PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (36)
 

Clipboard (0)
None

Select a Filter Below

Year of Publication
1.  Etiology and Clinical Outcomes of Acute Respiratory Virus Infection in Hospitalized Adults 
Infection & Chemotherapy  2014;46(2):67-76.
Background
Etiologies and clinical profiles of acute respiratory viral infections need to be clarified to improve preventive and therapeutic strategies.
Materials and Methods
A retrospective observational study at a single, university-affiliated center was performed to evaluate the respiratory viral infection etiologies in children compared to that in adults and to document the clinical features of common viral infections for adults from July 2009 to April 2012.
Results
The common viruses detected from children (2,800 total patients) were human rhinovirus (hRV) (31.8%), adenovirus (AdV) (19.2%), respiratory syncytial virus (RSV) A (17.4%), RSV B (11.7%), and human metapneumovirus (hMPV) (9.8%). In comparison, influenza virus A (IFA) had the highest isolation rate (28.5%), followed by hRV (15.5%), influenza virus B (IFB) (15.0%), and hMPV (14.0%), in adults (763 total patients). Multiple viruses were detected in single specimens from 22.4% of children and 2.0% of adults. IFA/IFB, RSV A/B, and hMPV exhibited strong seasonal detection and similar circulating patterns in children and adults. Adult patients showed different clinical manifestations according to causative viruses; nasal congestion and rhinorrhea were more common in hRV and human coronavirus (hCoV) infection. Patients with RSV B, hRV, or AdV tended to be younger, and those infected with RSV A and hMPV were likely to be older. Those with RSV A infection tended to stay longer in hospital, enter the intensive care unit more frequently, and have a fatal outcome more often. The bacterial co-detection rate was 26.5%, and those cases were more likely to have lower respiratory tract involvement (P = 0.001), longer hospital stay (P = 0.001), and higher mortality (P = 0.001).
Conclusions
The etiologic virus of an acute respiratory infection can be cautiously inferred based on a patient's age and clinical features and concurrent epidemic data. Large-scale prospective surveillance studies are required to provide more accurate information about respiratory viral infection etiology, which could favorably influence clinical outcomes.
doi:10.3947/ic.2014.46.2.67
PMCID: PMC4091371  PMID: 25024868
Adult; Children; Etiology; Respiratory virus
2.  Clinical Implications of Pneumococcal Serotypes: Invasive Disease Potential, Clinical Presentations, and Antibiotic Resistance 
Streptococcus pneumoniae can asymptomatically colonize the nasopharynx and cause a diverse range of illnesses. This clinical spectrum from colonization to invasive pneumococcal disease (IPD) appears to depend on the pneumococcal capsular serotype rather than the genetic background. According to a literature review, serotypes 1, 4, 5, 7F, 8, 12F, 14, 18C, and 19A are more likely to cause IPD. Although serotypes 1 and 19A are the predominant causes of invasive pneumococcal pneumonia, serotype 14 remains one of the most common etiologic agents of non-bacteremic pneumonia in adults, even after 7-valent pneumococcal conjugate vaccine (PCV7) introduction. Serotypes 1, 3, and 19A pneumococci are likely to cause empyema and hemolytic uremic syndrome. Serotype 1 pneumococcal meningitis is prevalent in the African meningitis belt, with a high fatality rate. In contrast to the capsule type, genotype is more closely associated with antibiotic resistance. CC320/271 strains expressing serotype 19A are multidrug-resistant (MDR) and prevalent worldwide in the era of PCV7. Several clones of MDR serotype 6C pneumococci emerged, and a MDR 6D clone (ST282) has been identified in Korea. Since the pneumococcal epidemiology of capsule types varies geographically and temporally, a nationwide serosurveillance system is vital to establishing appropriate vaccination strategies for each country.
doi:10.3346/jkms.2013.28.1.4
PMCID: PMC3546102  PMID: 23341706
Streptococcus pneumoniae; Polysaccharides, Bacterial; Bacterial Capsules; Serotyping; Pneumococcal Infections
3.  Clinical and Molecular Epidemiological Features of Hemorrhagic Fever with Renal Syndrome in Korea over a 10-year Period 
Background
Laboratory diagnosis of hemorrhagic fever with renal syndrome (HFRS), an infectious disease caused by rodent-borne hantaviruses in Asia and Europe, depends primarily on serological methods. Since the advent of such serodiagnostic tests, few reports are available about the clinical and molecular epidemiological features of HFRS.
Objectives
To investigate the epidemioclinical features of HFRS treated at a tertiary-care teaching hospital in Seoul over a 10-year period.
Study design
Medical records of HFRS patients, visited to a tertiary-care teaching hospital during February 2002 to February 2012, were reviewed. Sera from patients were tested for Hantaan virus (HTNV) and Seoul virus (SEOV) RNA using RT-PCR.
