Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Asymptomatic Middle East Respiratory Syndrome coronavirus infection using a serologic survey in Korea / 한국역학회지

OBJECTIVES@#The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.@*METHODS@#Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.@*RESULTS@#The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.@*CONCLUSIONS@#The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

The Usefulness of In Vitro Interferon-gamma Assay for Differential Diagnosis between Intestinal Tuberculosis and Crohn's Disease / 대한소화기학회지

BACKGROUND/AIMS: It is difficult to clinically and endoscopically differentiate intestinal tuberculosis (ITB) and Crohn's disease (CD). The aim of this study was to evaluate the usefulness of in vitro interferon-gamma (INF-gamma) assay for differential diagnosis between ITB and CD. METHODS: Sixty patients for whom differential diagnosis between ITB and CD was difficult were enrolled between January 2007 and January 2009. The INF-gamma-producing T-cell response to early secreted antigenic target 6 and culture filtrate protein 10 were measured by T-SPOT.TB blood test in vitro. We evaluated the usefulness of T-SPOT.TB blood test by comparing its results with the final diagnosis. RESULTS: Twenty and forty patients were revealed to be positive and negative in T-SPOT.TB blood test, respectively. Of the 20 patients found to be positive, 12 patients (60%) were finally diagnosed as ITB, 6 patients as CD, and 2 patients as Behcet's enterocolitis. Of the 40 patients with negative results, 38 patients (95%) were diagnosed as CD; one as Behcet's enterocolitis; one as nonspecific colitis; none as ITB. The sensitivity and specificity of T-SPOT.TB blood test for ITB were 100% and 83.3%, respectively. Positive and negative predictive values of T-SPOT.TB blood test for ITB were 60.0% and 100%, respectively. CONCLUSIONS: When differential diagnosis between ITB and CD is difficult, T-SPOT.TB blood test may be a helpful and rapid diagnostic tool to exclude ITB. Prospective large-scaled studies are required for further evaluation of the usefulness of T-SPOT.TB blood test for differential diagnosis between ITB and CD.

2 Cases of Gastric Mucosa-associated Lymphoid Tissue Lymphoma Presenting as a Submucosal Tumor-like Lesion / 대한소화기학회지

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is the most common form of primary extranodal lymphomas. In most cases, it is developed as multifocal and mucosal lesions, and its initial diagnosis is made by biopsy of suspicious lesions on endoscopy. However, when gastric MALT lymphoma afflict submucosal site without typical mucosal lesion, further procedures are necessary for diagnosis, such as endoscopic mucosal resection and endoscopic ultrasonography. We recently experienced two cases of submucosal tumor-like gastric MALT lymphoma. Both cases were without any mucosal lesion. One case was confirmed by endoscopic mucosal resection, and the latter was by wedge resection. Treatment modalities included endoscopic mucosal resection, surgery, H. pylori eradication, and/or chemotherapy. Both cases achieved complete remission until our 18 months' and 16 months' follow up.

Clinical and Endoscopic Characteristics of Acute Hemorrhagic Rectal Ulcer and the Risk Factor of Rebleeding

BACKGROUND/AIMS: Acute hemorrhagic rectal ulcers (AHRUs) are rare and have not been thoroughly studied. This study aimed to assess the clinical and endoscopic characteristics of AHRUs and to determine the risk factors for rebleeding after the initial management. METHODS: Thirty patients who underwent colonoscopy within 48 hours of the onset of hematochezia were consecutively enrolled between January 2004 and December 2007. The patients were divided into a rebleeding group and a non-rebleeding group according to presence of recurrent bleeding after initial management. We analyzed the clinical features, including the underlying disorder, the Karnofsky performance status (PS), the use of anticoagulant or antiplatelet agents, the endoscopic findings, and the methods used for hemostasis. RESULTS: All of the patients were elderly, in a bedridden status, and all had experienced the sudden onset of massive, fresh rectal bleeding without pain. The characteristics of the lesions on colonoscopy included solitary or multiple rectal ulcers, or Dieulafoy lesions located in the distal rectum. There were no differences between the two groups based on mean age, gender, use of anticoagulant or antiplatelet agents, PS, methods of hemostasis, and clinical outcomes. The PT (INR) and endoscopic findings (Dieulafoy types), however, differed significantly between the two groups (p=0.024 and p=0.013, respectively). CONCLUSIONS: When massive hematochezia occurs in bedridden patients with severe comorbid illnesses, AHRUs should be considered in the differential diagnosis. It is advisable to be vigilant for rebleeding in patients with prolongation of the PT (INR) and Dieulafoy-type ulcers on colonoscopy.

Comparison of oral N-acetylcysteine(NAC) and prehydration for preventing contrast-induced nephropathy in patients with renal dysfunction / 대한내과학회지

BACKGROUND: Contrast induced nephropathy (CIN) is an important cause of acute renal failure in patients with renal dysfunction. We investigated whether oral NAC alone was sufficient to prevent CIN to the same extent as hydration in patients with renal dysfunction, and whether these treatments resulted in diffierences in the urinary excretion of nitric oxide, a vasodilator. METHODS: A total of 27 patients with renal dysfunction, who underwent radiographic examination with nonionic and low osmolar contrast, were randomly assigned to receive either NAC (600 mg orally twice daily; N=11) or 0.45% saline hydration (1 mL/kg/Hr; N=16) 12 hours prior to and 12 hours after the contrast procedure. We measured serum creatinine (sCr), fractional excretion of sodium (FENa), creatinine clearance (CCr), and urinary nitrite before and after contrast administration. RESULTS: The mean volume of contrast used was similar in the two groups (100.9+/-54.8 mL vs 114.7+/-38 mL; p=0.43), as was baseline sCr in the two groups (2.31+/-1.59 mg/dL vs 2.18+/-1.41 mg/dL; p=0.98). Treatment did not significantly affect the incidence of CIN, with 18.2% and 12.5% in the NAC group and hydration group, respectively (p=1.0). The urinary nitrite/creatinine ratio (micro mol/mg) was 1.26+/-0.57 and 1.43+/-0.64 at baseline and 48 hours after contrast exposure in the NAC group, respectively, and 0.80+/-0.40 and 1.18+/-0.60 in the hydration group, respectively, which were not significantly different. FENa increased significantly after contrast exposure in the NAC group compared with hydration group (p=0.04) CONCLUSIONS: NAC alone may prevent CIN. When bolus hydration is contraindicated in patients with renal dysfunction, administration of NAC alone may be sufficient.