Jae Hyoung Im

Incidence and risk factors of linezolid-induced lactic acidosis

BACKGROUND The use of linezolid has increased with the emergence of multidrug-resistant bacteria. Serum lactic acidosis has been reported as a serious side effect of linezolid use, therefore we evaluated the incidence and characteristics of linezolid-related lactic acidosis. METHODS Patients admitted to an 860-bed university hospital were enrolled. The patients were divided into two groups, those who used linezolid and those who used teicoplanin (control group). The study was conducted by review of the medical charts. RESULTS Seventy-two patients were included in the linezolid group. The control group comprised 72 patients matched to those in the linezolid group for age and indication for antibiotic use. Lactic acidosis occurred in five cases (6.8%) in the linezolid group. None of the patients who used teicoplanin developed lactic acidosis, which was a comparable result. The median change in anion gap in the linezolid group was -0.8 mmol/l (interquartile range (IQR) -3.55 to 1.28 mmol/l), which was significantly higher than in the teicoplanin group, 0.05 mmol/l (IQR -1.75 to 2.3 mmol/l) (p=0.026). The number of increased anion gap events in patients who used linezolid for more than 6 weeks was higher than in the group who used linezolid for less than 6 weeks (p=0.0014). However, no statistically significant difference was observed according to age, estimated glomerular filtration rate, or diabetes. CONCLUSIONS Linezolid showed an association with treatment-related lactic acidosis. A longer duration of linezolid use (>6 weeks) was one of the risk factors for metabolic acidosis. We suggest checking serum lactate concentrations regularly, especially in those on long-term use.

Paradoxical reaction of tuberculous vertebral osteomyelitis: a case series

Abstract Paradoxical reactions of tuberculosis (TB) in vertebral osteomyelitis are very rarely reported. We experienced four cases of severe paradoxical reactions in tuberculous vertebral osteomyelitis. Four cases of tuberculous vertebral osteomyelitis were confirmed by an acid-fast bacilli smear or culture. The patients were human immunodeficiency virus negative, and were all initially treated with isoniazid, ethambutol, rifampicin and pyrazinamide. Their symptoms improved with anti-TB drugs. However, after 2–12 weeks, their symptoms had recurred, and spinal magnetic resonance imaging at the time of readmission revealed an aggravation of vertebral osteomyelitis. Operations were carried out to relieve severe pain or spinal cord decompression. Through continued anti-TB drug therapy, all patients recovered without sequelae.

Therapeutic drug concentrations of teicoplanin in clinical settings.

Background Teicoplanin is a glycopeptide antibiotic that is widely used in clinical practice for the treatment of infections caused by drug-resistant Gram-positive bacteria. The aim of this study was to analyze plasma teicoplanin concentrations to determine the percentage of patients in whom therapeutic concentrations of teicoplanin were achieved in clinical practice. Materials and Methods The plasma teicoplanin concentrations of hospitalized patients receiving treatment at a teaching hospital were retrospectively analyzed. The target level was defined as a plasma teicoplanin concentration of 10 mg/L or greater, since this was generally regarded as the lower limit of the optimal concentration range required for the effective treatment of a majority of infections. Results Patients with sub-optimal (< 10 mg/L) plasma teicoplanin concentrations constituted nearly half of the total study population. The majority of these patients received the recommended loading dose, which were three 400 mg doses administered every 12 hours. Sub-group analysis showed a trend that the group receiving loading dose was more likely to reach the optimal teicoplanin concentration. Conclusions The data revealed that a significant proportion of patients in clinical practice achieved only sub-optimal teicoplanin concentrations, which emphasizes the importance of the mandatory use of loading dose and routine therapeutic drug monitoring. Treatment reassessment and simulation of individual dose regimens may also be necessary to achieve optimal drug concentrations.

In Vitro Activity of Tigecycline Against Orientia tsutsugamushi

Scrub typhus is a zoonosis caused by Orientia tsutsugamushi (O. tsutsugamushi) occurring mainly in autumn in Korea. The need of new antibiotics has arisen with a report on strains resistant to antibiotics and chronic infection. This study aims to identify susceptibility of tigecycline in-vitro as a new therapeutic option for O. tsutsugamushi. Antibacterial activity of tigecycline against the O. tsutsugamushi was compared with doxycycline using flow cytometry assay. The inhibitory concentration 50 (IC50) was 3.59×10-3 µg/mL in doxycycline-treated group. Whereas in 0.71×10-3 µg/mL tigecycline-treated group. These findings indicate that tigecycline may be a therapeutic option for the treatment of scrub typhus.

