A study on serodiagnosis of scrub typhus in a Teaching Hospital of\nSouth India

Abstract

Background: crub typhus is caused by Orientia tsutsugamushi\n(rickettsial disease) commonly transmitted by the bite of larval\nchiggers of trombiculid mites. It has been one of the important\ncauses of febrile illness, especially in south India. The clinical\ndiagnosis is difficult owing to the non-specific presentation.\nWe in the current study tried to evaluate the serodiagnosis of\nscrub typhus with the Weil Felix test and IgM ELISA.\nMethods: This study was conducted in the Department of\nMicrobiology, Prathima Institute of Medical Sciences,\nNaganoor, Karimnagar. All the sera samples were subjected to\nthe Weil Felix test using Proteus OX2, OX19, OX-K strain\nagglutination test, and subsequently, Scrub typhus IgM ELISA\ntest.\nResults: All the samples were subjected to the Weil Felix test\nn=4(6.06%) were positive for scrub typhus (OXK antigen)\nn=11(16.67%) were positive for the spotted group of fever (OX2\nantigen) and n=10 (15.15%) were positive of typhus group\n(OX19 antigen). N=5 sera samples were positive for more than\none type of antigens. All the n=66 serum samples were\nsubjected to IgM ELISA for scrub typhus. Out of n=66, only\ntwo serum samples (3.03%) were positive by IgM ELISA.\nConclusion: Scrub typhus is emerging as an important public\nhealth issue. It is one of the important causes of acute febrile\nillness. Although it is difficult to distinguish scrub typhus based\non the clinical symptoms alone a simple test such as Weil Felix\nwas found to be promising in the diagnosis of scrub typhus.\nELISA IgM test may be performed additionally in laboratories\nwith adequate facilities. Hence for clinicians, any case with a\nfever of unknown origin should arouse suspicion of scrub\ntyphus