Infective
colitis can be a cause of massive lower gastrointestinal
bleeding requiring acute surgical intervention. Causative organisms include entamoeba and histoplasma species. However, concurrent colonic
infection with both these organisms is very rare, and the in vivo consequences are not known. A 58-year-old male presented initially to the physicians with
pyrexia of unknown origin and bloody
diarrhea.
Amoebic colitis was diagnosed based on biopsies, and he was treated with
metronidazole. Five days later, the patient developed massive lower gastrointestinal
bleeding with
hemorrhagic shock. Emergency total
colectomy with end-
ileostomy was performed. However, he deteriorated and died on the second postoperative day. Histopathological examination revealed multiple deep
ulcers at the hepatic flexure where fungal bodies of mycelial and yeast forms were noted. Isolated lymph nodes showed
abscess formation with fungal bodies. Infective fungal
colitis with Histoplasma capsilatum was diagnosed. In vitro, amoebic parasites can increase virulence and pathogenicity of histoplasma which may account for the fulminant presentation in this patient. Although rare, this unusual dual
infection should be considered in the differential diagnosis of infective
colitis, as appropriate antimicrobial treatment may prevent progression to massive lower gastrointestinal
bleeding, obviating the need for urgent surgical intervention.