DAVAO CITY—Scientists from state-ran University of the Philippines (UP) urged the government to consider adapting a wastewater-based surveillance system during a pandemic or for other public-health management in order to enhance data accumulation and enable quicker science-based decisions.
The suggestion was an outcome of the research of a team led by Dr. Caroline Marie Jaraula of the UP Diliman College of Science’s Marine Science Institute.
Jaraula was already doing water quality research in the Davao region and decided to expand into wastewater-based epidemiology (WBE), or the analysis of biological and chemical markers in wastewater, in order to provide information on public health.
In the research in 2020 that evolved into multiple studies, when more scientists collaborated with her, it was found out that traces of genetic materials from the ribonucleic acid (RNA) of the Severe Acute Respiratory Syndrome Corona Virus-2 (SARS CoV-2), the virus that causes the Covid-19, were in wastewater samples.
While scientists said the genetic materials were not infectious anymore and that more studies should be conducted on other issues surrounding the result, the scientists believed that “there is potential in the conduct of WBE for monitoring public health across the Philippines,” especially during the Covid-19 and other pandemic diseases in the future.
The research
Researchers said the RNA found in the wastewater “may have also come from pre-symptomatic, asymptomatic, or symptomatic individuals, who did not report to their local health monitoring unit.”
Maria Catherine Otero of UP Manila and one of those who joined the collaboration in the Davao City wastewater research said the virus’s RNA was detected in 22 out of 24 samples (91.7 percent) regardless of the presence of new Covid-19 cases in those areas.
She said this “echoed” similar trends in Covid-19 cases reported through 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 said.
Invaluable detection tool
It was during the first year of the pandemic in 2020, when Jaraula began her research on water quality that soon evolved into a multiple work as other scientists and researchers from UP Mindanao and UP Manila joined and formed a collaboration. They included Dr. Lyre Anni Murao, Dr. Emmanuel Baja, Dr. Vladimer Kobayashi, Dr. Dann Marie del Mundo and Otero.
The team has expanded its efforts to look at other possible beneficial uses of WBE.
With funding from the Department of Science and Technology’s 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.
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 has no report of new infections, the researchers said.
The WBE research is eyed to be expanded to Tagum in Davao del Norte and Digos City in Davao del Sur.
What emerged after the research was the significance of using wastewater-based epidemiology “to aid with public health management.”
“The collaboration resulted in multiple studies that underscore the value of wastewater research in public health surveillance,” the researchers said.
While there was an assurance that the SARS Cov-2 virus may not be infectious anymore, further studies may be needed to address some more issues, including the finding that some of RNA materials were the mutations of the virus.
Otero said there may be a need to improve the equipment of government laboratories to be able to effectively determine the type of variants that mutated.
Del Mundo, Project iWAS leader, said the research, “Multifaceted Assessment of Wastewater-Based Epidemiology for SARS-CoV-2 in Selected Urban Communities in Davao City, Philippines: A Pilot Study,” 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 [reverse transcription-polymerase chain reaction] 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,” del Mundo said.
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 barangays are at risk and may need closer monitoring, rather than a blanket lockdown,” Jaraula said in a news release.
“We should consider this as science-based tools to determine which barangay is more susceptible,” she added.
Image credits: Shedy Masayon, UPD-CS SciComm , Dr. Dann del Mundo