Among the following, ELISA is commonly used as a screening test for infection…

Concept

An enzyme-linked immunosorbent assay (ELISA) detects a target antigen or antibody through antigen–antibody binding and an enzyme-generated measurable signal.

A screening test identifies people who may have an infection; a reactive screening result is interpreted with the recommended confirmatory testing algorithm.

Application

HIV infection can be screened with ELISA-based immunoassays that detect antibodies to HIV and, in some formats, HIV antigen.

HIV is the virus that causes acquired immunodeficiency syndrome (AIDS), so AIDS is the disease associated with the screening use asked about here.

Contrast

• Typhoid is caused by Salmonella Typhi and is ordinarily confirmed with culture-based testing; the Widal test is a distinct serological test.

• Active tuberculosis is evaluated with sputum-based molecular tests, microscopy, and culture rather than routine HIV-style antibody screening.

• Diabetes is diagnosed from blood-glucose criteria or glycated haemoglobin (HbA1c), not from an infectious-disease antibody screen.

Cross-check

The test target and disease link agree: ELISA-based HIV screening detects HIV-related markers, and HIV is the causative virus of AIDS.

Therefore, among the offered diseases, the best answer is AIDS.