ABSTRACT
To provide optimal cut-off values of anti-Middle East respiratory syndrome coronavirus (MERS-CoV) serologic tests, we evaluated performance of ELISA IgG, ELISA IgA, IFA IgM, and IFA IgG using 138 serum samples of 49 MERS-CoV-infected patients and 219 serum samples of 219 rRT-PCR-negative MERS-CoV-exposed healthcare personnel and patients. The performance analysis was conducted for two different purposes: (1) prediction of neutralization activity in MERS-CoV-infected patients, and (2) epidemiologic surveillance of MERS-CoV infections among MERS-CoV-exposed individuals. To evaluate performance according to serum collection time, we used 'days post onset of illness (dpoi)' and 'days post exposure (dpex)' assessing neutralization activity and infection diagnosis, respectively. Performance of serologic tests improved with delayed sampling time, being maximized after a seroconversion period. In predicting neutralization activity, ELISA IgG tests showed optimal performance using sera collected after 21 dpoi at cut-off values of OD ratio 0.4 (sensitivity 100% and specificity 100%), and ELISA IgA showed optimal performance using sera collected after 14 dpoi at cut-off value of OD ratio 0.2 (sensitivity 85.2% and specificity 100%). In diagnosis of MERS-CoV infection, ELISA IgG exhibited optimal performance using sera collected after 28 dpex, at a cut-off value of OD ratio 0.2 (sensitivity 97.3% and specificity 92.9%). These new breakpoints are markedly lower than previously suggested values (ELISA IgG OD ratio 1.1, sensitivity 34.8% and specificity 100% in the present data set), and the performance data help serologic tests to be practically used in the field of MERS management.
Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Middle East Respiratory Syndrome Coronavirus/immunology , Serologic Tests/methods , Coronavirus Infections/blood , Coronavirus Infections/immunology , Coronavirus Infections/virology , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Sensitivity and SpecificityABSTRACT
BACKGROUND: The International Liaison Committee on Resuscitation (ILCOR) recommends that strategies should be implemented that promote cardiopulmonary resuscitation (CPR) training in the workplace. Non-medical employees at a hospital were therefore trained to conduct basic life support (BLS). Subject background information, test results and survey findings were examined and factors affecting BLS skill acquisition were studied. METHODS: Of 1432 non-medical employees at a hospital trained to conduct BLS, 880 agreed to participate in the survey. The training course consisted of a single session of 3 h of lectures, practice and testing. Skill acquisition was assessed using a 13-item skill checklist and a 5-point overall competency scale. The effects of age, gender, type of job, educational status, a previous history of CPR training and level of subject-perceived training difficulty were examined. RESULTS: According to total checklist scores, subjects achieved a mean (SD) score of 8.66 (3.57). 22.3% performed all 13 skills. Based on 5-point overall competency ratings, 43.7% of subjects were rated as "competent", "very good" or "outstanding". Age (<40 years and >or=40 years) was the only factor that significantly affected skill acquisition (skill acquisition by those >or=40 years of age was poorer than by those aged <40 years). CONCLUSION: Traditional BLS training is less effective in individuals aged >or=40 years.
