[1] Temple Univ, Coll Hlth Profess & Social Work, Philadelphia, PA 19122 USA
[2] Texas A&M Hlth Sci Ctr, Dept Epidemiol & Biostat, Sch Rural Publ Hlth, College Stn, TX USA
[3] Texas Dept State Hlth Serv, Emerging & Acute Infect Dis Branch, Austin, TX USA
[4] Texas Dept State Hlth Serv, Environm Epidemiol & Dis Registries Sect, Austin, TX USA
[5] Texas Dept State Hlth Serv, Birth Defects Epidemiol & Surveillance Branch, Austin, TX USA