Results
Among 35 HFRS patients (mean age was 44.2 ± 14.7 years), 29 were male (82.9%). Acute renal failure developed in 27 patients (77.1%), and 12 patients (34.3%) were admitted to the intensive care unit (ICU). Conjunctival injection (OR 10.32, 95% CI 1.09–97.77, P = .04) and initial serum albumin less than 3 g/dL (OR 22.83, 95% CI 1.45–359.93, P = .03) were risk factors for ICU admission. Of 35 acute-phase sera, 11 (31.4%) were positive for HTNV RNA. None were positive for SEOV RNA.
Conclusions
HFRS was characterized by the clinical triad of fever, renal insufficiency and gastrointestinal symptoms. Conjunctival injection and serum albumin level were related to severity. Large scaled multi-center study is needed to enhance an insight to epidemioclinical characteristics of HFRS in Korea.
doi:10.1016/j.jcv.2013.06.027
PMCID: PMC4153883  PMID: 23871164
Hantaan virus; Hantavirus; Hemorrhagic fever with renal syndrome; Korea
4.  Physician Attitudes toward the Herpes Zoster Vaccination in South Korea 
Infection & Chemotherapy  2014;46(3):194-198.
This survey investigated Korean physician attitudes toward the herpes zoster (HZ) vaccine. A total of 400 physicians answered a self-reported questionnaire. Most physicians knew that HZ poses a significant socioeconomic burden and had good knowledge about HZ and its vaccine. Physicians who did not recommend HZ vaccine were concerned about costs (90.7%, 78/86) and doubted the effectiveness of the vaccine (58.1%, 50/86). Patient demand had a profound effect on physicians decisions; 84.9% (73/86) of them who said not recommending HZ vaccine reported that they would provide the vaccine upon patient request. In conclusion, educational initiatives should be targeted toward both physicians and patients.
doi:10.3947/ic.2014.46.3.194
PMCID: PMC4189135  PMID: 25298909
Herpes zoster; Physician; Vaccination; Awareness; Health surveys
5.  Pulmonary Toxocariasis Mimicking Invasive Aspergillosis in a Patient with Ulcerative Colitis 
A 45-year-old-male who had underlying ulcerative colitis and presented with fever and dry cough. Initially, the patient was considered to have invasive aspergillosis due to a positive galactomannan assay. He was treated with amphotericin B followed by voriconazole. Nevertheless, the patient deteriorated clinically and radiographically. The lung biopsy revealed eosinophilic pneumonia, and ELISA for Toxocara antigen was positive, leading to a diagnosis of pulmonary toxocariasis. After a 10-day treatment course with albendazole and adjunctive steroids, the patient recovered completely without any sequelae. Pulmonary toxocariasis may be considered in patients with subacute or chronic pneumonia unresponsive to antibiotic agents, particularly in cases with eosinophilia.
doi:10.3347/kjp.2014.52.4.425
PMCID: PMC4170039  PMID: 25246722
Toxocara canis; toxocariasis; eosinophilia; respiratory disorder; aspergillosis; ulcerative colitis
6.  Comparison of the Immunogenicity and Safety of the Conventional Subunit, MF59-Adjuvanted, and Intradermal Influenza Vaccines in the Elderly 
The influenza vaccination is known as the most effective method for preventing influenza infection and its complications in the elderly. Conventional subunit (Agrippal S1; Novartis), MF59-adjuvanted (Fluad; Novartis), and intradermal (IDflu15; Sanofi Pasteur) influenza vaccines are widely used throughout South Korea. However, few comparative studies evaluating the safety and immunogenicity of these vaccines are available. Prior to the beginning of the 2011-2012 influenza season, 335 healthy elderly volunteers randomly received one of three seasonal trivalent influenza vaccines, the conventional subunit, MF59-adjuvanted, or intradermal influenza vaccine. Serum hemagglutination-inhibiting antibody levels were measured at the time of vaccination and at 1 and 6 months after vaccination. Adverse events were recorded prospectively. A total of 113 conventional subunit, 111 MF59-adjuvanted, and 111 intradermal influenza vaccine volunteers were followed up during a 6-month postvaccination period. One month after vaccination, all three vaccines satisfied Committee for Medical Products for Human Use (CHMP) immunogenicity criteria for the A/H1N1 and A/H3N2 strains but not for the B strain. Compared with the subunit vaccine, the intradermal vaccine exhibited noninferiority, while the MF59-adjuvanted vaccine exhibited superiority. Furthermore, the MF59-adjuvanted vaccine was more immunogenic against the A/H3N2 strain than was the subunit vaccine up to 6 months postvaccination. The most common local and systemic reactions to the conventional subunit, MF59-adjuvanted, and intradermal influenza vaccines were pain at the injection site (7.1%, 10.8%, and 6.3%, respectively) and generalized myalgia (0.9%, 8.1%, and 5.4%, respectively). Local and systemic reactions were similar among the three vaccine groups. MF59-adjuvanted vaccine exhibited superior immunogenicity compared with a conventional subunit vaccine and had a comparable safety profile. For older adults, the MF59-adjuvanted vaccine is preferable for providing superior immunogenicity.
