Scrub typhus a rickettsial disease is transmitted by vector mites Leptptrombidium deliense and Lakamushi is caused by Rickettsia tsutsugamushi. Many army personnel fell sick due to febrile illness. Scrub typhus is of animal origin like rodents and shrews which are considered as a source of infection for mites. Diseases is acquired through bite of an infective larva which can be prevented through personal protective measures and repellents. The most widely used chigger repellents include dimethylpthalate, dibutylphthalate , N,N-diethyl-mtolumide (DEET) and Diethyl phenyl acetamide (DEPA) against trombiculid mite.
Based on field study to determine relative efficacy of repellents against trombiculid mites conducted by Armed Forces Medical College (AFMC), Pune, Director General of Armed orces of Medical Services (DGAFMS) has recommended DEPA 50% as mite repellent and introduced in the inventory of Hygine chemical for Armed Forces vide letter .25114/DGAFMS/DG-3A dated 23 October 2002.