Differential Diagnosis for High Grade Cyclical Fever after Swimming in Puerto Rico

• Single Most Likely Diagnosis
  • Leptospirosis: This is a common infection in Puerto Rico, often contracted through exposure to contaminated water, making it highly plausible given the context of swimming. The cyclical nature of the fever is also consistent with leptospirosis, which can present with a biphasic fever pattern.
• Other Likely Diagnoses
  • Dengue Fever: Given Puerto Rico's tropical environment, dengue fever is prevalent and can cause high-grade fever. While not exclusively linked to swimming, the geographical location increases the likelihood.
  • Viral Hepatitis: Though less directly related to swimming, viral hepatitis can cause fever among other symptoms and is a consideration given the potential for waterborne transmission of hepatitis A.
• Do Not Miss Diagnoses
  • Malaria: Although less common in Puerto Rico compared to other tropical regions, malaria is a critical diagnosis not to miss due to its severity and the potential for fatal outcomes if not treated promptly.
  • Typhoid Fever: Caused by Salmonella Typhi, typhoid fever can present with fever and is a concern in areas with less reliable water treatment. It's crucial to consider due to its potential severity and the need for specific antibiotic treatment.
• Rare Diagnoses
  • Schistosomiasis: This parasitic infection, also known as snail fever, can be contracted through swimming in contaminated freshwater. While less common and more typically associated with chronic symptoms, it's a rare but possible diagnosis to consider.
  • Rickettsial Infections: Such as spotted fever, which can be transmitted by ticks or other vectors and might be encountered in outdoor activities, including swimming in areas where such vectors are present.