In 2015, a large outbreak of Middle East respiratory syndrome (MERS) occurred in the Republic of Korea. Half of the cases were associated with a tertiary care university hospital. To document the outbreak and successful control measures. Descriptive study. A 1950-bed tertiary care university hospital. 92 patients with laboratory-confirmed MERS and 9793 exposed persons. Description of the outbreak, including a timeline, and evaluation of the effectiveness of the control measures. During the outbreak, 92 laboratory-confirmed MERS cases were associated with a large tertiary care hospital, 82 of which originated from unprotected exposure to 1 secondary patient. Contact tracing and monitoring exposed patients and assigned health care workers were at the core of the control measures in the outbreak. Nontargeted screening measures, including body temperature screening among employees and visitors at hospital gates, monitoring patients for MERS-related symptoms, chest radiographic screening, and employee symptom monitoring, did not detect additional patients with MERS without existing transmission links. All in-hospital transmissions originated from 3 patients with MERS who also had pneumonia and productive cough. This was a retrospective single-center study. Statistical analysis could not be done. Because this MERS outbreak originated from a superspreader, effective control measures could differ in endemic areas or in other settings. Control strategies for MERS outbreaks should focus on tracing contacts of persons with epidemiologic links. Adjusting levels of quarantine and personal protective equipment according to the assumed infectivity of each patient with MERS may be appropriate. Samsung Biomedical Research Institute.

Measles and varicella still occur in the general population despite the widespread vaccination against them, and healthcare workers (HCWs) are still at risk of exposure to these diseases. Here, we evaluated the seroprevalence of measles and varicella-zoster virus (VZV) in HCWs and the trend of seroprevalence according to age, birth year, and occupational group. The serostatuses of measles and VZV of HCWs during new employee medical examinations between October 2015 and October 2021 were included. Thereafter, the trends of seroprevalence according to age, birth year, and occupational groups were evaluated. Overall, 2070 and 1827 HCWs were evaluated for VZV and measles serostatus, respectively. The seroprevalences of VZV and measles were 91% (1884/2070) and 70% (1284/1827), respectively. Younger HCWs had a significantly lower seroprevalence of measles (p = 0.02, age) and VZV (p = 0.003, birth year and p < 0.001, age). The seroprevalence of measles and VZV was significantly higher among doctors and nursing assistants than among nurses and other HCWs (p < 0.001 in both). In conclusion, the seroprevalence of measles and VZV significantly decreased in younger HCWs. Additionally, monitoring the serostatus of measles and VZV and the immunization of susceptible HCWs are required to prepare and control infectious diseases in healthcare facilities.

Asymptomatic/mildly symptomatic coronavirus disease 2019 (COVID-19) patients produce a considerable amount of virus and transmit severe acute respiratory syndrome virus 2 (SARS-CoV-2) through close contact. Preventing in-hospital transmission of SARS-CoV-2 is challenging, since symptom-based screening protocols may miss asymptomatic/mildly symptomatic patients. In particular, dental healthcare workers (HCWs) are at high risk of exposure, as face-to-face contact and exposure to oral secretions is unavoidable. We report exposure of HCWs during dental procedures on a mild symptomatic COVID-19 patient. A 32-year-old male visited a dental clinic at a tertiary care hospital. He experienced mild cough, which started three days before the dental visit, but did not report his symptom during the entrance screening. He underwent several dental procedures and imaging for orthognathic surgery without wearing a mask. Seven HCWs were closely exposed to the patient during dental procedures that could have generated droplets and aerosols. One HCW had close contact with the patient during radiologic exams, and seven HCWs had casual contact. All HCWs wore particulate filtering respirators with 94% filter capacity and gloves, but none wore eye protection or gowns. The next day, the patient experienced dysgeusia and was diagnosed with COVID-19 with high viral load. All HCWs who had close contact with the patient were quarantined for 14 days, and polymerase chain reaction and antibody tests for SARS-CoV-2 were negative. This exposure event suggests the protective effect of particulate filtering respirators in dental clinics. The recommendations of different levels of personal protective equipment (PPE) for dental HCWs according to the procedure types should be established according to the planned procedure, the risk of COVID-19 infection of the patient, and the outbreak situation of the community.

