Abstract
Sirs: We read with interest the case report entitled ‘Paromomycin treatment of recalcitrant Trichomonas vaginalis’ by Tayal et al. 1 We report a similar case in a 44-year-old woman initially presenting four years ago with vaginal discharge and a vulval itch. T. vaginalis was diagnosed via a wet mount preparation. This was treated with metronidazole 400 mg twice a day for five days. The rest of the screen (including blood borne virus testing) was negative. A test of cure two weeks later still showed evidence of T. vaginalis, despite a history of good compliance and sexual abstinence by the patient. A repeat course of metronidazole effected a cure both clinically and microscopically. Contact tracing was addressed and the patient stated that she was no longer with her current sexual partner. The patient reattended three years later with similar symptoms and gave a history of no penetrative intercourse for over a year and had no regular sexual partner. Once again T. vaginalis was seen on the wet mount preparation with metronidazole prescribed at the dose stated above. There were several attendances over the next few months with a history of good compliance with the medication, sexual abstinence and symptomatic relief while on therapy, but a recurrence of symptoms upon cessation of the antibiotics with detection of T. vaginalis at follow-up. As in the case report by Tayal, several other antibiotic regimens were prescribed in an effort to effect eradication – these included erythomycin 500 mg twice daily for 14 days, a course of metronidazole 400 mg twice daily for 28 days in conjunction with metronidazole gel one application a day for three weeks and a course of tinidazole 2 g twice a day for 14 days. None of these regimens resulted in eradication. During this period, the patient reiterated that there was no history of sexual intercourse and that she had no regular sexual partner.
Coincidentally, a routine ultrasound of the pelvis organized as a result of an inability to visualize intrauterine coil threads revealed a mass in the Pouch of Douglas. At laparotomy this was found to be a mature cystic benign teratoma. Intravenous metronidazole was administered perioperatively. The patient, however, returned a few months later with a recurrence of her symptoms and T. vaginalis once again seen on a wet mount preparation. At this point, and following discussion with the patient, acetarsol vaginal pessaries were used at a dose of 500 mg nightly for two weeks. This regimen effected a cure both clinically and microscopically with no side-effects reported by the patient at review two weeks after completion of the regimen. Acetarsol pessaries have been anecdotally successful in the treatment of recalcitrant T. vaginalis with few reported side-effects if used at standard doses. 2 Higher doses have been associated with systemic reactions including rigors and confusion. 3 The patient described above was warned about potential side-effects both verbally and in written form but experienced no problems during her treatment.
Anecdotally, it would appear that acetarsol pessaries not only effect a cure for recalcitrant T. vaginalis, but also have the possibility of fewer side-effects in comparison with paromomycin and therefore might be a preferable option in such cases.