Seven states have seen a rise in flu cases in the past week as the virus reemerges unusually early.
Covid lockdowns have distorted the flu season, leading to cases starting and peaking earlier than normal over the past two years – with last year’s season starting in October.
Data from the Centers for Disease Control and Prevention (CDC) showed flu infections surged in the Southern and Southwestern areas last week. In Louisiana, the hardest-hit state, admissions rose 50 percent, accounting for nearly six percent of all hospital visits.
Respiratory disease levels were also ‘high’ Alabama, FloridaGeorgia, MississippiNew Mexico and South Carolina, surveillance showed.
By comparison, only New Mexico and Alaska reported “high” flu levels last week.
Nationally, flu hospitalizations rose 50 percent in one week to 8,000 patients admitted since the start of the season. The number of deaths since the start of the season has increased by 48 percent to 490 fatalities.
This map shows flu levels by state. It shows that these were highest in the southern and southwestern regions of the US last week
This map shows flu levels in the US during the first week of November
And this graph shows how the number of people hospitalized with the flu begins to increase as winter approaches
The above shows flu cases in the US, showing that these are also increasing. The dominant type this year is Type A, which generally causes milder disease
The November peak comes before a typical flu season, which normally hits in December or January and peaks in late February.
Experts said this could still be a ‘lockdown effect’ as – after years of being separated by worry – more and more people are behaving as if it is ‘intensely normal’ and making plans to see family and friends.
They also pointed to anecdotal evidence suggesting there are even fewer face masks now available compared to the same time last year.
Flu surveillance relies in part on reports of people with flu-like symptoms going to doctors’ offices or hospitals.
However, many of these patients have not been tested for flu, so their infections have not been confirmed.
It is also possible that patients are infected with another respiratory disease – such as Covid or RSV – further confusing the numbers.
The CDC estimates that 780,000 people have already been infected with the flu and there have been 8,000 hospitalizations and 490 deaths so far this season.
The number of hospital admissions for flu is currently estimated at 1.7 admissions per 100,000 people.
This is above normal levels for this time of year.
In the five years before the pandemic, this rate did not exceed 1.3 per 100,000 for this time of year.
Experts say there may be fewer hospitalizations and deaths because Type A is the dominant strain this year — which typically causes milder infections.
Of the 3,000 flu cases reported to the CDC last week, 71 percent — or 2,144 cases — were caused by type A.
Surveillance also showed flu levels were moderate but rising in New York City, Arkansas, California, Maryland, New Jersey, North Carolina, Tennessee and Texas.
And while flu levels have been high in Alaska for weeks, the state did not report data last week, so it was not part of the latest count.
Alicia Budd, an epidemiologist who leads the CDC’s flu surveillance team, said several indicators showed a “sustained increase” in flu cases.
Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Tennessee, suggested lockdowns could still be behind the early flu season because they brought an “intense normality.”
He told DailyMail.com: ‘People are behaving in an intensely normal pre-Covid way and we don’t see many people wearing masks anymore.
“It has been reported that expected travel around Thanksgiving could set records.
‘This could be influenced by lockdowns, with people being out and about more and now feeling better about the economy and more willing to spend money on travel.
“I think all this traveling indicates that people are looking forward to reunions and gatherings during the Thanksgiving season.”
Dr. Scott Roberts, an infectious disease expert at Yale University in Connecticut, suggested lockdowns could also still be behind the early wave, as they may have weakened people’s immunity.
‘It is possible that we have undergone changes in our immunity to influenza since we have gone a year or more without exposure to the virus in some regions.
‘This essentially led to waning immunity with a year’s catch-up time.
‘The other point is the virus evolution. Is this H1N1 strain the same as before Covid? How much has changed from a pre-Covid genetic level to now? These are questions we need to answer.”
Official data shows that the Covid positivity rate – or the proportion of tests picking up the virus – is no longer falling. This suggests that the number of infections may increase again
Flu was virtually absent in 2020 as virus control measures – such as social distancing and staying home – also stopped its spread.
Cases only started to rise again in late 2021, when restrictions were largely eased and people started socializing more often after being vaccinated.
Last year’s flu season also struck early, arriving in October rather than December or January – which was also suggested at the time due to lockdowns shifting immunity levels and changing movement patterns.
A flu vaccine is currently being rolled out in the US, and is being offered to everyone six months and older.
The latest data showed that about 35 percent of adults had registered for the vaccinations, while 33 percent of children had received the vaccine.
The number of Covid-19 cases is also increasing, surveillance shows. This is a warning sign that the US could be hit by a ‘double whammy’ of infectious diseases.
Wastewater monitoring reported by Biobot suggests that Covid cases are increasing, with the virus concentration rising from 425 to 444 copies per milliliter (ml) of sewage.
The number of hospital admissions due to Covid-19 is also rising: in the week to November 11, the number of admissions was 16,000, compared to almost 15,000 the week before. However, this is still well below the 24,000 recorded in the same period last year.
Cases of respiratory syncytial virus (RSV) are also increasing, with indicators showing that the positivity rate – the percentage of tests that detect the virus – was 14 percent last week, compared to less than 10 percent last month.