[1] Univ Maryland, Inst Human Virol, Div Epidemiol & Prevent, Sch Med, Baltimore, MD 21201 USA
[2] Univ West Florida, Biol Dept, Pensacola, FL USA
[3] Ohio Univ, Coll Hlth Sci & Profess, Dept Social & Publ Hlth, Grover Ctr, Athens, OH 45701 USA
[4] St Catherine Univ, Dept Publ Hlth, St Paul, MN USA
[5] Univ West Florida, Coll Educ & Profess Studies, Pensacola, FL USA