The figure was announced at a press release by the CDC on Friday. Specialists said the number of HIV carriers had increased by 113 percent over the same period last year, while AIDS patients had increased by 74.3 percent, Shenzhen Daily reported Tuesday.

Most of the HIV carriers were young people, specialists said. Of the 274 who tested positive, 228 were under 40, while many of them were single. Also, 57.7 percent of the group was found to be drug users and sharing needles has been known to contribute to the spread of HIV.

The floating population was the high incidence group, accounting for 179 of those who tested positive. There were only 14 cases among permanent Shenzhen residents, the CDC figures showed.

Specialists said 116,000 pregnant women, 94.81 percent of the total, had taken the test in the first 10 months this year. Of these, eight had tested positive and another three who had given birth were also found to be HIV carriers. The CDC has been closely following the cases, taking measures to prevent the transmission from mother to baby, such as Caesarean deliveries and stopping breast-feeding.

Experts said the world had been experiencing fast spread of HIV and AIDS in recent years, and Shenzhen also suffered from the problem.

Experts attributed the fast increase to the large proportion of floating population, who they said had relatively unstable employment and were exposed to drugs.

At the same time, the city's inspection system of HIV/AIDS had been improved allowing more cases to be diagnosed. People also had a higher awareness of HIV/AIDS prevention, they said.