It's now three years after the previous post. There was bound to be a paper showing a possible link between histoplasma and PD, it's just one case and causality is unclear, but still interesting nevertheless.

Eid et al. report [1] a "case of Histoplasma capsulatum infection localized to the central nervous system (CNS). ... A 53-year-old woman ... presented with slowly progressive weakness in the lower extremities, new-onset numbness below the midthoracic area, urinary incontinence, and slurred speech. One year prior to presentation, she experienced left-sided transitory weakness involving the face and extremities. ... her brain imaging studies were unrevealing. She later developed tremor in the upper extremities and she was suspected to have central tremor or Parkinson’s disease."

They conclude:
"Histoplasmosis should be considered in the differential diagnosis of patients experiencing slowly progressive neurological deficit."

Reference:

[1] "Compartmentalized Histoplasma capsulatum Infection of the Central Nervous System"
Albert J. Eid, John D. Leever and Kathrin Husmann
Case Reports in Infectious Diseases Volume 2015 (2015), Article ID 581415
http://www.hindawi.com/journals/criid/2015/581415/

John