Mon. Jan 17th, 2022


There has been widespread global transmission of syphilis, especially within the last 20 years, according to research published in The microbiology of nature.

Image / CDC

Researchers at the London School of Hygiene & Tropical Medicine (LSHTM), Wellcome Sanger Institute, UK Health Security Agency and their collaborators mapped the recent resurgence of the disease around the world. They found almost identical syphilis samples between 14 countries, with the global syphilis population consisting of two tribes, SS14 and Nichols.

Detailed analysis of these lineages provides important insights into the genetic diversity of syphilis, with implications for vaccine design and antimicrobial resistance.

Syphilis is one of the most common sexually transmitted infections (STIs) globally, with approximately six million infections each year. Caused by the bacterium Treponema pallidum, it is easy to treat, although the symptoms may disappear before a person realizes that they are infected or may not appear at all. If left untreated, syphilis can cause serious long-term health problems.

Syphilis infections that occur during pregnancy can be transmitted to the baby, causing congenital syphilis. This is the second leading cause of stillbirth globally and can have serious developmental consequences for children being born. It can be prevented through early screening and treatment during pregnancy. Congenital syphilis is more common in countries without such screening programs.

For this study – funded by Wellcome – researchers at LSHTM and the Wellcome Sanger Institute coordinated the collection of 726 syphilis samples from 23 countries. This included areas with good sampling such as the United States and Western Europe, as well as areas with poor sampling such as Central Asia, Australia and Africa.

The Sanger Institute sequenced the genome of each sample and performed phylogenetic analyzes and cluster analyzes to map the global syphilis population.

Because DNA changes occur at a known and predictable rate over time, the ancestral relationships between different sequences can be established. The team found that all the samples came from only two deeply branched genera, Nichols and SS14. Both genera are currently circulating in 12 of the 23 countries selected, and almost identical samples were present in 14 of these countries.

Read more at LSHTM

Leave a Reply

Your email address will not be published. Required fields are marked *