22nd May 2024

Urinary and Sexually Transmitted Infections

Urinary Tract Infections

Background

Urinary tract infections (UTIs) can be classified into lower, upper (i.e. pyelonephritis) and catheter associated UTIs. Antibiotic management differs for each class and between men, non-pregnant women and in pregnancy. Initial investigations and additional management do not differ between groups. Initial investigations include obtaining a urine sample for urine dipstick and laboratory microscopy, culture and sensitivities. Additional management includes pain relief and ensuring the intake of sufficient fluids. There has been no evidence found for cranberry products or urine alkalinising agents to treat lower UTIs. All antibiotics should be reviewed when sensitivities are available, adjusting if resistance is present.

Asymptomatic bacteriuria is significant levels of bacteria in urine with no UTI symptoms. It is not screened for or treated in non-pregnant women, men, children or young people. For pregnant people, it is screened for and treated as it is a risk factor for pyelonephritis and premature delivery.

Catheter-Associated UTI

Catheter-associated UTI is a symptomatic infection of the bladder or kidneys in a person with a urinary catheter. Antibiotic prophylaxis to prevent catheter-associated UTIs is not recommended. Asymptomatic bacteriuria is common in people with catheters. It can be found in almost all catheterised people one month after catheterisation. It, therefore, does not need to be treated if asymptomatic.

Management

• Remove, or if not possible, change the catheter if it has been in situ for less than 7 days.
• Give oral antibiotics as a first-line if people can take oral medicines and the severity of their condition does not require intravenous antibiotics.
• Give IV antibiotics if vomiting, unable to take oral antibiotics or severely unwell. Review intravenous antibiotics within 48 hours and consider stepping down to oral antibiotics where possible

Upper UTI

Lower UTI

Lower UTI (cystitis) is a bladder infection usually caused by bacteria travelling up to the urethra from the gastrointestinal tract. Management involves antibiotics and symptomatic management as described in ‘Background’.

References

• National Institute for Health Care Excellence. Urinary tract infection (lower): antimicrobial prescribing. London: NICE; 2018.(NICE Guideline No. 109). Available from: https://www.nice.org.uk/guidance/ng109
• National Institute for Health Care Excellence. Urinary tract infection (catheter associated): antimicrobial prescribing. London: NICE; 2018.(NICE Guideline No. 113). Available from: https://www.nice.org.uk/guidance/ng113
• National Institute for Health Care Excellence. Urinary tract infections in adults. London: NICE; 2015. (NICE Guideline No. qs90). Available from: https://www.nice.org.uk/guidance/qs90

Sexually Transmitted Infections

Background

Sexually transmitted infections (STIs) include many diseases, the prevalence of which changes over time and geographical location. As with all diseases, prevention is better than cure. If any STI is suspected, it is important to take the opportunity to screen for syphilis and HIV. Depending on the patient demographics, other STIs may also need to be screened for, for example an IVDU should have hepatitis B testing. Remember that STIs can infect areas other than the genitalia, for example the pharynx and anus. Applicable to all STIs, partner notification is crucial, as is the possibility of reinfection. The complications of STIs can include pelvic inflammatory disease, infertility or wider systemic illness. People at most risk of contracting STIs include men who have sex with men, people from or who have visited areas of high HIV prevalence, people who misuse alcohol and/or substances, people who have early onset of sexual activity and people who have do not use barrier protection and frequently change or have multiple sexual partners.

Diagnosis and Treatment

Gonorrhoea

Caused by a monomorphic gram-negative diplococcus Neisseria gonorrhoeae. The main symptom is vaginal/urethral discharge. Men are diagnosed via direct microscopy from a urethral swab (the diplococci will be seen within polymorphonuclear leukocytes). Women and men can be diagnosed using nucleic acid amplification test (NAAT) from a vulvovaginal swab or male urethral swab. All patients should have samples for culture for antibiotic sensitivity (this is increasingly important as resistant strains are common). However, diagnostic tests may not be accurate if the initial infection was under 2 weeks ago. Treat with one dose of Ceftriaxone 1g intramuscularly, or if known to be sensitive, give one dose of Ciprofloxacin 500 mg orally (not in pregnancy). Remind the patient to abstain from sexual intercourse until seven days after they and their partner(s) have completed treatment. All patients should return for a test of cure.

Chlamydia

Caused by obligate intracellular (can only survive inside a cell) bacterium; Chlamydia trachomatis. It is the most commonly reported curable bacterial STI in the UK. It can be asymptomatic or cause discharge. Diagnosed using NAAT on vulvovaginal swab for women and first catch urine for men. Managed with Doxycycline 100mg BD for seven days (contraindicated in pregnancy) OR Azithromycin 1g orally as a single dose, followed by 500 mg OD for two days.

Trichomonas vaginalis (TV)

Caused by a flagellated protozoan. It can also be asymptomatic, though classically causes a frothy yellow discharge. Other symptoms include dysuria and local itching/irritation. Women are diagnosed by NAAT from a swab from the posterior fornix during speculum examination or by a self-taken swab. Men need NAAT from a urethral swab.

