The effective strategy of "test, track and treat" has yielded results at the height of the novel coronavirus pandemic, the centre said today in a reminder to the states that are witnessing a high active caseload. As per news report of NDTV, eight states and union territories - Haryana, Andhra Pradesh, Odisha, Goa, Himachal Pradesh, Uttarakhand and union territories of Delhi and Chandigarh - have been told to increase testing, contact tracing and accelerate vaccination for priority groups in the worst-hit districts.