Do you remember that story about the chlamydia
strains that were evading detection
, because they'd evolved away from the markers used in the laboratory tests? A study recently published in the journal Nature Genetics
just showed that chlamydia is far more crafty about evolution than scientists previously thought. In fact, it looks as though different strains of chlamydia can actively swap DNA with each other - including for some of the genes that are most often used in testing. This means that the nucleic acid techniques
currently used for testing and monitoring may actually be nearly useless in determining when individuals have been reinfected with the same strain or in monitoring shifts in antibiotic resistance
- even when they can detect the presence of chlamydia.
Although urine tests for chlamydia are unquestionably more convenient than bacterial culture, this paper made me wonder if perhaps doctors should actually be trying to do both - at least in the research setting. I'd hate to see anything decrease the frequency of STD screening, but I wonder if these results will encourage doctors to supplement urine tests with swabs when doing so doesn't put an unacceptable burden on either the patient or the clinic.