What should you know about parasitic food poisoning?

Parasites can enter food or water through contamination and may irritate the digestive tract after they are swallowed. Symptoms can include loose stools, abdominal pain or cramps, nausea, vomiting, fever, tiredness and reduced appetite. Some infections continue longer than a typical short stomach upset, and symptoms may return or persist after travel, untreated water or contact with an infected person. A clinician may request a stool sample when the pattern or exposure suggests a parasite.

Drink frequent small amounts of water or an oral rehydration drink, particularly after loose stools or vomiting. Eat light foods as tolerated and rest. Wash hands carefully, avoid preparing food for other people while unwell, and clean shared bathroom surfaces. Do not take anti-diarrhoeal medicines or leftover antibiotics without advice; the appropriate treatment depends on the suspected organism and your health. A clinician may prescribe targeted medicine after assessment.

Seek urgent care for inability to keep fluids down, very little urine, marked dizziness, confusion, blood in the stool, severe abdominal pain, persistent high fever or worsening weakness. Get medical advice sooner for an infant, older adult, pregnancy, immune suppression or a significant chronic illness. Emergency treatment may include intravenous fluids when drinking is not enough or dehydration is severe.

Ask whether a stool test is appropriate, which fluids and foods are suitable, whether treatment is needed, how long to avoid preparing food for others, and which changes should prompt urgent review.