Cases of the deadly drug-resistant superbug NDM-1 quadrupled in Hong Kong this year, rising from three to 12.
Patients undergoing medical procedures on the mainland are at the highest risk, with 11 of the 12 patients contracting the bug across the border.
The rise in untreatable superbugs, such as NDM-1 - a mutation of E coli - has been blamed on the misuse of antibiotics and a lack of new medicine in recent years.
University of Hong Kong microbiologist Ho Pak-leung said: "Superbugs are turning into megabugs ... Our medicine cannot catch up with the rate of these bugs now."
NDM-1, which stands for New Delhi metallo-beta-lactamase-1, is believed to have originated in New Delhi in 2008. It has since spread around the world to countries including the United States, Australia and the Netherlands and is one of many deadly superbugs.
Pak, who is also chairman of the Centre for Health Protection's Health Protection Programme on Antimicrobial Resistance said "third-world country" bacteria-testing equipment in Hong Kong hospitals made it hard for the city to tackle new medical threats.
From 2009 to this month, the city saw 17 cases of the NDM-1 superbug, with 12 of them contracted on the mainland, of which eight were in Guangdong. One person died.
Ho cited the growing numbers of Hongkongers heading to the mainland for medical treatment, including beauty operations, as a possible cause of the rise in cases. He noted that while the city had a wealth of experienced professionals to research superbugs, outdated testing hindered timely treatment.
"These [testing] reports are so slow. Late diagnosis only delays treatment," said Ho.
Ho called on the government to buy a high-speed testing machine, called the matrix-assisted laser desorption/ionisation mass spectrometer. This could produce test results in one hour on bacteria and superbugs. The waiting time at the moment ranges from one to two weeks.
Ho also recommended that the government more regularly make public the number of superbug cases and the hospitals where they were found.
"Higher transparency would warn and educate the public of [these superbugs], and heighten awareness of the issue," he said.
Dr Wong Tin-yau, head of the centre's Infection Control Branch, said the public still had misconceptions about the use of antibiotics, and many did not know that incorrect use of the drugs would increase the number of antibiotic-resistant bugs.
"Many people still don't know the difference between a virus and a bacteria. Antibiotics are useless on viruses, like the flu," said Wong.
He added that the government would continue to raise awareness with public education campaigns.
The centre recently published the fourth edition of a reference tool for medical professionals on the appropriate use of antimicrobial and antibiotic drugs, which will be available online and as a smartphone app.