Test Details: Widal test is used as an adjunct to clinical signs and symptoms in making the diagnosis of typhoid and paratyphoid fever. This test is recommended if an individual is having high grade fever, fatigue, headache, abdominal pain, diarrhoea, constipation, weight loss and rashes. Widal tube test is performed using tube agglutination method. This test measures the titres of antibodies against salmonella typhi and paratyphi bacteria.