Donovanosis¶
Chapter 178 | Part 5: Infectious Diseases
KEY CLINICAL POINTS¶
- Donovanosis is a chronic bacterial infection caused by Klebsiella granulomatis (formerly Calymmatobacterium granulomatis), primarily affecting the genital region.
- Clinical features include painless genital ulcers, granulomatous lesions, and extragenital involvement in 6% of cases.
- Diagnosis is confirmed by identification of Donovan bodies in tissue smears or PCR testing.
- Treatment involves antibiotics like azithromycin, doxycycline, or erythromycin, with lifelong suppressive therapy in immunocompromised patients.
- Complications include pseudoelephantiasis, urethral stenosis, and increased HIV transmission risk.
1. DEFINITION & OVERVIEW¶
Donovanosis is a chronic, progressive bacterial infection caused by Klebsiella granulomatis, primarily affecting the genital region. It is classified as a sexually transmitted infection (STI) with low infectivity. The disease presents with painless ulcers and granulomatous lesions, often mistaken for other STIs. The condition was first described in Calcutta in 1882 and named after Charles Donovan, who identified characteristic Donovan bodies in 1905.
1.1 Etiology and Taxonomy¶
The causative agent, Klebsiella granulomatis, was reclassified from Calymmatobacterium granulomatis based on phylogenetic analysis. However, some authorities prefer the original nomenclature due to 16S rRNA gene sequence analysis. The organism is a gram-negative coccobacillus that forms intracellular Donovan bodies in macrophages.
1.2 Clinical Spectrum¶
The disease presents in two phases: the acute ulcerogranulomatous stage (Donovanosis) and the chronic stage (pseudoelephantiasis). Lesions may involve the genitalia, perineum, and extragenital sites like the lips, gums, and pharynx. In pregnant women, lesions progress more rapidly.
2. EPIDEMIOLOGY¶
Donovanosis is endemic in tropical and subtropical regions, including Papua New Guinea, southern Africa, India, the Caribbean, and parts of South America. It is associated with poor hygiene and socioeconomic factors, predominantly affecting men. Global incidence has declined due to improved management of genital ulcers, which are risk factors for HIV transmission.
Geographic Distribution of Donovanosis¶
| Region | Status | Notes |
|---|---|---|
| Australia | Eliminated | Sustained public health programs |
| South Africa | Near elimination | Targeted interventions |
| Caribbean | Endemic | High prevalence in some islands |
| India | Endemic | Historically common in tropical regions |
2.1 Geographic Distribution¶
Endemic regions include: Papua New Guinea, southern Africa, India, the Caribbean, French Guyana, Brazil, and Aboriginal communities in Australia. Australia nearly eliminated the disease through public health initiatives.
2.2 Risk Factors¶
Poor hygiene, lower socioeconomic status, male gender, and sexual contact with infected partners. HIV-positive individuals are at higher risk for complications.
3. ETIOLOGY & PATHOPHYSIOLOGY¶
Klebsiella granulomatis infects epithelial cells and macrophages, forming Donovan bodies. The bacterium replicates intracellularly, causing chronic inflammation and granuloma formation. Hematogenous spread may occur, leading to extragenital lesions. The pathogenesis involves immune evasion through type IV secretion systems and effector proteins.
3.1 Transmission¶
Primary transmission occurs through direct contact with genital ulcers. Vertical transmission from mother to fetus and blood transfusion have been reported.
3.2 Pathogenesis¶
Bacteria invade epithelial cells, replicate intracellularly, and induce granuloma formation. Immune evasion mechanisms include type IV secretion systems and effector proteins that modulate host cell signaling.
4. CLINICAL FEATURES¶
The disease progresses through three stages: initial papule, ulcerative lesion, and chronic granulomatous phase. Lesions are typically painless, with a beefy red appearance. Extragenital involvement may occur in 6% of cases. Complications include pseudoelephantiasis, urethral stenosis, and increased HIV transmission risk.
Clinical Features of Donovanosis¶
| Stage | Lesion Type | Complications |
|---|---|---|
| Acute | Ulcerogranulomatous | Pseudoelephantiasis |
| Chronic | Sclerotic/cicatricial | Urethral stenosis |
| Extragenital | N/A | Squamous cell carcinoma |
4.1 Lesion Types¶
Four lesion types are described: (1) classic ulcerogranulomatous, (2) hypertrophic/verrucous, (3) necrotic ulcer, and (4) sclerotic/cicatricial lesions.
