Objectives: Scrub typhus is an emerging neglected tropical disease, reported from many parts of Asia including Nepal. This study aims to determine the seroepidemiology of scrub typhus among febrile patients attending Chitwan Medical College Teaching Hospital (CMCTH), Bharatpur, Nepal. Study design and setting: This was a hospital laboratory based prospective study conducted in CMC-TH (a 600-bed hospital) located in Bharatpur, Chitwan district of Nepal. Participants: A total of 1797 patients visiting CMC-TH with acute febrile illness (temperature more than 380C) were enrolled in this study. Methods: A total of 1797 blood samples were collected from patients presenting with acute febrile illness. The samples were processed for detection of antibody for scrub typhus by Enzyme Linked Immunosorbent Assay (ELISA) for specific immunoglobulin M (IgM) antibody and Weil-Felix test. Results: Out of 1797 serum sample of febrile patients, 524 (29.2%) were scrub typhus positive. Maximum seropositive cases were from Chitwan district 271 (51.7%) with predominance among females 314 (35.9%). Scrub typhus was common among age group 51-60 years (37.2%) and farmers 182 (37.8%). Highest seropositivity was found in July 60 (57.7%). Fever was common clinical symptom. Thrombocytopenia was seen in 386 (73.7%) and raised transaminase AST 399 (76.1%) among seropositive cases. Weil-Felix test positive were 397 (22.1%) and IgM ELISA 524 (29.2%). The correlation between IgM ELISA and Weil-Felix test showed statistically significant association (r = 0.319, p<0.001). Conclusion: High prevalence of scrub typhus implies that acute febrile patients should be investigated for scrub typhus with high priority. There is utmost need of reliable diagnostic facilities at all level of health care system in Nepal. Infection with scrub typhus was found high and this calls for an urgent need to introduce vaccine against scrub typhus. More sustain and vigorous awareness programs need to be promoted for early diagnosis, treatment and control. 

Study design and Participants: This was a hospital laboratory based prospective study conducted in CMC-TH (a 750-bed hospital) located in Bharatpur, Chitwan district of Nepal from July 2016 to June 2017. Study population: A total of 1797 patients visiting CMC-TH with acute febrile illness (temperature more than 380C) were enrolled in this study. After taking informed consent from the patients, a preformed questionnaire was used to collect the demographic and health related information. Inclusion and Exclusion criteria: All patients with acute febrile illness of all age group attending CMC-TH were included in this study. Acute febrile illness patients diagnosed with other associated infection such as dengue, leptospirosis, typhoid, brucella and malaria were excluded. Sampling procedure: (Blood sample collection, handling, and transportation) A total of 1797 specimens were collected from patients attending CMC-TH. All the specimens were collected by veinipuncture aseptically with the standard operating procedure in BD vacutainer, yellow color coded and lavender color-coded tube from suspected cases of acute febrile illness patients. Collection and transportation of specimens were done according to manufacturer’s instructions. Blood samples collected was received in the Department of Clinical Microbiology. Laboratory procedure: Blood samples were tested for Orientia tsutsugamushi antibody. Immunological profiles like Weil-Felix test, and IgM ELISA for detection of antibody was done according to the manufacturer’s instruction. The profile of laboratory investigation of various laboratory parameters of all the patients were recorded.

A total of 1797 patients visiting CMC-TH with acute febrile illness (temperature more than 380C) were enrolled in this study. Acute febrile illness patients diagnosed with other associated infection such as dengue, leptospirosis, typhoid, brucella and malaria were excluded. Outcome variables are IgM antibodies (positive, negative), Scrub typhus (Yes, No), Mostly occupational exposure peoples are farmers. There are only one group of participants, patients visiting CMC-TH with acute febrile illness were enrolled in this study. The data were entered into IBM statistical package for social science (SPSS) version 20 for statistical analysis and interpreted according to frequency distribution, percentage, Chi-square (χ2) test. In statistical analysis P-value < 0.05 were considered significant. All possible confounding variables were identified based upon similar previous studies and only those samples were selected for the study which fulfills the inclusion criteria.