Does a positive Widal test indicate that I am a typhoid carrier?
Professor & Head,
Dept. Of Microbiology, JIPMER, Pondicherry
Q: I am an 18 years old male. I have suffered from typhoid thrice and recovered with antibiotics. I didn't have any symptoms and was confident that I was cured. To be sure, I had a Widal test done, which came positive. My father, who is a doctor, told me that I have gone into the carrier stage. What should I do now? How can I get myself treated of typhoid permanently?
A:Just the fact that the Widal test has shown a positive result doesn't actually say that you are a carrier. The Widal test usually detects antibodies against flagellar and somatic antigens of the causative organisms of enteric fever, Salmonella typhi. To determine whether a person is a carrier or not, the test should detect for the presence of antibodies against another antigen called as Vi.
Since you are asymptomatic, the reason for the Widal test positivity may be the fact that you have suffered with typhoid in the past. Certain individuals have been known to have H titres due to previous infection or vaccination in the past. Further the O antibody titres also require some time, usually upto six months to fall following an infection. So in this case the test turning positive may not have much significance as there are no symptoms. A test to detect antibodies to Vi antigen is advised to test for carrier status. If proved to be carrier, detailed antibiotic history would be needed before any suggestions for a plan of action can be made.