[1] Med Univ South Carolina, Div Gen Internal Med, Charleston, SC 29425 USA
[2] Ralph H Johnson VAMC, Dept Med, Infect Dis Sect, Charleston, SC USA
[3] Med Univ South Carolina, Dept Med, Div Infect Dis, Charleston, SC 29425 USA
[4] Duke Univ, Sch Med, Dept Med, Div Infect Dis, Durham, NC 27706 USA
[5] Durham VAMC, Dept Med, Div Infect Dis, Durham, NC USA
[6] Ralph H Johnson VAMC, Sect Gastroenterol & Hepatol, Charleston, SC 29401 USA
[7] Med Univ South Carolina, Dept Med, Div Gastroenterol & Hepatol, Charleston, SC 29425 USA
[8] Univ Basque Country UPV EHU, Fac Med & Nursing, Dept Physiol, Leioa, Spain