Thursday, July 7

The ‘Sant Joan effect’ and the delta variant, the cocktail that explains the outbreak of infections in Catalonia

The epidemic is rampant in Catalonia. While waiting to see if hospital admissions increase a lot or a little – vaccination of the elderly population should attenuate serious cases – the infections detected have multiplied by five in just two weeks (from 5,000 to 25,000). Today the incidence in this community is more than double that of the Spanish average, and it especially affects young people. Without being immunized yet, the affectation among twentysomethings – from 20 to 29 years old – is 1,590 cases per 100,000 inhabitants in the last 14 days, something that had not been seen in any wave.

Catalonia will stop performing PCR on contacts who are vaccinated due to the saturation of Primary Care

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At the moment, 17 of the 25 municipalities with a high incidence are Catalan. In third place is Barcelona, ​​the capital, with an incidence of 708 cases. At the top, Sant Cugat del Vallès, one of the richest cities in the community, with 903.

The skyrocketing growth in cases, which began to saturate Primary Care centers at the end of last week, has forced policy makers to back down the escalation: from the outset, nightlife has been closed after fifteen days of opening with reduced capacity. But it has also caused experts and specialists in Public Health to have to re-evaluate what this upward curve responds to and why it has occurred with greater virulence in Catalonia. Among the main reasons is the ‘Sant Joan effect’ (the festivals of June 23, but above all social mobility linked to a four-day long weekend), to which has been added the rapid penetration of the delta variant of COVID- 19, more contagious than the current one.

“The peak of consultations in Primary Care centers occurs exactly when it comes to whether the contagions occur in the surroundings of Sant Joan”, states Enric Álvarez, from the research group in Computational Biology and Complex Systems (BIOCOM-SC) of the University Politècnica de Catalunya (UPC). For this academic, it is evident that during those days risky environments multiplied. Not only the festival of the 23rd at night, but all the social activity that surrounded those days, from the one he went to a disco to the one he took the opportunity to visit several family members, passing through the groups that made getaways together.

Asked about this, the director of the Catalan Public Health Agency, Xavier Llebaria, has also recognized that the explosion of infections coincides on those dates, although he has expanded the focus to other events. “The incidents are obviously related to this, with the end-of-year parties and with the activities related to the social interaction of these stages and age cohorts,” he declared at the press conference in which he gave details about the closing for 15 days of nightlife.

Magda Campins, head of Preventive Medicine and Public Health at the Vall d’Hebron Hospital in Barcelona, ​​exemplifies this with what they have detected in her center. “In the contact studies of patients who have come to the emergency room, many people were clear that they had shared festivals, dinners, meetings … During those days. This has led to many infections,” says this epidemiologist. Catalonia leads the contagions and it does so with a number of daily positives –more than 5,000– that had not been seen since the second wave, in November. These are figures that have overwhelmed the trackers and have made it necessary to adapt the number of antigen tests and PCR that are carried out.

In addition to Catalonia, there are other communities that have also greatly multiplied their infections. The other two autonomous regions that registered an increase of over 300% in the last two weeks are the Valencian Community and the Balearic Islands, two of the main tourist destinations in Spain and where Sant Joan is also celebrated. The fact of being holiday destinations involves a concentration of super contagious events and makes them fertile ground for the spread of the delta variant.

“To travelers coming from the UK [donde la variante delta ya es predominante] They have been asked for a negative PCR for four days, but more controls should have been taken much earlier “, assesses Joan Caylà, epidemiologist and president of the Barcelona Tuberculosis Research Unit Foundation. The Government allowed the entry of British citizens No negative tests until last Friday, shortly after the macro outbreak in Mallorca, when it began to demand them.

For all those consulted, the new delta variant is a determining factor in understanding the exponential growth of infections among the unvaccinated population. According to data offered this Tuesday by the Ministry of Health, the average among the six communities that send information on the variant is that it accounts for around 10% of infections (29% in Navarra). However, in Catalonia the director of the Public Health Agency has reported that the figure in the community is estimated to be already 40% last week.

Dr. Campins, for her part, assures that due to the time it takes to sequence – the data published today corresponds to ten or fifteen days ago – it is very likely that at this time the penetration of the delta variant reaches 60% of contagions. But on the other hand, he refuses to make comparisons between communities, since the results can depend a lot on the percentage of samples.

2% of young people infected

“The situation is dramatic, the numbers are very similar to those of the worst moments of the pandemic,” observed this Monday Joaquín López Contreras, head of infectious diseases at Hospital Sant Pau in Barcelona. Beyond the possible Catalan peculiarities, this doctor recalls that there are other shared factors, such as the feeling of the end of the pandemic that followed the announcement of the removal of masks on the street and the opening of nightlife, just when the vaccination campaign began among the young. “We were all tired of the pandemic and at the time it was decided that a little more activity could be done, many did what they had not been able to do during the entire pandemic,” he explains.

Álvarez, a researcher at the UPC, warns that the peak of infections is yet to come, even more so when the first restrictions – the closure of discos – have been announced this Tuesday for Friday. According to their estimates, the incidence in the 15 to 29 age group in the coming days will exceed 2,000 cases per 100,000 inhabitants in two weeks, that is, up to 2% of the population of this age will become infected “simultaneously” over the next few days.

In addition to decreeing the generalized closure of nightlife –except for activities outdoors or with little capacity–, the Generalitat has also published a new protocol these days to decongest Primary Care, which also denounced peaks in care that prevented them from engaging in other pathologies. For now, it has been decided that they will stop performing PCR on contacts who are fully vaccinated and follow-up calls by trackers will be eliminated. As for the hospitals, they begin to notice the pressure of the plant income. From the Hospital del Mar they assure that the income has tripled and that the average age of the new patients is 42 years. At the moment, the explosion of infections is not yet noticeable in a generalized way in ICUs.