postviral syndrome
noun /ˌpəʊstˈvaɪrəl sɪndrəʊm/
/ˌpəʊstˈvaɪrəl sɪndrəʊm/
(also postviral fatigue syndrome)
[uncountable]- a condition that follows a viral infection, in which somebody feels extremely weak and tired, and which can last for a long time