Rain Scald: The Future of a New Sexually Transmitted Disease

The Finnish public broadcaster Yle has reported that a new sexually transmitted infection has begun spreading in Europe. In fact, the disease is one that has long been known to affect horses and cattle: rain scald (also known as dermatophilosis). Previously, it had occurred mainly in people who worked closely with these animals, but it has now started to spread to others as well.

The disease is caused by bacteria and produces scaly skin lesions, raised bumps, and pus-filled blisters on various parts of the body. So far, however, it has responded well to antibiotic treatment, and the situation remains under control.

The infection has not been spreading among people engaging in conventional sexual activity. Rather, according to Yle's report, it "is currently found mainly among men who have visited gay saunas in France, Spain, Germany, and Sweden. Transmission has occurred through sexual contact or other forms of close skin-to-skin contact."

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It remains to be seen whether this emerging disease will develop into a genuine epidemic or remain a passing curiosity. In this regard, bisexual men are likely to play a key role, as they could enable the bacterium to cross the gender barrier from gay men to heterosexual women.

If rain scald does begin to spread more widely, another important question will be whether the pathogen starts adapting to humans. In other words, will genetic changes be selected in bacterial strains that circulate between people, making transmission during sexual contact more efficient than it is today?

Should that happen, the next likely development would be the evolution of antibiotic resistance. As a result, treating the disease would become more difficult than it is at present.

For now, we can only wait and see what the future brings. At present, the only certainty is that abstaining from sex, or having sex exclusively with one faithful partner—and, apparently, also using a physical barrier such as a condom—prevents infection.

Previous thoughts on the same topic:
Finland's COVID-19 policy saved approximately 2,600 people from death
A factory of five billion mosquitoes
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