Acute histoplasmosis outbreak in a family group: identification of infection source

Abstract

An outbreak of acute histoplasmosis occurring in 4 members of the same family, two women, a girl and a male, is reported. The index case presented acute respiratory symptoms, severe enough to require hospitalization. In the remaining persons, the infection was asymptomatic but was evidenced by reactive histoplasmin serologic tests. Search for the common source of infection led to an enriched soil obtained in a local nursery for growing in-door plants. BALB/c mice were inoculated with suspensions of soils from the potted plants. Histoplasma capsulatum var. capsulatum was isolated from various internal organs of the mice. Although histoplasmosis is observed more frequently in persons with occupations implying risk of exposure and is connected to rural areas, outbreaks and intra-family cases are now common in urban areas. This is due to massive urbanization, deforestation, demolitions and the use of soils enriched with organic compounds, mainly bird/bat excrements. This report calls the attention on the danger involved in using such enriched soils for plant nutrition.