Post-viral fatigue syndrome

Post-viral fatigue syndrome (PVFS) is a condition that presents a fatigue state resulting from a viral infection. The term is not widely used, but the state of prolonged or severe fatigue after illness is not uncommon. Some people experience fatigue and related symptoms for months or years following a severe viral infection.

Classification
In the WHO's ICD-10, PVFS is a sub-category within 'other disorders of the brain', a neurological category. It is furthermore explicitly excluded from neurotic disorders. Listed under PVFS is benign myalgic encephalomyelitis, several alternative diagnoses to ME such as chronic fatigue syndrome (CFS) and neuromyasthenia are included in the alphabetic index to the ICD-10.

Post-viral syndromes may also include: post-polio syndrome and possibly chronic mononucleosis or other severe chronic viral infections.

Some researchers claim that post-viral fatigue syndrome is a biological state of weakness or activation of, or damage to the immune system, and that it is common to many post-viral syndromes. It is hoped that immune system research, especially that connected to HIV, may lead to better understanding of, and treatments for, other post-viral syndromes.

Risk factors
Some research indicates that that the chance of developing a post-viral fatigue syndrome is more strongly related to the severity of the infection rather than on demographic, psychological or microbiological characteristics. Other research indicates the contrary and that doctor behaviour and patient attitudes were the best predictors.