Urinary Tract and Genital Infections including Sexually Transmitted Infections (STIs)

Abstract

Urethritis, characterized by inflammation of the urethra in men, is caused by Neisseria gonorrhoeae (gonococcus), Chlamydia trachomatis, Trichomonas vaginalis, and Mycoplasma genitalium. Other causes of non-gonococcal urethritis include ureaplasmas, adenoviruses, and herpes simplex viruses. The presence of urethritis is confirmed by the presence of five or more polymorphs in urethral smear by high-power microscopy. Symptoms can be minor to profound and vary from clear to mucopurulent discharge. Gonococcus is commoner in men who have sex with men (MSM) compared to heterosexuals, and high-risk activities such as chemsex parties increase spread with significant public health consequences. Antibiotic resistance in gonococcus has clinical and public health implications as three cases of extensively drug-resistant Neisseria gonorrhoeae with resistance to ceftriaxone (MIC = 0.5 mg/L) and high-level resistance to azithromycin (MIC > 256 mg/L) have been described compromising current treatment recommended by British Association for Sexual Health and HIV Guidelines (BASHH). In England an outbreak of high level azithromycin-resistant gonococcus has also been described by Public Health England (PHE), who alerted clinicians about the need for follow up and test of cure, contact tracing, and treatment failure. C. trachomatis infection can be treated with azithromycin 1g orally as a single dose or with seven days of oral doxycycline. Risk factors for chlamydia include age younger than twenty-five years, multiple sexual partners, and avoidance of barrier methods for contraception. Metronidazole 2g single dose or 400– 500mg twice daily for seven days is recommended for treatment of trichomonas, which can cause a moderate discharge in up to 60% of males. Resistance to azithromycin and doxycycline is common in M. genitalium strains and management of these patients with urethritis requires GUM referral for comprehensive investigation, contact tracing, and public health notification. Molecular methods are used for the diagnosis of these organisms and gonococcal culture is undertaken to obtain antimicrobial susceptibility data from patients with a previous diagnosis by molecular method, in GUM attendees, and their contacts. Herpes simplex infection results in a painful ulcer preceded by a vesicle. The diagnosis can be confirmed using polymerase chain reaction (PCR) tests of a swab taken from the vesicle or ulcer.