Differential Diagnosis for 44-year-old Female with Recent Trip to Brazil

Single Most Likely Diagnosis

• Zika Virus Infection: Given the recent trip to Brazil, where Zika virus is prevalent, and symptoms such as fever, rash, numbness, and tingling in all limbs, severe fatigue, and muscle pain, which are consistent with Zika virus infection, especially considering its outbreak history in Brazil.

Other Likely Diagnoses

• Dengue Fever: This is another common mosquito-borne illness in Brazil, characterized by fever, rash, severe fatigue, and muscle pain, making it a plausible diagnosis given the patient's travel history and symptoms.
• Chikungunya: Similar to Zika and Dengue, Chikungunya is a mosquito-borne virus common in Brazil, causing fever, rash, severe joint pain (which could be interpreted as numbness and tingling), and fatigue, fitting the patient's symptom profile.
• Leptospirosis: Although less likely without specific exposure history (like swimming in contaminated water), leptospirosis can cause fever, muscle pain, and in severe cases, neurological symptoms, making it a consideration given the broad range of symptoms.

Do Not Miss Diagnoses

• Guillain-Barré Syndrome (GBS): While not an infectious disease itself, GBS is an autoimmune disorder that can be triggered by infections such as Zika or Campylobacter, leading to numbness, tingling, and potentially life-threatening paralysis. Early recognition is crucial for treatment.
• Meningitis or Encephalitis: Infections that cause inflammation of the meninges or brain, respectively, can present with fever, rash, and neurological symptoms. Given the severity of these conditions, they must be considered and ruled out promptly.

Rare Diagnoses

• Venezuelan Equine Encephalitis (VEE): A rare but potentially severe mosquito-borne illness that could cause fever, headache, and in severe cases, encephalitis. Its rarity and the fact that it's more commonly associated with equines make it less likely but not impossible.
• Oropouche Virus: Another virus transmitted by mosquitoes in Brazil, which can cause fever, headache, and in some cases, aseptic meningitis. Its inclusion is due to the patient's travel history, though it's less commonly diagnosed compared to other mosquito-borne illnesses.