doi:10.1128/CVI.00615-13
PMCID: PMC4097439  PMID: 24828092
7.  Pneumococcal Vaccine and Opsonic Pneumococcal Antibody 
Streptococcus pneumoniae is a major human pathogen responsible for a majority of bacterial pneumonia as well as invasive pneumococcal diseases (IPD) with high mortality and morbidity. Use of conjugate vaccines targeting pneumococcal capsule has dramatically reduced the incidence of invasive diseases and there are active efforts to further improve the conjugate vaccines. However, in children new pneumococcal vaccines can no longer be tested with placebo-based clinical trials since effective vaccines are currently available. Thus, vaccine studies must depend on surrogate markers of vaccine efficacy. Although traditional antibody levels (e.g., ELISA) are useful as a surrogate marker of protection, they have limitations and a bioassay measuring the capacity of antibodies to opsonize pneumococci has been developed. This opsonophagocytosis assay (OPA) replicates the in vivo mechanism of antibody protection and should therefore better reflect protection by vaccine-induced antibodies. Technical improvements of OPA have made this bioassay rapid, multiplexed and practical for analyzing small samples including those from children. Strong correlations between ELISA and OPA have been observed in many studies of young children. However, poor correlations have been found in some important clinical situations (such as determination of protection by cross-reactive antibodies) and populations (such as elderly adults and immune-deficient patients). In these settings, OPA has become a useful supplementary measure of pneumococcal vaccine immunogenicity. Current efforts to standardize OPA will further expand its uses.
doi:10.1007/s10156-013-0601-1
PMCID: PMC3692352  PMID: 23657429
Opsonophagocytic killing assay; Pneumococcal vaccine; Immunogenicity; Streptococcus pneumoniae
8.  Impact of Preceding Flu-Like Illness on the Serotype Distribution of Pneumococcal Pneumonia 
PLoS ONE  2014;9(4):e93477.
Background
Even though the pathogenicity and invasiveness of pneumococcus largely depend on capsular types, the impact of serotypes on post-viral pneumococcal pneumonia is unknown.
Methods and Findings
This study was performed to evaluate the impact of capsular serotypes on the development of pneumococcal pneumonia after preceding respiratory viral infections. Patients with a diagnosis of pneumococcal pneumonia were identified. Pneumonia patients were divided into two groups (post-viral pneumococcal pneumonia versus primary pneumococcal pneumonia), and then their pneumococcal serotypes were compared. Nine hundred and nineteen patients with pneumococcal pneumonia were identified during the study period, including 327 (35.6%) cases with post-viral pneumococcal pneumonia and 592 (64.4%) cases with primary pneumococcal pneumonia. Overall, serotypes 3 and 19A were the most prevalent, followed by serotypes 19F, 6A, and 11A/11E. Although relatively uncommon (33 cases, 3.6%), infrequently colonizing invasive serotypes (4, 5, 7F/7A, 8, 9V/9A, 12F, and 18C) were significantly associated with preceding respiratory viral infections (69.7%, P<0.01). Multivariate analysis revealed several statistically significant risk factors for post-viral pneumococcal pneumonia: immunodeficiency (OR 1.66; 95% CI, 1.10–2.53), chronic lung diseases (OR 1.43; 95% CI, 1.09–1.93) and ICI serotypes (OR 4.66; 95% CI, 2.07–10.47).
Conclusions
Infrequently colonizing invasive serotypes would be more likely to cause pneumococcal pneumonia after preceding respiratory viral illness, particularly in patients with immunodeficiency or chronic lung diseases.
doi:10.1371/journal.pone.0093477
PMCID: PMC3972234  PMID: 24691515
10.  Age- and Influenza Activity-Stratified Case Definitions of Influenza-Like Illness: Experience from Hospital-Based Influenza Surveillance in South Korea 
PLoS ONE  2014;9(1):e84873.
Objectives
This study aims to identify clinical case definitions of influenza with higher accuracy in patients stratified by age group and influenza activity using hospital-based surveillance system.
