Viral Etiology of Community-acquired Pneumonia in Korean Adults / 감염

PURPOSES: To investigate the viral etiology of community-acquired pneumonia in Korean adults, we have detected respiratory viruses (Respiatory syncytial virus, adenovirus, influenza virus and parainfluenza virus) in the way of prospective, multi-center study. METHODS: From July 1997 to April 2000, nasal aspirates or sputum were obtained from adults patients with community pneumonia admitted to the participating hospitals and transferred immediately to the central laboratory in the Seoul National University Children's Hospital. The specimens were divided into three parts. One part was used for indirect immunofluorescent test for respiratory viruses, the other part for the culture of RSV and adenovirus in HEp-2 cell monolayer. Another part was used for the culture of influenza virus and parainfluenza virus in MDCK or LLC- MK2 cell monolayers. RESULTS: Of 317 samples, 32 (10.1%) specimens were positive for viral isolation by indirect IF staining or culture, including one dual-infected specimen (adenovirus and parainfluenza virus). Influenza virus was most commonly detected (16 specimens). Parainfluenza virus, adenovirus and RSV were detected in 10, 4 and 3 patients, respectively. All isolated influenza viruses were type A (H3N2 in 9 patients, H1N1 in 2 and unspecified in 5), and 8 out of 10 parainfluenza virus isolates were type 3. CONCLUSION: Similar to previous foreign reports, a significant portion of community-acquired pneumonia in Korean adult is caused by respiratory viruses. Our data empathized the need of referral system for viral diagnosis and of nationwide investigation on respiratory virus infections.

An Infant with Vertical Transmission of Human Immunodeficiency Virus Infection Detected Due to Failure to Thrive

Five to fifteen percent of patients affected by human immunodeficiency virus(HIV) are children in developing countries. In Korea, most of HIV infections in children have been transfusion-related, and cases of vertical transmission have been very rare so far and are usually suspected due to a maternal positive history. We experienced a case of vertical transmission of HIV in a 19 month- old girl, incidentally diagnosed in the process of work-up for failure to thrive without suspicion from maternal HIV history. With the increasing number of adult HIV patients in Korea, HIV in fection should be included in the differential diagnosis of children with symptoms compatible with HIV infection even when parental HIV history is not suggestive.

Serotypes and antimicrobial susceptibility in clinical isolates of Haemophilus influenzae from Korean children in prevaccination era

Fifty-five strains of Haemophilus influenzae recovered at a children's hospital in Korea from 1992 through 1997, were analyzed for serotype and antibiotic resistance. Antimicrobial susceptibility was tested by broth dilution method. Among the 55 strains, 26 were from normally sterile body fluids, of which 17 were from the immunocompetent children. Spectrum in the immunocompetent included meningitis (47%), bacteremic pneumonia (18%), and bacteremia without focus (35%). Three (12%) of 26 invasive infections were caused by non-type b: one type d and two type f. Nine of 29 non-sterile body fluid isolates belonged to one of encapsulted serotypes: four a, two c, one of each of b, d and e. Thirty two (58%) strains were resistant to ampicillin, and all of which produced beta-lactamase. All of the strains were highly susceptible to amoxicillin/clavulanate, cefixime, cefuroxime, azithromycin and ciprofloxacin, while 1 (2%), 7 (13%), 4 (7%) and 4 (7%) strains were intermediate to cefprozil, cefaclor, loracarbef, and clarithromycin, respectively. The serotype distribution of H. influenzae in Korean children is similar to those in developed countries before the introduction of Hib conjugate vaccine, and ampicillin resistance rate is among the highest published to date.

Etiologic Agents and Clinical Features of Acute Pyogenic Osteoarthritis in Children

