• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.75-80
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• 2016

This study explored epidemiological trends in trichomoniasis in Daegu, South Korea. Wet mount microscopy, PCR, and multiplex PCR were used to test for Trichomonas vaginalis in vaginal swab samples obtained from 621 women visiting 2 clinics in Daegu. Of the 621 women tested, microscopy detected T. vaginalis in 4 (0.6%) patients, PCR detected T. vaginalis in 19 (3.0%) patients, and multiplex PCR detected T. vaginalis in 12 (1.9%) patients. Testing via PCR demonstrated high sensitivity and high negative predictive value for T. vaginalis. Among the 19 women who tested positive for T. vaginalis according to PCR, 94.7% (18/19) reported vaginal signs and symptoms. Notably, more than 50% of T. vaginalis infections occurred in females younger than 30 years old, and 58% were unmarried. Multiplex PCR, which simultaneously detects pathogens from various sexually transmitted infections, revealed that 91.7% (11/12) of patients were infected with 2 or more pathogens. Mycoplasma hominis was the most prevalent co-infection pathogen with T. vaginalis, followed by Ureaplasma urealyticum and Chlamydia trachomatis. Our results indicate that PCR and multiplex PCR are the most sensitive tools for T. vaginalis diagnosis, rather than microscopy which has been routinely used to detect T. vaginalis infections in South Korea. Therefore, clinicians should take note of the high prevalence of T. vaginalis infections among adolescent and young women in order to prevent persistent infection and transmission of this disease.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.121-128
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• 2023

Purpose: This study aimed to investigate the recent age distribution of Mycoplasma pneumoniae in patients with respiratory infections and the differences in diagnostic usefulness according to the methods used in these patients. Methods: We retrospectively reviewed the medical records of patients aged ≤18 years with respiratory infectious diseases who underwent polymerase chain reaction (PCR) or a specific immunoglobulin M (IgM) test between July 2016 and February 2019. The diagnosis of M. pneumoniae infection was confirmed by a positive result in the PCR or IgM test. Results: Of the 2,721 patients tested for M. pneumoniae, 2,197 underwent IgM, and 1,144 underwent PCR, with positivity rates of 17% and 20%, respectively. Among the 620 patients tested for both IgM and PCR tests simultaneously, 35% had M. pneumoniae infection, with 14% under 1 year old and 13% under 1-2 years old. The positive rate increased with age in both tests. Higher positive rates were observed in the IgM test before 3 years of age and in the PCR test after 3 years of age. The agreement rate between the two tests was 77.9% (Cohen's kappa 0.402). Conclusions: As age increased, the rates of M. pneumoniae infection also increased. In patients under 2 years of age, 4¬-14% of infections were confirmed depending on the method used. The moderate agreement between the PCR and IgM tests suggests that the simultaneous use of PCR and the IgM test for the early diagnosis should be approached with caution.

• Tuberculosis and Respiratory Diseases
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• v.80 no.4
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• pp.358-367
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• 2017

Background: Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Methods: Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. Results: A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ${\geq}16years$, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. Conclusion: The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia.

• Pediatric Infection and Vaccine
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• v.14 no.1
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• pp.124-128
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• 2007

Bronchiolitis obliterans is a clinical syndrome of chronic obstruction associated with inflammatory changes in the small airways. There are marked variations in the epidemiology of this disease. In childhood, bronchiolitis obliterans has been described as a result of a number of infections such as adenovirus, measles, Bordetella pertussis, Mycoplasma pneumoniae, and influenza A infection. Most common agents are adenovirus types 3, 7, and 21. Diagnosis of bronchiolitis obliterans can be made based on clinical findings, high resolution computed tomography (HRCT) and lung biopsy. In addition to diagnosis, treatment is not yet clearly established. The authors experienced a case of bronchiolitis obliterans developed in 3 year-old girl who suffered from type 7 adenoviral pneumonia. She had been hospitalized and treated for 15 days due to pneumonia. After discharge, productive cough was not improved and auscultation revealed wheezing. HRCT demonstrated multifocal mosaic patterns suggesting bronchiolitis obliterans. She was managed with inhaled steroid and bronchodilator, and her symptoms were improved. However, follow up HRCT showed no interval change.

