If we assume that coronavirus does not cause new unpleasant surprises – something that can never be completely ruled out – the sixth wave of the pandemic that is currently subsiding in Spain could be the last, where the health authorities count every single positive case. In any case, this is the intention, as months of work have already been put into searching for a new surveillance system that would make it possible to detect the virus with fewer resources, something that would also lead to a more natural way of living with the virus.
A guard surveillance network of this kind used to monitor influenzais the preferred choice for many public health specialists: it is solid, it has proven to be credible for many years, and Spanish regions have launched pilot schemes to roll it out to all respiratory diseases, including Covid-19.
It consists of a network of primary health care professionals located throughout the country, which covers approx. 2% of the population and whose patients are demographically representative: ie. they treat the appropriate proportion of men, women, seniors and in both rural and urban environments. These doctors collect samples for laboratory analysis from patients with respiratory symptoms, and these data serve as a basis for a kind of study: they can extrapolated to the rest of the population to analyze how each pathogen develops as infections rise or fall. At the same time, hospitals have a similar network that serves to calculate how many of these cases are serious.
Such a monitoring system has everything to its advantage in being used for Covid-19 except for one thing: Not all European countries have one in place. And in order to have standardized databases that can be compared across the EU, it is necessary that they all operate under the same procedures.
Spain is one of the countries that is drives this paradigm shift in Europe. This is something that has been welcomed by the European Center for Disease Prevention and Control (ECDC) as well as some Member States. The debate now, say sources from the Spanish Ministry of Health, is that the new protocol must be implemented across the continent.
The Sentinel surveillance network is still on the table, but if the rest of the countries concerned are not in a situation where they can set it up in time, there will also be an opportunity to put other, less sophisticated options in place. such as extrapolation from hospitalization data to count the number of infections. This monitoring method is much simpler, but it also has a lower capacity to predict waves and is always somewhat backward because only the most severe cases are detected.
La Rioja is one of the Spanish regions currently working on a pilot scheme using a monitoring network for detect respiratory diseases. In addition to influenza, they have included Covid and other viruses, such as respiratory syncytial virus. Eva Martínez, the head of public health epidemiology in the region, explains that the results returned by these tests are very similar to the real cases of Covid-19: a sample from only a small number of doctors is able to measure the waves and their tendencies with a precision similar to that obtained by testing all suspected infections.
In La Rioja, a pediatrician and a general practitioner from each health center participate in this network. They request laboratory analysis of their first five patients on the day with respiratory symptoms. “Epidemiological information is collected from all of them, including clinical characteristics, risk factors, whether they have been vaccinated or not …,” Martínez explains.
From there, they are taken to the laboratory at San Pedro Hospital, where Míriam Blasco Alberdi works as a microbiologist. “We do a PCR and we send the positive samples to be sequenced,” she explains. “In this way, we can check whether there are mutations or new variants. This data is sent to the ECDC and the World Health Organization. In the case of influenza, the information collected by the laboratories of the northern hemisphere serves to design the vaccine for the next season in the south, and vice versa. With coronavirus, if it becomes a seasonal pathogen, something similar will no doubt happen. “