Gastrointestinal infections

Viral gastrointestinal infections are usually self limiting. Hence, patients are given symptomatic treatment and a full-on lab diagnosis is not performed. Bacteria (such as Yersinia and Campylobacter) however, cause immune mediated secondary diseases e.g. reactive arthritis. Thus, they are confirmed through serological testing. Similarly, H. pylori causes chronic active gastritis and complications such as peptic ulcer disease and stomach carcinoma. Therefore, in suspected cases of non-acute and chronic infections, antibody detection is done to confirm the diagnosis.

Parasites such as schistosoma and strongyloides stercoralis also cause gastrointestinal symptoms with a chronic course. For them, a combination of direct and indirect methods is employed to confirm the diagnosis in cases of chronic infections (antibody testing). However, antibody testing is not useful for acute diagnostics.