Sero prevalence of Scrub Typhus among Suspected Cases in Selected Area of Nepal

Abstract

Introduction: Scrub typhus is a mite-borne acute, febrile, infectious illness that is caused by Orientia tsutsugamushi the causative organism, Orientia tsutsugamushi, is transmitted to the human beings by the bite of larval stage (chiggers) of the trombiculid mites, Leptotrombidium delience. This disease is most common in rural areas of low income countries. It is difficult to differentiate clinically from other tropical infections such as malaria, dengue, enteric fever and leptospirosis. Hence the study aim was to determine the seroprevalence of scrub typhus among the acute febrile illness patients attending in different hospitals of Chitwan district.

Methods: The study was based on patients with suspected scrub typhus cases in Chitwan district from March 2017 to August 2017. Blood samples were collected from the suspected patients of scrub typhus, having acute febrile illness. IgM antibody to Orientia tsusugamushi was detected by using Scrub Typhus Detect™ Kit, In Bios International, USA.

Results: A total of 451 samples, 112 (24.80%) were positive for IgM Antibodies. Multivariate analysis demonstrated that the following factors were significantly associated with the scrub typhus. 1. Females (odd ratio [OR] =2.088, P=<0.004, confidence interval [CI] =1.268-3.438) 2. House near grassland (odd ratio [OR] =10.380, P=<0.001, confidence interval [CI] =3.615-29.802), 3. Piling weeds in house (odd ratio [OR] =0.498, P=0.011, confidence interval [CI] =0.290-0.855), 4. Presence of mouse inside the house (odd ratio [OR] =2.157, P=0.003, confidence interval [CI] =1.290-3.608), 5. Working in the field (odd ratio [OR] =10.295, P=0.002, confidence interval [CI] =2.309-45.905). All cases enrolled have presented fever (100%) followed by headache (56.2%), nausea (55.4%), shortness of breath (40.2%), abdominal pain (14.3%), jaundice (8.9%), hypertension (8.9%), COPD (8.0%), tachypnoea (4.5%), diabetes (4.5%), eschar (2.7%) and seizure (1.8%).

Conclusion: In the study the proportion of Scrub typhus infection was 25% among acute febrile cases. Our finding also explored the burden of scrub typhus in relation to demographic trend, risk factors, clinical characteristics and findings of different laboratory parameters. Early diagnosis, appropriate treatment along with health education and vector control measures are best way to prevent and management of scrub typhus.