Coronavirus disease (COVID-19) technical guidance by WHO Considerations in investigation of COVID-19 cases

Considerations in the investigation of cases and clusters
of COVID-19
Interim guidance
13 March 2020
This document offers operational guidance to Member States for the rapid investigation of suspected COVID-19 cases after an alert
or signal. It is to be used by local, regional, or national health authorities as considerations for investigating cases of COVID-19.
This should not be considered a comprehensive guide to outbreak investigation. Detailed outbreak investigation guidance has been
developed for other respiratory pathogens, including MERS-CoV and influenza. Further information on outbreak investigation for
COVID-19 can be found on the OpenWHO website.
This guidance may be implemented in different countries with varying resources and epidemiological patterns, and should be
adapted accordingly. This document is intended to describe the specific components required to undertake an investigation.
This document is informed by current knowledge of the COVID-19 outbreak and similar considerations for other respiratory
pathogens, including MERS-CoV and influenza viruses. WHO will continue to update these recommendations as new information
becomes available.
Considerations in the investigation of COVID-19 cases
The table below serves as operational guidance for time-sensitive (within first few days of notification) priority actions after the
signal of a COVID-19 case/cluster.
Objectives of the
investigation The objectives of any investigation of a suspected COVID-19 case include:
Composition,
protection of and
tools for the
investigative
team Composition
Personnel with the capacity, knowledge, and authority to:
• Interview persons with suspected COVID-19 and conduct contact tracing
• Triage suspected COVID-19 cases and contacts for health care depending on clinical condition
• Collect respiratory specimens from suspected COVID-19 cases
• Recommend and implement measures to prevent further transmission
•
•
Rapidly detect COVID-19 and any evidence of human-to-human transmission among contacts
Reduce human-to-human transmission, prevent outbreaks, and delay the spread of disease
Protection
The COVID-19 virus is spread through contact, droplet, and fomites. To minimize risk of infection of the
investigation team:
•
•
•
Optimize size of team to minimize contact with a suspected COVID-19 case
Ensure all those in the investigation team are trained in IPC measures specific to COVID-19 1
Interview suspected cases and contacts over the phone, if feasible, or at a distance of more than 1
metre.
Tools
•
•
•
Investigation
case definition
Contact Tracing
•
Provide sufficient and appropriate PPE 2
Gather biological specimen collection material, transport containers, viral transport media, labels,
bags, coolers, and cold packs
Gather copies of case investigation protocols, questionnaires, contact tracing and monitoring
tools, and the national case definition
Adjust national/WHO case definitions 3 for the purpose of investigation (define time, person,
place) for additional case finding and contact tracing (Figure)
Identify all social, familial, work, and health care worker contacts who have had contact 8 with a confirmed
case from 2 days before symptom onset of the case and up to 14 days after their symptom onset. Create a
line list, including demographic information, date of first and last common exposure or date of contact
with the confirmed or probable case, and date of onset if fever or respiratory symptoms develop. The
common exposures and type of contact with the confirmed or probable case should be thoroughly
1