Mr. as rickettsioses are a group of vector borne infectious diseases caused by organisms belonging to the generaRickettsiaandOrientia. The incidence of rickettsial infections have increased worldwide in the recent past and Sri Lanka has also experienced a similar trend according to the notification data of Epidemiology Unit, Ministry of Health, Sri Lanka [1]. The notification of the disease is mainly based on clinical awareness coupled with rapid (-)-Nicotine ditartrate defervescence of fever in response to appropriate antibiotic therapy (macrolides or chloramphenicol) as the only laboratory test currently available for diagnosis is the Weil Felix test [1]. Two to three research centers in the country offer IFA as a means of diagnosis, but the population catered to is limited. In addition to reducing morbidity in the local population, the recent development of eco tourism adds impetus to the need for identifying different rickettsial infections present in different regions of Sri Lanka, their reservoirs and vectors. A first step for this would be mapping rickettsial infections in patients in the different regions of Sri Lanka. Although clinical features of rickettsial infections are generally non specific, certain patterns of clinical features could be recognized as being specific to some diseases. Collective grouping of clinical features may help identify patterns which in conjunction with epidemiological data would aid in diagnosis, especially in settings where laboratory facilities for diagnosis is minimal. Thus, clinical profiling and mapping of the disease for Sri Lanka is a justifiable endeavor in rickettsial research in Sri Lanka. Limitations of an island wide study would include logistics of sample collection, transportation and finance. A feasible alternative to begin mapping would be to select a few sentinel sites with high levels of case reporting and using established laboratory methods, determine the pattern of rickettsioses in these areas. The objective UCHL2 of the study was to map rickettsial infections in selected localities of Sri Lanka by using serological testing and to describe the clinical profiles of patients with laboratory confirmed rickettsial infections. == Methods == Clinicians of selected hospitals were informed about the study through letters and workshops conducted in collaboration with the Epidemiology Unit and (-)-Nicotine ditartrate were requested to send serum samples from patients in whom a clinical diagnosis of rickettsioses was being considered according to the surveillance case definition given by the Epidemiology Unit of Sri Lanka which included fever with [2]. Paired sera taken at 10-14 day intervals were encouraged over single serum samples. Samples were stored at -20C on arrival at the Department of Microbiology, Faculty of Medicine, University of Peradeniya and batch tested on a weekly basis. Clinical data (-)-Nicotine ditartrate were collected by using a validated questionnaire. Ethical clearance was obtained from the Ethical Review Committee of the Faculty of Medicine, University of Peradeniya, Sri Lanka and informed written consent was obtained from the patients. == Serological testing == Samples were tested using scrub typhus and spotted fever IgM and IgG ELISA kits (Panbio, Australia), IFA kits donated by the Rickettsial reference laboratory, Geelong, Australia and IFA kits prepared using antigens donated by the Rickettsial reference laboratory in Marseille, France. Patients were categorized into three groups according to the test used (Table1). == Table 1. == Description of the three cohorts *Titre determination carried out for species (-)-Nicotine ditartrate shown below on screen positive samples Scrub typhus–O.tsutsugamushiGilliam, Karp and Kato strains Spotted fever–R..