Pythiosis

[1] The disease is contracted after exposure to stagnant fresh water such as swamps, ponds, lakes, and rice paddies.

P. insidiosum is different from other members of the genus in that human and horse hair, skin, and decaying animal and plant tissue are chemoattractants for its zoospores.

Pythiosis occurs in areas with mild winters because the organism survives in standing water that does not reach freezing temperatures.

Pythiosis is suspected to be caused by invasion of the organism into wounds, either in the skin or in the gastrointestinal tract.

[3] The disease grows slowly in the stomach and small intestine, eventually forming large lumps of granulation tissue.

In horses, subcutaneous pythiosis is the most common form and infection occurs through a wound while standing in water containing the pathogen.

[16] A recently published review lists nine cases of vascular pythiosis with five survivors receiving surgery with free margins and all except one requiring amputation.

[citation needed] Other animals reported to have contracted pythiosis are bears, jaguars, camels, and birds, although these have only been singular events.

[citation needed] Pythiosis is suspected to be heavily underdiagnosed due to unfamiliarity with the disease, the rapid progression and morbidity, and the difficulty in making a diagnosis.

In cytology and histology, the organism does not stain using Giemsa, H&E, or Diff-Quick, but the hyphae are outlined by surrounding tissue.

The symptoms are usually nonspecific and the disease may not be included in a differential diagnosis in human medicine, though it is familiar to veterinarians.

Biopsies of infected tissues are known to be difficult to culture, but can help narrow the diagnosis to several different organisms.

[19] Case reports indicate the use of the following prescription drugs with varying levels of success: potassium iodide,[20] amphotericin B,[20] terbinafine,[20][21] itraconazole,[16][21] fluconazole,[16] ketoconazole,[16] natamycin,[16] posaconazole,[16] voriconazole,[16] prednisone,[22] flucytosine,[22] liposomal nystatin[22] and azithromycin + doxycycline.