ARI Acute Respiratory Infection CDC Centers for Disease Control and Prevention, Atlanta Ct Cycle threshold GIP Global Influenza Programme GISRS Global Influenza Surveillance and Response System ICD International Classification of Diseases ILI Influenza-like Illness NIC National Influenza Centre NICD National Institute for Communicable Diseases PHE Public Health England QCMD Quality Control for Molecular Diagnostics RSV Respiratory Syncytial Virus rRT-PCR real-time reverse transcription polymerase chain reaction SARI Severe Acute Respiratory Infection United Kingdom United Kingdom of Great Britain and Northern Ireland USA United States of America WGS Whole Genome Sequencing WHO World Health Organization WHO regions: AFR African Region AMR Region of the Americas EMR Eastern Mediterranean Region EUR European Region SEAR South-East Asia Region WPR Western Pacific Region