Omicron dominates streets but is anecdotal in hospitals

Santa Coloma de GramenetThe Omicron variant causes practically all infections in Catalonia but its presence in hospitals is still anecdotal, especially in intensive care. In the Vall d'Hebron laboratory, for example, 93% of the samples analysed from primary care centers (CAP) show that the mutation that emerged in South Africa has replaced the delta variant in the streets, but this change is not reflected in the admission areas, at least for the time being. None of the critically ill patients currently treated at the Barcelona centre has been infected with Omicron and only one in four patients on regular wards has it. "This means that 100% of critically ill patients are infected with the delta variant, despite the fact that omicron is already the dominant variant," José Manuel Domínguez, deputy director of care at Vall d'Hebron, explained to ARA.

In Catalonia, the Omicron variant has become dominant in a matter of weeks and has caused an unprecedented outbreak of infections that has coincided with the Christmas holidays. Between December 26 and January 1 alone, 134,000 positives have been declared, more than 19,000 per day on average, and this figure is not yet definitive. Despite the boom in cases, early studies suggest that this mutation is milder than previous versions of covid because it does not affect the lungs. This Wednesday, the Secretary of Public Health Carmen Cabezas spoke along these lines, although the current rampant volume of cases in Catalonia increases the vulnerability of the elderly (especially those who have not received a booster vaccine) and, therefore, increases risk. This Wednesday there are 1,856 covid patients (60 more in a single day) and 468 patients in critical areas (7 less), and although the numbers of hospitalisations are similar to those of previous waves, they are low and growing more slowly than the number of infections.

According to Cabezas, currently, for every 1,000 infections, nine people are hospitalised and two are admitted to ICU. When the Delta variant was dominant, 26 people were admitted to the ward (three times as many) and four to intensive care (twice as many). However, covid patients make up half of the patients at Germans Trias i Pujol Hospital in Badalona and represent more than 70% of the patients in the ICU. At the moment, most of them are affected by the delta variant.

"On the ward there are some patients with omicron, but their presence is anecdotal," the head of the hospital's intensive care medicine department, Pilar Ricart, confirms. However, the specialist believes that these days it is too early to draw conclusions because the impact of New Year's Eve is still unknown. "We don't know how many of these patients could end up in an ICU bed in ten days, nor if they will be milder cases, without pneumonia," she points out.

Half of those admitted are unvaccinated

Ricart points out that the average age of patients admitted for covid is around 60, while mortality (124 deaths in the last seven days) is slightly higher, up to seventy. In hospitals, half of those admitted for covid have not been vaccinated. "The rest have received the second dose over six months ago or have not yet received a booster vaccine and were vaccinated with AstraZeneca or Janssen [whose protection wears off faster]," she said

According to Cabezas, receiving the booster dose reduces by 15 the risk of entering ICU and by 7 the chance of being admitted to hospital. "Getting the booster dose when it is due greatly increases the probability of avoiding hospitalisation," he says, noting that a British government study confirms that protection 14 days after the third dose increases to 88% and stagnates at 52% among those who do not receive it.

In addition, omicron also increases the risk of reinfection. According to studies conducted in the United Kingdom and South Africa, there is a five-fold increase in the likelihood of re-infection if exposed to the new variant. The Department of Health has reported that during the entire pandemic 28,402 reinfections out of 1.4 million covid cases, or 2% of confirmed cases, have been recorded, half of which were caused by the Omicron variant. Currently, 8% of cases in the under-50s and 5.25% of those among the over-50s of age are reinfections. Cabezas also specified that 330 Catalans have had covid three times and that there is evidence that one person has been infected up to four times.

Peak of contagions

The fact that Omicron, much more transmissible, is the dominant variant and represents virtually all cases causes an enormous impact on primary healthcare centres, which on Monday made 75,595 virus-related visits. "These are record figures that had not been seen in any previous wave," said Cabezas. And this high transmissibility and the fact that the variant partially escapes vaccines in asymptomatic or mild cases fully impacts the workforce. Right now, 3.38% of healthcare professionals are on sick leave due to covid infection, many of whom have been identified with periodic tests and were asymptomatic. Their infection rate is no higher to that of the community as a whole.

Cabezas admitted that a "certain stabilization" is beginning to be seen in the infection data, but also warned that it is necessary to wait for the effect of New Year's Eve. "Some indicators would point to the fact that we are not going up as much, but we have to wait. Until January 10 we do not believe that we will see the peak of infections", said the secretary. In fact, cumilative incidence in Catalonia is very high, with 1,718 cases per 100,000 inhabitants. Currently, the most affected age group is between 30 and 49 years of age (2,028 cases), a group that has not yet begun to receive the third dose.