Hee Jung Yoon

Differences in clinical features according to Boryoung and Karp genotypes of Orientia tsutsugamushi.

Background Scrub typhus is an infectious disease caused by Orientia tsutsugamushi. The differences in virulence of O. tsutsugamushi prototypes in humans are still unknown. We investigated whether there are any differences in the clinical features of the Boryoung and Karp genotypes. Methodology/Principal Findings Patients infected with O. tsutsugamushi, as Boryoung and Karp clusters, who had visited 6 different hospitals in southwestern Korea were prospectively compared for clinical features, complications, laboratory parameters, and treatment responses. Infected patients in the Boryoung cluster had significantly more generalized weakness, eschars, skin rashes, conjunctival injection, high albumin levels, and greater ESR and fibrinogen levels compared to the Karp cluster. The treatment response to current antibiotics was significantly slower in the Karp cluster as compared to the Boryoung cluster. Conclusion The frequency of occurrence of eschars and rashes may depend on the genotype of O. tsutsugamushi.

Clinical risk factors for Clostridium difficile-associated diseases.

Many factors appear to influence the chance of acquiring Clostridium difficile (C. difficile) infection, and an accurate identification of risk factors could be beneficial in many ways. Thus, in the present study, clinical risk factors for C. difficile-associated disease (CDAD) in Korea were identified. A total of 93 patients who met the inclusion criteria and 186 age/gender/ward/admission period-matched control patients were included in this study. Statistically significant associations were found with presence of chronic lung diseases (odds ratio [OR], 3.41; 95% confidence interval [CI], 1.25-9.32; p = 0.017), presence of ileus (OR, 10.05; 95% CI, 2.42-41.80; p = 0.001), presence of intensive care unit (ICU) stay (OR, 9.79; 95% CI, 3.03-31.68; p < 0.001), use of cephalosphorins (OR, 3.30; 95% CI, 1.13-9.62; p = 0.029), history of surgery (OR, 10.89; 95% CI, 3.96-29.92; p < 0.001), and history of long-term care facility stay (OR, 14.90; 95% CI, 4.02-55.26; p < 0.001). Awareness of CDAD is critical to provide appropriate clinical care. Surveillance of the national incidence rate and multicenter studies are needed, and the potential value of a C. difficile vaccine should be studied.

Does IL-17 play a role in hepatic dysfunction of scrub typhus patients?

Scrub typhus is a zoonotic disease that is caused by Orientia tsutsugamushi. Although hepatic dysfunction occurred in 77-96.7% of the scrub typhus patients, its mechanism is unknown. IL-17 is a potent proinflammatory cytokine known for its role in several chronic disease conditions. Abundant IL-17 was found in conditions affected by microbial pathogens, including the synovial fluid of patients with Lyme arthritis or Chlamydia-induced reactive arthritis, Helicobacter pylori-infected gastric mucosa, and listeria infection. It is also suggested as a marker of acute hepatic injury. In our study, we postulated that IL-17 might be a cytokine with a role in hepatic dysfunction in scrub typhus. In September-November 2006, our study involved 43 patients with Boryong-type scrub typhus patients and 40 age- and sex-matched control healthy people. Scrub typhus was confirmed on the basis of immunofluorescence and a nested polymerase chain reaction assay. IL-17 was measured using human IL-17 immunoassay. We gathered the clinical and laboratory data by chart reviews. We used an independent t-test, Kolmogorov-Smirnov test, and correlation analysis. The IL-17 levels were significantly higher in scrub typhus patients than in the healthy group. Also, the patients with scrub typhus showed significantly higher aspartate aminotransferase and alanine aminotransferase levels, and lower hemoglobin levels than the healthy group. However, in our correlation analysis, we did not find any correlation between IL-17 and hepatic, kidney, and hemogram panels. The IL-17 level in patients with headaches was higher than in patients without headaches, showing a borderline significance. This suggests that IL-17 level might be a cause of a vasculitis-associated headache. More prospective, large-scale studies are needed about the mechanism of hepatic dysfunction and headaches in scrub typhus patients.

Risk factors for Opisthorchis viverrini and minute intestinal fluke infections in Lao PDR, 2009-2011.

The purpose of this report is to compare the prevalence of Opisthorchis viverrini/minute intestinal fluke (Ov/MIF) in Lao Peoples Democratic Republic according to different regions and evaluate the effect of ingestion of raw freshwater fish on the infection. Demographic data, behavioral data, and symptoms were obtained, and the Kato-Katz method was used for the diagnosis of Ov/MIF. In total, 3,046 individuals were enrolled. The risk factors associated with acquisition of Ov/MIF were raw fish consumption and province. Khong Island showed the highest prevalence (odds ratio = 80.1, 95% confidence interval = 47.9-133.9, P < 0.001) compared with other districts, and raw fish consumption was related to Ov/MIF infection. Administration of praziquantel to entire populations, education (avoiding consumption of raw food dishes and improved hygiene), and access to clean water and sanitation should be considered.

