The number of HIV-positive drug users who inject has reached its highest level for more than a decade.
The number of new drug users with HIV has risen dramatically
Official data from 2005 shows that one in 62 injecting drug users (1.6%) in England and Wales are HIV-positive. This compares with one in 110 in 2002.
Last year the number of HIV diagnoses among injecting drug users rose and rates among new users are also up.
The Health Protection Agency said the rise was partly due to an increase in the numbers injecting crack cocaine.
The level of HIV infection among injecting drug users remained stable in London but saw a six-fold increase in areas outside the English capital from one in 500 (or 0.2%) in 2002 to one in 83 (1.2%) in 2005.
Professor Peter Borriello, director of the HPA's centre for infections, said: "This coincides with a reported increase in more risky behaviours among injecting drug users, as well as a rise in hepatitis C injection.
"There is also evidence of an increase in the injecting of crack cocaine which has shown to be associated with transmission of blood-born viruses such as HIV and hepatitis C."
Dr Fortune Ncube, who monitors the health of injecting drug users for the agency, said the findings highlighted the importance of preventing the spread of HIV and other infections.
"Necessary steps to achieve this include the provision of enough needles and syringes and available information and practical advice on safer injecting practices, as well as guidance on safe disposal of used equipment."
There was also a need for easy access to diagnostic tests for HIV.
Will Nutland, head of health promotion services at HIV/Aids charity Terrence Higgins Trust, said: "In the late 80s and early 90s, the UK investment in harm reduction services for injecting drug users was a crucial element in reducing HIV in this country.
"It's essential that investment in drug education programmes continues and that free provision of clean injecting needles and needle exchange programmes are properly provided."
Liberal Democrat health spokesman Steve Webb said action needs to be taken to stop an alarming trend.
"The devastating social impact of illegal drugs will only worsen with an increased prevalence of HIV amongst substance abusers," he said
"There must be a greater focus on drug treatment and testing as an alternative to other criminal sanctions and further development of specialist heroin treatment clinics where addictions can be treated under controlled conditions."