Current epidemiological situation of Middle East respiratory syndrome coronavirus clusters and implications for public health response in South Korea

Since May 20, 2015, when the first case of Middle East respiratory syndrome (MERS) in South Korea was confirmed, the cluster case in South Korea has grown to become the largest observed case following Saudi Arabia within the span of one month. Akin to what was observed in the Middle East, confirmed cases were infected through nosocomial transmission where the cluster is largely limited to patients, healthcare workers, and visitors to patients in healthcare facilities with confirmed cases. A major difference from the outbreaks in the Arabian Peninsula has been the large number of tertiary transmission cases in South Korea, which had reached forty cases by June 12. This observation may suggest that despite the lack of genetic mutation of Middle East respiratory syndrome coronavirus (MERS-CoV) in South Korea, the virus may be behaving differently from that of the Middle East. The higher infectiousness of 'super-spreaders' in South Korea also suggests that this assertion should be under further investigation. Suggestions of inadequate triage in emergency rooms, particularly at Samsung Medical Center which accounts for the most nosocomial infection with 60 cases, have been made by several organizations as the basis for this rapid spread. This, however, does not account for the fact that triage was impossible to implement, since the presence of MERS-CoV in South Korea was unknown during the index patient's stay at the healthcare facilities. This paper aims to identify the key factors in the amplified spread of MERS-CoV in South Korea. The first is the initial failure to confirm diagnosis promptly and to isolate the index case after confirmation of MERS in hospital and the lack of detail in tracking potential exposures in the community of the index case before isolation. The second is the early inadequate measures the Korea Centers for Disease Control and Prevention took in categorizing close contacts. Due to inconsistencies in defining what constitutes close contact, a number of cases were neglected from quarantine and were not subjected to investigation. Finally, confirmed or potential MERS patients were admitted for treatment and observation at medical facilities without adequate disease control measures or rooms, such as ventilated single rooms or airborne precaution rooms. Due to the rigid position that MERS-CoV cannot be transmitted via airborne means, infection control measures has so far neglected evidence that smaller droplets (aerosol) containing the virus can act similar to airborne agents, which may account for the widespread and rapid transmission in a emergency room and a patient's room in hospital. Although the South Korean government expects newly confirmed cases to abate in the coming few weeks, without stringent implementation of clearly defined guidelines to control further transmissions, the cessation of the current trend may continue for an extended period. Additionally, due to the high infection rate of super-spreaders in South Korea, efforts to screen for potential super-spreaders and a thorough investigation of those confirmed to be super-spreaders should be done to quickly identify source of infection, to potentially lower the number of secondary, tertiary transmissions and prevent possible quaternary transmissions.

Usefulness of Comorbidity Indices in Operative Gastric Cancer Cases / 예방의학회지

OBJECTIVES: The purpose of the current study was to evaluate the usefulness of the following four comorbidity indices in gastric cancer patients who underwent surgery: Charlson Comorbidity Index (CCI), Cumulative Illness rating scale (CIRS), Index of Co-existent Disease (ICED), and Kaplan-Feinstein Scale (KFS). METHODS: The study subjects were 614 adults who underwent surgery for gastric cancer at K hospital between 2005 and 2007. We examined the test-retest and inter-rater reliability of 4 comorbidity indices for 50 patients. Reliability was evaluated with Spearman rho coefficients for CCI and CIRS, while Kappa values were used for the ICED and KFS indices. Logistic regression was used to determine how these comorbidity indices affected unplanned readmission and death. Multiple regression was used for determining if the comorbidity indices affected length of stay and hospital costs. RESULTS: The test-retest reliability of CCI and CIRS was substantial (Spearman rho=0.746 and 0.775, respectively), while for ICED and KFS was moderate (Kappa=0.476 and 0.504, respectively). The inter-rater reliability of the CCI, CIRS, and ICED was moderate (Spearman rho=0.580 and 0.668, and Kappa=0.433, respectively), but for KFS was fair (Kappa=0.383). According to the results from logistic regression, unplanned readmissions and deaths were not significantly different between the comorbidity index scores. But, according to the results from multiple linear regression, the CIRS group showed a significantly increased length of hospital stay (p<0.01). Additionally, CCI showed a significant association with increased hospital costs (p<0.01). CONCLUSIONS: This study suggests that the CCI index may be useful in the estimation of comorbidities associated with hospital costs, while the CIRS index may be useful where estimatation of comorbiditie associated with the length of hospital stay are concerned.

Three Dimensional Fourier Transformation Constructive Interferencein Steady State Magnetic Resonance Imaging (3DFT-CISS MRI) ofthe Inner Ear in Patients with Sensorineural Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Three dimensional fourier transformation constructive interference in steady state magnetic resonance imaging (3DFT-CISS MRI) allows fast and precise imaging of the inner ear structures and provides excellent cerebrospinal fluid-nerve contrast within the internal auditory canal and cerebellopontine angle. This study was performed to delineate the inner ear structure in patients with sensorineural hearing loss (SNHL) using 3DFT-CISS MRI and to evaluate the correlation between structural abnormality and clinical symptoms of the affected ear. MATERIALS AND METHODS: Fourteen patients with sensorineural hearing loss were studied using 3DFT CISS axial and coronal MRI scans of both ears. We observed the visualization of the inner ear structures and measured them individually. The radiological measurements were analyzed to compare the findings in non-affected ears with those in affected ears of SNHL patients. In addition, the onset of symptoms was also evaluated for any relationship to their MR findings. RESULTS: The inner ear structures including cochlea, semicircular canal, vestibule, and cranial nerve VII, VIII were precisely visualized. There was statistically no difference in the measurements of the inner ear structures between affected and non-affected ears in patients with sudden SNHL. However, statistically significant differences in the width and height of the vestibule were observed in the affected ears between sudden SNHL and idiopathic chronic SNHL. CONCLUSION: 3DFT-CISS MRI allows detailed study of the normal and pathologic inner ears. Therefore, this MR technique can be a useful method as a routine protocol in the study of the inner ear diseases.