PURPOSE: Though acute pyogenic infections of musculoskeletal system are infrequent in children, delayed diagnosis or inadequate management may cause serious chronic sequelae. We analysed 40 cases of children who were affected by acute septic osteomyelitis and/or septic arthritis to find etiologic agents and to establish proper initial antimicrobial therapy. METHODS: Medical records of 40 cases of microbiologically confirmed acute pyogenic osteomyelitis and/or septic arthritis diagnosed at the Seoul National University Children's Hospital from January 1985 to September 1998 were reviewed. RESULTS: There were 12 cases of acute osteomyelitis, 28 of acute septic arthritis, and 4 of concurrent cases of two diseases. Of 12 cases of acute pyogenic osteomyelitis, there were 7 boys and 5 girls whose average age was 75.4 months. Calcaneus was infected in 4 cases and it was the most common site. Ten cases (83.3%) of them were attributable to Staphylococcus aureus, 1 to Streptococcus viridans and 1 to Pseudomonas aeruginosa. Among the 28 cases of acute septic arthritis, male to female ratio was 16 : 12. The hip joint was the most frequent site involved in 13 cases (46.3%), followed by the ankle joint, which was involved in 6 cases (21.4%). The majority of the children were infected by S. aureus (20 cases, 71.4%). Two cases were infected by S. viridans or Salmonella (group D) species, and 1 by Haemophilus influenzae. CONCLUSION: S. aureus was the most common pathogen of acute pyogenic osteoarthritis, and H. influenzae was an infrequent cause of septic arthritis. Regarding initial empirical anibiotic therapy, anti-staphylococcal agent should be included.

Infective Endocarditis in Children : Review of 35 Cases over 11 Years (1987-1997)

PURPOSE: Infective endocarditis (IE) is a serious complication in children with structural heart disease. We reviewed 35 cases of IE to identify the recent changes in the pattern of preexisting heart diseases, the spectrum of causative organisms and prognosis. METHODS: The clinical records of children diagnosed as IE at the Seoul National University Children's Hospital from January 1987 through December 1997, were reviewed retrospectively. Duke criteria was used for diagnosis. Cases were categorized into primary group(PG) IE in an unoperated heart and post operative group(POG), and the latter further into early POG(within 2 months after operation) and late POG. RESULTS: There were 35 cases of IE developed in 34 patients; 18 cases in the PG, 6 cases in the early POG, and 11 cases in the late POG. Male to female ratio was 16 : 19. Mean age of POG, especially early POG was less than that of PG (early POG : late POG : PG=1.65 years : 6.5 years : 8.34 years, P=0.0267). Preexisting heart diseases were identified in 30 cases; rheumatic heart disease 1 case and congenital heart disease (CHD) 29 cases. Causative organisms were identified in 80%; viridans streptococci, 10 cases (33.3%); pneumococci, 2 cases; Group-D streptococci, 3 cases; staphylococci, 8 cases; Gram (-) organisms, 5 cases and Candida albicans, 2 cases. Vegetation was detected in 88.9% of PG and 64.7% of POG. The most common indication for surgery was uncontrolled infection, which were required in 9 cases. The overall mortality rate was 12.1%. Mortality in POG was higher than that of PG (23.5% versus 0%, P=0.033). CONCLUSION: The discrepancy of mean age among patient groups and the high proportion of patients belonging to POG, were consistent with the increase in the number of newly risky population that survived after cardiac surgery. A more aggressive consideration for operative management may improve the treatment results.

Detection of Chlamydia pneumoniae by Use of the Nested Polymerase Chain Reaction in Children with Lower Respiratory Tract Infection / 감염

BACKGROUND: Chlamydia pneumoniae is a common cause of respiratory tract infection in adults, but little is known about its role in acute respiratory tract infection in children. The aim of this study was to detect C. pneumoniae by use of the nested polymerase chain reaction (nPCR) in Korean children with acute lower respiratory tract infection. METHODS: This study included 95 nasal aspirates obtained from children of 3 years of age or older with acute lower respiratory tract infection admitted to the Seoul National University Children's Hospital from January 1993 through December 1997. They were all negative by culture for RSV, adenovirus, influenza A and B, parainfluenza 1, 2, and 3. The nPCR was performed by use of two primer pairs (HL-1/HR-1, HM-1/HR-2). After amplification, PCR products were digested with Rsa I to confirm the sequence. RESULTS: C. pneumoniae was detected in one sample taken from an 11-year-old girl. She was referred with fever and productive cough for 10 days and she was revealed to have systemic lupus erythematosus and pneumonia. Her chest radiograph showed a left lower lobe infiltrate. Her fever and cough resolved slowly over 15 days without proper antibiotic therapy for C. pneumoniae. CONCLUSION: This study reveals C. pneumoniae as a cause of pneumonia in Korean children. Further studies are required to reveal the epidemiology and the role of C. pneumoniae in respiratory infection in Korean children.

