Acanthamoeba keratitis cases in Sweden: genotypes and clinical course

Acanthamoeba keratitis is a sight-threatening corneal infection. A delay in diagnosis and lack of amoeba-specific treatment contribute to a generally poor prognosis. Genotyping of pathogenic Acanthamoeba may offer deeper insights into the disease. Sixteen culture-positive Acanthamoeba ocular samples from 2006 to 2022 were identified and genotyped in patients from the northern and central regions of Sweden. Data from the patients' records were collected, and their respective clinical courses were reviewed. The most common Acanthamoeba genotype was T4 (11 cases), followed by T3 (4 cases) and T6 (1 case). All but one patient was a contact lens user. There were no cases of previous trauma. No statistically significant differences were found between the T4 and non-T4 groups. The influence of genotype on the clinical course warrants further investigation.IMPORTANCEThis study provides insights into the rare but serious eye infection Acanthamoeba keratitis, which can cause blindness. Our research presents data from Sweden on the genotypes of the parasite causing this infection. While the most common genotype worldwide, T4, was also predominant in our study, we found an unexpectedly high number of cases caused by the T3 genotype. This may indicate regional differences and highlights the need for ongoing research. The study also examines the link between genotype and patient outcomes. Although our findings did not establish a statistically significant correlation, knowledge of such a connection could prove valuable in efforts to improve management, and further multicenter studies may be warranted.