Nontuberculosis mycobacterial infections at a specialized tuberculosis treatment centre in the Republic of Korea

BackgroundThe incidence of nontuberculous mycobacteria (NTM) infections is increasing worldwide, however formal evaluations of the epidemiology of NTM infections are limited. Understanding the trends and true prevalence of NTM is a major priority for optimizing infection control programmes and resources. The purpose of this study was to investigate the epidemiology, clinical manifestations, and radiologic findings in NTM-infected patients at specialized Tuberculosis (Tb) treatment centre in South Korea, which is endemic to Tb, and find solutions to control NTM infections.MethodsA retrospective descriptive study was conducted among patients who were diagnosed with NTM from November 2011 to January 2016 at Seoul Metropolitan Government Seobuk hospital, Korea, using medical records and chest radiography results. Prevalence of NTM using national health insurance data was compared to the prevalence and incidence of Tb using National statistics data.ResultsThe age- and sex- adjusted prevalence of NTM infection per 100,000 population increased between 2009 (9.4) and 2016 (36.1). However, the prevalence and incidence of Tb per 100,000 population decreased from 106.5 to 74.4, and 81.2 to 61.8, respectively. In total, 64 patients (37 [57.8%] men) were enrolled in the study. Among 33 (51.6%) patients with slowly growing nontuberculous mycobacteria (SGM) infection, 29 were detected with Mycobacterium avium complex (nxa0=xa013, M. avium; nxa0=xa016, M. intracellulare), and 4 with M. kansasii. Among 31 (48.4%) patients with rapidly growing nontuberculous mycobacteria (RGM) infection, 27 and 4 patients were detected with M. abscessus complex and M. fortuitum complex, respectively. RGM patients were more likely to have current Tb (Pxa0=xa00.041), cough (Pxa0<xa00.05), and sputum (Pxa0<xa00.01) than SGM patients in the univariate analysis, but not in the multivariate analysis.ConclusionGiven the increasing prevalence of NTM infections, precise epidemiological and surveillance data should be obtained by reporting NTM infections to public health authorities. Introducing nucleic acid amplification tests to differentiate between Tb and NTM in smear-positive specimens should be considered.

Evaluation and sensitivity analysis of the effectiveness of unadjuvanted A(H1N1)pdm09 vaccine in hospital workers using multi-center cohort study in Korea

The A(H1N1)pdm09 vaccine was developed and administered to hospital workers at first during the peak of the outbreak in Korea. The present multicenter cohort study was conducted to evaluate whether the A(H1N1)pdm09 vaccine effectively protected hospital workers. The study vaccine contained 15μg of A/California/7/2009 NYMC X-179A(H1N1) without adjuvant, Greenflu-S™. Participants were requested in December 2009 and April 2010 to answer a questionnaire about whether they had been confirmed to be A(H1N1)pdm09 patients based on the real-time reverse transcription-polymerase chain reaction (RT-PCR) assay and had received the A(H1N1)pdm09 vaccine. The vaccination and incidence rates of the A(H1N1)pdm09 were 96.4% (8769/9097), and 0.6% (57/9097), respectively. The crude vaccine effectiveness (VE) was calculated to be 81.8% [95% confidence interval (CI); 61.0-91.5%], while the effectiveness adjusted for hospital, immunization with seasonal trivalent influenza vaccine (TIV) in 2009-10, contact with A(H1N1)pdm09 patients, pre-existing disease, smoking history, and date of follow-up start was 81.9% (95% CI; 52.8-93.1%). When we defined insufficiently immunized cases as unvaccinated, instead of deleting them from the cohort, the adjusted VE increased up to 93.3%. In conclusion, the unadjuvanted monovalent A(H1N1)pdm vaccine was highly protective in hospital workers against laboratory-confirmed A(H1N1)pdm09 infections. VE estimates were sensitive to varying adjustment or assumptions (75.4-93.3%), which suggest the necessity of careful analysis of VE.

Prevalence and risk factors for human immunodeficiency virus infection in pregnant women in Eastern Ghana

Dear Editor, Determining HIV incidence is a useful tool for improving the targeting of populations for interventions and assessing the effectiveness of prevention strategies. A reduction in perinatal transmission of HIV is dependent on women seeking prenatal care, having access to an HIV test, agreeing to interventions such as antiretroviral therapy, and considering alternatives to breastfeeding. Thus, the aim of this study was to determine the seroprevalence and risk factors for human immunodeficiency virus (HIV) positivity among pregnant women in Eastern Ghana. Between December 2008 and March 2009, a total of 1,500 apparently healthy pregnant women who visited three hospitals in Eastern Ghana – Asesewa Government Hospital (AGH) in Upper Manya Krobo district, Holy Family Hospital (HFH) in Kwahu West district, and Somanya Polyclinic (SPC) in Yilo Krobo district – were consecutively recruited for this study after obtaining their informed consent. At every visit a standardized questionnaire was interview-administered to obtain data on socio-demographics, reproductive history, job status, social support, mental health, and health care utilizations. HIV, hepatitis B surface antigen (HBsAg), hemoglobin and sickling tests were done as a prenatal check-up. Univariate and multivariate odds ratios (OR), both with 95% confidence interval (CI), were calculated. A total of 1,109 apparently healthy pregnant women with a mean age of 26.85 ± 6.71 years were screened. Overall HIV positive rate was 8.0%. The risk factors associated with acquisition of HIV-1 in univariate analyses were older age, HBsAg positive status, and substantial alcohol use. These factors were analyzed in multiple logistic regression analysis. Age groups 25-29 (OR 2.770; 95% CI; 1.023-7.499) and > 35 (OR 3.141; 95% CI; 1.131-8.723), and HBsAg positive status (OR 2.376; 95% CI; 1.261-4.476) remained significantly associated with acquisition of HIV (Table 1). HIV prevalence among young pregnant women (15-24 years) is used as a proxy for measuring the rate of new infections in a population.1 In contrast, in this study, women aged 25-29 years were 2.77 times more likely to be infected than women of < 20 age. This suggests that women who are at the peak of their reproductive years are more prone to HIV infection. Due to shared routes of transmission,

Risk factors for mortality in Acinetobacter bacteremia

and surgical drainage (52.8%), followed by mechanical ventilation (50.9%), and hemo-dialysis (5.7%). Mean duration of hospital stay before the onset of bacteremia was 15 days. Twenty-one of the 53 (40%) patients were in the ICU at the time of AB onset, and the mean duration of ICU stay before the onset of bacteremia was eight days.