Weil-Felix test: A diagnostic tool for rickettsial diseases

Rickettsial diseases are generally classified under the causes of pyrexia of unknown origin (PUO) and high prevalence of this disease is found in developing countries like India. Diagnosis in such cases is difficult because early sign and symptoms are non-specific and varied. Mortality may be as high as 3040% if untreated. Weil Felix in one of the cheapest screening method available for laboratory diagnosis of rickettsial diseases but the major drawback of this method is its less sensitivity. A prospective testing was carried out in clinical pathology department in Haffkine Institute as a routine testing for the patients who are advised for extended Widal test. These patients comes from the various government hospitals, private hospitals and tertiary care centres. The serum samples from 1464 PUO cases which included patients of all age group and from both government and private hospitals, were subjected to Weil–Felix test (R.K. Diagnostics, Malad, Mumbai, India). The test was performed according to the manufacturer’s instructions. Titers of ≥ 1:80 for OX K, OX 2 and OX 19 were considered significant. Of 1464 samples, rickettsial diseases were detected in 485(33.13%) samples. Seropositivity was higher among male subjects 262(54.02%) when compared with female subjects 223(45.98%) Most of the positive cases were in 5-10 age group. Prevalence of rickettsial diseases 485(33.13%) is significantly high, especially in children’s and hence should be included in the differential diagnosis of PUO.