A resistant strain of the “flesh-eating” MRSA bacteria is moving amongst gay men in San Francisco and Boston, giving health specialists sleepless nights.

An online study by journal Annals of Internal Medicine gives that the bacteria seemed to be spread most easily through anal intercourse. At the same time, casual skin-to-skin contact and touching contaminated surfaces are also reported as other sources whereby the bacteria can be picked up.

Unless microbiology laboratories are able to identify the strain and doctors prescribe the proper antibiotic  therapy, it could be foreseen that the infection may spread among other groups and become a wider threat, warn the authors.

The researchers also observed that that the new strain seems to have “spread rapidly” in gay populations in San Francisco and Boston. It  “has the potential for rapid, nationwide dissemination” among gay men, they add.

The study stemmed from an examination of medical records sourced from outpatient clinics in San Francisco and Boston and nine medical centers in San Francisco.

Incidentally, the Castro district in San Francisco has the highest number of gay residents in the country.  One in 588 residents shows an infection by infected the new multidrug-resistant MRSA strain. This is against 1 in 3,800 people in San Francisco, says the statistical analyses based on ZIP codes.

A different part of the study found that gay men in San Francisco were about 13 times more likely to be infected than other people in the city.