DIMAPUR: HIV prevalence rate in Nagaland has come down to 0.78 per cent since December 2010 from a prevalence rate of 1.27 per cent on October 2010 - a drop of 0.49 per cent. A major concern, however, is that sexual route of transmission has gone up to 89 per cent in the State although HIV infection through injecting drug had dropped to 3.5 per cent.