Phil, RRV probably stands for Ross River Virus. People who are infected with RRV often develop polyarthritis - this is a form of arthritis which involves five or more joints simultaneously.

If you are infected with RRV there would be antibodies (IgM, produced shortly after infection and IgG, produced later) in your blood specific for it.

Those tests came back negative (EIA = Enzyme ImmunoAssay is the name of the procedure that was used).

I am impressed that your doctors checked that possibility out.