Health Calls to Strengthen Polio Surveillance in the Face of Global Increase in Cases | Society

The increase in polio cases worldwide and its detection in non-endemic countries warn health authorities. The Coordination Center for Health Alerts and Emergencies (CCAES) has published an assessment in which he asks to strengthen surveillance systems in the face of a “considerable” probability that the virus will circulate again in Spain. The risk to citizens’ health is, on the other hand, “very low”, due to the high vaccination rates maintained by the country.

Polio went from being to disease close to eradication, cornered in only two countries in the world (Pakistan and Afghanistan), to reappear in places that have not registered cases for decades. It started in 2021 in Malawi, when the virus was first detected in non-endemic countries since 2016; The same year followed Ukraine, and then Mozambique and Israel, which in March reported its first case since 1989. The international alert went off shortly after, when The UK has detected the virus in its wastewater, almost at the same time as New York reported the first case of paralytic poliomyelitis.

Non-immunized children are the main potential victims of this virus, although cases of paralysis increase with age and during pregnancy. First, the threat to vaccinated people is virtually non-existent and the chances of the pathogen causing public health problems in countries with high immunization rates, such as Spain, are considered “very low”. No native cases have been detected in the country since 1988.

The challenge is not to overlook these vaccination levels, which have dropped in other countries: in particular, in areas where traces of the virus have been detected in the United States and the United Kingdom, rates have been below the average for their respective countries. . “These insufficient coverage favors the existence of pockets of susceptible population, which can favor the circulation of the poliovirus”, warns the CCAES.

The agency warns that while there is a circulation of polio around the world, there is a possibility of introducing the disease to Spain. “However, the high quality of the surveillance systems, the high standards of environmental sanitation, the high vaccination coverage and the high ability to detect and respond to poliovirus-related events, support that the associated risk in our country is currently considered very low ”, points out the CCAES.

In any case, the center he directs Fernando Simone recommends taking precautions: “Given the epidemiological situation and the decline in vaccination coverage at international level, and the decrease in the sensitivity of surveillance systems in the last 10 years in our country, it is important to focus on coordination between all the components that are part of the Spanish action plan for the eradication of polio ”.

This plan provides for the updating of the vaccination calendar, especially among children, the strengthening of epidemiological and environmental surveillance systems and the carrying out of training activities among the actors with a role in the system to remember the current situation of polio in the world.

Why is the virus circulating again?

Eradicating a disease is not easy. The human being has achieved it only with smallpoxThanks to the vaccines. The goal was for polio to follow the same fate. Only a few dozen cases a year have been detected, but taking the next step, until their disappearance, is a goal that is now increasingly seen.

In both Pakistan and Afghanistan, fundamentalist groups have violently tried to boycott vaccination, preventing it from reaching the whole world. Furthermore, in countries that have not completely eradicated the disease, a vaccine with an attenuated virus is used, which on very rare occasions can cause real infections.

It is not known how the virus got to the United Kingdom (where, despite being detected in sewage, no cases have been diagnosed) or New York, but it is possible that it was through these attenuated viruses or asymptomatic cases, which are more than 90% of the total. For this reason, despite there are very few patients in the world, the health authorities remain vigilant: detecting one is usually a symptom of uncontrolled transmission of the virus.

As the CCAES warns, a number of events have occurred in recent years that have made it difficult to achieve eradication. “On the one hand, the effects of the covid pandemic have interfered with the ability to detect diseases early and with the development and implementation of vaccination programs. This may have adversely affected the perception of the benefits of childhood vaccination, generating adverse effects in maintaining adequate vaccination coverage. Furthermore, violent acts against vaccination campaigns, as well as the initiation of armed conflicts and increasing political instability in the affected countries, also hinder progress in the eradication process ”.

Europe, which has been a polio-free region for decades, risks losing this status in the near future. It will be a step backwards in the fight against the disease. The good news is that there is a vaccine, a tool to keep it at bay so that it no longer becomes a health problem for citizens.