Outbreak Reporting in IDSP: Triggers, RRT and Weekly Outbreak Reports

What counts as an outbreak

IDSP training material gives two working definitions:

• The paramedical staff manual: "occurrence of a disease or illnesses of similar nature occurring in greater number than normal expectation". A single case of a rare disease, such as plague or polio, may qualify.
• The IHIP Event Alert and Outbreak Investigation manual gives a field definition: "two or more epidemiologically linked cases of a disease of outbreak potential".

An epidemic is similar but "covers large geographic areas and has more than one focal point", according to IDSP Module 8. Clustering of cases or deaths in time or place is a warning sign. The paramedical manual says clustering from the same locality should be phoned to the District Surveillance Officer (DSO). More terms are in our public health glossary.

Trigger levels: when to raise the alarm

A trigger level is a threshold that starts a response. IDSP describes levels from 1 (suspected outbreak) to 5 (disaster). The examples below come from Module 5 of the older IDSP training manual for State and District Surveillance Officers ("Case Definitions of Diseases & Syndromes Under Surveillance"). This is older training guidance; check whether your state uses updated thresholds.

Several of these signals (fever, diarrhoea, jaundice, AFP) match syndromes on the S form, so health workers at sub-centre level may be the first to notice. See the S form guide and the IDSP diseases list.

The early warning signal (EWS) format

IDSP's "Format for instantaneous reporting of Early Warning Signal / outbreaks" is meant to be sent "as soon as it is detected". It opens with one question: "Is there any unusual increase in Cases/Deaths or unusual event in any area? Yes/No". The fields include:

• Disease or syndrome, marked Provisional or Confirmed
• Area affected and population
• Number of cases and deaths
• Date of start
• Lab results
• Control measures, including whether the RRT investigated
• Present status

The format says the State Surveillance Unit (SSU) must "report instantaneously as well as weekly compilation on every Monday to the CSU including NIL reports". NCDC also says "Nil reports are also required". The week used is the Monday to Sunday IDSP week, explained in our reporting schedule guide.

How an outbreak moves through IHIP: step by step

In our reading, the IHIP Event Alert works as the online counterpart of the paper EWS format. Based on the IHIP Event Alert and Outbreak Investigation Manual (v3.0) and the SSO manual:

1. Spot the signal. A health worker, MO or lab notices unusual cases or deaths, or a trigger level is crossed.
2. Phone the DSO. The paramedical manual says clustering should be phoned to the DSO. Do not wait for the weekly cycle.
3. Raise an Event Alert. The Event Alert Form can be raised by health workers through the IHIP mobile app, and by MOs, IDSP nodal officers and district, state or national users on the official IHIP portal.
4. Assign the RRT. The DSO picks RRT members in IHIP.
5. Investigate in the portal. Outbreaks are initiated and investigated in IHIP by the RRT.
6. Control and update. Control measures and status are updated as the response goes on.
7. Close it properly. An outbreak can be marked "Completed" when there have been no new cases for twice the incubation period after the last onset.
8. Publication. States and UTs report responded outbreaks, which appear in NCDC's weekly outbreak report.

For using the app in the field, see our IHIP app guide.

The Rapid Response Team (RRT)

Rapid Response Teams exist at national, state and district levels, according to the NCDC newsletter (2023). An RRT investigates rising illness "to diagnose and control the outbreak". IDSP Module 8 names the core members as an epidemiologist, a clinician and a microbiologist; that 2008 module called the team DEIT. In IHIP, the DSO selects RRT members for each outbreak.

If you are a health worker, your help in an RRT visit can include local knowledge: households affected, dates of onset and contacts, shared without exposing patient identities outside the official system. Our IHIP user roles page explains who does what.

The weekly outbreak report and its columns

NCDC publishes a "WEEKLY OUTBREAK REPORT", subtitled "Disease Alerts/Outbreaks reported and responded to by States/UTs through Integrated Disease Surveillance Program (IDSP)". Its columns are:

For example, the report for the 49th week of 2025 (1 to 7 December 2025) listed 41 outbreaks.

Outbreak numbers, 2020 to 2026

NCDC says about 40 outbreaks reach the CSU each week. Media also play a part: the Media Scanning and Verification Cell, set up in July 2008, had scanned 15,746 media alerts up to 31 August 2026. These figures do not by themselves show whether disease rose or reporting improved.

Helplines: what is current and what is old

The older paramedical manual mentions a 24x7 IDSP call centre on toll-free 1075. That number is now widely used as the national health helpline, and we could not verify that it still routes to IDSP. The IHIP manuals list 1-800-180-1104 as the IDSP Helpdesk, but that is for technical portal problems, not outbreak alerts, and it was not verified as live in 2026. For outbreaks, the reliable route is your MO and DSO.