Methods
In seven tertiary hospitals across South Korea during 2011–2012 influenza season, respiratory specimens were obtained from patients presenting an influenza-like illness (ILI), defined as having fever plus at least one of following symptoms: cough, sore throat or rhinorrhea. Influenza was confirmed by reverse transcriptase-polymerase chain reaction. We performed multivariate logistic regression analyses to identify clinical variables with better relation with laboratory-confirmed influenza, and compared the accuracy of combinations.
Results
Over the study period, we enrolled 1417 patients, of which 647 had laboratory-confirmed influenza. Patients with cough, rhinorrhea, sore throat or headache were more likely to have influenza (p<0.05). The most accurate criterion across the study population was the combination of cough, rhinorrhea, sore throat and headache (sensitivity 71.3%, specificity 60.1% and AUROC 0.66). The combination of rhinorrhea, sore throat and sputum during the peak influenza activity period in the young age group showed higher accuracy than that using the whole population (sensitivity 89.3%, specificity 72.1%, and AUROC 0.81).
Conclusions
The accuracy of clinical case definitions of influenza differed across age groups and influenza activity periods. Categorizing the entire population into subgroups would improve the detection of influenza patients in the hospital-based surveillance system.
doi:10.1371/journal.pone.0084873
PMCID: PMC3901651  PMID: 24475034
12.  Hospital-based influenza morbidity and mortality surveillance system for influenza-like illnesses: a comparison with national influenza surveillance systems 
The Hospital-based Influenza Morbidity and Mortality (HIMM) surveillance system is an emergency room (ER)-based influenza surveillance system in Korea that was established in 2011. The system was established under the assumption that integrated clinical and virologic surveillance could be performed rapidly and easily at seven tertiary hospitals' ER. Here, we assessed the correlation between data generated from the HIMM surveillance system and the Korean national influenza surveillance systems during the 2011–2012 influenza season using cross-correlation analysis and found strong correlations. Rapid antigen-test-based HIMM surveillance would predict the start of influenza epidemic earlier than pre-existing influenza-like-illness-based surveillance.
doi:10.1111/irv.12175
PMCID: PMC4177793  PMID: 24020512
Influenza; influenza-like illness; Korea; surveillance
13.  Case-Control Study of the Effectiveness of the 2010-2011 Seasonal Influenza Vaccine for Prevention of Laboratory-Confirmed Influenza Virus Infection in the Korean Adult Population 
We evaluated the effectiveness of the 2010-2011 seasonal influenza vaccine for preventing laboratory-confirmed influenza in a South Korean population. A retrospective case-control study was conducted among patients who visited selected hospitals from September 2010 to May 2011. A total of 483 laboratory-confirmed influenza patients were included in the analysis as case subjects. For each case patient, two types of control patients were chosen at a ratio of 1:1:1, and 966 control subjects were selected. Vaccine effectiveness (VE) was defined as 100 × (1 − odds ratio for influenza in vaccinated versus nonvaccinated persons). The VE of the 2010-2011 seasonal influenza vaccine was 49.5% to 45.8% for both influenza A and B viruses and 50.8% to 47.2% for influenza A virus, according to the control type. The age-specific adjusted VE was 50.8% to 46.5% among subjects aged 19 to 49 years and 58.7% to 63.3% among those aged 50 to 64 years, according to the control type. Statistically significant VE was not found among those aged ≥65 years or against influenza B virus. The 2010-2011 seasonal influenza vaccine was effective for preventing laboratory-confirmed influenza, especially for influenza A virus, in a South Korean population. Evidence of the effectiveness of the influenza vaccine in older adults or against influenza B virus was not found.
doi:10.1128/CVI.00009-13
PMCID: PMC3675970  PMID: 23576674
14.  Diagnosis of Pneumococcal Pneumonia: Current Pitfalls and the Way Forward 
Infection & Chemotherapy  2013;45(4):351-366.
Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. However, it can also asymptomatically colonize the upper respiratory tract. Because of the need to distinguish between S. pneumoniae that is simply colonizing the upper respiratory tract and S. pneumoniae that is causing pneumonia, accurate diagnosis of pneumococcal pneumonia is a challenging issue that still needs to be solved. Sputum Gram stains and culture are the first diagnostic step for identifying pneumococcal pneumonia and provide information on antibiotic susceptibility. However, these conventional methods are relatively slow and insensitive and show limited specificity. In the past decade, new diagnostic tools have been developed, particularly antigen (teichoic acid and capsular polysaccharides) and nucleic acid (ply, lytA, and Spn9802) detection assays. Use of the pneumococcal antigen detection methods along with biomarkers (C-reactive protein and procalcitonin) may enhance the specificity of diagnosis for pneumococcal pneumonia. This article provides an overview of current methods of diagnosing pneumococcal pneumonia and discusses new and future test methods that may provide the way forward for improving its diagnosis.
