Yu Mi Jo

Long-term immunogenicity of influenza vaccine among the elderly: Risk factors for poor immune response and persistence ☆

The elderly have been considered as the priority group for influenza vaccination, but their influenza vaccine-induced antibody was believed to decline more rapidly. Long-term immunogenicity of the influenza vaccine among the elderly was evaluated as compared to young adults. Serum hemagglutinin inhibition (HI) titers were determined at pre- and post-vaccination periods (at 1, 6, and 12 months after vaccination). Of the 1018 subjects, 716 (70.3%) were followed up during a 12-month period. Seroprotection rates at 1 month post-vaccination ranged from 70.1% to 90.3% depending on the age group and influenza vaccine virus strain. At 6 months post-vaccination, seroprotection rates for all three strains had declined significantly in adults >or=65 years (P<0.01), but still met the EMEA criteria. Low pre-vaccination HI titer (<1:40) and advanced age were associated with early decline of HI titers, falling below seroprotective levels around 6 months after vaccination.

Influenza vaccine coverage rates and perceptions on vaccination in South Korea

Summary Objective This survey was performed to assess the level of influenza vaccine coverage, to understand the driving forces and barriers to vaccination and determine vaccination interventions for the following year in Korean population. Methods A national sample of 1720 community dwelling adults of age 18 and older were surveyed by individual visits during April 2005. Demographics, state of influenza vaccination, reasons for vaccination or non-vaccination and perceptions on vaccinations were asked by questionnaire. Results Influenza vaccination coverage in general population and high risk group was 34.3% and 61.3%, respectively. Predictors for vaccination were ≥65 of age, performance of regular exercise, vaccination in the previous season, experience of influenza-like illness, belief that vaccine can prevent common cold and opinion that vaccine must be taken annually. The most common reason for vaccination for both whole population and high risk groups was to prevent both influenza and common cold, while the most common reason for non-vaccination was the thought that he/she was healthy enough not to be in need for vaccination. Having more information on influenza and vaccination as well as doctors recommendation for vaccination appeared to be the most important modus operandi to encourage influenza vaccination among non-vaccinees. Conclusions Doctors recommendation was the most important factor in encouraging people to be vaccinated against influenza. Doctors should be geared up with precise information and actively encourage high risk population in order to increase vaccination coverage.

Vancomycin-resistant Enterococcus colonization before admission to the intensive care unit: A clinico-epidemiologic analysis

BACKGROUND Asymptomatic vancomycin-resistant Enterococcus (VRE) colonization is known to precede actual infection. Since VRE was first isolated in Korea in 1992, the VRE isolation rate has rapidly increased in tertiary hospitals. METHODS We performed a prospective observational study to estimate the prevalence of VRE colonization among inpatients at the time of intensive care unit (ICU) admission. From March through December 2007, rectal swab cultures were taken in all patients admitted to the ICU. We aimed to identify the risk factors for VRE colonization on admission. RESULTS During the study period, 34 (4.4%) out of 780 patients were already colonized with VRE before ICU admission: 21 out of 323 patients from general wards (6.5%) and 13 out of 437 patients from outside the hospital (2.97%). VRE-colonized patients were more likely than uncolonized patients to have infectious diseases and to have been referred from outside hospitals (P < .01). Previous hospitalization (P = .01) and antibiotic exposure (P < .01) were risk factors for VRE colonization before ICU admission. Pulsed-field gel electrophoresis patterns were diverse. Initial VRE colonization correlated to poor prognosis. CONCLUSION VRE colonization rate was not negligible among newly admitted ICU patients, suggesting that an active surveillance program focusing on high-risk groups may be helpful.

