Lo streptococcus A it is affecting more than in the past. Last winter, circulation began early and this contributed to triggering a very strong explosion of cases, even serious ones.
A study by the Policlinico and Humanitas of Milan discovered two previously unpublished aspects of the bacterium circulated in Milan in the six months between 2022 and 2023with differences compared to the waves of the five years preceding Covid-19.
The Humanitas and Policlinico study
Streptococcus A affected adults more and with much more serious forms than in the past. The greatest increase was observed precisely for “invasive” infections which in the first quarter of 2023 alone reached 34 cases, i.e. approximately triple compared to the average number constantly observed in the same period of the year before the pandemic, which marked a before and after also due to the limitations, which lowered immunity to viruses and bacteria in the population.
Of the 28 cases for which researchers from the two hospitals managed to reconstruct the entire genetic profile of the bacterium (for epidemiological analysis), 11 patients had consequences that put their lives at risk: 5 were saved, but required hospitalization in intensive care, 6 died.
It is a bacterium commonly found in the throat and on the skin which in most cases triggers infections with mild symptoms. One of the most common is streptococcal pharyngitis, but impetigo, otitis media and scarlet fever can also occur. Group A Streptococcus (GAS) is considered the most common cause of bacterial pharyngotonsillitis in school-age children, but it can also affect younger children.
The conclusions of the study
The novelty lies in the fact that this disease has affected “adults” rather than children. The researchers tried to understand which were the most dangerous strains in circulation by trying to discover any transmission chains in Milan where, last winter, several types circulated. From the studio they don’t seem to be there associations with particular places or social groupssuggesting that the bacterium has spread more widely in the community.