Granuloma inguinale, also known as granuloma venereum or donovanosis, is a chronic, mildly contagious STD caused by the bacterium Calymmatobacterium granulomatis, which contaminates food and water. It produces thick, puffy, red sores on and around the genitals and anus and, occasionally, in nongenital areas.
Incidence and Prevalence of Granuloma
Granuloma inguinale occurs most commonly in underdeveloped tropical regions (i.e., parts of India, South America, Australia, southern Africa, and the Caribbean) where irrigation and agriculture are chiefly unregulated. Fewer than 20 cases are reported each year in the United States, and these probably were contracted while traveling in an endemic area. It usually occurs in heterosexual men between the ages of 20 and 40.
Causes and Risk Factors for Granuloma
The bacterium that causes granuloma inguinale is found in contaminated food or water and, once digested, is then sexually transmitted, often through anal or oral-anal sex. The disease also can be transmitted from mothers to newborns during delivery.
Though only moderately contagious, it is transmitted most easily before symptoms appear.
Signs and Symptoms of Granuloma
Donovanosis may first cause gastrointestinal problems, such as diarrhea and rectal pain. Its primary symptom is the development of lesions that resemble ulcers caused by chancroid, syphilis, or herpes, but are typically larger. Lesions usually appear on the skin or mucous membranes of the genitals, anus, and groin 2 weeks to 3 months after infection.
In men, sores usually first appear on the head (glans) or shaft of the penis; in women, they appear at the entrance to the vagina or on the inner labia. The sores are not especially painful, but often spread along the warm, moist folds of skin throughout the groin to the anus, and cause discomfort. Re-infection to other parts of the body through touching or scratching is possible, but uncommon.
Untreated donovanosis can spread throughout the groin, leading to inguinal (i.e., inner thigh area) subcutaneous tissue swelling that resembles lymph node infection. Longstanding lesions can cause scarring.
Diagnosis involves visual observation of physical signs, sexual and travel history, and biopsy, in which a lesion tissue sample is collected and examined microscopically. Blood tests are performed to identify the bacterium and differentiate it from other STDs that produce sores.
Treatment for Granuloma
Antibiotics are prescribed for at least 3 weeks or until lesions heal, which may take months. Doxycycline, minocycline, erythromycin, and sulfamethoxazole are common treatments. Sores generally begin to clear within a week after initiating treatment and often heal completely in 5 weeks. Observation is necessary for about 6 months after successful treatment.