Abstract
We report a case of simultaneous identical Escherichia coli urinary tract infections in a male homosexual couple practising unprotected insertive anal intercourse, and propose sexual transmission between the couple.
INTRODUCTION
The relationship of sexual activity and urinary tract infections (UTIs) in women is well documented. We report a case of simultaneous UTIs in a male homosexual couple and propose sexual transmission between the couple.
CASE REPORT
A 35-year-old male presented to genitourinary medicine clinic with a one-day history of dysuria, frequency and haematuria. He was otherwise medically well with no history of urinary infections. He had been treated for urethral chlamydia one year previously. Examination revealed evidence of mucopurulent urethral discharge and urethral microscopy confirmed urethritis. He was informed he had non-specific urethritis (NSU) and treated accordingly with azithromycin. His urinalysis showed leukocytes, but this was presumed to be due to a frank urethritis. He was provided with a contact slip for his partner. Laboratory tests were subsequently negative for chlamydia and gonorrhoea. Urine culture grew Escherichia coli. He was recalled and given UTI treatment with cefalexin 500 mg three times a day, which resulted in complete resolution of his symptoms.
Two days after the 35-year-old's NSU diagnosis, his 30-year-old partner presented to the clinic as a symptomatic contact. He complained of one day of mild dysuria.
Examination was normal and there was no evidence of urethritis on urethral microscopy. His HIV test was negative. He was treated empirically with azithromycin as a contact of NSU. Chlamydia and gonorrhoea tests were subsequently negative.
One week later, he reattended with one day history of severe dysuria and macroscopic haematuria. There had been no further sexual exposure. Urethral microscopy yielded 20 pus cells/field. Urine dip showed evidence of UTI with positive nitrites, leukocytes and blood. He was prescribed seven days of cefalexin 500 mg three times a day.
His midstream urine (MSU) specimen subsequently grew E. coli, with an identical antibiogram to his partner. Following seven days of treatment he had persistent urinary symptoms. Repeat MSU confirmed ongoing infection with E. coli and he was treated with an additional prolonged course of trimethoprim. Ultrasound imaging of his renal tract was normal and his symptoms settled.
SEXUAL HISTORY
The men were in a monogamous relationship. They both practised unprotected insertive and receptive anal sex.
DISCUSSION
This appears to be a case of sexual transmission of E. coli in a homosexual couple resulting in almost simultaneous UTIs. The role of sexual transmission in relation to UTIs in homosexual men is unclear. E. coli are commonly part of normal bowel flora. We hypothesize that one or both men were infected by uropathogenic E. coli (UPEC) via sexual exposure. E. coli are a consistent inhabitant of the human gastrointestinal tract. 1 Individuals usually carry more than one serotype and acquisition is thought to be by the oral route. UPEC cause 90% of UTIs in people with anatomically normal urinary tracts. 1 Various virulence factors associated with UPEC make them highly adapted as urinary tract pathogens, for example virulence factors such as fimbrial adhesins, e.g P fimbria.
Reports demonstrate that household contacts 2–5 are frequently colonized with similar populations of gut bacteria, particularly E. coli. Sexual partners/couples are more commonly colonized with shared strains than other household contacts, thus sexual transmission of E. coli has been postulated. 2 Lietzau et al. investigated concurrency of resistant E. coli bowel colonization in male and female sexual partners. They found that carriage of resistant E. coli in the partner was a risk factor for colonization, and suggested a conjugal role for transmission of resistant E. coli. 6
A report in the Lancet in 1986 showed high rates of E. coli bacteriuria in sexually active homosexual and bisexual men with urinary symptoms, when compared with heterosexual men. 7 However, there is little recent literature describing UTI in men engaging in anal sex. Reports are sparse for both anal sex between men, and heterosexual anal intercourse and UTI is not generally been considered a sexually transmitted infection.
The simultaneous manifestation of acute severe UTI with identical organisms following anal sex as described in this male couple suggests a possible role of sexual transmission in gay men practising unprotected anal sex.