Doxycycline post-exposure prophylaxis, or doxy-PEP, could help slow rising rates of chlamydia, syphilis, and gonorrhea, but experts say antibiotic resistance will need to be monitored.
Researchers say the case suggests an unidentified Treponema pallidum strain tied to higher risk for systemic involvement.
The FDA said the test offers a private and quick testing option, along with streamlined treatment, if needed.
Most of the newly affected Finnish farms raised foxes, but some also produced raccoon dogs.
Officials said a key step would be offering syphilis screening in nontraditional settings such as emergency departments, jail intake, and maternal-child health programs.
The study authors say the findings could provide opportunities to identify local transmission chains and educate sexual networks.
The WHO said more investigations are needed to the rise in GBS cases, though some patients tested positive for Campylobacter infection.
Of 300 cases recorded since April, 106 have been in the US, with the rest in Europe.
Gonorrhea infections in China are showing decreasing susceptibility to ceftriaxone along with high levels of resistance to other antibiotics.
The designation means that the NgG vaccine, which is in a phase 2 trial, will receive expedited review by FDA officials.