Global Influenza Surveillance and Response System (GISRS) Information PDF

(2) === Global Influenza Surveillance and Response System (GISRS) ========================================================= GISRS is a global public health network, coordinated by the World Health Organisation (WHO), that monitors and responds to influenza viruses. This system is vital for prevent...

(2) === Global Influenza Surveillance and Response System (GISRS) ========================================================= GISRS is a global public health network, coordinated by the World Health Organisation (WHO), that monitors and responds to influenza viruses. This system is vital for preventing seasonal flu and managing potential pandemics. Data Collection --------------- - **Sources of Data**: GISRS collaborates with more than 140 National Influenza Centres (NICs) and research laboratories worldwide. These centres collect respiratory samples from: i. Hospitals and clinics (routine reporting) ii. Community health settings iii. Laboratories testing for flu and similar respiratory illnesses. - **Types of Surveillance**: iv. **Passive Surveillance**: Healthcare providers report cases of influenza and related illnesses voluntarily. v. **Active Surveillance**: NICs actively collect data by contacting healthcare facilities to ensure consistent data, especially during flu seasons or outbreaks. vi. **Sentinel Surveillance**: Data is collected from a limited number of selected locations (sentinel sites) to observe trends in the population. This helps in monitoring the spread and impact of influenza across different demographics. vii. **Syndromic Surveillance**: Focuses on the early detection of unusual patterns of symptoms (like fever or respiratory distress) to spot potential outbreaks before confirmed diagnoses are available. Data Analysis ------------- - **Trend Identification**: NICs analyse data to monitor which influenza strains are circulating, their prevalence, and potential mutations. This helps in identifying seasonal patterns and geographic spread. - **Vaccine Strain Prediction**: Twice a year, GISRS experts evaluate the collected data to forecast which flu strains are likely to be most common. This predictive work underpins the formulation of the seasonal flu vaccine, which must be prepared months in advance. - **Genetic Analysis**: Laboratories perform genetic sequencing of the influenza virus samples to track mutations, allowing them to detect changes that could make the virus more virulent or resistant to existing treatments. Reporting Mechanisms -------------------- - **Frequency**: NICs send regular reports (weekly or bi-weekly) to the WHO's FluNet, an online platform that displays real-time data on influenza activity worldwide. - **Data Accessibility**: FluNet data is publicly available and provides visualised information on flu trends by region, virus types, and severity. - **Global Coordination**: GISRS data is shared with international health organisations, national governments, and the pharmaceutical industry. This collective data helps align public health policies and production of vaccines and antiviral drugs. Public Health Response ---------------------- - **Annual Vaccine Composition**: GISRS data informs the WHO's biannual decision on which influenza strains to include in the seasonal vaccine. Vaccines are developed several months before the flu season based on predicted dominant strains. - **Outbreak Detection and Management**: By monitoring unusual patterns, GISRS can detect emerging flu outbreaks early. This early warning supports public health interventions like: i. **Awareness Campaigns**: Alerting the public on symptoms and prevention measures. ii. **Quarantine and Travel Advisories**: Issuing guidance to prevent the spread of the virus across borders. iii. **Antiviral Stockpiling**: Ensuring sufficient supplies of antivirals and flu vaccines in high-risk areas. - **International Collaboration**: GISRS collaborates with organisations like the CDC and the European Centre for Disease Prevention and Control (ECDC) to maintain global readiness and share critical information on emerging threats. Challenges and Limitations -------------------------- - **Underreporting**: Not all countries have the resources to conduct consistent surveillance, leading to data gaps. Underreporting can reduce the accuracy of global trends and vaccine predictions. - **Timeliness**: Effective influenza response depends on timely data. Delays in reporting can lead to slower public health responses, impacting the success of control measures. - **Virus Mutation**: Influenza viruses mutate rapidly, and sometimes strains evolve after the vaccine composition is decided. This can reduce vaccine effectiveness, although GISRS works to adjust recommendations quickly in such cases. - **Resource Constraints**: Low-income countries often face limited laboratory and human resources, making it challenging to maintain routine surveillance or respond to outbreaks effectively. - **Data Quality and Accuracy**: Ensuring high-quality data collection and avoiding biases in sampling are ongoing concerns, especially in regions where influenza may not be seen as a high-priority health issue.