-2 in humans. The possibility of transmission of SARS-CoV-2 from humans to mink has been determined. In addition, the transmission of SARS-CoV-2 from humans to cats through contact has been considered possible. The data so far show that livestock and poultry are less likely to be infected with SARS-CoV-2. However, if infections are established through a new mutation, the resulting diseases are expected to have enormous ripple effects on various fields, such as human food security, the economy, and trade. In addition, there are concerns about the endemic prospect of SARS-CoV-2 and the high accessibility of companion animals. This is because the evolution of the virus likely occurs in animal hosts. Once SARS-CoV-2 is established in other species, they might serve as intermediate hosts for the re-emergence of the virus in the human population. Thus, it is necessary to ensure a rapid response to future outbreaks by accumulating research data on the animal infection of SARS-CoV-2. These data can have implications for the development of animal models for vaccines and therapeutics against SARS-CoV-2. Therefore, in this study, epidemiological reviews were analyzed, and response strategies against SARS-CoV-2 infection in animals were presented using the One-health approach.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1059-1070
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• 2007

Prion diseases, often called transmissible spongiform encephalopathies (TSEs), are infectious diseases that accompany neurological dysfunctions in many mammalian hosts. Prion diseases include Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform encephalopathy (BSE, "mad cow disease") in cattle, scrapie in sheep, and chronic wasting disease (CWD) in deer and elks. The cause of these fatal diseases is a proteinaceous pathogen termed prion that lacks functional nucleic acids. As demonstrated in the BSE outbreak and its transmission to humans, the onset of disease is not limited to a certain species but can be transmissible from one host species to another. Such a striking nature of prions has generated huge concerns in public health and attracted serious attention in the scientific communities. To date, the potential transmission of prions to humans via foodborne infection and iatrogenic routes has not been alleviated. Rather, the possible transmission of human to human or cervids to human aggravates the terrifying situation across the globe. In this review, basic features about prion diseases including clinical and pathological characteristics, etiology, and transmission of diseases are described. Based on recently accumulated evidences, the molecular and biochemical aspects of prions, with an emphasis on the molecular interactions involved in prion conversion that is critical during prion replication and pathogenesis, are also addressed.

• Tuberculosis and Respiratory Diseases
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• v.74 no.2
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• pp.63-69
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• 2013

Background: Aiming to improve outcome of lung transplantation (LTx) patients, we reviewed risk factors and treatment practices for the LTx recipients who experienced respiratory infection in the late post-LTx period (>1 month after LTx). Methods: We analyzed the clinical data of 48 recipients and donors from 61 LTx, who experienced late respiratory infections. Late respiratory infections were classified according to the etiology, time of occurrence, and frequency of donor-to-host transmission or colonization of the recipient prior to transplantation. Results: During the period of observation, 42 episodes of respiratory infections occurred. The organisms most frequently involved were gram (-) bacteria: Acinetobacter baumannii (n=13, 31.0%), Pseudomonas aeruginosa (n=7, 16.7%), and Klebsiella pneumoniae (n=4, 10.0%). Among the 42 episodes recorded, 14 occurred in the late post-LTx period. These were bacterial (n=6, 42.9%), fungal (n=2, 14.3%), viral (n=4, 28.5%), and mycobacterial (n=2, 14.3%) infections. Of 6 bacterial infections, 2 were from multidrug-resistant (MDR) A. baumannii and one from each of MDR P. aeruginosa, extended spectrum ${\beta}$-lactamase (+) K. pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae. Infection-related death occurred in 6 of the 14 episodes (43%). Conclusion: Although the frequency of respiratory infection decreased sharply in the late post-LTx period, respiratory infection was still a major cause of mortality. Gram (-) MDR bacteria were the agents most commonly identified in these infections.

• Biomedical Science Letters
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• v.10 no.3
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• pp.309-315
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• 2004

Methicillin resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. Many hospitals are facing the problems which they have to use expensive antibiotics and suffer from long term hospital study of patients due to MRSA. This study is to survey MRSA nasal colonization of patients and doctors, and to investigate the mode of transmission of MRSA by pulsed field gel electrophoresis (PFGE) and then use these data to prevent further spread of cross infection and reduce nosocomial infection. Subjects of this study were 201 patients with MRSA infection at an university hospital in Busan from Sept. 1997 to Aug. 1998. Bacterial genotypes of MRSA strains isolated from nares and wound of patients (14 cases) and nares of doctors (8 cases) were analyzed by PFGE. Nasal cultures of 20 I patients for detecting nasal colonization of MRSA were performed and incidence rate of nasal colonization was 40％ (80/201). Among 201 patients MRSA were acquired from hospital in 140 (70％) patients and were acquired from community 61 (30％) patients. Among 14 pairs of MRSA from colonized or infected sites and anterior nares, DNA patterns of 10 pairs (71.4％) were equal. 86％ (12/14) MRSA strains isolated from patients and 12.5％ (1/8) MRSA strains isolated from doctors show same pattern. DNA patterns were changed in some doctors after nasal oint. Treatment. It could be inferred that the most sources of MRSA in hospital are the endemically existing MRSA. Therefore, we believe that it would be necessary to control MRSA nasal colonization of the patients and the related medical teams to reduce the medical cost and to improve the efficacy of medical cares.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.695-701
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• 2013

