In a region full of tourists and with the beaches still crowded, the flu was already around in August, poised to hit mostly children and teenagers. While the count of the first cases of “Australian” registered in our country continues, this unusual scenario emerges from Puglia: between 14 and 31 August last, an outbreak of flu developed in the Tacco of Italy capable of affecting the territory almost in its entirety.
There were 19 cases detected by molecular swab. For 18 of these, the infection was H3N2, the strain that began to circulate in the cold season in Australia (hence the name given to seasonal flu), which in Italy was sequenced for the first time in late August from Hygiene Laboratory directed by Professor Giancarlo Icardi of the San Martino Polyclinic in Genoa. In another of the cases examined, however, the white coats recognized the presence of A / H1N1, the form of the virus that emerged in 2009 in Mexico and responsible for the most serious flu epidemic of the last ten years. But the numbers could be much higher, considering not all people who have had symptoms have been tested.
Covid and flu, a double epidemic on the horizon
by Donatella Zorzetto
In Puglia the flu arrived in August
If in the last two winters the number of infections was limited thanks to the use of masks and distance measures, the next few months could be a real test for the flu. Both in quantitative terms, considering the dozens of cases already reported between Genoa, Bologna and Rome: before this Apulian “iceberg” emerged; both qualitative, because for many of the people affected so far hospitalization has been necessary.
Findings from which it is clear that “the upcoming flu season could be characterized by widespread circulation and greater aggressiveness of infections”, he says. Maria Chironnaresponsible for virological surveillance at regional level and head of the molecular epidemiology laboratory of the university hospital of Bari, where the swabs carried out following an investigation conducted by the doctors of the health and public health service of the ASL were processed of Lecce.
85 patients under examination
Their attention was focused on a group of 85 patients who, between 7 and 17 August (in three groups), had stayed in a sanctuary in nearby Basilicata for a spiritual retreat. Of these, 65 returned with symptoms similar to those of the flu: general malaise, fever, cough, headache, nausea, vomiting and abdominal pain the most frequent. Subjected to swab for Sars-CoV-2 research, coronavirus infection was excluded. Hence the decision to continue the epidemiological evaluation. From 17 further tests carried out on symptomatic people, 11 influenza A / H3N2 infections (in two cases associated with a rhinovirus) emerged. Five more cases were added to the Salento cases, recorded between 22 and 31 August: four of which were children, forced into hospitalization. Plus another, caused by the A / H1N1pdm09 strain.
Influenza, GPs: “Vaccines available from mid-October”
What if it was the tip of the iceberg?
“Considering the total number of symptomatic people, and the fact that many of them did not want to undergo the swab or in the meantime had recovered, the total number of cases of flu could be much higher”, underlines the expert, who starting from these data presented a study together with seven other members of his group and the doctor of the Lecce ASL who coordinated the epidemiological investigation. From which – considering an incubation period between one and four days and the overlap of the samples with those taken from other people who tested positive in Puglia, but not involved in the same trip – it emerged that the first infections would have occurred before departure. To then spread during the stay in Basilicata.
The risk of widespread circulation
There is also another aspect to suspect widespread circulation. “Many of the children affected by the flu virus were forced to hospitalize in various pediatric wards in the region – continues Chironna -. This means that in all probability there were many more infected people in the community, with less severe symptoms”. The analyzed samples revealed that the virus that has been circulating in Puglia for several weeks is very similar to the one expected for the next flu season and not to that observed during the last one. As if to say: what we have seen so far is nothing more than an appetizer of what awaits us.
Australian flu, first cases identified at Bambino Gesù Hospital
The causes of this unusual epidemic
The hypotheses with which to try to explain the peak of influenza cases recorded in Puglia during the summer – the season during which influenza viruses circulate mainly in the subtropical area of the planet – are different. But all connected to each other. What is certain is that the use of prevention measures adopted in the hardest phases of the pandemic – mandatory use of masks, social distancing, hand hygiene – has helped to greatly reduce the impact of influenza in the winter months. And, more generally, it may have broken the patterns of the infectious respiratory disease seasonality we were used to. Not only in Puglia, but everywhere: in Italy as well as abroad. To this there is another aspect to be added, linked to one of the most debated issues of this period: climate change.
“The high temperatures recorded since June have certainly led to live more indoors, with air conditioners on – concludes Chironna -. A choice that could have facilitated the spread of flu viruses, which have found fertile ground especially among more fragile “.
You can also protect yourself from the flu with vaccination
Hence the need to keep our guard up already in this period, thanks to the resumption of the school. And to reiterate the importance of vaccination, at least for all those people to whom it is recommended: among them are children (6 months-6 years) and the elderly. “Vaccination in the coming months will be even more important, especially for those over 65 – he says Alberto Cella, geriatrician and manager of the simple intermediate care structure of the Galliera hospital in Genoa -. After a growing trend from the 2015-2016 to the 2020-21 season, in the last year we have witnessed a significant decline in subscriptions in this target population. Considering the data observed in the southern hemisphere, we must prepare for a particularly aggressive flu virus, which has had time to evolve and which in most cases finds an immune system that has never been solicited in the last two seasons “.