OBJECTIVE: Cytopenia is a common hematologic complication of viral infections. However, information regarding hematologic effects of common respiratory virus infections is scarce. This study aimed to evaluate hematologic complications and the clinical course of patients infected with common respiratory viruses. METHODS: We retrospectively analyzed 496 patients with respiratory tract infections admitted to the Department of Pediatrics, Wonkwang University Hospital from November 2011 to March 2012 using multiplex real-time polymerase chain reaction to detect the presence of respiratory viruses and hematologic abnormalities. RESULTS: Respiratory viruses were identified in 379 patients. Respiratory syncytial virus (RSV) was most frequently detected (55.7%), followed by influenza A (Flu-A, 23.0%). Further, cytopenia was observed in 35.5% of RSV-infected patients, 25.0% of Flu-A-infected patients, and 34% of patients infected by other viruses. Each virus caused a decrease in 3 blood cell component values, which corresponded with cytopenia frequency. Of the 379 infected patients, 83 had anemia (9.71+/-1.09 g/dL); 46 had neutropenia (803.70+/-263.09 cells/mm3); and 23 had transient thrombocytopenia (142,434.78+/-86,835.18 cells/mm3). However, no patient required treatment. A comparison of clinical characteristics between RSV- and Flu-A-positive patients with anemia revealed that RSV-infected patients had significantly longer duration of hospitalization. RSV was detected more commonly in young neutropenic patients, who had a shorter duration of fever. CONCLUSIONS: Our findings suggest that infections, particularly RSV and Flu-A, result in varying degrees of cytopenia, which usually improves without treatment and does not affect the clinical course of the infection.
Anemia ; Blood Cells ; Fever ; Hospitalization ; Humans ; Influenza, Human ; Neutropenia ; Pediatrics ; Real-Time Polymerase Chain Reaction ; Respiratory Syncytial Viruses ; Respiratory Tract Infections ; Retrospective Studies ; Thrombocytopenia ; Viruses*

PURPOSE: To identify the clinical and epidemiological characteristics of human metapneumovirus infections (hMPV) in children compared to respiratory syncytial virus A (RSV A) and B (RSV B). METHOD: A retrospective review of medical records was performed in 36 patients with hMPV infection, 106 with RSV A infection, and 51 with RSV B infection, from September 2007 to July 2012. RESULTS: The peak incidence of hMPV infection was observed in May, whereas for RSV infections in November and December. hMPV infection occurred in older patients compared to RSV A and B infection (29.9+/-32.5 months vs. 13.6+/-15.4 months, P<0.001; 29.9+/-32.5 months vs. 12.1+/-13.5 months, P<0.001, respectively). hMPV infection was more often associated with fever compared to RSV A (97.2% vs. 67.9%, P<0.001), while wheezing was less frequent compared to RSV A and B infection (16.7% vs. 47.2%, P=0.001; 16.7% vs. 37.3%, P=0.037, respectively). hMPV infection was more often diagnosed as pneumonia compared to RSV A infection (72.2% vs. 50.0%, P=0.047) while bronchiolitis was less frequent than in RSV A (5.6% vs. 34.9%, P=0.001) or RSV B infection (5.6% vs. 29.4%, P=0.006). In addition, intravenous antibiotic was more often prescribed for patients with hMPV infection than those with RSV A and B (69.4% vs. 39.6%, P=0.002; 69.4% vs. 43.1, P=0.015, respectively). CONCLUSION: This study identified characteristics of hMPV infection compared to RSV A and B infection. Seasonality in spring, higher age group, and higher proportion of pneumonia in hMPV infections may be a useful guide for management of respiratory viral infections in children.
Bronchiolitis ; Child ; Fever ; Humans* ; Incidence ; Medical Records ; Metapneumovirus* ; Pneumonia ; Respiratory Sounds ; Respiratory Syncytial Viruses* ; Retrospective Studies ; Seasons

