The report said HIV has assumed the proportion of a 'generalised epidemic' among injecting drug users in Manipur and Nagaland.
"Northeastern states which are distant from the Myanmar border have generally reported fewer episodes of heroin injecting compared to the states which are closer to the border. Thus, there is a direct correlation between proximity to the border and drug abuse," the UNODC said.
"Injecting drug users represent a significant incubus for the indirect spread of HIV to people who have never used drugs."
India's northeast - Assam, Manipur, Meghalaya, Mizoram, Nagaland, Arunachal Pradesh, Sikkim and Tripura - has been declared as one of the country's high-risk zones with close to 100,000 people infected with HIV, according to estimates by the regional government authorities and private healthcare workers.
Manipur with a population of 2.24 million accounts for about 20,000 HIV-positives although unofficial estimates put the figure in the state at closer to 35,000. Authorities in the northeast fear the disease may spread further.
India's northeast lies on the edge of the heroin-producing "Golden Triangle" of Laos, Myanmar and Thailand and independent estimates have put the number of regular intravenous drug users in the region at up to 300,000 -- a key cause of HIV infection here.
The unabated flow of amphetamines from Myanmar into the northeast is another area where the UNODC has expressed concern.
"Myanmar has a significant illicit amphetamine type substance (ATS) manufacturing capacity," the report said.
In its recommendations, the report called for "intervention to promote safe sex among drug users", besides suggesting "accurate monitoring and evaluation of the drug use problem" of past and ongoing interventions.
Myanmar and India have signed a number of agreements aimed at collaborating on fighting drugs along the border, the first of which was in 1993. India accounts for about 5.1 million HIV-positive people, next only to South Africa.
--Edited IANS