Antibiotic resistance is a topic that often crops us in scientific conferences and has been widely covered by mainstream media over the past few years and the NHS has run an awareness campaign. The most recent area to be scrutinised has been resistance to macrolide antibiotics when treating mycoplasma genitalium. In light of a recent study, we reconsider the debate to see whether the new perspective offers new insight or new misconceptions.
Three commonly prescribed antibiotics are part of the macrolide antibiotic family. You can read more about macrolides here. These include erythromycin, clarithomycin and azithromycin. It has been argued that prior antibiotic use is the main risk factor for developing macrolide resistance. Since 1990, the increase of macrolide resistance has been substantial however this has not merely been for treatment for mycoplasma genitalium.
The study, which was published in Clinical Infectious Diseases, was a retrospective survey analysing symptomatic and asymptomatic specimens from nearly 30 000 patients. The researches gathered a total of 31600 specimens from 28 958 patients between 2006 and 2010 Out of these 1121 were positive specimens, and 1085 were useful for completing testing for macrolide resistance. The main findings suggested that 38.2% of the sample showed macrolide resistance. This was seen in two types of mutations, A2058G and A2059G, with the former accounting for 61% of macrolide resistance. The findings also suggested that patients who had used private specialists had a lower rate of macrolide resistance. Based on these findings the researchers concluded that individuals who did not seek out private specialists were likely to take part in more risky sexual behaviour, which could lead to previously undetected illnesses that could potentially induce macrolide resistance prior to the mycoplasma genitalium treatment.
Whilst the study brings interesting findings, we are dubious as to the basis of their conclusion and lack of consideration for alternative explanations.
First, it is worth noting that a small sub sample of their initial specimens was applicable to the purpose of the study. This sample was hardly representative, as it was skewed toward a majority of women when the most consistent data suggests that macrolide resistance is higher among men.
Secondly, although there was data on where the patients sought care, no information on symptoms and co-morbidity at point of testing (for instance did the patients seek treatment for gonorrhoea and chlamydia at the same time). There was also no data on previous risky sexual behaviour that would support the conclusion. This brings us to the final point. If the individuals had indeed taken part in more risky sexual behaviour, then how were they treated the first time they sought treatment?
The final point brings us to the key area that was missed in this study. To date, we know that GUM clinics tend to treat mycoplasma genitalum by prescribing a single done of azithromycin. However, a more suitable treatment is to provide a five-day course of azithromycin. If these factors had been considered, then it is likely the results would have been more insightful and valuable. You can read more about how this infection is detected and treated at this online GUM clinic - www.theGUMclinic.com
It is unfortunate that this area was not considered as a layperson could come to read the study as ‘proof’ that antibiotic resistance is on the rise, and that it is likely to affect individuals who take part in risky sexual behaviour. This is a dangerous belief to have as it can shield individuals into two extremes of false beliefs; either that they are not at risk as their sexual behaviour is far from ‘high risk’ or that the increase in resistance is catastrophic and they cannot be treated. Clearly, this is far from the truth and we hope it does not create an obstacle for treatment.