Widal reaction

medicine

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July 15, 2026

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The Widal reaction is a diagnostic procedure developed by French physician Fernand-Isidore Widal in 1896. It is used to diagnose typhoid fever, a communicable disease caused by the bacterium Salmonella typhi. The test works by detecting antibodies in the blood of an infected individual. These antibodies cause the Salmonella typhi bacteria to clump together, a phenomenon known as agglutination. Widal also made contributions to the treatment and prevention of diseases, including developing an antityphoid vaccine during World War I.12

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preventive medicine
…were developed, such as the Widal reaction for typhoid fever (1896) and the Wassermann test for syphilis (1906). An understanding of the principles of immunity led to the development of active immunization to specific diseases. Parallel advances in treatment opened other doors for prevention—in diphtheria by antitoxin and in syphilis…
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…were developed, such as the Widal reaction for typhoid fever (1896) and the Wassermann test for syphilis (1906). An understanding of the principles of immunity led to the development of active immunization to specific diseases. Parallel advances in treatment opened other doors for prevention—in diphtheria by antitoxin and in syphilis…
Read More