What is the most common cause of fever and hospitalization in travelers returning to the United States?

Malaria is indeed the most common cause of fever and hospitalization among travelers returning to the United States. This disease is endemic in many tropical and subtropical regions, particularly in sub-Saharan Africa and parts of Southeast Asia, where travelers are often exposed to malaria-infected mosquito bites. The symptoms of malaria typically include high fever, chills, sweats, headaches, nausea, vomiting, and general malaise, making it a significant health concern for individuals returning from these regions.

While dengue fever is prevalent in many tropical areas and can also cause significant clinical disease, it does not result in as high a rate of hospitalization as malaria in returning travelers. Similarly, typhoid fever, caused by Salmonella Typhi, is less commonly encountered by travelers due to vaccination and improvements in water sanitation, and while yellow fever can be severe, it is preventable through vaccination and typically found in specific endemic areas. Thus, malaria stands out as the leading cause due to its widespread prevalence, potential severity, and the travel patterns seen in returning U.S. travelers.