The Leeds Teaching Hospitals NHS Trust

Research and Innovation

ISARIC/WHO Clinical Characterisation Protocol for Severe Emerging Infections


The aim of this study is to collect vital information and samples on those people who have severe Covid-19 symptoms.  This study will assist in understanding the clinical features, response to treatment, transmission and clinical outcomes with the aim of improving clinical management of patients who with severe acute respiratory infections. 

This study has three different elements which will be based on the local resources available and patient preference and incudes a single data, serial data and detailed pathogen collection.


This is a study which is considered a national priority.


Patients will be given standard care based on the LTHT’s current guidelines.   The will have biological samples (such as blood, Covi-19 swabs) and data (such as clinical information, symptoms etc) collected on them.  This trial is important for us to understand more as to how Covid-19 presents, is transmitted and 

Who can participate?

Everyone with severe community acquired pneumonia requiring mechanical ventilation and/or ECMO support, including children and pregnant women.  Patients (or their parent/guardian) will need to be able to provide consent. 

Patient burden

There are three different levels of participation, based on patient preference and local resources.

  1. Collection of patient data and single/limited biological sampling
  2. Collection of patient data and biological sampling every other day until acute symptoms have resolved
  3. Collection of patient data, biological sampling every other day and pathogen swabs

Where possible, the sampling will coincide with clinical management, but sometimes they may occur separately.  Patients will be followed up for six months following their discharge from hospital, either via outpatient or telephone appointments.