Sri Lanka College of Paediatricians, Family Health Bureau and

World Health Organisation (WHO)- Sri Lanka

5. Case Definition And Diagnosis

5.1. Case definitions

Suspected Case:
A child with acute illness (at least one sign/ symptom, e.g., cough, shortness of breath with/without fever, AND having been in contact with a confirmed or probable patient with COVID-19 infection during the last 14 days,
A child with an acute illness as above is a resident in an area with the high transmission or traveled to an area with high prevalence or arrived from overseas during the previous 14 days before the onset of symptoms
A child with severe acute respiratory illness AND the absence of an alternative diagnosis that fully explains the clinical condition.
However, a high degree of suspicion is important as there are atypical presentations reported in children, particularly in the presence of close contacts or from an area with a high prevalence rate.

Probable Case:
A suspected case for whom RAT or RT-PCR testing for SARS CoV-2 virus is inconclusive.
A suspected case for whom RAT or RT-PCR test could not be performed for any reason.

Confirmed Case:
A child with laboratory confirmation of Covid-19 infection by a positive RAT or RT-PCR irrespective of clinical signs and symptoms.

5.2 Choice of testing for a suspected case
Rapid antigen test (RAT) would be preferred as the first test in symptomatic patients. It is cheap and has a reasonable sensitivity and specificity. It correctly identifies COVID-19 in an average of 72% of people with symptoms than 58% of people without symptoms. It is most accurate when used within the first week after the onset of symptoms).
If the rapid antigen test is negative and still, there is a high index of suspicion of COVID-19, a PCR test should be performed.
A second PCR may be performed in a symptomatic child in whom the initial test was negative to confirm the diagnosis.