• Tuberculosis and Respiratory Diseases
• /
• v.65 no.2
• /
• pp.91-98
• /
• 2008

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is the most common organism associated with nosocomial infections. MRSA infections are becoming increasing important because they have emerged no only as healthcare-associated (HA) infections but also as community-associated (CA) ones. This study examined the moleculo-epidemiology of MRSA, which was isolated from nasal swabs in the intensive care unit (ICU) at Konyang University Hospital. MRSA are classified into HA-MRSA and CA-MRSA. Methods: From June to September 2006, 353 patients who were admitted to the ICU in Konyang University Hospital were enrolled in this study. Single nasal swabs were obtained for culture in the ICU on the 1st day. Pulsed-field gel electrophoresis and the antimicrobial resistant patterns were analyzed between HA- and CA-MRSA. An antimicrobial sensitivity test was also performed. Results: Forty two strains of MRSA were isolated from 353 patients (11.9%). Among the 42 isolates, HA-MRSA and CA-MRSA were found in 33 (78.6%), and 9 (21.4%), respectively. Eleven different PFGE types (type A to K) were identified. Types A (n=9) and B (n=7) were the most common for HA-MRSA, and types A (n=2) and B (n=2) were identified in CA-MRSA. The proportion of types A and B in CA-MRSA (44.4%) was similar to that in HA-MRSA (48.5%). The rates of resistance rates to erythromycin and ciprofloxacin were higher in HA-MRSA than in CA-MRSA. Conclusion: The rate of isolation of MRSA in an ICU setting was 11.9%. HA-MRSA was isolated more frequently than CA-MRSA. The rate of resistance of HA-MRSA to erythromycin and ciprofloxacin was higher than that of CA-MRSA. Despite the small number of subjects, the main isolates (type A and B) of CA-MRSA were similar to those of HA-MRSA.

• Pediatric Infection and Vaccine
• /
• v.19 no.3
• /
• pp.111-120
• /
• 2012

Purpose: The aim of this study is to investigate the colonization rate of Methicillin-resistant Staphylococcus aureus (MRSA) in neonates by different clinical characteristics, to presume the origin of MRSA acquisition, and to identify the risk factors associated with MRSA colonization. Methods: We retrospectively reviewed the medical records of 1,733 neonates admitted to Seoul Eulji hospital Neonatal Intensive Care Unit between January 2008 and December 2011. Nasal, inguinal and rectal swab specimens were obtained upon admission and each week until discharge. We classified the route of MRSA acquisition as; hospital associated (HA-MRSA) and community associated (CA-MRSA) according to the case definition. Results: Among 1,733 neonates, 415 (23.9%) were colonized with MRSA. Gestational age, birth weight, delivery type, maternal antibiotics usage before delivery, birth place and care place before admission were influencing factors in colonization of MRSA. The colonization rate was significantly high in neonates without maternal prophylactic antibiotics use before delivery than in the other group (relative risk 2.77, 95% CI 1.88-4.07; P<0.01), and outborns showed higher MRSA colonization rate compared to inborns (relative risk 2.28, 95% CI 1.17-4.42; P=0.015). Conclusion: We identified the neonatal MRSA colonization rate to be 23.9%. We estimated HA-MRSA colonization rate to be 10% (51/511) and CA-MRSA colonization rate to be 36% (309/858). We ascertained that risk factors in MRSA colonization in neonates were prophylactic use of antibiotics in mothers and the birth place.

• Pediatric Infection and Vaccine
• /
• v.19 no.3
• /
• pp.149-156
• /
• 2012

Purpose : We conducted a prospective comparative clinical study to determine the field efficacy of the 2010-2011 influenza vaccines [Influenza virus strains; A/California/7/2009 (H1N1), A/Perth/16/2009 (H3N2), B/Brisbane/60/2008] in healthy Korean children under 18 years of age. Methods : In this study, we enrolled subjects aged between 6 months and 18 years and divided them into 2 study groups: a group who received the influenza vaccines (407 subjects), and a control group who did not receive the influenza vaccines (230 subjects). Ours was a multicenter study that involved 7 hospitals, including the Korea Cancer Center Hospital. The study was conducted between September 2010 and February 2011. We collected nasal wash or throat swab samples from subjects who presented with acute febrile respiratory or influenza-like illnesses at the hospital. We used PCR to confirm the presence of the influenza virus in the respiratory samples and characterize the virus type. Results : In this study, we collected 22 respiratory samples from the influenza-vaccinated group and found 3 cases of influenza virus infection. Similarly, we collected 21 samples from the control group and found 12 cases of influenza virus infection among 10 subjects during the study period. We determined the field efficacy of the 2010-2011 seasonal influenza vaccines to be 83.2% in healthy Korean children and adolescents. Conclusion : In this study, we determined the field efficacy of the 2010-2011 seasonal influenza vaccines in healthy Korean children and adolescents. We found that the field efficacy of 2010-2011 seasonal influenza vaccines was adequate.

