[1] Johns Hopkins Univ, Sch Med, Baltimore, MD USA
[2] Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Baltimore, MD USA
[3] Univ Malawi, Coll Med, Blantyre, Malawi
[4] Rutgers State Univ, Piscataway, NJ USA
[5] NIH, Rockville, MD USA
[6] Ctr Dis Control & Prevent CDC, Atlanta, GA USA