MOSCOW, September 18 (RIA Novosti) - The total number of registered HIV cases in Russia since 1987 has reached half a million, Russia's chief sanitary official said on Friday.

In an interview with Ekho Moskvy radio, Gennady Onishchenko said that initially the number of people registered as HIV-positive in Russia ran at 40,000-42,000 people annually.

"The annual figures later dropped to some 36,000 registered cases, but last year's figures showed 40,000 again," he said, adding that intravenous drug use is still the main method of transmitting the virus.

According to the State Statics Service, Russia's population stood at 141.9 million people in the first half of 2009.