Specimen collection, storage, laboratory testing
All respiratory specimens (including participant-collected and
nurse-collected swabs) were transported to refrigerators at sub-district
health centers within 24 hours of collection, kept between 2 – 8 °C
before being frozen in liquid nitrogen tanks below -70 °C, and sent
weekly to the Thai National Institute of Health (NIH) in Nonthaburi.
Respiratory specimens were tested for influenza viruses and RSV with
real-time reverse-transcription polymerase chain reaction test (rRT-PCR)
according to CDC/WHO protocols [15, 16].