Diagnosis of poliomyelitis: what to know

Poliomyelitis is diagnosed through the symptoms and neurological examination, supported by laboratory testing for poliovirus. A clinician also considers vaccination history, possible exposure, travel, and whether similar illness is circulating. Because early symptoms can resemble other infections, testing and prompt public-health assessment may be needed when polio is suspected.

The assessment begins with questions about fever, sore throat, vomiting, headache, muscle pain, stiffness, weakness, and changes in movement. The neurological examination checks muscle strength, reflexes, sensation, coordination, and whether weakness is developing or affecting one side more than the other. Non-paralytic illness can be difficult to distinguish from other viral infections, while new limb weakness or breathing-muscle weakness raises concern for paralytic disease.

Laboratory confirmation commonly uses stool samples because poliovirus may be detected there. Samples from the throat or other body fluids may also be collected, and a lumbar puncture can help examine cerebrospinal fluid when inflammation around the brain or spinal cord is suspected. Additional tests, such as imaging or nerve studies, may help rule out other causes of weakness; they do not by themselves confirm polio.

Contact a doctor urgently if polio is a possibility, especially after travel to an area where poliovirus may circulate or after contact with a suspected case. Tell the clinician when symptoms began, whether weakness is changing, which vaccinations were received, and any recent travel or close-contact exposure. Avoid close contact with vulnerable people until a clinician gives advice, and follow instructions about samples, infection precautions, and public-health notification.

Do not wait for a routine appointment if weakness is appearing. Bring vaccination records if they are available. Prevention remains central: discuss whether routine immunisations are up to date, including [Childhood Immunisation](/treatments/preventive-care-and-vaccination/childhood-immunisation/).

Seek emergency care for sudden or worsening weakness, difficulty breathing or swallowing, inability to move a limb, severe neck or back stiffness, or unusual drowsiness. These signs can indicate involvement of the spinal cord, brainstem, or muscles used for breathing. Keep the person safe while help is arranged and do not drive if weakness or breathing trouble is severe.

Useful questions include: Which symptoms make polio a concern? Which samples or examinations are needed? Should I be assessed in hospital? Do I need to avoid contact with anyone while testing is arranged? Are my vaccinations complete for my age and travel plans? What changes in strength, swallowing, or breathing should prompt an emergency call?