Differential Diagnosis for Adult Patient with 3 Days of Diarrhea and Vomiting Visiting from Australia
- Single Most Likely Diagnosis
- Viral gastroenteritis: This is the most common cause of acute diarrhea and vomiting in adults, and given the patient's symptoms and recent travel, a viral etiology such as norovirus is highly plausible.
- Other Likely Diagnoses
- Bacterial gastroenteritis (e.g., Salmonella, Campylobacter): These pathogens are common causes of gastrointestinal infections and could be acquired through contaminated food or water during travel.
- Food poisoning: Given the patient's travel history, consuming unfamiliar or undercooked foods could lead to food poisoning, which presents with similar symptoms.
- Traveler's diarrhea: Although more commonly associated with travel to certain regions like South Asia, traveler's diarrhea can occur in visitors to Australia, especially if they consume contaminated food or water.
- Do Not Miss Diagnoses
- Cholera: Although rare in travelers to Australia, cholera is a life-threatening condition that requires prompt diagnosis and treatment. The patient's symptoms could be consistent with cholera, especially if they have been exposed to contaminated food or water.
- Giardiasis: This parasitic infection can cause severe gastrointestinal symptoms and is a consideration in travelers who have been exposed to contaminated water sources.
- Inflammatory bowel disease exacerbation: If the patient has a pre-existing condition like Crohn's disease or ulcerative colitis, an exacerbation could present with similar symptoms and must be considered to avoid missing a critical diagnosis.
- Rare Diagnoses
- Intestinal parasitism (e.g., amoebiasis, cryptosporidiosis): These infections are less common but can occur in travelers, especially those who have been exposed to contaminated water or have engaged in high-risk activities like swimming in freshwater lakes or rivers.
- Brainerd diarrhea: A rare condition characterized by chronic diarrhea, the cause of which is often unknown, but could be considered in a patient with persistent symptoms.
- Listeriosis: Although more commonly associated with immunocompromised individuals or outbreaks related to contaminated food products, listeriosis could present with gastrointestinal symptoms and is important to consider due to its potential severity.