<s>[INST] My son has a platelet count of 71 is asymptomatic, however tested positive to CMV & glandular fever. How long do platelets take to regenerate? If positive to the virus, could this be a cause of persistent thrombocytopenia? Autoimmune disorders have all tested negative. Thanks [/INST] Hi, yes many viral infections are known to cause thrombocytopenia(decrease of platelets) due to their direct effect on bone marrow and decreased production.glandular fever is generally caused by ABV.CMV is not a routine causative.treatment with valgancyclovir is good for CMV infection.as soon as the infection comes down the platelet counts start raising.in fact there is an excess production in the initial recovery.hope my answer helps you if you have any more queries I would be happy to answer. </s>