Sexually transmitted infections (STIs) present a major public health concern worldwide with more than 1 million people acquiring an STI every day. Timely access to testing and treatment services can reduce the risk of onward transmission, however many STIs are asymptomatic and some display similar or overlapping symptoms, thus co-infections may remain undiagnosed. Furthermore, over the years STIs have evolved and acquired resistance to many antibiotic treatments, resulting in a depleted pool of therapeutic options available to treat these increasingly common infections.1-2

The minimum investigations recommended in British Association for Sexual Health and HIV (BASHH) guidelines, whether symptomatic or asymptomatic, include tests for chlamydia, gonorrhoea and syphilis (Treponema pallidum); symptomatic women maybe also tested for Trichomonas vaginalis. The latter causes vaginitis and cervicitis in women and urethritis in men, however, infections are often asymptomatic and not tested for because the prevalence is assumed to be too low for testing to be cost effective. In addition, wet mount microscopy, the standard diagnostic method for Trichomonas in women, is insensitive and therefore T. vaginalis infection remains underdiagnosed.  Herpes Simplex Virus (HSV) testing is offered to both men and women in the presence of genital ulceration. Mycoplasmas and Ureaplasmas are not routinely tested for although M. genitalium is now well recognised as an STI and has been implicated in urethritis and cervicitis. U. urealyticum has also been associated with recurrent urethritis and, along with M. hominis and M. genitalium with some cases of pelvic inflammatory disease (PID).

In this context, the need for efficient means of detecting these infections has become increasingly important. This study undertaken by Randox reports the evaluation of a multiplex array on a biochip platform for the simultaneous detection of ten common STI pathogens from a single sample.  This approach increases the detection capacity, with the potential of identifying more asymptomatic infections and co-infections.

The results present a strong correlation between the Randox multiplex biochip with industry leading single pathogen tests (>94%). In addition, 7% of the study group tested positive for at least one additional infection.

The data indicates that this multiplex STI array assay detects simultaneously 10 common STI pathogens from a single sample without compromising sensitivity or specificity. Furthermore it facilitates the identification of co-infections. This leads to increased diagnostic capabilities, which may allow tailored treatment, reducing broad spectrum antibiotic use and, in turn, the build-up of antibiotic resistance.

From the patient’s perspective, accurate and rapid diagnosis at first presentation reduces the length of exposure to infectious diseases for improved long-term reproductive health. The necessity for repeat visits to the clinician is also reduced and appropriate therapeutics can be administered in a timely manner, for optimal treatment of infection.

References

  1. World Health Organization. Global incidence and prevalence of selected curable sexually transmitted infections 2008. Available online: http://www.who.int/reproductivehealth/publications/rtis/stisestimates/en/. Last accessed 13 February 2015.
  2. U.S. Department of Health and Human Services Centers for Disease Control and Prevention. Antibiotic Resistance Threats in the United States 2013. Available online: http://www.cdc.gov/drugresistance/pdf/ar-threats-2013-508.pdf. Last accessed 13 February