In 2018, the Clinical and Laboratory Standards Institute (CLSI) revised ciprofloxacin (CIP)-susceptible breakpoint for Enterobacteriaceae from ≤1 μg/mL to ≤0.25 μg/mL, based on pharmacokinetic-pharmacodynamic (PK-PD) analysis. However, clinical data supporting the lowered CIP breakpoint are insufficient. This retrospective cohort study evaluated the clinical outcomes of patients with bacteremic urinary tract infections (UTIs) caused by Enterobacteriaceae, which were previously CIP-susceptible and changed to non-susceptible. Bacteremic UTIs caused by Enterobacteriaceae with CIP minimal inhibitory concentration (MIC) ≤ 1 μg/mL were screened, and then patients treated with CIP as a definitive treatment were finally included. Patients in CIP-non-susceptible group (MIC = 0.5 or 1 μg/mL) were compared with patients in CIP-susceptible group (MIC ≤ 0.25 μg/mL). Primary endpoints were recurrence of UTIs within 4 weeks and 90 days. A total of 334 patients were evaluated, including 282 of CIP-susceptible and 52 of CIP-non-susceptible. There were no significant differences in clinical outcomes between two groups. In multivariate analysis, CIP non-susceptibility was not associated with recurrence of UTIs. CIP non-susceptibility based on a revised CIP breakpoint, which was formerly susceptible, was not associated with poor clinical outcomes in bacteremic UTI patients were treated with CIP, similar to those of the susceptible group. Further evaluation is needed to guide the selection of definitive antibiotics for UTIs.

Back ground. Asymptomatic/mildly symptomatic coronavirus disease 2019 (COVID-19) patients produce a considerable amount of virus and transmit severe acute respiratory syndrome virus 2 (SARS-CoV-2) through close contact. Preventing in-hospital transmission of SARS-CoV-2 is challenging, since symptom-based screening protocols may miss asymptomatic/mildly symptomatic patients. In particular, dental health workers (HCWs) are at high risk of exposure, as face-to-face contact and exposure to oral secretions is unavoidable. We report exposure of HCWs during dental procedures on a mild symptomatic COVID-19 patient. Methods. A 32-year old male visited a dental clinic at a tertiary care hospital. He experienced mild cough, which started three days before the dental visit, but did not report his symptom during the entrance screening. He underwent several dental procedures and imaging for orthognathic surgery without wearing a mask. Seven HCWs were closely exposed to the patient during dental procedures that could have generated droplets and aerosols. One HCW had close contact with the patient during radiologic exams, and seven HCWs had casual contact. All HCWs wore particulate filtering respirators with 94% filter capacity and gloves, but none wore eye protection or gowns. The next day, the patient experienced dysgeusia and was diagnosed with COVID-19 with high viral load. Results. All HCWs who had close contact with the patient were quarantined for 14 days, and polymerase chain reaction and antibody tests for SARS-CoV-2 were negative. Conclusion. This exposure event suggests the protective effect of particulate filtering respirators in dental clinics. The appropriate personal protective equipment for routine patient care during COVID-19 pandemic should be established. The appropriate personal protective equipment for routine patient care during COVID-19 pandemic should be established.

Background: A limited number of studies have explored the association between rheumatoid arthritis (RA) and heart failure (HF) based on HF subtype (ischemic and non-ischemic) and RA serostatus. Objective: This study aimed to examine the association between RA and incident HF, considering serostatus (seropositive RA[SPRA], seronegative RA[SNRA]) and HF subtype. Methods: This retrospective cohort utilized nationwide population data from the National Health Insurance Service (NHIS) of Korea. The study analyzed 46,975 RA patients (33,424 SPRA, 13,551 SNRA) diagnosed in 2010–2017, along with 140,925 matched non-RA controls. Results: The RA patients had a higher risk of overall HF (adjusted hazard ratio (aHR) 1.97, 95% confidence interval (CI) 1.68–2.32), and risk was more prominent for ischemic HF (aHR 2.24, 95% CI 1.86–2.71) than non-ischemic HF (aHR 1.36, 95% CI 0.97–1.90). Compared with controls, the risk of overall HF was increased in both SPRA (aHR 2.13, 95% CI 1.78–2.55) and SNRA (aHR 1.59, 95% CI 1.19–2.11), with a non-significant trend toward a higher risk in SPRA than in SNRA (aHR 1.35, 95% CI 0.99–1.83). For non-ischemic HF, the risk was increased in SPRA (aHR 1.60, 95% CI 1.12–2.28) but not in SNRA (aHR 0.71, 95% CI 0.32–1.51); however, this finding was based on a small number of events. Conclusions: This study demonstrates that RA was significantly associated with an increased risk of overall and ischemic HF, with a non-significant trend toward an increased risk of non-ischemic HF. The increased risk of ischemic HF was observed in both SPRA and SNRA, whereas the difference in non-ischemic HF risk by serostatus should be interpreted with caution due to the small number of events.