Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. Most people recover from fever and other symptoms within a week without requiring medical attention. However, influenza can cause severe illness or death, particularly among high risk groups including the very young, the elderly, pregnant women, health workers and those with serious medical conditions.

Given the risk to vulnerable groups and the potential for seasonal influenza viruses to cause outbreaks and epidemics, WHO's Health Emergencies Programme monitors and assesses the spread of these viruses on an ongoing basis. 

Influenza surveillance in the Western Pacific Region is based on outpatient and inpatient indicator-based surveillance (IBS) systems, as well as event-based surveillance. Case definitions, population groups and data formats differ among countries. This influenza surveillance summary includes countries and areas where routine IBS is conducted, and information is available.

WHO in the Western Pacific monitors and assesses the spread of these viruses on an ongoing basis publishing a bi-weekly summary of the situation in the Region.

Featured publications

All →
Seventeenth Biregional Meeting of National Influenza Centres and Influenza Surveillance in WHO’s South-East Asia and Western Pacific Regions, Manila, Philippines, 20-22 November 2024

To ensure better and holistic preparedness for the next pandemic, the 17th biregional meeting of NICs and influenza surveillance brought together key stakeholders...

Pandemic influenza severity assessment (‎PISA)‎: a WHO guide to assess the severity of influenza in seasonal epidemics and pandemics, second edition

The updated WHO pandemic influenza severity assessment (PISA) framework set out in this document provides a systematic approach for interpreting data...

Defining access to countermeasures: landscape report 2024

This landscape report on the current status of activities related to medical countermeasures (MCMs) for pandemic response underscores the urgent need...

Status of influenza in the WHO South-East Asia Region – 2023

Influenza – a global public health problemInfluenza is an important cause of global morbidity and mortality, resulting in an estimated 3–5...

Infographics

Other regional surveillance