A Case of Congenital Rubella Syndrome / 감염

Congenital rubella syndrome is a transplacental fetal infection with rubella virus and shows a wide spectrum of clinical expression from severe malformation to asymptomatic in the neonatal period. For the confirmation of congenital rubella, one of the following laboratory criteria should be present: isolation of rubella virus, demonstration of rubella-specific IgM antibody, or a rubella IgG antibody that persists and fails to drop at a rate of twofold dilution per month. Recently a reverse transcription-nested polymerase chain reaction (RT-nPCR) method for the prenatal diagnosis of rubella virus infection has been used. We experienced a case of congenital rubella in a 15- month old male who had suffered from respiratory difficulty. He had low birth weight. Thrombocytopenia was noticed shortly after his birth. He was transferred to our hospital because persistent respiratory difficulty had been developing since the age of one month. His growth and development were delayed. Physical examination revealed micrognathia, hepatosplenomegly, lymphadenopathy, and petechiae. Laboratory examination revealed a rubella specific IgM antibody. Chest X-ray suggested a chronic lung change. Rubella virus RNA was detected in the serum by RT-nPCR. This is the first case of congenital rubella, which was confirmed by the detection of rubella virus RNA, in Korea.

A Case of Congenital Rubella Syndrome / 감염

Congenital rubella syndrome is a transplacental fetal infection with rubella virus and shows a wide spectrum of clinical expression from severe malformation to asymptomatic in the neonatal period. For the confirmation of congenital rubella, one of the following laboratory criteria should be present: isolation of rubella virus, demonstration of rubella-specific IgM antibody, or a rubella IgG antibody that persists and fails to drop at a rate of twofold dilution per month. Recently a reverse transcription-nested polymerase chain reaction (RT-nPCR) method for the prenatal diagnosis of rubella virus infection has been used. We experienced a case of congenital rubella in a 15- month old male who had suffered from respiratory difficulty. He had low birth weight. Thrombocytopenia was noticed shortly after his birth. He was transferred to our hospital because persistent respiratory difficulty had been developing since the age of one month. His growth and development were delayed. Physical examination revealed micrognathia, hepatosplenomegly, lymphadenopathy, and petechiae. Laboratory examination revealed a rubella specific IgM antibody. Chest X-ray suggested a chronic lung change. Rubella virus RNA was detected in the serum by RT-nPCR. This is the first case of congenital rubella, which was confirmed by the detection of rubella virus RNA, in Korea.

Clinical Features of Infections Caused by Streptococcus pyogenes in Children and their Antimicrobial Susceptibility / 감염

BACKGROUND: Streptococcus pyogenes causes most often pharyngitis or tonsillitis but may also be responsible for severe diseases including bacteremia and pneumonia. Recent publications from several geographic areas showed high rates of resistance to erythromycin and newer macrolides, often used in patients allergic to penicillin, in clinical isolates of S. pyogenes. METHODS: Minimum inhibitory concentration of 31 strains of S. pyogenes, isolated at the Seoul National University Children's Hospital from October 1991 through April 1998, were determined for penicillin, ceftriaxone, vancomycin, clindamycin, erythromycin, roxythromycin, and clarithromycin by agar dilution method or E-test. In addition, clinical features of the patients from whom the organisms were isolated were reviewed retrospectively. RESULTS: Of the 28 patients whose medical records were reviewed, the most common clinical presentations were soft-tissue infection (8 cases) and pharyngitis (5 cases). Other presentations included bacteremia without focus, pneumonia, vaginitis, lymphadenitis, omphalitis (two of each); primary peritonitis, rheumatic fever with carditis, scarlet fever, acute otitis media, and disseminated disease (one of each). All of the isolates were susceptible to penicillin, ceftriaxone, and vancomycin. However, 5 isolates (16%) were resistant to erythromycin, and all of the erythromycin-resistant strains were resistant to roxythromycin and clarithromycin as well. Three of these erythromycin-resistant strains were also resistant to clindamycin. CONCLUSION: S. pyogenes may cause serious infections in children. Emergence of resistance in clinical isolates of S. pyogenes to macrolides and clindamycin should be considered in empirical antimicrobial therapy of suspected group A streptococcal infections and in establishment of antibiotic policy in Korea.