There were no other reports of close contact

with bats or exploration of caves during the field trip. One student with serologically confirmed histoplasmosis had merely peered into the tree through the window in its trunk. Nine of the 13 students developed symptoms in the first 15 days after leaving the buy NU7441 rainforest (symptom onset was 40 days in one case; unknown in three). The students left the rainforest on July 20, 2011. Seven students specified a date between July 26 and August 4, 2011, when their symptoms began, supporting the likelihood of a common source. Six were not in their country of residence when they first needed medical attention (two still in Uganda, two in Kenya, one in Indonesia, and one in Canada). At least three were hospitalized for further investigation. Not all the cases were diagnosed as acute pulmonary histoplasmosis, but in each case the clinical picture was highly suggestive of this diagnosis retrospectively. In five cases the diagnosis of histoplasmosis was confirmed with positive serology. At least six students

were initially thought to have miliary tuberculosis and two commenced antituberculous medication. This is the largest outbreak of pulmonary histoplasmosis reported in short-term travelers to Africa, with an intriguing source, a hollow selleck chemical bat-infested tree trunk in the Ugandan rainforest. The presentation and Thiamet G diagnosis of pulmonary histoplasmosis in travelers are discussed below. Histoplasma capsulatum is a dimorphic fungus. There are two varieties that are pathogenic to humans, var. duboisii and var. capsulatum. The former exists only in Africa, while var. capsulatum is most prevalent in regions of North, Central, and South America but has also been reported from parts of Africa, Southern and Eastern Europe, Eastern Asia, and Australia.[1, 2] Histoplasmosis grows as a mold in soil enriched with large amounts

of bird or bat guano.[1] Humans become infected when such soil is disturbed, allowing aerosolization and inhalation of the infectious microconidia. Activities associated with exposure include cleaning chicken coops, bird roosts, attics, and barns; caving; excavation; construction, renovation, and demolition.[3] Histoplasma capsulatum var. duboisii mainly involves the skin, subcutaneous tissues, lymph nodes, and bones. It rarely affects the lungs and appears to pose less of a risk to travelers.[4] The clinical features of the outbreak described in this article are much more consistent with infection caused by H capsulatum var. capsulatum. Its clinical manifestations vary according to host immunity and exposure intensity, ranging from asymptomatic infection (in most healthy persons exposed to a low inoculum) to life-threatening pneumonia with respiratory failure.