doi:10.3947/ic.2013.45.4.351
PMCID: PMC3902818  PMID: 24475349
Streptococcus pneumoniae; Pneumococcal pneumonia; Diagnosis; Polymerase chain reaction
15.  Long-Term Immunogenicity of the Pandemic Influenza A/H1N1 2009 Vaccine among Health Care Workers: Influence of Prior Seasonal Influenza Vaccination 
Health care workers (HCWs) are at great risk of influenza infection and transmission. Vaccination for seasonal influenza is routinely recommended, but this strategy should be reconsidered in a pandemic situation. Between October 2009 and September 2010, a multicenter study was conducted to assess the long-term immunogenicity of the A/H1N1 2009 monovalent influenza vaccine among HCWs compared to non-health care workers (NHCWs). The influence of prior seasonal influenza vaccination was also assessed with respect to the immunogenicity of pandemic H1N1 influenza vaccine. Serum hemagglutinin inhibition titers were determined prevaccination and then at 1, 6, and 10 months after vaccination. Of the 360 enrolled HCW subjects, 289 participated in the study up to 10 months after H1N1 monovalent influenza vaccination, while 60 of 65 NHCW subjects were followed up. Seroprotection rates, seroconversion rates, and geometric mean titer (GMT) ratios fulfilled the European Union's licensure criteria for influenza A/California/7/2009 (H1N1) at 1 month after vaccination in both the HCWs and NHCWs, without any significant difference. At 6 months after vaccination, the seroprotection rate was more significantly lowered among the NHCWs than among the HCWs (P < 0.01). Overall, postvaccination (1, 6, and 10 months after vaccination) GMTs for A/California/7/2009 (H1N1) were significantly lower among the seasonal influenza vaccine recipients than among the nonrecipients (P < 0.05). In conclusion, HCWs should be encouraged to receive an annual influenza vaccination, considering the risk of repeated exposure. However, prior reception of seasonal influenza vaccine showed a negative influence on immunogenicity for the pandemic A/H1N1 2009 influenza vaccine.
doi:10.1128/CVI.00725-12
PMCID: PMC3623406  PMID: 23365206
16.  Long-term immunogenicity of the influenza vaccine at reduced intradermal and full intramuscular doses among healthy young adults 
Purpose
To prepare for vaccine shortages under an influenza pandemic, several antigen-sparing strategies have been investigated. This study was aimed to evaluate the immunogenicity of influenza vaccine at reduced intradermal and full intramuscular dose.
Materials and Methods
We compared the effect of one-fifth and one-half intradermal doses to the full intramuscular dose on immunogenicity in healthy young adults, using a commercial influenza vaccine. A hemagglutination inhibition assay was used to compare the immunogenicity of the vaccination methods.
Results
The one-fifth intradermal dose (3 µg hemagglutinin antigen, HA) was given to 30 participants, the one-half intradermal dose (7.5 µg HA) was given to 30, and the full intramuscular dose (15 µg HA) was given to 32. No significant differences among injection routes and dosages were seen for seroprotection rate, seroconversion rate, or geometric mean titer (GMT) fold-increase for A/H1N1, A/H3N2, and B at around 4 weeks from vaccination. Although GMT for influenza B was significantly lower at six months for the one-fifth intradermal vaccination compared to the full-dose intramuscular vaccination (32.8 vs. 63.2, p=0.048), all three groups met the Evaluation of Medicinal Products (EMA) immunogenicity criteria through 1 to 6 months.
Conclusion
Intradermal administration of a one-fifth dose of influenza vaccine elicited antibody responses comparable to the intradermal one-half dose and a conventional intramuscular vaccination at 1 month post-vaccination. The immunogenicity of the one-fifth intradermal dose was sufficient to meet the requirement for the EMA criteria at six months after influenza vaccination.
doi:10.7774/cevr.2013.2.2.115
PMCID: PMC3710919  PMID: 23858402
Vaccines; Influenza vaccines; Immunogenicity; Intradermal injections; Adult
17.  Depression Among HIV-infected Patients in Korea: Assessment of Clinical Significance and Risk Factors 
Infection & Chemotherapy  2013;45(2):211-216.
Background
With prolonged life expectancies, mental illness has emerged as a disabling disorder among people with HIV.
Materials and Methods
This study was conducted to assess the prevalence of depression and its risk factors among Korean patients with HIV infections. Eighty-two HIV-infected patients completed structured questionnaires including the Beck Depression Inventory and the State-Trait Anxiety Inventory. Subjects with depression were compared to those without depression in terms of demographics, comorbidities, CD4 T-cell count, RNA copy numbers, highly active antiretroviral therapy (HAART) regimens, and adherence.
