Scientists from the Faculty of Pharmacy of the University of Granada have demonstrated that the waters and aerosols from the wastewater treatment plants (WWTPs) in Granada Province, in which the genetic material of the SARS-CoV-2 Coronavirus has been detected, do not generate a notable incidence of the virus among WWTP workers
Researchers analyzing 134 workers from 76 WWTPs in Granada Province have identified the same level of antibodies (IgG and IgM) against Coronavirus as that generally observed in the general population
Researchers from the Faculty of Pharmacy of the University of Granada (UGR) have demonstrated that the SARS-CoV-2 Coronavirus is not transmitted via wastewater, suggesting that there is no faecal–oral transmission of the disease (the process whereby a disease is transmitted through the faeces of an infected person).
In a study published in the International Journal of Water Resources Development, the scientists show that the waters and aerosols from the wastewater treatment plants (WWTPs) in Granada Province, in which the genetic material of the SARS-CoV-2 Coronavirus has been detected, do not generate a notable incidence of the virus among WWTPworkers.
“This indicates that both WWTP workers and the populations living close to the plants do not carry any additional risk of catching the virus, because the sample registered an incidence of antibodies (both IgG and IgM) no higher than the level observed in the general population,” explains Maximino Manzanera Ruiz of the UGR’s Department of Microbiology, the main author of this work.
During the treatment of wastewater, the nucleic acids of SARS-CoV-2 have been detected. Together with the aerosols that are generated, these represented, in theory, a high risk for WWTPworkers and for residents of the areas surrounding the plants.
Through a comparative seroprevalence study during the third wave of the COVID-19 pandemic in Spain, the UGR researchers identified the same level of Coronavirus antibodies (IgG and IgM) among 134 workers from 76 WWTPs in Granada Province as in the rest of the population.
This analysis included all the WWTPs in the province (except those of the City of Granada), where the greatest incidence of the virus was associated with those areas with the highest population density (such as the Costa Tropical and the Baza-Guadix area). This phenomenon is in line with the results observed in the Spanish national seroprevalence study.
Useful information for vaccination
“These results indicate that the risk of infection through the faecal–oral route is almost nil, under the conditions we studied” observes Manzanera. “These types of studies make it possible to prioritize which professional sectors should be vaccinated before others, because of the greater risk of contagion they face. On the other hand, our research enables the pandemic to be monitored via wastewater without the need to use high bio-safety facilities (such as level 3 or 4 laboratories), which means we can work at a greater number of laboratories and thus achieve better monitoring of incidence levels.” The study also suggests that the virus detected in the wastewater is inactive, perhaps due to the presence of certain other particles.
This study has benefited from the collaboration of: the Junta de Andalucía regional government (and its aid programme in the fight against COVID under project CV20-01559, via the Department for Economy, Knowledge, Business and University); the UGR; the Granada Provincial Council; and private companies Aqualia, Aguas y Servicios de la Costa Tropical de Granada, and VitaNtech Biotechnology.
This research team, together with lecturers from the UGR’s School of Civil Engineering and the company Gis4Tech, is currently designing a more effective method of identifying infected persons through the water sanitation network.
Bibliography:
Muñoz-Palazon, P.R., Bouzas, J., González-López, & M. Manzanera (2021) “Transmission of SARS-CoV-2 associated with wastewater treatment: A seroprevalence study”, International Journal of Water Resources Development, DOI: 10.1080/07900627.2021.1910935
For direct access to the article, click here.
Media enquiries:
Maximino Manzanera Ruiz
Department of Microbiology, University of Granada
Tel.: +34 958 248 324
Email: manzanera@ugr.es
