Syphilis cases rise sharply in China

China has seen a dramatic rise in cases of syphilis, as a result of rapid social change, US researchers say.

A report in the New England Journal of Medicine says syphilis is now the most commonly reported communicable disease in Shanghai, the second-largest city.

Pregnant women are also increasingly passing the disease to their children, with more than one baby with congenital syphilis born every hour in 2008.