Chronic fatigue can occur after any infection however there are some viruses that have earned a reputation for this. Glandular fever (Epstein Barr Virus), Ross River virus, influenza viruses and of course our new favourite SARS-CoV19 are all common culprits. The biological impact of viruses on our human health is complex and there is still much to learn however there are few things we do know about why we might feel such extreme ongoing fatigue after infection.
MITOCHONDRIAL DAMAGE
Viruses can alter the internal workings of the mitochondria to allow them to replicate more efficiently. This can cause damage to the mitochondria resulting in a reduction of ATP (energy) production, increased oxidative stress (free radicals) and increased cell death. When mitochondria are impaired by viral damage our capacity to produce energy is significantly reduced.
CHRONIC LOW-GRADE INFLAMMATION
The invasion of a virus triggers the release of several pro-inflammatory cytokines (chemicals that promote inflammation). This response can continue some time past infection and higher levels of certain inflammatory chemicals have been observed in patients with post-infectious chronic fatigue syndrome (ME/CFS) and long COVID. When the inflammatory process doesn’t resolve the way it should, ongoing chronic inflammation can result and this is thought to play a role in ongoing post-viral symptoms.