A preliminary study conducted by the Chennai Metrowater showed the presence of viral RNA in the samples of sewage water.
According to a source from the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) sewage samples were randomly collected from 5 sewage pumping stations across the city. The samples were tested via RT-PCR which showed the presence of viral RNA.
RNA, or ribonucleic acid, is a molecule similar to DNA (deoxyribonucleic acid) which is essential for life.
“We cross-checked the areas where samples returned positive for the virus with positive cases in the city and found there was a correlation between the two,” adds the source, stating that two areas in the city in which sewage samples were positive were areas where there had been known COVID-19 cases.
However, officials from the state have said that there is no reason to panic as this does not necessarily mean that there is a chance of people contracting the virus in such a manner.
“We had the idea to test samples based on several studies which have already been done worldwide. The World Health Organisation has acknowledged that the virus may be shed in fecal matter and this is why we might be seeing some samples containing viral RNA,” states DPH Dr Kolandaswamy K.
The WHO has stated in a report dated April 23 that though the virus has been detected in sewage systems, there is no evidence that the disease can be spread in this manner. However, it has cautioned that since viral particles have been found, as a precautionary measure wastewater should be well managed.
The Centers for Disease Control and Prevention (CDC) in the US also reiterated this, adding that there is no evidence present for the risk of transmission of COVID-19 in this manner.