Results
The estimated depression rate was 21% (17 of 82 subjects). Comorbidities (47% vs. 20%, P = 0.01) and unemployment (65% vs. 31%, P = 0.02) were risk factors for depression. Depressive patients were more likely to be anxious (71% vs. 29%, P < 0.01), to frequently miss clinical appointments each year (P = 0.04), and to have higher cumulative time lost to follow-up per month (P <0.01) compared to non-depressive patients. Only three depressive patients were referred to neuropsychologists.
Conclusions
More than 20% of the Korean HIV patients in this study suffered from depression associated with poor adherence. Considering the low level of recognition of depression by clinicians, risk factor-based active assessment is recommended to manage depression properly in HIV-infected patients.
doi:10.3947/ic.2013.45.2.211
PMCID: PMC3780946  PMID: 24265969
HIV; Acquired immunodeficiency syndrome; Depression; Anxiety
18.  Perceptions of Tetanus-diphteria-acellular pertussis (Tdap) Vaccination among Korean Women of Childbearing Age 
Infection & Chemotherapy  2013;45(2):217-224.
Background
The number of cases of pertussis reported has increased gradually in the last decade. Pertussis vaccination is the most effective strategy for the prevention of infection. Despite the fact that young infants are at the highest risk for pertussis, the rate of tetanus-diphtheria-acellular pertussis (Tdap) vaccination is presumed to be very low among women of childbearing age in Korea. The purpose of this study was to investigate the perceptions of women of childbearing age regarding Tdap vaccination in Korea.
Materials and Methods
Women of childbearing age, who visited the Department of Obstetrics and Gynecology at 3 University hospitals in the Seoul and Gyeonggi-do provinces of Korea, were surveyed. Individual questionnaires were administered from April to May 2012. Demographic data, Tdap vaccination history, general knowledge about pertussis, and information on factors associated with decision on vaccination were collected.
Results
Of the 500 reproductive-age women enrolled, only 4 (0.8%) had received the Tdap. The most common reason for non-vaccination was the lack of awareness of pertussis and information about the Tdap. Totally, 171 (34.2%) responded that they would receive a Tdap vaccination in the future. By multivariate analysis, general confidence in the effectiveness of the vaccine (odds ratio [OR] = 1.88, 95% confidence interval [CI] 1.17 to 3.01) was indicated as an important factor for deciding whether to receive the Tdap vaccine (P < 0.01).
Conclusions
The coverage of Tdap vaccination of women of childbearing age, including pregnant women, is very low because of the lack of awareness of pertussis and the Tdap. Education of women of childbearing age about pertussis is very important to increase Tdap vaccination rates among these women, particularly during the perinatal period.
doi:10.3947/ic.2013.45.2.217
PMCID: PMC3780958  PMID: 24265970
Pertussis; Vaccination; Tdap; Childbearing age; Perception
19.  Laboratory Surveillance of Influenza-Like Illness in Seven Teaching Hospitals, South Korea: 2011–2012 Season 
PLoS ONE  2013;8(5):e64295.
Background
A well-constructed and properly operating influenza surveillance scheme is essential for public health. This study was conducted to evaluate the distribution of respiratory viruses in patients with influenza-like illness (ILI) through the first teaching hospital-based surveillance scheme for ILI in South Korea.
Methods
Respiratory specimens were obtained from adult patients (≥18 years) who visited the emergency department (ED) with ILI from week 40, 2011 to week 22, 2012. Multiplex PCR was performed to detect respiratory viruses: influenza virus, adenovirus, coronavirus, respiratory syncytial virus, rhinovirus, human metapneumovirus, parainfluenza virus, bocavirus, and enterovirus.
Results
Among 1,983 patients who visited the ED with ILI, 811 (40.9%) were male. The median age of patients was 43 years. Influenza vaccination rate was 21.7% (430/1,983) during the 2011–2012 season. At least one comorbidity was found in 18% of patients. The positive rate of respiratory viruses was 52.1% (1,033/1,983) and the total number of detected viruses was 1,100. Influenza A virus was the dominant agent (677, 61.5%) in all age groups. The prevalence of human metapneumovirus was higher in patients more than 50 years old, while adenovirus was detected only in younger adults. In 58 (5.6%) cases, two or more respiratory viruses were detected. The co-incidence case was identified more frequently in patients with hematologic malignancy or organ transplantation recipients, however it was not related to clinical outcomes.
Conclusion
This study is valuable as the first extensive laboratory surveillance of the epidemiology of respiratory viruses in ILI patients through a teaching hospital-based influenza surveillance system in South Korea.
doi:10.1371/journal.pone.0064295
PMCID: PMC3661466  PMID: 23717587
20.  Clinical and economic burden of invasive pneumococcal disease in adults: a multicenter hospital-based study 
BMC Infectious Diseases  2013;13:202.
