ForumIAS announcing GS Foundation Program for UPSC CSE 2025-26 from 10th August. Click Here for more information.
Source-This post on Widal Testing has been created based on the article “How the Widal test is clouding India’s sense of its typhoid problem | Explained” published in The Hindu on 10 May 2024.
Why in the news?
The Widal Test is complicating the assessment of India’s typhoid burden. This test has also escalated the costs, and heightened the risk of antimicrobial resistance.
About Widal test
| Aspects | Description |
| What is it? | 1. It is a serological test used for diagnosing typhoid fever. 2. It is a point-of-care test and doesn’t need special skills or infrastructure. |
| Purpose | 1. The Widal test detects antibodies against Salmonella Typhi in a patient’s blood sample. These antibodies indicate whether the individual has been infected with the bacteria. 2. It helps diagnose a current or recent infection or determine if someone has had a previous typhoid infection. |
| Limitations | 1. Single Test Accuracy: A single positive result doesn’t confirm typhoid and a negative result doesn’t rule it out. 2. Serial Testing: It requires multiple tests over 7-14 days to detect changes in antibody levels, which is impractical. 3. Cross-reactivity: Antibodies from other infections or vaccines may cause false positives. 4. Antibiotic Influence: Previous antibiotic use can suppress antibody production, leading to false negatives. 5. WHO advises caution as the test can be influenced by various factors, making it unreliable for definitive diagnosis. |
About Typhoid
1. About Typhoid fever: It is an infectious disease caused by the bacterium Salmonella enterica serotype Typhi. It primarily affects the intestinal tract and occasionally the bloodstream.
2. Symptoms: Symptoms typically appear 6 to 30 days after exposure and include high fever, weakness, stomach pains, headache, and loss of appetite. Some patients may develop a rash of flat, rose-colored spots.
3. Transmission: The disease is transmitted through ingestion of food or water contaminated with the feces of an infected person. It can also spread through close contact with an infected individual.
4. Diagnosis: Typhoid fever is diagnosed through blood, stool, or urine tests to detect S. Typhi bacteria. Early detection is crucial for effective treatment.
5. Prevention: Prevention strategies include vaccination, ensuring safe drinking water, proper sanitation, and adequate hygiene. Travelers to areas where typhoid is prevalent should consider getting vaccinated.
UPSC Syllabus: Science and technology ( Health)
