 Untreated, it has a mortality of 8 % to 58 %, with a greater death rate in males. The symptoms of syphilis have become less severe over the 19th and 20th centuries, in part due to widespread availability of effective treatment and partly due to decreasing virulence of the spirochaete. With early treatment, few complications result. Syphilis increases the risk of HIV transmission by two to five times, and coinfection is common (30 – 60 % in some urban centers). In 2015 Cuba became the first country in the world to eradicate mother to child transmission of syphilis.
