Influenza and Apergillosis

Aspergillus is a genus consisting of a few hundred different mold or fungi species found in various climates worldwide. Some species, such as Aspergillus fumigatus and Aspergillus flavus, can cause serious disease in humans.

[Aspergillus fumigatus]

Aspergillus fumigatus infections are primary pulmonary infections and can potentially become a rapidly necrotizing pneumonia with a potential to disseminate. Aspergillosis is the name given to a wide variety of diseases caused by infection by any species of Aspergillus.

It is estimated that most humans inhale thousands of Aspergillus spores daily, but they do not affect most people’s health due to effective immune responses.

Invasive pulmonary aspergillosis typically occurs in an immunocompromised host. For almost a century, influenza has been known to set up for bacterial superinfections, but recently patients with severe influenza were also reported to develop invasive pulmonary aspergillosis.

To investigate, researchers collected data of 432 patients admitted to the hospital with an Influenza A or B infection. Invasive pulmonary aspergillosis was diagnosed in 83 (19%) of these patients[1].

For patients with influenza who were immunocompromised, incidence of invasive pulmonary aspergillosis was as high as 32% (38 of 117 patients), whereas in the non-immunocompromised influenza case group, incidence was 14% (45 of 315 patients).

The 90-day mortality was 51% in patients in the influenza cohort with invasive pulmonary aspergillosis and 28% in the influenza cohort without invasive pulmonary aspergillosis.

The results show that Influenza is an independent risk factor for invasive pulmonary aspergillosis and is associated with high mortality. If there ever was a sound reason to get vaccinated, this is it.

[1] Schauwvlieghe et al: Invasive aspergillosis in patients admitted to the intensive care unit with severe influenza: a retrospective cohort study in Lancet – 2018