Why an early diagnosis of dengue is essential Dengue should be diagnosed early as the patient has maximum viremia during early phase with more infectivity. The test to be done is NS1 antigen and not IgM. NS1 is positive in less than 5 days and the IgM becomes positive after 5 days. IgG and IgM kits are provided free by the government of India but not the NS1 kits, which need to be procured by the states themselves. IMA feels that the priority of the government should be NS1 kits and not IgM kits. Also all cases of severe dengue with rapid test positive for NS1 or IgM should be notified as dengue cases. Currently the government requires ELISA test as the criteria.