Feature: Israeli scientists use waste water samples to track COVID-19

Scientists from Israeli Ben Gurion University of the Negev say the COVID-19 virus can be tracked in waste water and the research findings could be used as a tool to locate outbreak regions.

The researchers from Zuckerberg Institute for Water Research at the university have been taking sewage samples since the outbreak of the pandemic in Israel in March.

Hala Abu Ali, a master's student for desalination and water treatment and member of the team, has been crisscrossing the country's several waste water plants in recent months. Scientists are looking for RNA, the genetic matter of the virus.

"We found a correlation between... the concentration of the RNA virus with the number of the positively tested patients in each area," said Abu Ali.

Waste water plants are divided into various stages of purification of the water until the water can be brought to a level that it can be used again for different purposes.

Samples are taken from each purification stage. Results from the laboratory take about eight hours.

According to the research team, the virus can be found in very high levels when the waste water is at its first stage, straight from the sewage pipes. As the water passes through each purification stage, the presence of the virus decreases.

The Ben Gurion study is not the only one, some other researchers all over the world are trying to determine the survival of COVID-19 in waste water, sewage and drinking water.

According to the World Health Organization (WHO), there is no clear conclusion yet on the matter, but it is believed that the virus can be found in human excrements.

Similar studies elsewhere have demonstrated the same correlation.

"The research is trying to develop a precursor method, this is good but it will not solve the problem," said Prof. Dror Avisar, director of the Water Research Center at the Tel Aviv University.

The goal of many of the studies is to pinpoint outbreaks by monitoring virus levels. One of the greatest challenges of the COVID-19 pandemic is the relatively lengthy period, in which carriers of the virus remain asymptomatic and can therefore spread it amongst the population considerably. This silent transmission is baffling researchers and medical teams around the globe.

"Because (the virus) can be directly detected in the feces even before the symptoms start appearing in the body...it's an early stage warning that you have...it will help us predict if the virus will come back again," Abu Ali told Xinhua.

Sewage surveillance is not new. The presence of disease in waste water has been studied for decades.

Just a few years ago, Israel's sewage monitoring system detected an outbreak of the polio disease which had previously been thought to have been eradicated in the country. The findings led to a concerted effort by the government to increase vaccination rates against the disease.

The WHO has conducted sewage monitoring in several African countries in recent years in order to predict outbreaks of polio. According to researchers around the world, there is a list of pathogens that can be detected in sewage systems.

"If the virus survives in waste water, if it is contagious directly or through animals, the waste water must be treated, otherwise we will find ourselves in an endless cycle of disease spread," Avisar told Xinhua.

As Israel, like other countries, finds itself in a turbulent period between easing restrictions and needing to impose new ones as virus levels fluctuate, sewage surveillance could be an effective tool.

"In the future, waste water treatment plants will be requested to give weekly or monthly samples to the Ministry of Health to be detected for coronavirus," Abu Ali said.

"We can pinpoint the area where there are patients and we can follow all the safety precautions by the Ministry of Health to all the people in the area, whether to be quarantined or tested," added Abu Ali.

The research could be a significant change in how governments formulate policy that allows for relative flow of the economy and routine, while living alongside the virus.

The research is being conducted in cooperation with the Bio-technology department of the Ben Gurion University and with the Israeli Ministry of Health.