Background
Streptococcus pneumoniae causes a broad spectrum of illnesses ranging from mild upper respiratory tract infections to invasive pneumococcal disease (IPD). Quantitative data on the burden of pneumococcal disease, important for the establishment of appropriate vaccination strategies, is currently lacking in adults.
Methods
This multicenter, retrospective cohort study was designed to estimate the clinical and economic burden of IPD in adults over the last decade. Data were collected from patients with IPD at 10 university hospitals in South Korea. We estimated the proportion of IPD among all hospitalized patients, the case fatality rate, and the direct medical costs of IPD. Data were further analyzed according to age and risk groups.
Results
During the study period, 970 patients with IPD were identified. The mean age for all patients was 60.9 years; patients aged 50–64 years (33.0%) were most numerous, followed by those aged 65–74 years (27.4%). Overall, the proportion of IPD was 0.36 cases/1000 hospitalized patients and the case fatality rate was 30.9%, which increased significantly with age (p < 0.01). The mean direct medical costs were estimated to be US $7,452 without a difference between age and risk groups. On multivariate analysis, old age, advanced ECOG performance status, bacteremic pneumonia, and nosocomial infection were independent risk factors of 30-day case fatality.
Conclusions
The clinical disease burden of IPD increased significantly with age and direct medical costs from IPD were substantial, regardless of age and co-morbid conditions. The current age-based vaccination strategy appears to be appropriate.
doi:10.1186/1471-2334-13-202
PMCID: PMC3660270  PMID: 23641904
Cost of illness; Pneumococcal infection; Pneumococcal vaccines; Streptococcus pneumoniae
21.  A Comparison of the Clinical and Epidemiological Characteristics of Adult Patients with Laboratory-Confirmed Influenza A or B during the 2011–2012 Influenza Season in Korea: A Multi-Center Study 
PLoS ONE  2013;8(5):e62685.
Background
During the 2011/2012 winter influenza season in the Republic of Korea, influenza A (H3N2) was the predominant virus in the first peak period of influenza activity during the second half of January 2012. On the other hand, influenza B was the predominant virus in the second peak period of influenza activity during the second half of March 2012. The objectives of this study were to compare the clinical and epidemiological characteristics of patients with laboratory-confirmed influenza A or influenza B.
Methodology/Principal Findings
We analyzed data from 2,129 adult patients with influenza-like illnesses who visited the emergency rooms of seven university hospitals in Korea from October 2011 to May 2012. Of 850 patients with laboratory-confirmed influenza, 656 (77.2%) had influenza A (H3N2), and 194 (22.8%) influenza B. Age, and the frequencies of cardiovascular disorders, diabetes, hypertension were significantly higher in patients with influenza A (H3N2) (P<0.05). The frequencies of leukopenia or thrombocytopenia in patients with influenza B at initial presentation were statistically higher than those in patients with influenza A (H3N2) (P<0.05). The rate of hospitalization, and length of hospital stay were statistically higher in patients with influenza A (H3N2) (P<0.05), and of the 79 hospitalized patients, the frequency of diabetes, hypertension, cases having at least one of the comorbid conditions, and the proportion of elderly were significantly higher in patients with influenza A (H3N2) (P<0.05).
Conclusions
The proportion of males to females and elderly population were significantly higher for influenza A (H3N2) patients group compared with influenza B group. Hypertension, diabetes, chronic lung diseases, cardiovascular disorders, and neuromuscular diseases were independently associated with hospitalization due to influenza. Physicians should assess and treat the underlying comorbid conditions as well as influenza viral infections for the appropriate management of patients with influenza.
doi:10.1371/journal.pone.0062685
PMCID: PMC3643978  PMID: 23671624
22.  Outpatient-Based Pneumococcal Vaccine Campaign and Survey of Perceptions about Pneumococcal Vaccination in Patients and Doctors 
Yonsei Medical Journal  2013;54(2):469-475.
Purpose
Despite the ready availability of pneumococcal vaccine, vaccination rates are quite low in South Korea. This study was designed to assess perceptions and awareness about pneumococcal vaccines among subjects at risk and find strategies to increases vaccine coverage rates.
Materials and Methods
A cross sectional, community-based survey was conducted to assess perceptions about the pneumococcal vaccine at a local public health center. In a tertiary hospital, an outpatient-based pneumococcal vaccine campaign was carried out for the elderly and individuals with chronic co-morbidities from May to July of 2007.
Results
Based on the survey, only 7.6% were ever informed about pneumococcal vaccination. The coverage rates of the pneumococcal vaccine before and after the hospital campaign showed an increased annual rate from 3.39% to 5.91%. The most common reason for vaccination was "doctor's advice" (53.3%). As for the reasons for not receiving vaccination, about 75% of high risk patients were not aware of the pneumococcal vaccine, which was the most important barrier to vaccination. Negative clinician's attitude was the second most common cause of non-vaccination.