PURPOSE: This study was performed to describe the clinical manifestations of hospitalized children due to varicella-zoster virus (VZV) infection. METHODS: This study included 40 children who were hospitalized for varicella or herpes zoster at Seoul National University Children's Hospital, 2009-2012. Diagnosis of VZV infection was confirmed by VZV PCR or culture from vesicular fluid. Medical records were reviewed to collect clinical features and outcome, antiviral treatment, history of varicella vaccination, and underlying diseases. RESULTS: Sixteen patients with varicella and 24 patients with herpes zoster were included. Their median age was 10.5 years (16 days-19 years). Thirty-five (87.5%) patients had underlying diseases. Among 24 patients with herpes zoster, 11 patients had previous history of varicella and 1 had herpes zoster. Twenty patients (50%) had a history of varicella vaccination, and 19 immunocompromised patients had VZV infection despite of vaccination. Most (95%) patients were treated by intravenous or oral acyclovir, and no treatment failure of intravenous acyclovir was found. The median duration of fever was 4.4 days (1-10 days), and that of antiviral treatment was 12 days (7-23 days) in immunocompromised patients. Immunocompromised patients received longer duration of antiviral treatment than imunocompetent patients (P=0.014). Eleven (27.5%) immunocompromised patients had postherpetic neuralgia, 2 (5%) had proven co-infection by Streptococcus pyogenes and Klebsiella oxytoca, and 1 (2.5%) complicated with pneumonia. CONCLUSION: Immunocompromised children require longer duration of treatment and are at risk of severe complication associated with VZV infection. Early initiation of antiviral therapy and close monitoring are necessary for those in immunocpompromised conditions.
Acyclovir ; Chickenpox ; Child ; Child, Hospitalized* ; Coinfection ; Diagnosis ; Fever ; Herpes Zoster ; Herpesvirus 3, Human* ; Humans ; Immunocompromised Host ; Klebsiella oxytoca ; Medical Records ; Neuralgia, Postherpetic ; Pneumonia ; Polymerase Chain Reaction ; Seoul ; Streptococcus pyogenes ; Treatment Failure ; Vaccination

PURPOSE: Although the overall incidence of hepatitis A in Korea has been decreasing recently, the adolescents born before the introduction of the hepatitis A vaccine remain to be highly vulnerable to outbreak. This study examines the unvaccinated adolescents' and their parents' knowledge and health beliefs toward hepatitis A vaccination. METHODS: Healthy adolescents aged 13-19 years old who had no previous history of hepatitis A vaccine and hepatitis A infection, and their parents or legal guardians were the subjects of the study. The survey was conducted using a structured questionnaire based on the Health Belief Model, and examined the subjects' demographics, knowledge, and health beliefs (i.e., perceived susceptibility, severity, benefits, and barriers). RESULTS: We included 157 adolescents and their parents/guardians (mean age: 16.0+/-1.6 and 45.6+/-4.7 years, respectively). The average knowledge item score for adolescents and parents was 6.4+/-3.7 and 7.3+/-3.4 (out of 18), respectively. Similarly, average Health Belief Model item scores were: susceptibility, 5.6+/-1.6 and 5.9+/-1.7 (range: 2-10); severity, 16.3+/-4.1 and 18.3+/-3.6 (range:5-25); benefits, 19.7+/-3.3 and 20.6+/-2.1 (range:5-25); and barriers, 41.3+/-8.9 and 39.0+/-9.1 (range:7-85). The major reason for not undergoing hepatitis A vaccination was lack of knowledge about its importance. CONCLUSIONS: Refresher health lectures about hepatitis A and the vaccine are needed by both the adolescents and their parents. Furthermore, the inclusion of hepatitis A vaccine in the national immunization program should be considered to reduce the risk of hepatitis A outbreak and to raise the vaccination coverage among the adolescents in Korea.
Adolescent ; Demography ; Hepatitis A Vaccines ; Hepatitis A* ; Hepatitis* ; Humans ; Immunization Programs ; Incidence ; Korea ; Lectures ; Legal Guardians ; Parents* ; Surveys and Questionnaires ; Vaccination*