Current Status of Tick-Borne Diseases in South Korea

BACKGROUND Bites with tick-borne pathogens can cause various bacterial, viral, or parasitic diseases in humans. Tick-transmitted diseases are known as contributing factors to the increasing incidence and burden of diseases. The present article investigated the epidemiology of tick-borne diseases in South Korea. METHODS The incidence and distribution of common tick-borne diseases in Korea (Lyme disease, Q fever, and severe fever with thrombocytopenia syndrome [SFTS]) were investigated and analyzed, using data from the Korea Centers for Disease Control and Prevention (KCDC) infectious disease reporting system. A literature review was compiled on the current status of uncommon tick-borne diseases (Rickettsia, anaplasmosis, ehrlichiosis, bartonellosis, tularemia, tick-borne encephalitis, and babesiosis). RESULTS AND CONCLUSIONS In South Korea, SFTS is an emerging disease, showing a rapid increase in reports since 2012, with high mortality. Likewise, reports of Lyme disease and Q fever cases have also been rapidly increasing during 2012-2017, although caution should be taken when interpreting these results, considering the likely influence of increased physician awareness and reporting of these diseases. Other tick-borne diseases reported in South Korea included spotted fever group rickettsiae, anaplasmosis, ehrlichiosis, tularemia, Bartonella, and babesiosis. Evidences on human infection with tick-borne encephalitis virus and Crimean-Congo hemorrhagic fever were recently unavailable, but both need constant monitoring.

The seroprevalence of Bartonella henselae in healthy adults in Korea

Background/Aims Cat-scratch disease (CSD), caused by Bartonella henselae is one of the most common zoonosis. However, only several cases of B. henselae infection have been reported in Korea. This study investigated the seroprevalence of B. henselae in healthy adults and related risk factors. Methods Serum samples from 300 healthy participants were analyzed using an immunoglobulin G immunof luorescence assay (IFA) for B. henselae isolated in Korea. Surveys on the risk factors for B. henselae infection were conducted simultaneously. Results Of the participants, 47.7% and 15.0% raised dogs and cats, respectively. The overall seroprevalence of B. henselae was 15.0% (IFA titer ≥ 1:64). Participants who had raised cats showed 22.2% seropositivity against B. henselae, and those with no experience with cats showed 13.7% seroprevalence (p = 0.17). Participants who had cats as pets or been scratched by cats, showed 9.8% seropositivity against B. henselae (IFA titer ≥ 1:256). However, those who had not raised or been scratched by a cat showed 2.0% seropositivity (p = 0.015). Conclusions In Korea, the seroprevalence of B. henselae is higher than expected, suggesting that Bartonella infection due to B. henselae is not uncommon. Cats are proposed to play a more important role than dogs in transmission of CSD.

Enterovirus Infection in Adults Presenting with Nonspecific Febrile Illness during Summer

www.icjournal.org Enterovirus Infection in Adults Presenting with Nonspecific Febrile Illness during Summer Areum Durey, Young Su Je, Hea Yoon Kwon, Jae Hyoung Im, Ji-Hyeon Baek, Sun-Myoung Lee, Young Kyoung Park, and Jin-Soo Lee Department of Emergency Medicine, Department of Laboratory Medicine, Department of Internal Medicine, Translation Research Center, Inha University School of Medicine, Incheon, Korea

A Case of Scrub Typhus Complicated by Adult Respiratory Distress Syndrome and Successful Management with Extracorporeal Membrane Oxygenation

A 67-year-old woman was diagnosed as having scrub typhus with pneumonitis. On admission, she was started on a combination therapy with levofloxacin and doxycycline. However, the patient developed severe acute respiratory distress syndrome (ARDS) on the 2nd day, and as a result, she underwent extracorporeal membrane oxygenation (ECMO). She was weaned from ECMO on the 10th day, as her respiratory status gradually improved. She was discharged without sequelae on the 23rd day. The outcome suggests that the use of ECMO should be considered for patients with ARDS induced from scrub typhus.