Influenza (Flu) Surveillance


To understand when and where influenza activity is occurring, to monitor influenza-related illness, outbreaks, hospitalizations, and deaths, and to determine circulating and emerging influenza virus strains.

Key Information

Geographic spread and activity level of influenza in the state, laboratory test results, and influenza-related hospitalizations and deaths. Influenza-like-illness (ILI) is defined as patients with a fever over 100°F with cough and/or sore throat (unless there is a known cause other than the flu).

Collection Period

Data is collected and analyzed weekly throughout the flu season from October to May.

How data are collected The Department of Health has a number of methods for gathering data. This includes gathering reports on the number of patients with influenza-like illness (ILI) from a sample of sentinel physicians and collecting data from hospitals throughout the state. The services of the State Health Laboratory are used to determine the circulating strains of influenza. Additionally, a staff of epidemiologists work with CDC guidance to determine flu activity levels. more

Rhode Island Numbers

No Activity

Last updated: May 24, 2017

Activity is categorized as: No Activity, Sporadic, Local, Regional, or Widespread based on evaluation by the State Epidemiologist according to guidelines established by the Centers for Disease Control and Prevention. more scroll to Category 5)


This data is reported weekly to Centers for Disease Control Prevention by physicians enrolled as "sentinel providers", a group of community-based practices and university health clinics. There are 17 sentinel providers in the 2016-2017 season who report the number and age group of patients with "influenza-like-illness" (ILI) - those with a fever over 100°F, a cough and/or sore throat with no other known cause.


Data are preliminary and will be updated as more results become available.


State Health Laboratory influenza results reported to the World Health Organization (WHO) and the National Respiratory and Enteric Virus Surveillance System (NREVSS) through a secure online website. The weeks are based on the Morbidity and Mortality Weekly Report (MMWR) by the Centers for Disease Control Prevention.