OBJECTIVE: As per the requirement of Korean Food and Drug Administration, this post-marketing surveillance was conducted in Korea to evaluate the safety and reactogenicity of Poliorix(TM) following its introduction in 2006. METHODS: In this open, multicenter study, the vaccine was administered as per the current practice of Korean doctors and in reference to the guidebook by the Korean Pediatric Society and as indicated in the Korean label which was as follows - for primary vaccination three doses were given to infants at ages 2, 4 and 6 months whereas, for the booster dose a single dose was given to children aged 4-6 years. Safety data during this six year surveillance was collected using diary cards which were distributed to the parents to record adverse events. RESULTS: A total of 639 subjects were enrolled into the study. Of these, 617 subjects and 22 subjects received the vaccine as a primary and booster dose, respectively. At least one unsolicited symptom was reported in 11.4% (73/639) of the subjects during the 7-day follow-up period; upper respiratory tract infection (2.5%;16/639) was the most frequently reported unsolicited symptom. One subject reported at least one unsolicited symptom (gastroenteritis) of grade 3 intensity within the 31-day post-vaccination period. Approximately 1.7% (11/639) of subjects reported 13 serious adverse events (SAEs). All SAEs were resolved by the end of the study. CONCLUSION: In Korea, primary and booster vaccination with Poliorix(TM) was well-tolerated in healthy subjects when administered according to the prescribing information as part of routine clinical practice.
Child ; Follow-Up Studies ; Humans ; Infant ; Korea* ; Parents ; Poliomyelitis* ; Respiratory Tract Infections ; United States Food and Drug Administration ; Vaccination

PURPOSE: This study aimed to study the antibody response of Japanese encephalitis vaccination in children using different kinds of vaccines (inactivated vaccine, live attenuated vaccine or interchanged) and evaluate the effectiveness of the vaccines to provide the basis of efficient immunization schedule of Japanese encephalitis. METHODS: Measurement of the neutralization antibody (NTAb) titers following Japanese encephalitis vaccination using different vaccines for 170 children, 2-6 year of age, who visited six university hospitals and are confirmed by immunization records. RESULTS: Among 170 children who were given primary immunization on Japanese encephalitis, 103 children were given inactivated vaccine, 64 children were given live attenuated vaccine and 3 children were given interchangeably. NTAb titers were more than 1:10 in all children of three groups. The geographic mean antibody titer was 322 in inactivated vaccine group and 266 in live attenuated vaccine group. However, there was no significant difference between two groups. In both groups, the NTAb titer showed the peak at 1-4 months after the third immunization and declined. The NTAb titers of three children who were given two kinds of vaccines alternately were 1:135, 1:632, and 1:2511, respectively. CONCLUSION: According to the results of this study in children younger than 6 years old, there is no significant difference in effectiveness between inactivated and live attenuated vaccines. However, further studies for the changes of antibody titers for a longer period of time on larger population are required.
Antibodies, Neutralizing ; Antibody Formation ; Asian Continental Ancestry Group* ; Child ; Cohort Studies* ; Encephalitis, Japanese* ; Hospitals, University ; Humans ; Immunization ; Immunization Schedule ; Prospective Studies* ; Vaccination ; Vaccines ; Vaccines, Attenuated

PURPOSE: Subacute sclerosing panencephalitis (SSPE) is a neurodegerative disease due to persistent measles virus infection. We investigated the role of programmed death-1 (PD-1) molecule which is related with chronic viral infection in developing SSPE in mouse. METHODS: We adopt the PD-1-/-, PD-1-/+, and wild type BALB/c 3 week old mice to make an animal model of SSPE by injecting measles virus (SSPE strain) intraventricularly. Three months after infusion of virus, the mice were sacrificed and examined if the typical pathologic lesions had been progressed. The sera were collected from each group of mice and the serum level of IL-21 was measured with ELISA kit. RESULTS: The necrotic lesions on white matter and gliosis were found in focal areas in wild type BALB/c. The extent of lesion was smaller in heterotype BALB/c. Scanty lesions were found in PD-1-/- mice. The sera level of IL-21 was not elevated in all three groups. CONCLUSION: Our data suggest that the PD-1 molecule may play a role in persistent viral infection.
Animals ; Enzyme-Linked Immunosorbent Assay ; Gene Knockout Techniques* ; Gliosis ; Measles virus ; Measles* ; Mice* ; Models, Animal ; Subacute Sclerosing Panencephalitis ; Viruses

