Poor agreement between clinical screening and universal pre-procedure SARS-CoV-2 PCR testing prior to endoscopy.

INTRODUCTION: scientific societies recommend screening for SARS-CoV-2 in patients prior to endoscopy. There is no solid evidence regarding the efficiency of universal screening by PCR testing for SARS-CoV-2. The present study aimed to assess the usefulness of clinical screening and universal pre-procedure PCR testing for the identification of patients capable of transmitting the SARS-CoV-2 infection. Concordance between both strategies was also evaluated. METHOD: a retrospective review was performed in a consecutive cohort of patients undergoing endoscopy at a tertiary teaching hospital between April 22 and June 22, 2020, following a screening protocol. RESULTS: three hundred and sixty-one patients were included. Clinical screening detected 13 patients with a high risk of infection (3.6 %, 95 % CI: 2.62-4.58) while the pre-procedure PCR test was positive in five patients (1.40 %, 95 % CI: 0.20-2.60). Three patients developed COVID-19 and one died from the disease. Agreement between both strategies was poor, with a kappa value of 0.093 (95 % CI: 0.001-0.185). Clinical screening only identified one of the five patients with a positive PCR test. CONCLUSION: clinical screening prior to endoscopy has a poor agreement with pre-procedure PCR testing.

[Laboratory diagnosis of Clostridium difficile infection]. / Diagnóstico microbiológico de la infección por Clostridium difficile.

Clostridium difficile is the leading cause of nosocomial diarrhoea in developed countries, and is one of the main aetiologic agents of community diarrhea. The eruption of the hypervirulent strain BI/NAP1/027 has given rise to an increase in the morbidity and mortality of C.difficile infection (CDI). This document aims to review the main clinical pictures of CDI and the laboratory diagnosis, including sampling, transport and storage of specimens, specimen processing, diagnostic procedures, antimicrobial susceptibility testing, and molecular characterisation of the isolates. The main purpose of the article is to develop a practical document that provides answers to the main questions that arise in the laboratory diagnosis of CDI.