Researchers from the University of the Philippines (UP) are positing the use of wastewater-based epidemiology (WBE) to aid with public health. They presented their findings to the public on January 19.

During the COVID-19 lockdowns in 2020, Dr. Caroline Marie Jaraula of the UP Diliman College of Science’s Marine Science Institute (MSI) and Dr. Lyre Murao of UP Mindanao were already conducting water quality research in the Davao region and decided to expand into WBE, or the analysis of biological and chemical markers in wastewater to provide information on public health. Dr. Jaraula and Dr. Murao worked with scientists and researchers from UP Mindanao and UP Manila including Dr. Emmanuel Baja, Dr. Vladimer Kobayashi, Dr. Dann Marie Del Mundo and Maria Catherine Otero. The collaboration resulted in multiple studies that underscore the value of wastewater research in public health surveillance.

Invaluable detection tool for COVID-19

In her presentation of their published study, Multifaceted Assessment of Wastewater-Based Epidemiology for SARS-CoV-2 in Selected Urban Communities in Davao City, Philippines: A Pilot Study, Dr. Del Mundo explained how WBE research can provide effective and faster analysis of community-level COVID-19 infection using fewer resources.

“Clinical monitoring, such as RT-PCR testing, and contact tracing are limited in the early detection or prediction of community outbreaks and can be logistically demanding and expensive when applied to a large population,” Dr. Del Mundo said.

Wastewater samples from six Davao City barangays contained a high volume of SARS-CoV-2 RNA genetic material even though the barangays were classified as having a low risk of COVID-19 transmission and no reports of new infections. The RNA found in the wastewater “may have also come from pre-symptomatic, asymptomatic, or symptomatic individuals who did not self-report to their local health monitoring unit,” according to the researchers.

Otero further elaborated that the virus RNA was detected in 22 out of 24 samples (91.7%) regardless of the presence of new COVID-19 cases in those areas, echoing similar trends in COVID-19 cases reported via standard clinical surveillance. “Danger of reinfection due to wastewater research will not be an issue because the virus is already dead in the water. They can still be detected because of the RNA, but they are no longer infectious,” Otero assured.

Urging government adoption of WBE

The researchers urged the Philippine government to consider WBE as a powerful and cost-effective tool for public health surveillance. 

“Detecting RNA in wastewater could help LGUs forecast what barangay are at risk and may need closer monitoring, rather than a blanket lockdown,” said Dr. Jaraula. “We should consider this as science-based tools to determine which barangay is more susceptible.”

The team has expanded its efforts to look at other possible beneficial uses of WBE. With funding from the Department of Science and Technology Niche Centers in the Regions for R&D (DOST-NICER), they have expanded their work into other areas through the Integrated Wastewater-Based Epidemiology and Data Analytics for Community-Level Pathogen Surveillance and Genetic Tracking (iWAS) Project. 

The team is expected to publish further findings on WBE within the year, and are also looking to conduct similar research in other highly urbanized areas outside of Davao City.