Study samples
The study include archived nasopharyngeal swab (NPS) and oropharyngeal
swab (OPS) samples of the RITM-PNIC in Muntinlupa City, Philippines.
Samples were selected systematically with the number of samples from
each site proportionate to the number of samples collected from children
age (<5y) with influenza-like illness (ILI) or severe acute
respiratory infection (SARI) between January 2006 to December 2016 per
year per site. The sentinel sites were composed of different 17
hospitals and 34 health centers nationwide that were chosen based on
their geographic locations and their capacity to qualify based on the
criteria set by the DOH. Samples were placed in a viral transport medium
(VTM) or universal transport medium (UTM) and stored at the
institutional biobank (-80oC). According to the World
Health Organization (WHO), ILI cases were defined as patients with acute
respiratory illness with cough, runny nose, and/or sore throat with
history of fever (38oC or above) with or without other
system manifestations within the past five days. Meanwhile, SARI cases
were defined by the Philippine Department of Health (DOH) as patients
with an acute respiratory illness that fits the ILI case definition and
requires hospitalization. Specifically, the integrated management of
childhood illness (IMCI) guidelines also included in the SARI
surveillance any child between two months to five years of age suspect
case for pneumonia with cough or difficulty of breathing. For children
with severe pneumonia, any child between two months and five years of
age with danger signs including: inability to drink or breastfeed,
vomits everything, convulsion, lethargic or unconscious, and with chest
indrawing or stridor in calm child .