BACKGROUND

Pathogenic free-living amoeba (FLA) such as spp., , and are causative agents of fatal amoebic encephalitis/meningoencephalitis. The diagnosis of such infections is challenging due to a lack of clinical suspicion and expertise in microscopic identification. We evaluated the performance of molecular assays for the timely and accurate detection of FLA-causing central nervous system (CNS) afflictions.

METHODS

This study included samples from 156 patients with suspected encephalitis/meningoencephalitis, including 149 cerebrospinal fluid (CSF) samples, 5 brain tissue biopsies, and 2 brain abscess samples. All the samples were subjected to PCR-based detection of spp., , and . The diagnostic characteristics and the inter-rater reliability scores were evaluated for parasite-specific polymerase chain reaction (PCR) using culture on non-nutrient agar (NNA)/microscopy or histopathological examination as a confirmatory test for spp. and and histopathology for .

RESULTS

We detected 11 samples positive for FLA, including 6 spp., 3 , and 2 . Furthermore, all 11 samples were positive according to the confirmatory tests, i.e., culture on NNA/microscopy/histopathology in the case of spp. and and histopathology of tissue biopsies for . The inter-rater reliability between the PCRs and the confirmatory tests for the detection of spp., , and was 100%.

CONCLUSIONS

The PCR-based detection of FLA in patients suspected of encephalitis/meningoencephalitis was found to be fast, efficient, and reliable in our study. We suggest the use of these PCRs in laboratories to obtain additional data on their efficiency in diagnosing FLA infections of the CNS. The present study was conducted with a small sample size of 156 patient samples, and we found only six spp., three , and two . The present study should be conducted on a larger sample size for better evaluation of the primer pairs.