1. 1Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;
2. 2Department of Microbiology and Parasitology, Center of Infectious Diseases, Faculty of Medical Sciences, National Autonomous University of Nicaragua, León (UNAN-León), León, Nicaragua;
3. 3Department of Family Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina;
4. 4Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina