Alex Lettau is the pen name of Ludwig Alexander Lettau M.D., an infectious disease specialist who currently lives and works in Charleston, South Carolina.

In practice for more than 30 years, he holds degrees from the University of Wisconsin, London School of Hygiene and Tropical Medicine, and Tulane School of Public Health and Tropical Medicine. Early in his career, Dr. Lettau was a medical missionary in Malawi (one year), Nicaragua (2 months), and Papua New Guinea (3 months). For two years he was a medical epidemiologist at the Centers for Disease Control in the Epidemic Intelligence Service (EIS) assigned to the Viral Hepatitis Branch of the Division of Viral Diseases.