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.755-763
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• 1997

Recently new technologies for the establishment of high health herds are becoming efficient tools in the control of PRRS virus and secondary infections. Medicated early weaning(MEW) and nursery depopulation(ND) have shown to be one of the most successful procedures in the eradication and control of pathogens. Indirect evidence of the role of PRRSV in precipitating secondary infection comes from successful improvement in growth and in decreasing mortality on farms that have eliminated PRRSV through ND. Hence the present experiments were conducted in an effort to compare ND with MEW procedures as a means of eliminating PRRSV controlling secondary pathogens and improving performance of pigs in endemically infected swine herds. Following MEW and ND procedures practiced in the farms, some benefits obtained were as follows: 1. A decrease in PRRSV circulation in the nursery, but no entire elimination. 2. Decrease in the frequency of secondary bacteria and in the use of antibiotics. 3. Mycoplasma hyopneumoniae infection was prevented during the nursery stage. 4. ND protocol had a lower cost and management changes than MEW techniques. 5. Nursery performance was improved after the depopulation, cleaning and disinfection procedures, even though PRRSV still being cycled in the old nursery rooms. These studies revealed that the MEW and ND protocols are not always successful for PRRS virus elimination but it's great effect on control of secondary pathogens and improvement of performance make MEW and ND an efficient tools for the establishment of healthier and more efficient herds.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.359-367
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• 2001

A serological survey was performed to establish basic data for the prevalence of antibodies to some major diseases of domesticated boar serum samples from January to December 2000. Sera collected in breeding farms in Gyeongbuk province were tested for Aujeszky's disease virus(ADV), Porcine reproductive and respiratory syndrome virus(PRRSV), Porcine parvovirus(PPV), Japanese encephalitis virus (JEV), Bordetella bronchiseptica(B bronchiseptica), Mycoplasma ; APP), Toxoplasma, and Brucella. There was no antibody to ADV in domesticated boars serum samples detected by Anti-ADV-gpI assay kit. Sero-positive samples to PRRS by IFA were 0.9%(3/330) The HI titers to PPV ranged variously from less than 10 to over 1,280. Two hundred ninety-four out of 330 tested sera showed HI titer of less than 10. In HI test to JEV, 90.3% of the sera (298/330) were below 10. The majority of the serum samples had low prevalence of the antibody B bronchiseptica. ELISA titers to M hyopneumoniae ranged variously from $\leq$ 10 to $\geq$ 1,280. Antibody titers to A pleuropneumoniae type 2(APP2) and type 5(APP5) were 58.2% and 52.7%, respectively, and the tested samples showing ELISA antibody titers of less than 20. There was no significant geographical difference between APP2 and APP5 in this study. In the antibody test of Toxoplasma, 11.5%(38/330) were positive and samples were all negative in sera test of Brucella.

• Clinical and Experimental Pediatrics
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• v.61 no.9
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• pp.291-300
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• 2018

Purpose: Understanding changes in pathogen and pneumonia prevalence among pediatric pneumonia patients is important for the prevention of infectious diseases. Methods: We retrospectively analyzed data of children younger than 18 years diagnosed with pneumonia at 117 Emergency Departments in Korea between 2007 and 2014. Results: Over the study period, 329,380 pediatric cases of pneumonia were identified. The most frequent age group was 1-3 years old (48.6%) and the next was less than 12 months of age (17.4%). Based on International Classification of Diseases, 10th revision diagnostic codes, confirmed cases of viral pneumonia comprised 8.4% of all cases, pneumonia due to Mycoplasma pneumoniae comprised 3.8% and confirmed cases of bacterial pneumonia 1.3%. The prevalence of confirmed bacterial pneumonia decreased from 3.07% in 2007 and 4.01% in 2008 to 0.65% in 2014. The yearly rate of pneumococcal pneumonia also decreased from 0.47% in 2007 to 0.08% in 2014. A periodic prevalence of M. pneumoniae pneumonia (MP) was identified. Conclusion: The increased number of patients with pneumonia, bacterial pneumonia, pleural effusion, and empyema in 2011 and 2013-2014 resulted from an MP epidemic. We provide evidence that the frequency of confirmed cases of bacterial pneumonia and pneumococcal pneumonia has declined from 2007 to 2014, which can simultaneously reflect the effectiveness of the pneumococcal conjugate vaccine.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.191-196
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• 1998

