Himachal Pradesh state of India is situated in the outer Himalayan ranges. During the rainy season, several cases of acute febrile illness of unknown origin occurred. Orientia tsutsugamushi was identified as the causative agent by microimmunofluorescence and PCR. Two new genotypes of O. tsutsugamushi were identified in the region.

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Scrub typhus usually presents as pyrexia with or without multiple organ involvement. Acute hearing loss occurs in about one third of cases and is a useful clue toward the diagnosis. We present two cases of scrub typhus with acute reversible hearing loss from an endemic area. The diagnosis was confirmed by nested PCR. ©

The three strains of non-pathogenic Proteus species namely, Proteus vulgaris OX2, P. vulgaris OX19 and Proteus mirabilis OXK used in the Weil-Felix test are the group-specific cross-reactive antigens for Rickettsia and Orientia species. Earlier studies have revealed that the group specific and cross-reactive antigens responsible for the Weil-Felix test lie mostly in the lipopolysaccharide (LPS) moiety of the bacterial cell wall [Amano et al. (1993a) Infect Immun 61:4350-4355, (1993b) Microbiol Immunol 37:927-933, (1998) Infect Immun 66:923-926]. The three Proteus strains (OX2, OX19 and OXK) were used to raise murine monoclonal antibodies (MAbs) by hybridoma technology. Several MAb-producing hybridomas could be stabilized following limiting dilution. Affinity and specificity of these MAbs were checked by indirect ELISA using a battery of homologous and heterologous antigens including LPS. Amongst these, one MAb was found to be specific for P. vulgaris OX19 LPS. Since the Weil-Felix reaction is based on the cross-reactivity between the LPS based epitopes, this MAb could be of potential use in mapping of epitopes on the cross-reactive LPS and may also be useful as a potential diagnostic reagent.