Iranian officials believe that a surge in intravenous drug use is to blame for the country's increase in HIV infections, Agence France-Presse reports.

According to the article, the number of HIV infections in Iran has reached 18,320—a 30 percent increase since 2007. While sexual contact accounts for 11.9 percent of infections, nearly 81 percent of HIV cases are linked to intravenous drug use.

Iranian officials estimate that out of the country's 71 million citizens, 2 million are drug users. The country is currently located on a prominent drug-trafficking route from the opium fields of Afghanistan to consumer markets in Europe and the Persian Gulf.