An unusual cause of persistent postpartum vaginal discharge

Introduction

Vaginal discharge is one of the most common gynaecological presentations ¹ . It is most commonly either physiological or infective, which may be sexually or non-sexually transmitted. Commensal organisms have been known to cause vaginal discharge including anaerobes, α-haemolytic streptococci, Staphylococcus aureus and certain β-haemolytic streptococci ² . It is known that vulvovaginitis may occur as a result of Group B and Group A β-haemolytic Streptococci. However, the roles of the other groups of β-haemolytic Streptococci are poorly understood. ³ Postpartum vaginal infections are experienced in 3% of women. ⁴ This is a case report regarding a patient in whom the only organism identified was Group C Streptococcus. Her symptoms resolved following appropriate antimicrobial therapy.

Case

A 27-year-old white British woman presented with a three-month history of green, offensive vaginal discharge that started nine days following vaginal delivery (with episiotomy) of her first child. The discharge was described as profuse, watery, occasionally blood-stained and associated with intermittent lower abdominal pain. There was no significant past medical history and there had not been any change in sexual partner for seven years. She was exclusively breast-feeding. A full sexual health screen including two high vaginal swabs (HVSs) taken on two separate occasions by the general practitioner were negative. She subsequently attended the Genitourinary Medicine clinic. Speculum examination revealed a moderate amount of green stringy vaginal discharge. Bimanual pelvic examination was unremarkable.

Polymorphonuclear leukocytes were noted upon microscopic examination of vaginal and cervical specimens. There was no evidence of bacterial vaginosis (Hay-Ison grade I). The patient was reviewed by a gynaecologist who arranged a trans-vaginal ultrasound scan which was unremarkable. The sexual health screen was negative for Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis. The HVS was negative for Candida albicans and anaerobes. However, the HVS cultured heavy growth of Group C β-haemolytic Streptococci sensitive to erythromycin, penicillin and tetracycline. A one-week course of erythromycin was initiated as advised by Microbiology based on the sensitivities identified, but was continued for a further week as her symptoms although markedly improved had not fully resolved at seven days. She was reviewed at two weeks and reported that her discharge had significantly decreased but was now altered. Repeat microscopic examination revealed bacterial vaginosis (Hay-Ison grade III) which was successfully eradicated with metronidazole. Her symptoms fully resolved and repeat HVS post-treatment demonstrated moderate growth of mixed faecal-type flora only.

Discussion

This patient had been experiencing continuous profuse postpartum vaginal discharge for three months. Normal physiological changes postpartum with lochia would have been expected to settle within six weeks. The fact that her symptoms improved following treatment of Group C β-haemolytic Streptococci combined with a lack of any other positive tests suggests this was the cause of the patient's symptoms. To our knowledge, this is an unusual cause of postpartum vaginal discharge. We could not find any other case reports or studies that indicate that this is a common occurrence. A case-control study on non-group B β-haemolytic Streptococcus and vaginal discharge and vulvo-vaginitis found that although the incidence of Group A was significant in cases compared to controls, the incidence of Groups C, F and G was not significantly different between the groups.¹

Another study of HVSs submitted via general practice found that women with groups A, C and G Streptococci frequently had clinical vulvo-vaginitis but the numbers were too small for statistical confirmation. It did however indicate that providing antimicrobial sensitivities was relevant in clinical practice. ⁵

This case report demonstrates the importance of considering the other groups of β-haemolytic Streptococci as a pathogen in women presenting with persistent vaginal discharge after childbirth. Exclusive breast-feeding may have been a relevant predisposing factor as lactation has been reported to cause decreased oestrogen levels resulting in atrophic vaginitis. ⁶ It is also possible that these organisms are potential causes of persistent vaginal discharge during pregnancy or in a non-obstetric setting. In addition, repeat HVSs may be required to confirm the diagnosis in patients presenting with discharge that does not appear physiological as sensitivity of swabs may be suboptimal. The existing scientific knowledge of Group C β-haemolytic Streptococci in patients with vaginal discharge is limited. Further research is required into these commensal bacteria as potential pathogens.