The Australian flu marches ahead of at least a month and a half and has already infected two out of 100 Marches, with peaks in the pediatric range up to 4 years. We are passing the low intensity phase, even if in the last update the threshold had not yet been crossed, and the viral diffusion proceeds with an incidence defined as “rapidly growing”.
These are the data that emerge from the latest report on the ’22-23 flu season drawn up a few days ago by Ars, the regional health agency. An analysis based on the incidence estimates of the Influnet network, made up of 73 “health sentinels”, family doctors and paediatricians active in all the Marches, who monitor the progress of the H3N2 virus through their patients, renamed “Australian” because as it happens every year, considering the early winter, it comes from the other hemisphere.
Patient-0 in Torrette
In the Marches, the first case of seasonal flu had already been intercepted at the end of September by the Virology Laboratory of the United Hospitals of Ancona, on a patient hospitalized in Torrette. From that patient zero to today, according to projections based on real cases ascertained by sentinel doctors among their clients, 31,151 infections are estimated to have already occurred in the Marches since the beginning of the Influnet survey, more than 2% of the population. The calculation is the result of a statistical analysis. The weekly reporting of cases of suspected flu found in sentinel clinics provides data which, compared to the number of patients, allows an estimate of how widespread the flu is in the entire regional population.
And in this phase the spread of the H3N2 virus is rapidly increasing, despite an anti-flu campaign launched by the Marche Region as early as October 18, with 374,000 doses of vaccine available and a network made up of family doctors and 40 affiliated pharmacies.
In the week from 7 to 13 November last, the last analyzed in the report prepared by the Ars, the regional flu epidemic curve remains placed in the epidemic threshold of low intensity, but with rapidly increasing incidence. “The estimated cases of flu syndrome have increased compared to the previous week – reads the report – reaching the value of 13,557”. In the second week of November (the 45th week of the year) there was therefore a sharp acceleration of the viral spread, with an incidence of new estimated cases rising to 9.1 cases per 1,000 assisted. The epidemic threshold in which it passes from low to medium intensity is set by the Higher Institute of Health at 10 and it is assumed that it has already been exceeded, as will emerge from the next report. Already in the week of 7-13 November the incidence of cases in the Marche (9.1) was higher than the national average (6.57 per 1,000 assisted) and our region is among those where a higher incidence of cases is currently estimated, even if other , like Lombardy and Umbria, had already passed the low intensity threshold in mid-November.
The mask effect
Compared to the previous regional epidemic curves, not only those of the last two years depressed by the Covid effect (between prevalence of the Sars-Cov-2 virus, lockdown and masks), the current H3N2 epidemic trend shows values clearly higher than those recorded in earlier in the same period, in line with a trend recorded at national level. In comparison with the flu curves in the Marches of the last ten years, only in 2009 in mid-November (45th week) was there a weekly incidence of cases higher than the current one (it was around 25, with an exceptional peak) while in all the other years the incidence of new cases in this period was around 2 per 1,000 inhabitants.
To reach the viral circulation levels of today (9.1) in previous years (apart from the aforementioned 2009) it was necessary to wait for the weeks between Christmas and New Year’s. This year’s flu curve is therefore progressing 6-7 weeks ahead of the average and currently the age group most affected, as in the rest of Italy, is the 0-4 year olds, which in the Marche in week 7- November 13 recorded an estimated 27 cases per 1,000 patients cared for by pediatricians. The weekly incidence among children aged 5 to 14 is also high (12.6 cases per thousand) while for the over 64s we are still under three cases per thousand.