Wastewater based epidemiology (WBE), widely used during the coronavirus pandemic to detect viral circulation in populations, is now being used in the U.S. to track other infectious diseases: polio and monkeypox, informs CNN.
Sewage surveillance to monitor the incidence and spread of community-wide infectious disease dates back to the 1940s, when it was used to detect the poliovirus. Prior to the pandemic, WBE was best known as a tool to study the consumption of illicit drugs and other chemicals at the community level.
When the COVID-19 pandemic hit, the method was put to practical use to monitor the presence of SARS-CoV-2 RNA in wastewater all over the world, providing an early warning of disease spread in communities. In the U.S., the Centers for Disease Control and Prevention (CDC) launched the National Wastewater Surveillance System (NWSS) in September of 2020.
Another separate initiative, WastewaterSCAN – a partnership of scientists at Stanford and Emory University, life sciences company Verily, and local wastewater and public health officials – aims to “seed a national sentinel system using wastewater that informs public health measures for COVID-19, flu, respiratory syncytial virus (RSV), and monkeypox”, as well as establish infrastructure that will help to be better prepared for pandemics in the future.
Wastewater surveillance can be done at the community level, as well as at the building level, for example a large hotel, a prison, or a hospital. NYC Health + Hospitals, the municipal health care system in New York City, has a wastewater surveillance program in place at its 11 hospitals that tests for coronavirus, flu, polio and monkeypox viruses in samples collected from sewage pipes in the basement of the hospital or from a manhole on the hospital’s campus. The data obtained has successfully predicted changed in disease rates 10-14 days in advance of clinical test results. The data informs efforts toward preventing or treating illness and preparing staff and supplies to meet needs.
As the COVID-19 pandemic wanes down, WBE is proving useful to monitor for virus that are not typically seen in the U.S., such as the poliovirus and the monkeypox virus. Earlier in September, the New York governor declared a state disaster emergency as a result of evidence of the poliovirus circulating in the state, based on wastewater surveillance by the CDC.
Polio vaccines are highly effective against paralytic polio, the severe form of the disease. In the U.S., the last case of polio caused by wild poliovirus occurred in 1979. Last June a case of vaccine-derived paralytic polio in Rockland County (New York) prompted a public health response that included wastewater testing in Rockland and surrounding counties, yielding positive tests for poliovirus, showing evidence of community spread.
According to the CDC, the chain of transmission originated from a person who received the oral polio vaccine abroad, which in rare cases can cause paralytic polio in unvaccinated individuals and thus in the U.S. was replaced by the inactivated polio vaccine in 2000. The vaccine-related poliovirus has recently been detected in wastewater in Israel and the U.K. The authorities are concerned because polio vaccination rates are just 60% in Rockland County. The state disaster emergency declaration increases the availability of resources to expand immunization.
WBE for public health is at a critical moment, the pandemic gave it momentum and the established infrastructure for wastewater surveillance is already helping as an effective public health tool to monitor for other infectious diseases.