The prevalence of sexually transmitted disease syphilis reached an all-time low in 2000-2001. It was expected that incidents of syphilis would decrease even further as available treatments become more accessible. Nevertheless, there has been an upward trend in cases of this STD in the last decade or so.

Scientists have been trying to figure out the root cause of the surprising trend. After considerable research, they have discovered a damning reason for the increasing number of people suffering from syphilis.

Researchers from the University of Zurich recently published a paper detailing the effect of the predominance of a syphilis strain to cures and treatments of the disease. Through DNA-capture and genome sequencing, scientists determined that all contemporary infections of syphilis emerged from a cluster named SS14- Ω.

"Our findings highlight the need to study more extensively the predominant strain type in the contemporary epidemic," explained Natasha Arora, one of the authors of the study, as reported by Science Daily.

SS14-Ω is a syphilis strain that emerged in the mid-20th century, well after the development and widespread use of antibiotics. The predominance of this strain is particularly worrying since it exhibits high resistance to available medications like azithromycin, the second-line treatment for syphilis. Arora was quick to explain that the first-line antibiotic used to cure syphilis, penicillin, is not affected by the SS14-Ω strain, or at least data hasn't revealed it to be resistant to the drug.

"The good news is that, so far, no Treponema strains have been detected that are resistant to penicillin, the first-line antibiotic for syphilis treatment."

According to Center of Disease Control and Prevention or CDC, more than 20,000 cases of syphilis have been reported in the United States. The statistics is daunting considering how the prevalence of the disease has increased 20 percent in only one year.