Nat’l Polio Lab trains CARAGA, Maynilad on environmental surveillance
Participants of the environmental surveillance (ES) training held via Zoom.

In order to improve environmental surveillance (ES) activities and to orient new members of the ES network, the National Polio Laboratory (NPL) of the Research Institute for Tropical Medicine (RITM) capacitated its stakeholders via Zoom last February 10, 2023 on the ES process flow: planning, water sampling preparation, site sampling, collection and transport of samples, laboratory analyses, and reporting of results.

 “Most of us know that poliovirus may silently circulate without being detected in our human surveillance. However, environmental surveillance has been an effective tool for locating the virus, even if there is no reported case in the community,” said RITM Virology Department Officer-in-Charge Mr. Rex J. Centeno about the importance of conducting environmental surveillance.

Participants of the training include NPL’s partners from Maynilad Water Services, Inc. and CARAGA health units (e.g. local government units, disease surveillance units, public health offices, Centers for Health Development).

Unfolding the ES Process Flow

During the training, the stages of the ES Process Flow were discussed: from media and cell culture preparation, virologic investigation of polio from samples, and to reporting and feedback of data.

NPL staff emphasized that strict adherence to the procedures for the collection and transport of samples is crucial, so as not to compromise the quality of ES samples.

The roles and responsibilities of agencies in the ES network were also highlighted during the training. The primary roles of RITM through NPL is to regularly convene and conduct trainings among stakeholders to continuously improve ES capacities. The NPL is also tasked to report the results of testing directly to concerned agencies.

Partner agencies, on the other hand, should be focused on recommending new sampling sites and designate point persons/collectors of ES samples.

In instances of a polio event or outbreak, NPL shall work hand-in-hand with the following agencies for a multi-sectoral, coordinated, and programmatic response:

  • Department of Health-Epidemiology Bureau (DOH-EB);
  • DOH-Expanded Program on Immunization (DOH-EPI);
  • Department of Environment and Natural Resources-Environmental Management Bureau (DENR-EMB);
  • Regional Epidemiology Surveillance Units (RESus);
  • Environmental and Occupational Health Offices (EOHOs);
  • World Health Organization-West Pacific Regional Office (WHO-WPRO); and
  • Global Specialized Laboratories in Japan
  • Local government offices (PESU, CESU, MESU)

Leveraging a strengthened ES network

Anchored to the guidelines set by WHO for the global eradication of polio, NPL uses a three-pronged approach to stop the transmissions of circulating vaccine-derived poliovirus (cVDPV) and to enhance detection and response through sensitive surveillance.

The three-pronged approach includes 1) building of surge capacity to suppport acute flaccid paralysis (AFP) surveillance strengthening and ES expansion; 2) fast-tracking of establishment and validation of a Quality Assurance System or AFP specimens; and 3) establishing a WHO-accredited sequencing facility.

The first prong concerns the expansion of ES sites to cover “silent” areas in AFP surveillance. Since 2022, the ES network covers all 17 regions in the country, and 60 samples per month. By 2025, the ES network is envisioned to cover 88 provinces/cities, processing 88 samples per month.

In line with the expansion of the ES network, NPL aims to establish ES concentration laboratories in Visayas and Mindanao. The erection of the Mindanao ES laboratory is currently underway, while the preparations for the Visayas ES laboratory is set to commence this 2023.

“What we’re eyeing is that we decentralize the laboratory activities from the National Polio Lab and we will delegate them to our regional partners. One from Luzon, one from Visayas, and one in Mindanao,” said NPL Technical Supervisor Dr. Lea Apostol.

The second prong involves final validation and implementation of new novel oral poliomyelitis vaccine type 2 (nOPV2) detection, pepper mild mottle virus (PMMoV) testing, and detection of other viral pathogens. As per Dr. Apostol, NPL is ready to detect nOPV2 once included in the routine immunization program. For PMMoV, NPL aims to conduct PMMoV detection as internal quality control for laboratory testing and criterion for ES site selection. And as for other viral pathogens, NPL shall begin detecting SARS-CoV-2 in the environment this 2023.

Tracking the source of our poliovirus, SARS-CoV-2, and in the future other viruses in the environment will be an excellent tool for our national government’s evidence-based policies and actions,” said Dr. Apostol.

Lastly, the third prong is focused on strengthening the laboratory capacity of NPL for genome sequencing. As the WHO Regional Reference Laboratory for Environmental Surveillance in the Western Pacific, NPL aims to boost its capacities in genome sequencing to further improve its services and operations. The detection of polio from processing of  samples to shipment of positive samples to Japan may take more or less 35 days. But upon establishment of a sequencing laboratory, the wholelaboratory process may be trimmed down to only 28 days or earlier.

“Indeed, the environmental surveillance network is growing and we will not stop from here. Expanding not only in terms of geographical coverage, but also in viral pathogen testing…with this partnership, I am sure and I think so are you, that a healthier tomorrow for our beloved country can be ascertained,”  said Dr. Apostol in her closing remarks.

by Anel Azel Dimaano