Influenza at the Human-Animal Interface: PAHO Recommendations to Strengthen Intersectoral Work for Surveillance, Early Detection, and Investigation, 9 July 2020

Abstract

This document provides a summary of influenza viruses at the human-animal interface. It presents recommendations for surveillance strategies, monitoring, early detection, and steps of general case investigation that should be taken for influenza viruses at the human-animal interface, as well as guidance in their reporting. It is intended as a reference for public health authorities in human and animal sectors who deal with surveillance of influenza viruses. Animal influenza viruses are distinct from human seasonal influenza viruses and have not yet demonstrated the ability to be sustainably transmitted from person-to-person among humans. However, zoonotic influenza viruses (animal influenza viruses that may occasionally infect humans through direct or indirect contact prior to symptom onset) can cause disease in humans ranging from a mild illness to death. If these viruses acquire the capacity to spread easily among humans, either through adaptation or acquisition of certain genes from human viruses, they could trigger an epidemic or a pandemic. When the swine influenza virus infects a human, the term "variant" influenza virus is used and the letter "v" (for "variant") is used after the name of these swine viruses, to distinguish these from human viruses of the same subtype. PAHO/WHO reiterates that all human infections caused by a novel influenza subtype are notifiable under the International Health Regulations (IHR) and that States Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed case of recent human infection caused by an influenza A virus with the potential to cause a pandemic.