Polio detected in wastewater in the Baix Llobregat region

BarcelonaProfessionals from the Catalan Public Health Agency have detected the presence of poliovirus, known as polio, in the sewage from two wastewater treatment plants in the Baix Llobregat region. The Department of Health has already alerted primary care centers (CAP) and hospitals in case a person with symptoms compatible with the disease comes to the clinic, and they have begun an investigation to try to locate them. Even so, the Secretary of Public Health, Esteve Fernández, emphasizes to ARA that the risk of spread is very low because vaccination coverage is up to 97%.

Polio is a highly contagious disease that primarily affects children under 5 years of age. It is transmitted through contact with water and food contaminated by the feces of an infected person and can cause paralysis, especially in the lower extremities. Last year The presence of this pathogen has already been detected in wastewater from the Besòs River. And the alert was closed without incident, as no infected person or cases of community transmission were identified.

As happened a year ago, during a routine inspection of sewage, professionals detected the presence of an attenuated virus used in the oral vaccine, which is not the one administered in Catalonia. This vaccine is developed with artificially modified viruses in a laboratory to give it the capacity to generate immunity, but it also carries a risk of mutating inside the person's body, gaining the ability to replicate and infect. This is the case with the samples found in Baix Llobregat.

The oral vaccine is used in countries where the poliovirus is endemic because it does not require much preparation or equipment. It also improves herd immunity, as it confers protection to contacts of vaccinated people. This is because the virus modified in the laboratory is capable of infecting other people, but they only generate immunity and do not develop the disease. However, when the virus mutates, it regains its ability to infect other people.

Nevertheless, Fernández insists that Catalonia has high vaccination coverage and good hygiene and sanitary conditions, so the risk of transmission is very low. For now, the department has already notified health centers in case any compatible cases appear and is conducting periodic analyses of sewage to detect more positive samples.