Aha - location wasn't there earlier...
Calici and myxo are the things rabbits get vaccinated for or have to worry about avoiding in some parts of the world. Calici = Rabbit haemorrhagic disease (RHD), also known as rabbit calicivirus disease (RCD) or viral haemorrhagic disease (VHD); myxo = myxomatosis. Both are a BIG concern for people in Australia or the UK. Domesticated rabbits are vaccinated for RHD in both countries and in the UK, they're also vaccinated against myxy... however, pet rabbits in Australia can't be vaccinated for myxomatosis because wild rabbits are basically a plague on both farmers and the environment in general - myxy was actually deliberately introduced in Australia as a means of keeping the wild rabbit population somewhat under control; the vaccine is banned for fear of it spreading to the wild rabbits and making more of them immune.
As for the US, RHD is not transmitted by the wild rabbit population and, while there were previously outbreaks amongst domesticated rabbits, it has since been eliminated:
After outbreaks of RHD in 2000, 2001, and 2005 in domesticated rabbits, the United States has eradicated RHD from its rabbit populations. The native species,
cottontails (Sylvilagus floridanus),
black-tailed jackrabbits (Lepus californicus) and
volcano rabbits (Romerolagus diazzi) seem not to be susceptible to the virus.
(source: Wikipedia)
Myxomatosis does seem to exist here to some degree, however, it's extremely rare - so much so that rabbits aren't vaccinated for it:
http://en.wikipedia.org/wiki/Rabbit_haemorrhagic_disease#cite_note-IAS-3
In rabbits of the genus Sylvilagus (cottontail rabbits) living in the Americas, myxomatosis only causes localized skin tumors, but the
European rabbit (
Oryctolagus cuniculus) is more severely affected.
(Source: Wikipedia)
June 2010: We have found out about three confirmed cases of Myxomatosis (Myxo) in San Gabriel, California. All three rabbits died.
(Source: HRS; also indicates that it's a different strain of Myxo in the US, which is why the vaccine in the UK can't be given to prevent Myxo here)
In the United States, myxomatosis is most commonly seen along the Pacific coast. There are several strains of the virus. The virus that is present in the Western USA is referred to as the California strain of myxoma virus and possesses characteristics that differ slightly from other strains. California strains have been known to cause over 99% mortality.
(
Source)
In other words, as far as anyone knows, wild rabbits in the New England states wouldn't potentially have any viruses that could be spread to domesticated rabbits. That said, there's still the concern of parasites (fleas, ticks, mites, etc.).