| Clinical
Features |
Symptomatic infection usually presents
as a flu-like illness with fever, cough, headaches, and myalgias.
Some patients fail to recover and develop chronic pulmonary
infection or widespread disseminated infection (affecting
mucosal surfaces, liver, spleen, adrenal gland and meninges).
Acute septic presentation seen in some HIV-infected persons |
| Etiologic
Agent |
Histoplasma capsulatum var.
capsulatum. In Africa: H.capsulatum var. duboisii. |
| Reservoir |
Soil contaminated with bird or bat
droppings. Endemic in parts of the central and eastern United
States along Ohio and Mississippi river valleys. Microfoci
in Central and South America, Africa, India, and Southeast
Asia. |
| Incidence |
Approx. 80% of population living
in areas with endemic disease is skin-test positive. Of HIV-infected
persons in these areas, 10% - 25% develop disseminated histoplasmosis. |
| Sequelae |
Permanent lung damage with chronic
disease. Mortality rate is about 10% in HIV-infected persons
with disseminated disease. |
| Transmission |
Inhalation of airborne conidia (spores)
after disturbance of contaminated soil. |
| Risk
Groups |
Persons in areas with endemic disease
with exposures to accumulations of bird or bat droppings (e.g.,
construction or agricultural workers, spelunkers). High risk
groups are immunocompromised persons (e.g., persons with cancer,
transplant recipients, persons with HIV infection). |
| Surveillance |
Reportable in some states in areas
with endemic disease. No national surveillance exists. |
| Challenges |
Defining risk factors for disease
in immunocompromised persons. Developing more sensitive and
specific tests for diagnosis. |
|
December 2003
|