Follicular bronchitis/bronchiolitis is pathologically characterized by peribronchiolar lymphoid follicles, which is one of reactive pulmonary lymphoid disorders. It is associated with 1) the result of infections such as mycoplasma, chlamydia etc., 2) immunodeficiency syndromes, 3) connective tissue diseases such as rheumatoid arthritis and Sjogren's syndrome and 4) local or systemic hypersensitivity reaction. And it can be also developed without obvious causes and associated diseases(idiopathic). Radiologically it represents as bilateral interstitial patterns of pulmonary infiltrates. In this case, a 49 year-old woman was presented with intermittent cough and sputum. On chest X-ray and CT, $5\times4$ cm sized mass in right upper lobe and paratracheal lymphadenopathies were detected, by which lung malignancy was suspected. Bronchoscopy, trans bronchial lung biopsy and transthoracic needle aspiration showed non-specific findings only. After right upper lobectomy, we could confirm a case of follicular bronchiolitis which presented as an unusual mass-like radiologic finding.

• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.27-32
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• 2009

We studied the seroprevalence of four respiratory pathogens in Korean swine farms located in Chungnam, Chungbuk, Gyeongnam and Gyeongbuk provinces during the period of spring of 2007 to winter of 2008. Serological tests were performed using commercial ELISA kits. A total of 530 serum samples were tested for the antibodies against porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (M. hyo) and Actinobacillus pleuropneumoniae (APP). Seroprevalence for four respiratory pathogens were estimated by ELISA-positive rates of the submitted samples. The overall seropositive rates of PRRSV, APP, M. hyo and PCV2 were 32.6%, 10.6%, 38.4% and 88.5%, respectively. By production stage, the seropositive rate for PRRSV was highest in nursery pig populations (46.2%). In contrast, the highest seropositive rates of APP and M. hyo were observed in sow and growing pigs. However, the seroprevalence of PCV2 was ranged from 85.7% to 89.6%, showing no significant difference among the production stages. In the seroprevalence by season, PRRSV, APP and M. hyo infections revealed typical seasonal patterns that the peaks of the seropositive rates were observed between early winter and late spring. In case of PCV2, no particular seasonal patterns were noticed. The pig herds in Gyeongbuk province where PMWS was endemic during the period of survey showed the highest seropositive rates for PRRSV (44.6%), M. hyo (47.5%), and PCV2 (92.7%). Seropositive rates for APP of four provinces were approximately 10%. These results might be valuable for control and prevention of the respiratory diseases and helpful to define strategies related to vaccine applications.

• Korean Journal of Veterinary Service
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• v.42 no.3
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• pp.145-152
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• 2019

Canine vector-borne diseases (CVBDs) are transmitted by different groups of hematophagous arthropod vectors that are distributed worldwide and can cause significant health problems for dogs. The aim of this study was to investigate and compare the prevalence of selected CVBD pathogens in rural outdoor dogs based on prevention status. Between June 2017 and February 2019, blood samples were collected from 343 clinically healthy rural dogs composing two different groups: systematically managed dogs (SMD; n=92) and personally managed dogs (PMD; n=251). Vaccination and preventive medications were applied strictly following the programmed schedule for the SMD group; in contrast, in the PMD group, they were applied only when requested by the dog owners. Serological and molecular assessments showed that significantly more dogs in the PMD group were infected with B. gibsoni (P<0.001) and D. immitis (P=0.001) than those in the SMD group. These findings suggest that the regular use of preventive medications and environmental controlling efforts contribute to reducing the prevalence of CVBD pathogen infections. In addition, dogs infected with certain kinds of CVBD pathogens could remain asymptomatic, suggesting that continuous monitoring and periodic preventive treatment should be conducted even for clinically healthy dogs.