Treat with Metronidazole 2g PO in a single dose or Metronidazole 400-500mg BD for 5-7 days. Abstain from alcohol for the duration of treatment and for at least 48 hours after the treatment course ends.

Bacterial Vaginosis (BV)

Caused by an imbalance of usual vaginal bacterial flora, thus only affects those with a vagina. There is debate about whether BV is merely an imbalance in vaginal ecology or is initiated as a sexually transmitted infection. Important to counsel the patient on this. BV can be asymptomatic. Symptoms, if present, can include a thin, white, offensive fishy smelling discharge. Diagnosed using gram stain of vaginal smear. Treated with Metronidazole 400mg BD for 5-7 days OR Metronidazole 2 g single dose OR Intravaginal Metronidazole gel (0.75%) OD for 5 days (avoid alcohol with Metronidazole). Lifestyle advice includes avoiding vaginal douching, use of shower gel, and use of antiseptic agents or shampoo in the bath.

Herpes

Caused by either herpes simplex virus type 1 (HSV-1), now the most common cause of genital herpes, or type 2 (HSV-2), historically the most common cause of genital herpes. Following primary infection, the virus becomes latent in local sensory ganglia, periodically reactivating to cause symptomatic lesions or asymptomatic but infectious viral shedding. Any patient who presents with genital ulceration should be screened for herpes.

Initial infection and reactivation causes painful ulcers, dysuria, vaginal or urethral discharge and tender inguinal lymphadenitis (usually bilateral). Infection can also cause systemic symptoms such as fever and myalgia. This STI is characterised by numerous extremely painful ulcers and the severity of pain often increases on micturition.

Diagnosis is using NAAT from swabs from the base of the lesion.

Management is reliant on whether this is the first episode or a reactivation. If it is the patient’s first episode, they can be prescribed Aciclovir PO 400 mg TDS for 5 days or Valaciclovir 500 mg BD for 5 days. Recurrent episodes are self-limiting and generally cause minor symptoms. They can be treated symptomatically and, if the patient wishes, have a short course of Aciclovir 800 mg TDS for 2 days or Famciclovir 1g BD for 1 day. If the patient is pregnant, seek GUM advice and inform their obstetrician. All patients can manage their symptoms with saline bathing, analgesia and topical anaesthetic agents such as 5% Lidocaine (lignocaine) ointment.

Syphilis

Caused by spirochete bacterium Treponema pallidum subspecies pallidum. If untreated, the disease progresses through three stages. It can also be transmitted vertically, resulting in congenital syphilis, hence routine antenatal screening in the UK.

Syphilis causes a wide range of symptoms, being called “the great imitator”. Primary syphilis is characterised by a chancre which is a single, painless non-purulent and indurated ulcer with a clean base. It develops from a single papule and self resolves within 3-8 weeks. Secondary syphilis occurs 4-10 weeks after initial chancre and includes a widespread mucocutaneous rash typically involving the palms and soles as well as hepatitis, splenomegaly, glomerulonephritis and a range of neurological presentations. This stage then resolves spontaneously over 3–12 weeks, entering an asymptomatic latent stage. Finally, there is late (tertiary) disease which occurs in approximately one third of untreated patients 20-40 years after initial infection. It can be divided into gummatous, cardiovascular and neurological complications.

Diagnosis relies on clinical examination and dark ground microscopy. Examination of the genitals, skin (eyes, mouth, scalp, palms and soles) and neurological system will help identify the stage of progression. Dark ground microscopy from a swab sample of a lesion will allow actual visualisation of the live treponemes. VDRL/RPR blood tests are used to monitor treatment response or disease progression.

Management of primary, secondary and early latent stages require Benzathine Penicillin G 2.4 MU IM as a single dose. If pregnant and in the first and second trimesters, the same single dose is used. However, in the third trimester the dose is repeated on day 8. If the patient is not pregnant and the disease is in the late latent or tertiary stage, repeat the dose weekly for three weeks (three doses in total). If pregnant, repeat the dose on days 1, 8 and 15.

Follow up for all is recommended with clinical examination and RPR or VDRL at three, six and 12 months, then if indicated, six-monthly until VDRL/RPR negative.

Pelvic inflammatory disease (PID)

Pelvic inflammatory disease (PID) is an infection originating from the endocervix and ascending into the genital system, causing endometritis, salpingitis, parametritis, oophoritis, tubo-ovarian abscess and/or pelvic peritonitis. The risk of developing PID is increased for 5-6 weeks after insertion of an intrauterine device (IUD). PID is suspected in any non-pregnant woman under 25 years old who has recent onset, bilateral lower abdominal pain associated with local tenderness on bimanual examination. There is a low threshold for treating the patient with broad spectrum antibiotics as a delay increases the risk of long-term complications such as ectopic pregnancy, infertility and pelvic pain. Remember, if the patient also has right upper quadrant pain, they may have peri-hepatitis which is indicative of Fitz-Hugh-Curtis syndrome.

References

• British association for sexual health and HIV. Guidelines. Available from: https://www.bashh.org/guidelines
• National Institute for Health Care Excellence. Sexually transmitted infections and under-18 conceptions: prevention. London: NICE; 2007.(NICE Guideline No. ph3). Available from: https://www.nice.org.uk/guidance/ph3