Flu Season Update: New K Strain of A/H3N2 Virus Dominates as Cases Surge
The flu curve continues to grow, with the RespiVirNet surveillance system of the Istituto Superiore di Sanità recording over 816 thousand cases of acute respiratory syndromes in just one week. This represents an increase of almost 100 thousand cases compared to the previous week, with over 40% of infections attributable to influenza viruses. Notably, more than half of these cases are due to the new K strain of the A/H3N2 virus, which has become the dominant strain.
Characteristics of the New K Strain
According to the Istituto Superiore di Sanità, based on epidemiological data provided by the World Health Organization (WHO), the new K strain of the A/H3N2 virus has an “evolutionary advantage that increases its transmissibility.” However, it does not currently show “an increase in the severity of clinical manifestations.” Preliminary estimates suggest that the vaccines in use continue to protect against hospitalization, although their effectiveness against the clinical manifestations of the disease is still being assessed.
Age Groups Affected and Regional Variations
Children under the age of 4 remain the most affected age group, with an incidence of 42 cases per thousand inhabitants, triple the rate observed in the general population (14.7 cases per thousand). Regionally, Sardinia and Campania have seen a sudden explosion of flu cases, with incidence rates of 23.61 and 21.07 cases per thousand, respectively, moving from low or medium to very high intensity in just 7 days. Sicily also reports high intensity, with 17.61 cases per thousand.
Conclusion and Reference
As the flu season continues to evolve, it is essential to stay informed about the latest developments and take necessary precautions to prevent the spread of the virus. For more information on the current flu season and the new K strain of the A/H3N2 virus, please refer to the original article Here