Disease burden of herpes zoster in Korea

BACKGROUND The occurrence of herpes zoster can deteriorate the quality of life considerably, resulting in high disease burden. While Korea is assumed to have high disease burden of herpes zoster, there has been no researches analyzing this. OBJECTIVES We performed this study to investigate the disease burden of herpes zoster in the Korean population as a whole. STUDY DESIGN We used the database of the Health Insurance Review & Assessment Service of Korea and analyzed the data of patients who had herpes zoster as a principal diagnosis during the period from 2003 to 2007. We investigated the annual prevalence, rate of clinical visits, rate of hospitalization, and the pattern of medical services use. The socioeconomic burden of herpes zoster was calculated by a conversion into cost. RESULTS Rates of clinic visits and hospitalizations due to herpes zoster during the 5-year period from 2003 to 2007 were 7.93-12.54 per 1000 population and 0.22-0.32 per 1000 population, respectively. Prevalence rates according to age increased sharply after 50 years and reached a peak at 70 years. The total socioeconomic cost of herpes zoster was

Dose sparing strategy with intradermal influenza vaccination in patients with solid cancer.

75.9-143.8 million per year, increasing every year by 14-20%. CONCLUSIONS There is a heavy socioeconomic burden due to herpes zoster in Korea and indicate that appropriate policies need to be established to reduce this burden. Additional researches are also necessary to assess the safety, efficacy and cost-effectiveness of a herpes zoster vaccine in the Korean population.

Clinical and economic burden of invasive pneumococcal disease in adults: a multicenter hospital-based study

Influenza vaccine is considered to reduce influenza‐related morbidity and mortality in patients with underlying chronic medical conditions. Because of fear of vaccine shortage during an influenza pandemic, several antigen sparing strategies have been investigated. The immunogenicity of intradermal influenza vaccination with one half the antigenic contents was compared to that of conventional intramuscular vaccination in patients with solid cancer, and adverse events were assessed after vaccination. There was no significant difference between the injection routes in the hemagglutinin inhibition (HI) response and increase in the titer of A/H1N1, A/H3N2, and B 4–6 weeks after the vaccination; seroconversion factors increased by more than 2.5‐fold. Seroresponse rates were more than 40% and seroprotection rates were above 70% against all three influenza strains irrespective of the vaccination routes. No serious events were observed, and local skin reactions were more frequent in the intradermal injection recipients than in the intramuscular recipients (32.7% vs. 9.1%). This study shows that intradermal injection of one half the dose of a commercial influenza vaccine elicits immune responses comparable to those elicited by a full dose of intramuscular vaccine among cancer patients, and it can be tolerated without serious adverse reactions. J. Med. Virol. 81:722–727, 2009

Clinical, laboratory and radiologic characteristics of 2009 pandemic influenza A/H1N1 pneumonia: primary influenza pneumonia versus concomitant/secondary bacterial pneumonia

BackgroundStreptococcus 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.MethodsThis 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.ResultsDuring 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

A Novel Model for Metabolic Syndrome Risk Quantification Based on Areal Similarity Degree

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.ConclusionsThe 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.

Seroprevalence of varicella-zoster virus in Korea.

Please cite this paper as: Song et al. (2011). Clinical, laboratory and radiologic characteristics of 2009 pandemic influenza A/H1N1 pneumonia: primary influenza pneumonia versus concomitant/secondary bacterial pneumonia. Influenza and Other Respiratory Viruses 5(6), e535–e543.

Liver Abscess and Empyema due to Lactococcus lactis cremoris

Metabolic syndrome (MS) refers to a clustering of specific cardiovascular disease (CVD) risk factors whose underlying pathology is thought to be related to insulin resistance. The risk factors include insulin resistance, obesity, dyslipidemia, and hypertension and it is known to increase the risk for CVD and type II diabetes. Since MS helps to identify individuals at high risk for both CVD and type II diabetes, it has become a major public healthcare issue in many countries. There has been much effort to establish diagnostic criteria for MS, but the current diagnostic criteria of MS have weaknesses, such as binary decision based on diagnostic criteria, equal weight among risk factors, and difficulty in estimating the temporal progress of the risk factors. To resolve these problems, this paper proposes a risk quantification model for MS, which is based on areal similarity degree analysis between weighted radar charts comprising MS diagnostic criteria and examination results of risk factors. The clinical effectiveness of the proposed model is extensively evaluated by using data of a large number of subjects obtained from the third Korea National Health and Nutrition Examination Survey. The evaluation results show that the proposed model can quantify the risk of MS and effectively identify a group of subjects who might be classified into a potential risk group for having MS in the future.