WHO designates RITM-NPL as the Inter-Country Reference Lab for environmental surveillance for poliovirus

Posted on June 30, 2023 by Ma. Patricia M. Lansang

On April 13, 2023, the World Health Organization (WHO) designated the National Polio Laboratory (NPL) of the Research Institute for Tropical Medicine (RITM), as the Inter-Country Reference Laboratory (ICRL) for Environmental Surveillance (ES) for poliovirus in the Western Pacific Region (WPR).

WHO Regional Coordinator Ms. Varja Grabovac assessed NPL last 2022 as a potential regional laboratory for ES in the WPR. Based on the report, the laboratory demonstrated its capability and capacity with complementary human resources to perform the roles and responsibilities of an ICRL, as part of the WHO Global Polio Laboratory Network (GPLN).

WHO recognized the efforts done by NPL in conducting ES in the WPR. During the outbreak of circulating vaccine-derived poliovirus (cVDPV) type 1 from September 2018 until December 2019, NPL supported testing of ES samples from Papua New Guinea (PNG). In addition, it has also successfully conducted laboratory testing of hundreds of samples during the cVDPV 1 and 2 outbreak in the Philippines in 2019 and 2020. This has contributed to the timely and accurate detection of poliovirus even during the COVID-19 pandemic.

As an ICRL of the WPR, the NPL is expected to carry out the following responsibilities:

To conduct testing of sewage samples referred by assigned national laboratories/facilities and from other countries in the WPR using WHO standardized and recommended protocols for ES, virus isolation (VI), and intratypic-differentiation (ITD);
To refer, as per WHO algorithm, all non-Sabin like (NSL) polioviruses, VDPV, PV type 2 and isolates that give discordant or inconclusive results in ITD tests to sequencing laboratory at the National Institute for Infectious Diseases (NIID) in Japan;
To provide reports of ES testing to national partners and WHO in agreed schedule;
To assist network laboratories in addressing laboratory problems that may arise and participate in on-site assessment visits and training of other laboratories;
To provide technical advice by email communication or be available for on-site visit as requested by the country and WHO; and,
To participate in GPLN and RLPN meetings

Over the years, NPL has done significant work in support of maintaining the polio-free status of the Philippines and the WPR. Since its designation as a national reference laboratory in 2017, NPL has been conducting ES with its collection sites in all 17 regions of the country.

*The RITM-NPL Team joins participants and resource speakers from Papua New Guinea for the Hands-on Workshop for Concentration of Sewage Specimens for Environmental Surveillance of Polioviruses in 2018.*

ES plays a crucial role in identifying residual and wild poliovirus (WPV) transmission in endemic areas, particularly WPV circulating among infected individuals not showing signs of paralysis. It is considered as a valuable tool in providing early indication of new poliovirus importations into polio-free areas or of VDPV transmissions.

To date, there are more than 60 countries globally conducting ES in over 1000 sites in all the six (6) WHO regions. In the WPR, there are six (6) countries conducting ES – Australia, China, Japan, Malaysia, Vietnam, and the Philippines.

RITM-NPL is closely coordinating with the WHO for the testing of ES samples from Cambodia, Lao’s People Democratic Republic (LAO-PDR), and PNG as part of the expansion activities on ES in the WPR region.