| Rh | F rheumatic fever |
|---|---|
| RMSF | Rocky Mountain spotted fever |
| RVF | renal vascular failure; Rift Valley fever; right ventricular failure; right visual field |
| SFV | Semliki Forest virus; shipping fever virus; Shope fibroma virus; squirrel fibroma virus |
| SHF | simian hemorrhagic fever |