Overview: A pandemic-informed look at the Philippines’ respiratory virus surveillance
The April 2023 evaluation provides a comprehensive, mixed-methods assessment of the Philippines’ surveillance systems for COVID-19 and other respiratory pathogens. Conducted across national, regional, and local levels, the study examined six surveillance streams—COVID-19 case-based surveillance, traveler screening, SARS-CoV-2 genomic surveillance, influenza-like illness (ILI) surveillance, severe acute respiratory infection (SARI) surveillance, and an RSV sentinel pilot. The goal was to identify practical opportunities for sustainable, multisource surveillance that can adapt to evolving epidemiology while reducing burden on health systems.
What was evaluated and where
The evaluation encompassed systems designed to detect, report, and analyze person, place, and time patterns of respiratory virus transmission. Regions CAR, EV, and NCR served as purposive sites to reflect geographic and administrative diversity. Data collection tools captured system structure, data flows, and outputs, while qualitative interviews explored usefulness, acceptability, and challenges. The research team also analyzed data quality indicators such as completeness and timeliness to understand performance under post-pandemic conditions.
Key surveillance systems and upgrades
Following the COVID-19 surge, the Philippines expanded and upgraded its surveillance architecture. New information systems—Tanod-KontraCOVID (TKC) and the Epidemic-prone Disease Case Surveillance Information System (EDCS-IS)—replaced earlier platforms, with PIDSR-IS and other legacy tools continuing in use. Universal COVID-19 surveillance remained active during the evaluation, alongside sentinel networks for ILI and SARI and a pilot RSV system. These layers reflected a shift toward integrated respiratory virus surveillance, balancing rapid reporting with broader laboratory-based testing and genomic insights.
Performance highlights and challenges
Timeliness and data quality: COVID-19 case-based surveillance showed the fastest turnaround (median 3 days from symptom onset to reporting lab results). In contrast, sentinel systems exhibited longer lags (ILI: ~14 days; SARI: ~20 days; RSV: ~19 days). Completeness varied by system, with high data availability for basic demographics but gaps in other variables, particularly for non-COVID systems and laboratory results in passive reporting streams. RSV data were more complete, reflecting a tightly managed sentinel approach.
Geographic reach and representativeness: Sentinel sites varied by region, and catchment areas were not standardized, complicating direct burden comparisons. Regions with high COVID-19 counts did not always align with high ILI or SARI counts, underscoring how sentinel intensity, site distribution, and reporting incentives shape observed patterns rather than true disease burden alone.
Systems and workforce: Interoperability gaps among multiple information systems created duplicative workflows and data silos. Staff reported heavy workloads, constrained resources, and reliance on ad hoc solutions (Google Sheets, WhatsApp, etc.). While commitment remained high, staff turnover and short-term contracts threatened sustainability.
Laboratories, sequencing, and laboratory capacity
Testing capacity expanded rapidly, with a marked rise in PhilHealth-accredited SARS-CoV-2 labs and national sequencing capacity. Timeliness of genomic data improved, enabling lineage tracking, but in-country bioinformatics capacity lagged behind, limiting rapid interpretation of sequencing data for public health action.
Pathways to a sustainable, integrated model
The evaluation recommended two phases: (1) right-size universal COVID-19 surveillance by trimming case reporting, strengthening sentinel networks, and integrating information systems; and (2) planning for an integrated model that consolidates influenza, SARS-CoV-2, and RSV data into a single framework. Emphasis was placed on harmonizing data tools, standardizing reporting, and consolidating testing algorithms to reduce staff burden and improve data quality.
Implications for policy and practice
Transitioning away from an emergency, all-hands-on-deck approach toward a focused, sentinel-led model will preserve workforce capacity and essential capacities in molecular testing and sequencing. The report advocates targeted traveler screening, scaled-back universal case reporting, and robust monitoring of sentinel sites with regular data quality audits. Harmonized systems and clear stakeholder roles are central to enabling rapid, accurate public health responses to respiratory threats in the Philippines and beyond.
Limitations and broader context
Limitations include non-representative national sampling and incomplete sub-national data, reflecting the real-world complexity of evaluating rapidly evolving public health systems in a post-pandemic setting. Nevertheless, the findings offer transferable insights for countries pursuing integrated respiratory virus surveillance with sustainable staffing and interoperable information systems.
