Seroprevalence of scrub typhus in febrile patients visiting Sukaraj tropical and infectious disease hospital.

Thesis Report.

ABSTRACT: Scrub typhus caused by Orientia tsutsugamushi-an obligatory intracellular bacterium and transmitted via the bite of infected chigger mite; is acute febrile illness endemic to Nepal and other countries in so-called tsutsugamushi triangle. This disease is often under-diagnosed and misdiagnosed due to non-specific symptomatology and serological cross-reactivity with other febrile illnesses, leading to significant morbidity and mortality. This study aims to unveil the prevalence of scrub typhus in febrile patients visiting Sukraraj Tropical and Infectious Disease Hospital from August 31, 2018 to April 30, 2019. Blood samples were collected after obtaining written informed consent from the patient or their guardian, amongst 2070 febrile patients, 253 were seropositive to scrub typhus. Available blood samples were collected and subjected to hematological, biochemical and serological tests. Data thus generated were analyzed by using SPSS software. Scrub typhus accounted for 12.2% (n=253) of total febrile illness visiting that particular hospital. Mixed infections with two or more infections have been reported in the same febrile patient. Mixed infection of scrub typhus with dengue, brucella and leptospira were found in 12, 9 and 2 cases respectively. Most of the cases were recorded from Dhading (39 cases), Nuwakot (16 cases), Kathmandu (16 cases), and Sarlahi (11 cases) district. There was no statistically significant association between scrub typhus and age, however, gender was found to be significantly associated with scrub typhus, females are more likely to be infected with scrub typhus than males. The most common sign and symptoms were fever (100%), headache (79.2%), sweating (70.1%), breathing difficulty (51.3%), and redness in the eye (43.5%). The pathognomonic eschar was present only in 14 (9.1%) patients. Eschar, headache, rashes, sweating, redness in the eye, and difficulty in breathing were significantly associated with scrub typhus. Fifty percent of patients had low platelet count and elevated levels of alkaline phosphatase, SGPT, SGOT and creatinine were recorded in 28.6%, 34.4%, 55.2% and 8.2% respectively. As evident from this study, patients with acute febrile illness should be investigated for scrub typhus with high priority. Further epidemiologic and ecologic studies are needed to better clarify the features of scrub typhus and other rickettsial infections in Nepal and to investigate which strains of Orientia are present in Nepal. Keywords: Scrub typhus, Orientia, febrile illness, sero-prevalence