Donovanosis

The most common cause of donovanosis is sexual exposure to those infected with the Klebsiella granulomatis bacteria. Certain risk factors that can increase the risk of infection include having multiple sexual partners and engaging in unprotected sex. In rare instances, the bacteria may also be transmitted through fecal matter or direct skin-to-skin contact. For this reason, donovanosis can also be seen in young children and adults who are not sexually active.  

Donavanosis can be prevented by using condoms during penetrative sex and refraining from sexual activity when visible lesions are present. 

The incubation period of donovanosis can range widely, from 1-4 weeks to as long as a year, but the signs and symptoms generally appear within a few weeks.  

The infection usually starts as a firm, raised lump that ulcerates, or becomes red and tender. Genital ulcers are the most common symptom of donovanosis. About 10% of cases feature ulcers in the surrounding groin region, and ulcers may also be seen around the anus and mouth. Very rarely, donovanosis can spread to the bone and liver, often resulting in joint pain or swelling, weight loss, fever, night sweats, or malaise. 

There are four types of donovanosis based on the appearance of lesions: ulcerogranulomatous, hypertrophic, necrotic, and fibrous. Most commonly, the ulcer becomes ulcerogranulomatous, with a beefy-red appearance and granulation tissue that is highly vascular (i.e., containing many blood vessels). For this reason, these ulcers bleed easily despite being painless. Hypertrophic, or verrucous, ulcers have an irregular edge and can be completely dry, while necrotic ulcers are deeper, foul-smelling, and often painful to the touch. Lastly, fibrous ulcers resemble painless scar tissue.  

Donovanosis can be diagnosed by taking a culture of the ulcer using a cotton swab. The swab is then rolled across a slide and stained using Giemsa stain, a common microscopic stain used for diagnosis. Electron microscopy can then be used to identify donovan bodies, which are clusters of dark-staining bacteria seen within large, mononuclear cells. These are microscopic features specific to the bacteria that cause donovanosis.  

Other techniques that can be used for diagnosis include polymerase chain reaction (PCR), which allows clinicians to identify the specific bacteria in the ulcer based on its DNA, as well as blood tests and biopsies. Biopsies taken from the infected area would show changes in the cell types that indicate inflammation and can confirm diagnosis of donovanosis.  

Donovanosis is primarily treated using antibiotics, specifically azithromycin, which stops the growth of bacteria. The ulcers should start healing within days after starting antibiotic therapy. If the infection has persisted, or if it has progressed to a later stage, antibiotic therapy may need to last several weeks. Even if the symptoms start to subside, the antibiotic course should be completed, and a follow-up visit is usually recommended to make sure the infection is completely healed. Notably, the ulcers from donovanosis can bleed easily and are a known risk factor for the transmission of HIV, which cannot be treated with antibiotics but requires antiretroviral therapy (ART). Pain medications may also be administered to address discomfort. 

If donovanosis goes untreated, the ulcer will slowly keep growing and may destroy larger areas of healthy skin, cause scarring, and infiltrate the surrounding lymphatic vessels, causing obstruction. Long-standing infection may even be linked to cancer of the genitals. In these situations, surgery may be required to remove the concerning ulcers.