World Health Organization (WHO) has issued a report indicating that in the past week the world's genomic laboratories have detected about 140,000 more new cases of covid-19 than in the previous week.

The percentage of the omicron variant rose from 0.1% to 1.6% in just seven days, according to the study by GISAID, which works with the WHO.

Another aggravating fact, which prevents the sequencing of cases, is that only a small proportion of covid-19 cases - one in 40, according to the WHO - are analyzed in the laboratory.

Even though most new infections (96%) will still be of the delta variant, dominant in 2021, omicron has a "very high" associated risk, the WHO notes.

At first, omicron cases were travel-related, however, the WHO says that community transmission is responsible for the increasing number of cases, with the new variant already in 106 countries.

The current situation "is characterized by the predominance of the delta variant, the decline of the alpha, beta and gamma variants, which have been circulating at very low prevalences for several weeks, and the emergence of the omicron variant," the WHO notes.

Data on the clinical severity of omicron "remain limited," the WHO acknowledges, insisting that it is not possible to say whether omicron produces more or less severe covid-19 infections. But it is possible to see that there has been an increase in hospitalizations in countries where its prevalence is high, giving this variant the ability to put worrying pressure on health systems.