Acanthamoeba

Introduction

This amoeba is rare, but it can cause severe infections of the eye, skin, and central nervous system. It can cause three major infections: acanthamoeba keratitis, GAE, and disseminated infection. Acanthamoeba keratitis is an infection in the eye that can cause permanent visual impairment in healthy people. GAE is a serious brain and spinal cord infection that occurs in immunocompromised individuals. Disseminated infection is a widespread infection that affects the skin, sinuses, lungs, and other organs, which is more common in immunocompromised individuals.

Hosts

Humans and Animals 

Transmission / Exposure Route

Acanthamoeba can be found in soil, dust, fresh water sources, in brackish water, and sea water. It can also be found in recreational pools, drinking water systems, HVAC systems, and humidifiers. Acanthamoeba has been found in contact lenses, causing infection. Acanthamoeba can enter the body through cuts or wounds in the skin, or in the nose. Once inside, the amoebas travel through the bloodstream to other parts of the body, like the lungs and brain.

Case Fatality Ratio

Acanthamoeba keratitis and Disseminated infection is usually treatable, so there were little to no cases found that patients died with these infections. If treatment is started early, the results are more promising. GAE has been found to be fatal in most cases. 

Incubation Period

The incubation period varies depending on the disease. For acanthamoeba keratitis, the incubation period is a few days. For GAE, the length of the illness ranges from 7-120 days, the average being around 39 days. Disseminated infection’s incubation period is unknown, but it is hypothesized to be weeks or months.

Microbiology

Acanthamoeba is a microscopic, free living amoeba.

Enviromental Survival

Found in many different locations in the environment, like pools and humidifiers. It can also be found in the human body naturally, like in the nose.