Genotype distribution of Acanthamoeba in keratitis: a systematic review

Parasitol Res. 2021 Sep;120(9):3051-3063. doi: 10.1007/s00436-021-07261-1. Epub 2021 Aug 5.


Acanthamoeba spp. are among the most worldwide prevalent protozoa. It is the causative agent of a disease known as Acanthamoeba keratitis, a painful and severe sight-threatening corneal infection that can lead to blindness. In recent years, the prevalence of Acanthamoeba keratitis has rapidly increased, growing its importance to human health. This systematic review aims to assess the distribution of Acanthamoeba sp. genotypes causing keratitis around the world, considering the sample collected type and the used identification method. Most of the cases were found in Asia and Europe. Not surprisingly, the T4 genotype was the most prevalent worldwide, followed by T3, T15, T11, and T5. Furthermore, the T4 genotype contains a higher number of species. Given the differences in pathology, susceptibility to treatment, and clinical outcome between distinct genotypes, it is essential to genotype isolates from Acanthamoeba keratitis cases to help to establish a better correlation between in vitro and in vivo activities, resulting in better drug therapies and successful treatment in cases of this important ocular infection.

Keywords: Acanthamoeba spp.; Free-living amoebae; Genotype; Keratitis; Protozoan.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Acanthamoeba Keratitis* / epidemiology
  • Acanthamoeba Keratitis* / parasitology
  • Acanthamoeba* / genetics
  • Cornea
  • Genotype
  • Humans