Opisthorchis viverrini infection causes inflammation and liver injury leading to periductal fibrosis. Little is known about the pathological alterations in bile canaliculi in opisthorchiasis. This study aimed to investigate bile canalicular alterations in O. viverrini-infected hamsters and to examine the chemopreventive effects of curcumin on such changes. Hamsters were infected with O. viverrini and one group of animals was fed with 1% dietary curcumin supplement. Animals were examined during the acute infection phase, days 21 and 30 post-infection (PI) and chronic infection phase (day 90 PI). Scanning electron microscopy revealed that in the infected group fed with a normal diet, bile canaliculi became slightly tortuous by 30 day PI and more tortuous at day 90 PI. Transmission electron microscopy showed a reduction in microvilli density of canaliculi starting at day 30 PI, with a marked loss of microvilli at day 90 PI. These ultrastructral changes were slightly seen at day 21 PI, which was similar to that found in infected animals fed with 1% curcumin-supplemented diet. Notably, curcumin treatment prevented the reduction of microvilli density, reduced the dilation of bile canaliculi, and decreased the tortuosity of the bile canaliculi relative to non-infected animals on a normal diet at days 30 and 90 PI. These results suggest that curcumin reduces alteration of bile canaliculi and may be a promising agent to prevent the onset of bile duct abnormalities induced by O. viverrini infection.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.533-540
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• 2017

Schistosoma mansoni is highly endemic in Tanzania and affects all age groups at different degrees. However, its control approach does not include adult individuals who are equally at risk and infected. To justify the inclusion of adult individuals in MDA programs in Tanzania, the present study focused on determining the prevalence of S. mansoni infection and its related morbidities among adult individuals. This was a cross sectional study conducted among 412 adult individuals aged 18-89 years living in selected villages of Rorya and Butiama districts located along the shoreline of the Lake Victoria. A pretested questionnaire was used to collect socio-demographic and socio-economic information of participants. Ultrasonographic examinations were conducted for all study participants using the Niamey protocol. A single stool sample was obtained from all study participants and examined for S. mansoni using the Kato-Katz technique. The study revealed a high prevalence of S. mansoni (56.3%), and the majority of infected individuals had a light intensity of infection. Ultrasonographic findings revealed that 22.4% of adult individuals had periportal fibrosis (PPF) (grade C-F), with 18.4% having grade C and D and 4% having grade E and F. Males had the highest prevalence of PPF (31.7% vs 10.8%, P<0.001). Organomegaly was common with 28.5% and 29.6% having splenomegaly and hepatomegaly, respectively. S. mansoni infection and its related morbidities included PPF, hepatomegaly, and splenomegaly were common among adult individuals. To reduce the level of transmission of S. mansoni infection, planned mass drug administration campaigns should include adult individuals living in these villages.

• Journal of dental hygiene science
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• v.21 no.1
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• pp.1-7
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• 2021

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted primarily through droplets, and dental practitioners are at risk of occupational exposure to SARS-CoV-2 infection owing to direct contact with the patient's mouth, aerosols from dental procedures, and saliva. Wearing a mask is believed to be the best method of protection against infection, and a systematic literature review was conducted on whether the dental masks used in dentistry are effective in preventing Coronavirus Infectious Disease-19 (COVID-19). Methods: We used PubMed, Google Scholar, DBpia, NDSL, and KISS databases for this study. Of the 917 documents narrowed down by the search terms "Coronavirus, COVID-19, and dental," 83 documents were collected and studied. Ultimately, 42 of these papers were selected for analysis after considering duplication from the flow chart of the literature selection process. Results: While dental masks are often used when treating patients with unknown COVID-19 status, the Ministry of Food and Drug Safety stated that the use of dental masks is insufficient in preventing cross-transmission of COVID-19; instead, it was recommended that N95 masks, which correspond to KF94 masks, should be worn daily. On the other hand, wearing a dental mask and following precautions such as hand hygiene may not pose a significantly higher risk of infection than wearing an N95 mask when treating COVID-19 patients. Conclusion: There is an ongoing discussion regarding the use of dental masks when treating dental patients, and many argue that different types of masks should be selected according to the degree of infection and the individual's respiratory condition. By considering the safety and efficacy of dental masks in preventing infection, improvements can be made in the management of COVID-19 and dental-related infections.