Pacific Syndromic Surveillance System

The PPHSN Pacific Syndromic Surveillance System (PSSS) was created as an early warning tool for the Pacific Public Health Surveillance Network. 


In 2010, focal points of the International Health Regulations (IHR) together with PPHSN EpiNet representatives from the Pacific island countries (PICs) formed the PSSS. As a early warning tool, the PSSS becomes part of the WHO emergency surveillance and response (ESR) program that assists countries with strengthening infectious disease surveillance and response systems. The program includes providing technical advice, training, and equipment.

The PSSS collects, collates and reports surveillance data from twenty-three (23) PICs. Its main objective is to strengthen local outbreak response capacity, closely linked to PSSS alerts.

Consult the weekly PSSS reports 

Recent Developments
The following set of actions for the PSSS by PICs since 2010 has allowed for an improved monitoring of indicator infectious disease trends, local epidemics and spreading pandemics:

  1. Appointment of a surveillance officer by each PIC as the PSSS local focal point
  2. Appointment of a central coordinator based in Regional WHO Office in Fiji
  3. Expansion of sentinel surveillance sites within PICs for a wider coverage
  4. Expansion of the syndromic indicator infectious diseases from the four syndromes of acute fever and rash (AFR), diarrhoea, influenza-like-illness (ILI), and prolonged fever (PF) to include acute respiratory infections (ARI), severe ARI (SARI), pneumonia and COVID-19 (see Table 1)
  5. Weekly ESR reporting PICs to the central coordinator for overview and to provide infectious disease early warning alerts
  6. Availability of laboratory testing in country and/or improved accessibility to reference laboratories.
  7. Electronic surveillance through reporting of unusual events of illnesses or diseases in communities (event-based surveillance)

Syndromic Surveillance Data Sources in the Pacific

The PSSS uses existing health systems voluntary participation and cooperation in surveillance in order to provide early warnings of emerging health conditions for the PICs. In surveillance, a syndrome is a set of non-specific pre-diagnosis medical and other information that may indicate a disease outbreak. Syndromic surveillance thus focuses on early event detection: gathering and analyzing data in advance of diagnostic case confirmation to give early warning of a possible outbreak. Such early event detection is not supposed to provide a definitive determination that an outbreak is occurring. Rather, it is supposed to signal that an outbreak may be occurring, indicating a need for further evidence or triggering an investigation by public health officials.

More recently, syndromic surveillance has been expanded to include using ‘existing health data in real time to provide immediate analysis and feedback to those charged with investigation and follow-up of potential outbreaks.’ Moreover, a broader focus on electronic surveillance enables inclusion both early event detection and situational awareness.

Syndromic surveillance in the PSSS is based on data that can come from the following sources:

  1. Indicator-based – i.e., indicator diseases of standard case definitions (see Table 1) that all PICs have agreed to surveil. Surveillance is carried out through sentinel sites tasked to report case numbers and provide laboratory testing material from the cases with the indicator syndromic infectious diseases.
  2. Event-based – i.e., reporting unusual and unexplained occurrences of disease or illnesses or deaths in geographic regions or in human, livestock or animal populations.

Table 1. EWARS indicator syndromes,  case definitions and alert thresholds

SyndromeCase DefinitionAlert Threshold  
Acute Fever and Rash (AFR)  Fever plus rash (non-blistering)1 case if there is a measles outbreak. (for Pacific elimination purpose it needs Verification by laboratory confirmation or exclusion)  
Prolonged fever (PF)  Fever for 3 days or moreTwice the average number of cases seen in the previous 2 weeks    
Influenza-like illness (ILI)  An acute respiratory infection with: measured fever of ≥ 38 C° and cough; with onset within the last 10 days.  Twice the average number of cases seen in the previous 2 weeks  
Diarrhoea3 or more loose or watery stools in 24 hours (nonbloody)  Twice the average number of cases seen in the previous 2 weeks  
Suspected dengueFever for at least 2 days, plus at least two of the following: i. Nausea or vomiting; ii. Muscle or joint pain; iii. Severe headache or pain behind the eyes; iv. Rash; v. Bleeding  Twice the average number of cases seen in the previous 3 weeks  
Severe acute respiratory infection, requiring hospitalisation (SARI)Sudden onset of fever above 38°C, cough or sore throat, shortness of breath or difficulty breathing, and requiring hospitalization.  1 case  
COVID – 19Country-specific case definitions1 case

Alert thresholds (see Table 1) The alert thresholds have been automated and are set in EWARS. Instant email notification is sent once a country has surpassed the alert threshold.

For the additional Indicator diseases below:

  1. COVID-19 threshold one (1) case, and the case definition set to identify suspected COVID- 19 is country specific. COVID-19 suspects including multi-system Inflammatory cases in children (MIS-C). In addition, use the EBS to report details.
  2. SARI The alert threshold for SARI is set at one (1) case to increase sensitivity for its investigation as a suspected COVID-19 case and hence require laboratory confirmation or exclusion.

Report any suspicious condition or event urgently in Event Based form

Key documents

Snapshot of EWARS – Report Manager

More information on EWARS: Structure and functions, management, Sentinel Sites by Country, Global EWARS and PSSS, Algorithm for Infectious Disease Outbreak Investigation, Completeness of Reporting and Utilization of Data, EWARS Reported Data 2016-2021, Human Resource, Tools for the EWARS, Evaluation of a Public Health Surveillance System, Data and Alert Utilization,

Creation of the PSSS: Meeting for the Pacific IHR National Focal Points and PPHSN-EpiNet Representatives on Syndromic Surveillance, Auckland, New Zealand, 23–26 March 2010
Final meeting report

First practical Guide for Implementing Syndromic Surveillance in Pacific Island countries and territories, developed by WHO, SPC and PPHSN members and partners in 2010
in word format (499 KB)