Super flu slows down, but the reason is holiday-related: 'It will soon be back on the rise'

The super-flu, fuelled by the K variant, seems to have slowed down in Italy: there were around 820,000 new cases in the week of Christmas, from 22 to 28 December, a slowdown compared to the 980,000 infected the previous week. While the total number of Italians who have ended up in bed since the start of surveillance rises to 6.7 million cases. The new RespiVirNet report just published by the Istituto Superiore di Sanità (Iss) may seem surprising, but for experts it is too early to sing victory. Also because the decrease in the total incidence of acute respiratory infections in Italy has a 'physiological' reason, namely the fact that there are fewer reports from family doctors in this period as a result of the reduction in the number of visits during the holidays and also the closure of schools. However, the season promises to be intense and could surpass the record of more than 14 million total cases recorded in Italy in the 2024-2024 season. That this is a super flu is also confirmed by the data coming in from abroad with many cases, many hospitalisations and several deaths: from the USA to England.

The Iss report shows that in the week from 22 to 28 December, the incidence was 14.5 cases per 1,000 patients, compared to 17.1 cases in the previous seven days. The highest incidence was observed, as usual, in the 0-4 age group, with around 39 cases per 1,000 patients. Experts from the Institute's Department of Infectious Diseases point out that the drop is 'more evident in the data from the communities than in the hospital flow. The incidence could therefore rise again, or at least remain high in the coming weeks'. The intensity is very high in Sicily, high in Campania, medium in Piedmont, Emilia Romagna, Tuscany, Marche, Lazio, Abruzzo, Umbria and Apulia, while it is low in all the others. In the same week, both in the community and in the hospital stream, there was a high rate of positivity for influenza in people with respiratory infections, especially in hospitals (22.2% and 50.3% respectively). Surveillance of severe and complicated forms of influenza shows an increase in the number of cases in week 51 (corresponding to the period 16-22 December) compared to the same week in the previous season. The most prevalent subtype among severe forms is A(H3N2), the so-called K-variant. It should be noted that most cases of severe influenza with complications concern unvaccinated persons. As far as the characterisation of influenza viruses is concerned, the proportion of A(H3N2) viruses in the community is much higher than that of A(H1N1) pdm09 viruses. A higher proportion of A (H3N2) viruses is also observed in the hospital stream than of A (H1N1) pdm09 viruses.

"This is a classic drop of every holiday period," warns Fabrizio Pregliasco, director of the School of Specialisation in Hygiene and Preventive Medicine at the University of Milan. 'We remain waiting for the results in the coming weeks. It is possible that we are really on the plateau, on the top of the incidence value, but then the critical moment will be precisely that of the return from the holidays. I am thinking in particular,' the virologist points out, 'of the reopening of the schools. On the other hand, the Iss experts also point out: 'The drop recorded this week could be attributable to the fewer reports made by family doctors during the Christmas week, as is also shown by the fact that it is more evident in the data coming from the communities compared to the hospital flow'. For the specialists of the Department of Infectious Diseases, 'the incidence could rise again, or at least remain high in the coming weeks'. Also for the Roman epidemiologist Massimo Ciccozzi "there has been a small slowdown in influenza, which is physiological, also due to the counts of surveillance systems that slow down during the Christmas holidays. I expect an increase in contagions from the next bulletin, but the important thing is that the vaccinated have much milder symptoms than the non-immunised who, however, are clogging up the emergency rooms. I too have been vaccinated and have caught the flu these days, but the highest temperature I've had is 37.2, and that's thanks to the vaccine, which keeps the symptoms of the disease down'.

Influenza cases are also beginning to stabilise in the UK, but hospitals remain full and health authorities are concerned about the effects of the incoming frost wave. In the country, which was among the first to experience the impact of the super flu, 'hospital admissions still exceeded 3,000 in the week before Christmas,' reads the update released by the National Health Service. Although 'slightly down on the previous week', hospitals 'remain extremely busy, with around 95 per cent of adult beds occupied' and a total of '94,118 patients admitted each day'. In addition to influenza, the NHHS points out, "other winter viruses also continue to circulate, with an average of 707 patients admitted with Covid, while last week 285 patients a day were admitted with norovirus". If 'flu cases have not increased further' it is also 'thanks to the intensified vaccination efforts by NHS staff'. At the moment 'nearly 18.5 million people have been vaccinated against influenza: half a million more than in the same week last year'. Meanwhile, there is a surge of flu cases in the US. The CDC, the US Centres for Disease Control and Prevention, estimates that in the current season - up to 20 December - there have been at least 7.5 million cases, 81,000 hospital admissions and 3,100 flu-related deaths; at least eight children have died. Among the most affected states, the agency cites Colorado, Louisiana, New Jersey, New York and South Carolina. The flow of data from laboratory tests, outpatient visits, hospital admissions and mortality are all increasing. Hospitalisations more than doubled in seven days: more than 19,000 people were hospitalised for influenza during the last monitored week, compared to about 9,900 the previous week. "Severity indicators remain low at the moment, but flu activity is expected to continue for several weeks," the CoC forecast.