• Korean Journal of Microbiology
• /
• v.43 no.3
• /
• pp.173-178
• /
• 2007

The occurrence of acute respiratory infections caused by the influenza virus are particularly high during the winter season in Busan, Korea. In 2004 and 2005, a study of the rate of occurrences of the influenza virus was conducted. The results reveal that in 2004, of the 1,869 people with an acute respiratory infection that 154 (8.2%) people were infected by the influenza virus. In 2005, of the 1,579 people infected with an acute respiratory infection that 19 people (1.2%) were infected with the influenza virus. The study shows a decrease in the numbers of an influenza virus infection from 2004 to 2005. Data was collected by inspecting throat swabs and nasal discharge from those with an acute respiratory infection. Further inspection of the throat swab and nasal discharge from the infected individuals during 2004 and 2005 study show the occurrence of the different types of influenza virus in the population: 6 cases (3.5%) of influenza type A/H1N1, 129 cases (74.5%) of A/H3N2, and 38 cases (22.0%) of type B. The study conducted in 2004 and 2005 reveal that children between the ages of two and five were more likely to be infected than any other age group. In the study, about 62.2% of the infected individuals were between two and five years old. The detection rates between males and females are similar. However, it is notable that females are slightly more likely to develop an acute respiratory infection caused by the influence virus compared to their male counterparts.

• Pediatric Infection and Vaccine
• /
• v.14 no.2
• /
• pp.179-187
• /
• 2007

Purpose : Acute viral respiratory tract infection is the most common illness among children. Involved organisms are respiratory syncytial virus (RSV), influenza virus, adenovirus, parainfluenza virus, etc. The objective of the present study is to determine epidemiology of each viral infection in Busan, South Korea between January 2004 and December 2006. Methods : We retrospectively analyzed the results of clinical samples of throat and nasal swab collected from Busan city, South Korea between January 2004 and December 2006. We collected these samples from the children with acute respiratory illness. Viruses were detected by virus culture Results : The identified pathogens were influenza A in 131 cases (46.6 percent), RSV in 40 cases (14.2 percent), influenza B in 37 cases (13.2 percent), adenovirus in 23 cases (8.2 percent), enterovirus in 37 cases (13.2%) [coxsackie virus in 20 cases (7.1 percent), atypical enterovirus in 9 cases (3.2 percent), poliovirus in 4 cases (1.4 percent), echovirus in 4 cases (1.4 percent)], rhinovirus in 9 cases (3.2 percent), parainfluenza virus in 2 cases (0.7 percent), coronavirus and bocavirus in each 1 case (0.4 percent). Influenza A were detected every year, mostly in December through April and RSV in October through February. Adenovirus were detected through out the year. Bocavirus occurred in December, 2006. Conclusion : We analyzed epidemiologic characteristics of viruses to cause the respiratory disease that prevailed at Busan area for recent three years, and from now on, a further continuous study will be necessary.

• Pediatric Infection and Vaccine
• /
• v.11 no.2
• /
• pp.158-169
• /
• 2004

Purpose : Although influenza is one of the most important cause of acute respiratory tract infections in children, virus isolation is not popular and there are only a few clinical studies on influenza and diagnostic methods. We evaluated the epidemiological and clinical features of influenza in children and rapid antigen detection test(QuickVue influenza test) on fist half of the year 2004 in Busan. Methods : From January 2004 to June 2004, throat swab and nasal secretion were obtained and cultured for the isolation of influenza virus and tested by rapid antigen detection test(QuickVue influenza test) in children with suspected influenza infections. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Influenza viruses were isolated in 79(17.2%) out of 621 patients examined. Influenza virus was isolated mainly from March to April 2004. The ratio of male and female with influenza virus infection was 1.2 : 1 with median age of 4 years 6month. The most common clinical diagnosis of influenza virus infection was bronchitis. There was no difference between influenza A and B infection in clinical diagnosis and symptoms. All patients recovered without severe complication. The sensitivity obtained for rapid antigen detection test (QuickVue influenza test) was 93.6% and the specificity was 80.2%, the positive predictive value 40.8%, the negative predictive value 98.8%. Conclusion : With rapid antigen detection test, it is possible early detection of influenza in children. reduction in use of antimicrobial agent and early use of antiviral agent.