Seroprevalence of Scrub Typhus among Febrile Patients from a Tertiary Care Hospital in Kerala

Abstract

Introduction: Scrub typhus or bush typhus is a form of typhus caused by the intracellular parasite Orientia tsutsugamushi. As the clinical features include fever, headache, vomiting, respiratory infections and rashes, this disease presents like typhoid, dengue, leptospirosis or malaria. Though Weil–Felix test is conventional, cheap and easy to perform, but IgM ELISA is a more sensitive test. There is no published data on this topic from this region. Aim: To determine the seroprevalence of scrub typhus among febrile patients using Weil-Felix and IgM ELISA tests. Materials and Methods: A cross-sectional study was carried out at the Government Medical College Hospital Thrissur, between the period of July 2015 to March 2016. Total 285 cases with febrile illness were screened for scrub typhus. Commercially available kits of Weil-Felix and IgM ELISA were used. Results: Out of 285 samples 54 (18.95%) were positive by either Weil–Felix or Ig M ELISA or both. 21-30 years age groups showed maximum cases during the monsoon and post monsoon period and there was no gender difference. Rise in titer of OX2 and OX19 was also seen showing the presence of rickettsial disease other than scrub typhus. Conclusion: Scrub typhus fever should be considered as one of the differential diagnosis of fever of unknown origin in this area.

Keywords

• chigger-borne disease
• eschar
• igm elisa
• orientia tsustsugamushi
• weil–felix