Tropical fevers are defined as infections that are prevalent in tropical & subtropical regions. These include Dengue, Malaria, Scrub Typhus, Typhoid, Brucllosis, Influenza, Leptospirosis etc. If not diagnosed well in time, these fevers can have high morbidity & mortality. The clinical picture is so overlapping that it is difficult to diagnose without relevant investigations. Brucellosis is caused by gram negative bacillus of genus Brucella either by direct contact or by ingestion of meat or milk. In cases of suspected Brucellosis, this assay assists in the diagnosis and plays a supplementary role to routine culture. Scrub Typhus / Tsutsugamushi fever is a zoonotic disorder transmitted to humans by the bite of a larval mite Orientia tsutsugamushi. The illness varies from mild self limiting to fatal with an incubation period of 6-21 days. Leptospirosis is a zoonotic disease transmitted through soil, food or water contaminated by urine of infected animal. Illness may be self limiting or cause Hepatorenal failure (Weil syndrome). IgM antibodies appear within 1-2 weeks after onset of illness and peak at 2-4 weeks.