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Fungal infections in AIDS. Histoplasmosis and coccidioidomycosis
1Infectious Disease Service, Memorial Sloan-Kettering Cancer Center, New York, New York.
Abstract:
Histoplasma capsulatum and Coccidioides immitis are two fungi that are regional in occurrence and cause opportunistic fungal infections in patients with AIDS. Many cases of histoplasmosis have been reported in patients months or years after they have been in an endemic area. These are obviously cases of reactivation of latent infections. With coccidioidomycosis, the cases have been reported from endemic areas, but some also appear to be reactivation infections, and we should anticipate such cases in nonendemic areas just as with histoplasmosis. The clinical presentations may be atypical, even mimicking acute bacterial sepsis. The diagnosis should be sought in any HIV-infected patient with an unexplained infection and residence or travel in an endemic area even in the remote past. Studies should include bone marrow examinations for histoplasmosis as well as skin biopsies with special strains and cultures for fungi for both infections. Sputum or bronchoscopy specimens have often been the source of a diagnosis in coccidioidomycosis. Serologic tests for antibody in both diseases yield inconsistently positive results in AIDS patients. Treatment of the acute infection should be with amphotericin B followed by maintenance suppressive therapy with ketoconazole or Amphotericin B.
Insights
Opportunistic fungal infections like histoplasmosis and coccidioidomycosis can reactivate in patients with AIDS, even years after exposure. Early diagnosis and treatment are crucial for managing these serious infections.
Area of Science:
- Mycology
- Infectious Diseases
- Immunocompromised Host Research
Background:
- Histoplasma capsulatum and Coccidioides immitis are endemic fungi causing opportunistic infections.
- Patients with acquired immunodeficiency syndrome (AIDS) are particularly susceptible.
- Reactivation of latent infections is a significant concern in both histoplasmosis and coccidioidomycosis.
Observation:
- Cases of histoplasmosis reactivation occur months or years after leaving endemic areas.
- Coccidioidomycosis cases, including reactivation, are reported from endemic and nonendemic areas.
- Clinical presentations can be atypical, mimicking bacterial sepsis.
Findings:
- Diagnosis requires considering travel or residence history in endemic areas for HIV-infected patients with unexplained infections.
- Diagnostic methods include bone marrow exams (histoplasmosis), skin biopsies, fungal cultures, and sputum/bronchoscopy specimens (coccidioidomycosis).
- Serologic tests for antibodies show inconsistent positivity in AIDS patients.
Implications:
- Anticipate reactivation of endemic fungal infections in HIV-infected individuals, regardless of current location.
- Prompt and thorough diagnostic workup is essential for timely treatment.
- Amphotericin B followed by suppressive therapy (ketoconazole or Amphotericin B) is the recommended treatment regimen.