Maybe some people believe syphilis is something from the past, but this would be a big mistake: a new research published in the journal Lancet Infectious Diseases shows that our negligence enabled the old deadly sexual bug to have a spectacular comeback in developed countries, boosted by drug consumption and high-risk sexual behaviors.

The infection was well under control in the '90s, but a steady rise started with the year 2000. 2007 has been the seventh consecutive year to witness a spread of the infection. Now 12 million new infections are recorded annually, most of them caused by unprotected sex, but also by mothers transmitting the bacterium to their newborn.

"The key message here is that syphilis is again on the rise in several developing countries. The resurgence demands new training efforts among health-care professionals. In many countries, physicians may have lost some of the skill sets associated with diagnosing syphilis," lead researcher Dr Kevin Fenton of the US Centres for Disease Control and Prevention told Reuters.

Homosexual and bisexual men represented 64 % of syphilis cases in 2007, compared to 5 % in 1999.

"The recent resurgence is among a sub-group of men who have sex with men and engage in high-risk sex with multiple partners. If not addressed, the disease could become far more widespread. We have seen with other epidemics of sexually transmitted diseases that even if the initial rise occurs in men who have sex with men, it is unlikely to stay in that group for any long periods of time. The data suggest we are now seeing increases among heterosexuals in the US and in Europe as well," said Fenton.

The syphilis was also neglected because of the exclusive focus on HIV/AIDS, which made people not to be aware of exposure to other severe and even deadly STDs. Moreover, like any other STDs, syphilis boosts the chances of getting infected with HIV itself.

The bacterium responsible for syphilis, Treponema palladium, first causes sores on the genital organs, which later generalize on the body and ,in the end, it attacks the nervous system, causing blindness, paralysis and dementia, before killing the patient, if the infection is not medicated.

"Efforts must be made to incorporate and evaluate new diagnostics tools, social network approaches, innovative evidence-based prevention interventions, robust disease surveillance and systematic monitoring and evaluation of prevention, treatment and care activities," wrote the authors.