No antibiotic-resistant strains of gonorrhea have been detected on the Chinese mainland, which has long been covered by a nationwide surveillance system targeting varied kinds of sexually transmitted diseases, a senior specialist said.

Wang Xiaochun, director of hepatitis C and STD prevention for the National Center for AIDS and STD Control and Prevention, made the remarks following media reports of an untreatable "superbug" gonorrhea, recognized as HO41, hitting countries such as the United States and Japan.

"China for a long time has had a sound surveillance system for STDs such as gonorrhea and syphilis across the mainland, and related drug resistance is also covered by the system," Wang said on Wednesday.

"So far we've not seen the bacteria-caused disease develop any resistance to the antibiotics, like cephalosporin that is commonly used to treat it. The effective surveillance system will help detect such a situation if it arises."

Gonorrhea is characterized as a major type of infection, and medical institutions nationwide are required by the National Health and Family Planning Commission to report each new case to an online database.

In recent years, more than 90,000 gonorrhea cases a year have been reported on the Chinese mainland.

"In general, gonorrhea and most other STDs are decreasing in the country, with the sole exception being syphilis," Wang said.

Gonorrhea is caused by the Neisseria gonorrhea bacterium and is transmitted via sexual activity. Unlike AIDS, which is caused by a virus, gonorrhea is not spread by blood.

Around the world, most cases are curable, Wang said.

"At the moment, I don't think we need to worry too much about the rare cases involving drug resistance in some parts of the world," he said.

"But we should constantly increase surveillance and improve prevention and control efforts."

As with HIV and AIDS, groups at high risk of gonorrhea include sex workers and homosexual or bisexual men, Wang said.

However, many of those infected show no major symptoms and commonly do not see a doctor right away, he said.

Delayed treatment can lead to serious complications, such as infertility among female patients, he warned, urging people in at-risk groups to go for the screening and receive timely treatment.

"It's a problem that some people simply try to treat themselves by buying medicines, because that can lead to drug resistance due to improper antibiotic use," he said.