The rate of HIV infections attributed to heterosexual sex tripled in China between 2005 and 2007, according to the UN's recently released "2009 AIDS Epidemic Update." Of new infections in China, 40 percent were acquired heterosexually, 32 percent homosexually, and most of the remainder were through drug use. Drug use was previously the main infection route, but last year health authorities said sex overtook it as the chief mode of infection. "We need to ensure resource allocation is responding to that change," said Michel Sidibe, UNAIDS' executive director. HIV/AIDS was designated the top killer among infectious diseases in China for the first time last year, possibly due to improved surveillance.