On November 4, 2022, the United States Centers for Disease Control and Prevention (CDC) published their weekly Influenza Surveillance Report for Week 43 (October 23, 2022, to October 29, 2022). With a cumulative hospitalization rate of 2.9/100,000 cases, which amounted to a total of 4,326 patients hospitalized during Week 43, influenza infection and hospitalization rates continue to increase at an alarmingly fast and early rate this year.
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Early and high flu hospitalization rates
As of the publication of this report, over 1.6 million flu cases were reported in the U.S. for the 2022-2023 influenza season. Of these cases, 13,000 patients have required hospitalization and 730 people have died from the flu.
Some of the most affected regions of the U.S. include Southeast and South-Central states such as South Carolina, Tennessee, Georgia, Mississippi, Texas, North Carolina, Alabama, and Virginia. Maryland, New York City, and Washington D.C. are also reporting high levels of influenza-like illnesses at rates that are significantly higher than those reported at the same time last year.
We’re seeing the highest hospitalization rates going back a decade.”
The threat of a ‘triple-demic’
Like the respiratory syncytial virus (RSV), which has also been infecting an increasing number of children at an unseasonably early rate as compared to previous years, influenza cases remained relatively placid throughout the coronavirus disease 2019 (COVID-19) pandemic. This is largely because lockdowns and other preventative measures that were implemented throughout the pandemic prevented many from being exposed to these and other respiratory viruses.
In addition to the already high rates of RSV and flu, COVID-19 cases are also expected to surge this year as a result of the transition of more people indoors and the continual emergence of new escape variants of the causative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Taken together, the circulation of these three viruses this season may lead to a ‘triple-demic,’ which will likely increase the burden on already strained healthcare systems. Despite the added pressure of these new hospitalizations in some states, adequate supplies of personal protective equipment (PPE) and ventilators remain available for their immediate use.
How to protect yourself this winter
The U.S. CDC recommends that all people over the age of six months get vaccinated against both influenza and SARS-CoV-2 viruses.
Current evidence suggests that the influenza vaccine for this year comprises influenza A(H3N2) viruses that are genetically and antigenically similar to currently circulating strains, thus indicating that these vaccines should offer sufficient protection against severe disease and/or infection. An increasing number of influenza A(H1N1) viruses, which are also included in the yearly influenza vaccine, have also been reported nationally.
Similarly, a new COVID-19 bivalent messenger ribonucleic acid (mRNA) vaccine booster dose has been approved for use in anyone over the age of five in the U.S. This booster vaccine dose appears to offer protection against severe disease following infection with both the ancestral SARS-CoV-2 strain, as well as the currently dominant Omicron BA.4 and BA.5 subvariants.
Despite the availability of these vaccines, the uptake this year has been relatively low. In fact, about five million fewer flu vaccine doses have been administered so far this year as compared to the same time last year in the U.S. Similarly, as of October 12, 2022, only about 11.5 million Americans had received the updated COVID-19 booster dose.
In addition to the importance of vaccination against both the flu and SARS-CoV-2, people should also continue to practice good hygiene including frequent handwashing, covering coughs and sneezes, staying home when sick, and avoiding close contact with symptomatic individuals.
Certain antiviral medications are also available to treat patients with severe illness following infection with either of these viruses. Currently, the CDC recommends that anyone with confirmed or suspected influenza infection who is at a higher risk for complications and/or is hospitalized to be immediately administered influenza antivirals. Some of the most common antivirals that may be used to treat influenza infection in the U.S. include oseltamivir or baloxavir.
Similar recommendations have been given for treating patients with suspected or confirmed SARS-CoV-2 infection who are at an increased risk for severe illness and meet current eligibility requirements to receive these agents. Currently, ritonavir and remdesivir have been successfully used to ameliorate mild to moderate COVID-19 in at-risk patient populations.
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