Coronavirus disease (COVID-19) technical guidance by WHO Laboratory testing for COVID-19 | Page 5

Laboratory testing for coronavirus disease 2019 (COVID-19) in suspected human cases
Table 1. Specimens to be collected from symptomatic patients and contacts
Patient
Test Type of sample Timing
NAAT Lower respiratory tract Collect on presentation.
- sputum
- aspirate
- lavage Possibly repeated sampling to monitor clearance.
Further research needed to determine effectiveness
and reliability of repeated sampling.
Upper respiratory tract
- nasopharyngeal and
- oropharyngeal swabs
- nasopharyngeal
wash/nasopharyngeal
aspirate
Consider stools, whole
blood, urine, and if
diseased, material from
autopsy
Patient Serology Serum for serological Paired samples are necessary for confirmation with
testing once validated and the initial sample collected in the first week of illness
available
and the second ideally collected 2-4 weeks later
(optimal timing for convalescent sample needs to be
established).
Contact NAAT
Nasopharyngeal
oropharyngeal swabs
and Within incubation period of last documented contact.
(in health-care centre associated
outbreaks or other settings Serology Serum for serological
where contacts have symptoms,
testing once validated and
or where asymptomatic contacts
available
have had high-intensity contact
with a COVID-19 case.
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Baseline serum taken as early as possible within
incubation period of contact and convalescent serum
taken 2-4 weeks after last contact (optimal timing for
convalescent sample needs to be established).