'Stealth' gonorrhea strains on the rise

NEW YORK (Reuters Health) - There is global dissemination of a type of gonorrhea that lacks an enzyme used by many commercial kits to confirm a diagnosis of infection, investigators report.

The enzyme -- called prolyliminopeptidase -- was previously thought to be common to all gonorrheal strains and its absence can result in incorrect, doubtful, or delayed diagnosis, they point out.

Dr. Magnus Unemo from Orebro University Hospital in Sweden and colleagues investigated the possibility of widespread transmission of prolyliminopeptidase-negative strains of gonorrhea in several countries.

They found that most of these strains -- identified in Australia, New Zealand, and Scotland -- were indistinguishable or highly related to a strain previously reported in an English and Danish outbreak.

The majority of the specimens also remained fully susceptible to several antibiotics used to treat gonorrhea, the researchers note.

The findings indicate "a widespread dissemination among several countries" of prolyliminopeptidase-negative gonorrhea that evolved from a single original strain, the investigators conclude in the medical journal Sexually Transmitted Infections.

Increased awareness of these gonorrhea strains worldwide is "crucial," and changes in the way the diagnosis is made may be needed in several geographic areas, Unemo and colleagues say. "For example, the use of at least two different assays ... which are based on different principles, is fundamental."

SOURCE: Sexually Transmitted Infections, February 2007.