Reemerging infectious diseases are infections that had decreased in incidence in the global population and were brought under control through effective health care policy such as vaccination, but more recently, began to resurge as a health problem due to many reasons. Measles, rubella, mumps and pertussis are the examples. Immunization with MMR (measles, mumps, rubella) and pertussis vaccine has contributed to marked decrease in measles, mumps, rubella and pertussis incidence worldwide. In Korea, measles and rubella almost disappeared after the introduction of 2 doses of MMR immunization schedule. Recently, these infections have been reemerging in many countries with low vaccination rates and can be introduced again in Korea. However mumps and pertussis outbreaks are reported among fully vaccinated populations. Declining vaccine effectiveness, an increased awareness and surveillance of the disease or improved laboratory diagnostic tools had been suggested as possible causes. For the clinicians, it is difficult to diagnose these reemerging infectious diseases partly because of few experience of typical cases of measles and rubella or partly because of modification of clinical symptoms and signs of infectious diseases in immunized population. In this article, the diagnosis of measles, mumps, rubella and pertussis will be reviewed in the aspects of clinical characteristics, serologic methods, virus isolation, and polymerase chain reaction.
Communicable Diseases* ; Communicable Diseases, Emerging ; Delivery of Health Care ; Diagnosis* ; Disease Outbreaks ; Immunization ; Immunization Schedule ; Incidence ; Korea ; Measles* ; Methods ; Mumps* ; Pertussis Vaccine ; Polymerase Chain Reaction ; Rubella* ; Vaccination ; Viruses ; Whooping Cough*

Dengue fever is an important health problem for international travelers to all endemic areas. The steadily increasing numbers of tourists visiting endemic areas raise the risk of exposure, and imported dengue cases are increasingly observed in nonendemic area. Dengue has a wide spectrum of clinical presentations, often with unpredictable clinical evolution and outcome. While most patients recover following a self-limiting, non-severe clinical course, a small proportion progress to severe disease such as dengue hemorrhagic fever or dengue shock syndrome. Therefore, it is important to suspect dengue fever in every febrile patient returning from the tropics. Whenever it is suspected, a quick diagnosis and adequate managements are essential to avoid complications. We report two cases of imported dengue fever in Korean children presenting with fever, headache, nausea, and rash.
Child ; Dengue ; Dengue Hemorrhagic Fever ; Exanthema ; Fever ; Headache ; Humans ; Korea ; Nausea ; Philippines

PURPOSE: This retrospective study was performed to identify the clinical characteristics of influenza B infection and compare to influenza A infection. METHODS: Medical records of patients diagnosed with influenza using a multiplex PCR test, admitted to Seoul St. Mary's Hospital, during the 2011-2012 influenza season were analyzed. Clinical and laboratory characteristics of influenza B patients were investigated and compared with those of influenza A patients. RESULTS: A total of 145 influenza patients were enrolled during this study period. Among these, 66 and 78 patients were diagnosed with influenza A and B, respectively, and 1 patient was diagnosed with co-existing influenza A and B. Cough (88.2%), rhinorrhea (77.1%) and sputum (60.4%) were the most common symptoms among these influenza patients, and most were diagnosed with upper respiratory infection (31.9%) or lower respiratory infection (49.3%). In comparison to influenza A patients, influenza B patients were older (4.7+/-4.1 years vs. 3.3+/-2.5 years, P=0.016), and the number of fever days before hospitalization were longer (3.0 days vs. 2.5 days, P=0.043). While sore throat (10.3% vs. 1.5%, P=0.039) and vomiting (20.5% vs. 6.1%, P=0.012) were more common in influenza B patients than in influenza A patients, other clinical and laboratory characteristics were not significantly different between the two groups. CONCLUSIONS: No significant differences in clinical and laboratory perspectives were manifested in influenza A and B infections. Preventive measures should be emphasized over treatment in influenza B due to prolonged fever duration before admission.
Child ; Cough ; Fever ; Hospitalization ; Humans ; Influenza B virus ; Influenza, Human ; Medical Records ; Multiplex Polymerase Chain Reaction ; Pharyngitis ; Retrospective Studies ; Seasons ; Sputum ; Vomiting