Add a definit viral onset as many have had severe onset illnesses and saw drs and had specific viruses show up or had tests shows non specific infections where certain immune cells were elevated that showed an infection was being fort.
Generally antivirals like acyclovir, valtrex, famvir and valcyte are used for herpes viruses such as cold sores, genital herpes, varicella which is chickenpox or shingles, ebv which is mono or glandular fever, cmv which is also known for similar mono and glandular fever as ebv, hhv6 and hhv7.
Some of these herpes antivirals do effect other viruses eg famvir has some effect on hepatitis.
So if your looking at those who respond to those types of avs its generally one or a combo of the herpes viruses. Dont forget some cfsers have had certain chronic bacterial infections improve their condition with long courses of antibiotics.
So an infectious onset could be viral, bacterial or fungal mostly???