Conclusion
Annual outpatient-based campaigns early in the influenza season may improve pneumococcal vaccine coverage rates. Doctor's advice was the most important encouraging factor for vaccination.
doi:10.3349/ymj.2013.54.2.469
PMCID: PMC3575991  PMID: 23364983
Pneumococcal infections; pneumococcal vaccination; health education
23.  Concurrent Tuberculosis and Influenza, South Korea 
Emerging Infectious Diseases  2013;19(1):165-167.
doi:10.3201/eid1901.111613
PMCID: PMC3557969  PMID: 23260033
Tuberculosis; influenza; pandemics; South Korea; respiratory infections; tuberculosis and other mycobacteria; viruses
24.  Comparison of the Long-Term Immunogenicity of Two Pandemic Influenza A/H1N1 2009 Vaccines, the MF59-Adjuvanted and Unadjuvanted Vaccines, in Adults 
Since the first reports of the A/H1N1 virus in April 2009, the pandemic influenza virus spread globally and circulated for a long time. The primary method for the control of influenza is vaccination, but levels of influenza vaccine-induced antibody are known to decline rapidly during a 6-month period. In adults aged 18 to 64 years, we compared the long-term immunogenicity of two of the influenza A/H1N1 2009 monovalent vaccines, 3.75-μg MF59-adjuvanted vaccine and 15-μg unadjuvanted vaccine. The serum hemagglutinin inhibition (HI) titers were determined prevaccination and at 1, 6, and 10 months after vaccination. One hundred six (88.3%) of the 120 subjects were monitored for the entire 10-month period after receiving the influenza A/H1N1 2009 monovalent vaccine. There were 60 patients who received the unadjuvanted vaccine and 46 patients who received the MF59-adjuvanted vaccine. The seroprotection rates, seroconversion rates, and the geometric mean titer (GMT) folds fulfilled the criteria of the European Medicines Agency (EMA) for influenza A/California/7/2009 (H1N1) at 1 month after vaccination irrespective of the vaccine composition. Although the GMTs at 1 month postvaccination were somewhat higher in the unadjuvanted vaccine recipients than in the MF59-adjuvanted vaccine recipients, the difference was not significant (P = 0.29). The seroprotection rates at 6 and 10 months postvaccination were preserved above 70% but only in the MF59-adjuvanted vaccine recipients. In conclusion, low-dose MF59-adjuvanted influenza vaccine, even with 3.75 μg hemagglutinin antigen, might induce excellent long-term immunity that is comparable to the conventional dose of unadjuvanted vaccine among healthy adults aged 18 to 64 years.
doi:10.1128/CVI.00026-12
PMCID: PMC3346343  PMID: 22379067
25.  Epidemiological and Clinical Characteristics of Community-Acquired Severe Sepsis and Septic Shock: A Prospective Observational Study in 12 University Hospitals in Korea 
Journal of Korean Medical Science  2012;27(11):1308-1314.
A prospective multicenter observational study was performed to investigate the epidemiology and outcomes of community-acquired severe sepsis and septic shock. Subjects included 1,192 adult patients admitted to the 22 participating intensive care units (ICUs) of 12 university hospitals in the Korean Sepsis Registry System from April, 2005 through February, 2009. Male accounted for 656 (55%) patients. Mean age was 65.0 ± 14.2 yr. Septic shock developed in 740 (62.1%) patients. Bacteremia was present in 422 (35.4%) patients. The 28-day and in-hospital mortality rates were 23.0% and 28.0%, respectively. Men were more likely to have comorbid illnesses and acute organ dysfunctions, and had higher mortality and clinical severity compared to women. While respiratory sources of sepsis were common in men, urinary sources were predominant in women. In the multivariate logistic regression analysis, cancer (odds ratio 1.89; 95% confidence interval 1.13-3.17), urinary tract infection (0.25; 0.13-0.46), APACHE II score (1.05; 1.02-1.09), SOFA score on day 1 (1.13; 1.06-1.21) and metabolic dysfunction (2.24, 1.45-3.45) were independent clinical factors for gender-related in-hospital mortality. This study provided epidemiological and clinical characteristics of community-acquired severe sepsis and septic shock in ICUs in Korea, and demonstrated the impact of clinical factors on gender difference in mortality.
doi:10.3346/jkms.2012.27.11.1308
PMCID: PMC3492663  PMID: 23166410
Epidemiology; Severe Sepsis; Septic Shock; Mortality; Risk Factor; Gender

Results 1-25 (36)