What is chancroid?
Chancroid is a sexually transmitted infection (STI) caused by the bacteria Haemophilus ducreyi. It is rare in New Zealand. It is characterised by painful ulcers on the genitals and painful swollen lymph glands.
Who is at risk of chancroid?
Sexually active people may be at risk of getting chancroid. It remains common in many countries in Africa, the Caribbean basin and Southwest Asia. In countries where it is less frequently seen, cases are most probably related to foreign travel. It is more commonly seen in heterosexual men than in women, particularly in uncircumcised males.
What are the signs and symptoms of chancroid?
Most people with chancroid will develop one or more red, inflamed lumps in the genital area 3-7 days after being infected during sexual intercourse. These become larger and pus-filled until they rupture, leaving a painful ulcer. If left untreated, 50% of cases develop infected lymph glands, which become large, hard painful lumps (buboes), on either one or both sides of the groin.
The site of most infections in men is the foreskin but other parts of the penis may be affected. Men usually seek medical care for these painful genital lesions.
In women, ulcers may be located on the labia, thigh, perineum and cervix. Women generally have less specific symptoms such as painful urination or pain on passing bowel motions (defaecation), vaginal discharge, painful sexual intercourse (dyspareunia) and rectal bleeding. Some women may have an infection but complain of no symptoms (asymptomatic carriers).
How is the diagnosis of chancroid made?
A definite diagnosis requires culture of Haemophilus ducreyi. This needs a special culture media that is not widely available. A probable diagnosis can be made if the clinical features are typical and other causes of genital ulceration, particularly syphilis and herpes simplex have been ruled out. Other tests such as polymerase chain reaction (PCR) are not routinely available.
Genital ulcer disease eg chancroid or syphilis, increases the risk of HIV infection so HIV testing should be undertaken as well.
What is the treatment for chancroid?
Chancroid is treated with antibiotics. The antibiotics of choice are azithromycin, ciprofloxacin, ceftriaxone or erythromycin. Chancroid ulcers should improve within 7 days once appropriate antibiotics have been started. However, those with HIV infection may respond more slowly. Anyone not responding to treatment within 7 days should be reassessed. In some cases, surgical treatment is required to drain infected lymph glands (buboes).
Sexual activity should not take place until all the lesions have completely healed. Untreated ulcers may persist for 1-3 months.
Can chancroid be prevented?
If you think you are infected, stop all sexual contact and see your doctor or sexual health clinic. Notify all sexual contacts immediately (including those within the last 10 days who may not have developed lesions) so they can be checked for infection and treated appropriately. Safe-sex practices to prevent the spread of chancroid include:
- Limiting the number of sex partners
- Use condoms