Re: How long can a calicivirus or rotavirus remain infective on a fomite?

Let's begin by noting that the singular of fomites is fomes. This is one of Latin's many idiosyncracies; and since the Romans who perpetrated it are now long dead, there is little we can do to change it. Of course, you can always ignore the Latin and say anything you want to, but then what kind of an authority are you?

As someone who has been working with viruses (but not these viruses) for over 40 years, I can tell you that many viruses are rapidly inactivated by air-drying. However, hepatitis A virus – with which I do work – may stay infectious for weeks or months under the conditions you postulate.

The caliciviruses (at least those that are called Norwalk-like and cause vomiting and diarrhea in humans) and the rotaviruses are somewhere in between. They will probably remain infectious for a few days on a doorknob. I do not regard this as an efficient means of transmission – those who wash their hands fairly regularly and don't put their fingers in their nose or mouth are virtually not at risk.

If you want to find some source materials on these viruses, I can direct you via a book I helped edit. In Hui, Y. H., J. R. Gorham, K. D. Murrell, and D. O. Cliver. (eds.). 1994. Foodborne Disease Handbook (in Three Volumes), Marcel Dekker, New York, Volume 2, Chapter 1 is about hepatitis A & E viruses (HEV is a calicivirus), Chapter 2 is about Norwalk-like viruses, and Chapter 3 is about rotaviruses. The authors of these chapters, who have themselves done research with the viruses they write about, cite original research publications that address these questions along with their summary conclusions.