4.2 Complications¶
Pseudoelephantiasis, urethral/vaginal stenosis, squamous cell carcinoma, and systemic spread to liver and bone. Neonatal infections may present as ear infections.
5. DIFFERENTIAL DIAGNOSIS¶
Donovanosis must be differentiated from syphilis, chancroid, lymphogranuloma venereum, genital herpes, and neoplasms. Histologic features include chronic inflammation with plasma cell infiltration and Donovan bodies. Mixed infections with other pathogens are common.
5.1 Key Differentiators¶
Painless ulcers vs. syphilitic chancres (which are typically painless), condylomata lata (secondary syphilis), and chancroid (painful ulcers). Histologic examination of granulation tissue reveals Donovan bodies.
6. INVESTIGATIONS & DIAGNOSIS¶
Diagnosis is confirmed by identifying Donovan bodies in tissue smears or using PCR. Serologic tests are not reliable. Direct microscopy with Giemsa or Wright’s stain is preferred. PCR testing detects K. granulomatis DNA and differentiates it from other Klebsiella species.
Diagnostic Tests for Donovanosis¶
| Test | Method | Result Interpretation |
|---|---|---|
| Microscopy | Giemsa/Wright stain | Donovan bodies visible |
| PCR | DNA amplification | Positive for K. granulomatis |
| Histopathology | Biopsy | Granulomatous inflammation |
6.1 Diagnostic Methods¶
Microscopic examination of tissue smears for Donovan bodies, PCR for K. granulomatis DNA, and histopathology showing granulomatous inflammation. Blood tests may reveal anemia and thrombocytopenia in systemic cases.
7. MANAGEMENT & TREATMENT¶
Treatment includes oral antibiotics (azithromycin, doxycycline, erythromycin) for 3–6 weeks. Lifelong suppressive therapy may be required in immunocompromised patients. Surgical intervention is indicated for complications like stenosis. Public health measures focus on education and hygiene promotion.
Antibiotic Regimens for Donovanosis¶
| Drug | Dose | Duration |
|---|---|---|
| Azithromycin | 1g single dose | 1 day |
| Doxycycline | 100mg BID | 3 weeks |
| Erythromycin | 500mg TID | 3 weeks |
7.1 Pharmacologic Therapy¶
First-line: Azithromycin 1g single dose, doxycycline 100mg BID for 3 weeks, or erythromycin 500mg TID for 3 weeks. Adjunctive treatment for secondary infections (e.g., Salmonella).
8. PROGNOSIS & COMPLICATIONS¶
Without treatment, mortality from Oroya fever (acute phase) can reach 40%. Chronic complications include pseudoelephantiasis, urethral stenosis, and increased HIV transmission risk. Early diagnosis and treatment improve outcomes, with cure rates exceeding 90% with appropriate antibiotics.
Prognostic Factors¶
| Factor | Impact |
|---|---|
| Early treatment | Improved cure rates |
| HIV co-infection | Increased mortality |
| Extragenital spread | Higher complication risk |
8.1 Mortality and Morbidity¶
Mortality from Oroya fever: 40% without treatment vs. ~10% with antibiotics. Complications include bacterial superinfection, neurologic manifestations, and cardiac involvement.
9. SPECIAL CONSIDERATIONS¶
Pregnancy: Lesions progress more rapidly but respond poorly to treatment. Neonatal infections may present as ear infections. HIV-positive patients require prolonged suppressive therapy. Public health measures focus on education, hygiene, and partner notification.
9.1 Pregnancy¶
Lesions develop more rapidly during pregnancy, with delayed response to treatment. Neonatal transmission is rare but possible.
9.2 HIV Co-infection¶
Donovanosis is a risk factor for HIV acquisition. Immunocompromised patients require lifelong suppressive therapy.
10. KEY POINTS & CLINICAL PEARLS¶
Donovanosis is a neglected STI with low infectivity. Diagnosis relies on identifying Donovan bodies in smears or PCR. Early treatment prevents complications. Public health initiatives are critical for reducing transmission. HIV-positive patients require prolonged suppressive therapy.