Post-Infection Syndrome

Abstract

Post-infection syndrome (PIS) or chronic fatigue syndrome (CFS) is a complex debilitating disorder. It is usually characterized by fatigue that is worsened by physical activity or mental exertion, and is experienced in the aftermath, or with ongoing concurrent infections. Other symptoms may also be present including myalgia, impaired concentration, impaired memory, insomnia, and post-exertion malaise that can last for more than twenty-four hours after exertion. PIS/ CFS is a complex disorder with symptoms related to cognitive, autonomous, and immune dysfunction. No single causal factor has been identified, but there is some evidence that indicates that immunological dysfunction and infections interacting with genetic and psychosocial factors probably contribute to the development of PIS/ CFS. There are no tests to diagnose PIS/ CFS. There are many conditions where the symptoms of PIS/ CFS can appear, and therefore diagnosing PIS/ CFS may rely on ruling out other conditions. There are published guidelines that are available in order to help with diagnosing these conditions. The most frequently used ones are from the CDC (the 1994 Fukuda criteria) and the 1991 Oxford criteria. The CDC case definition for CFS requires individuals to meet three criteria before receiving this diagnosis. These are: 1. Severe chronic fatigue which must have been present for six or more consecutive months, and not as a result of other medical conditions associated with fatigue. 2. Fatigue that interferes significantly with activities of daily life. 3. Four or more of the following symptoms are present: a. Post-exertion malaise that lasts for longer than twenty-four hours. b. Impairment of short-term memory. c. Myalgia. d. Unrefreshed sleep. e. Headache (of new type or severity). f. Arthralgia (without swelling or erythema around the joints). g. A frequent or recurring sore throat. h. Tender lymphadenopathy. However, the Oxford criteria differentiates CFS of unknown aetiology and CFS related to PIS, which is CFS that either follows an infection or is associated with an ongoing current infection. These guidelines suggest that in order to diagnose CFS, individuals must meet the following criteria: 1. The principle symptom experienced by patients should be fatigue that affects physical and mental functioning, and should have been present for at least six months.