False Positive Widal Reactions in Patients with Malariathe Diagnostic Challenges and Public Health Implications

Background and objectives: Malaria and typhoid fever are common endemic infectious diseases in many parts of Karnataka and they still remain major public health concern. False positive widal reactions have been reported in patients with non enteric salmonella infections, malaria, immunological disorders and chronic liver disorders. We undertook this study to find out false positive Widal reactions in malarial cases.

Method: A total of hundred cases admitted to McGann hospital were studied for malarial parasites. 50 healthy cases with age, sex, socio-economic and environmental background similar to the subject were selected as controls. Widal test was performed on 100 patients and 50 healthy controls.

Results: In 100 smear positive cases, 18(18%) cases were positive for widal reaction. Of 18 widal positive cases, 10(77%) cases were P.falciparum and 8(9%) cases were P.vivax. Among the control group, only non significant titre was noted in four cases. Out of 100 smear positive cases, P.vivax was noticed in 87(87%)&P.falciparum was noticed only in 13(13%) cases.

Conclusion: Widal test interpretation has to be done with caution in malaria and typhoid endemic region. If there is a suspicion of co infection of malaria and typhoid, only malaria should be treated, unless blood culture yields salmonella species.