Exploration of Various Diagnostic Modalities for Detection of Amoebic Liver Abscess and Co-Occurrence of Other Infective Aetiology, Eastern India.

BACKGROUND

Liver abscess (LA) remains a major clinical entity across the globe. Pyogenic liver abscess (PLA) caused by bacteria and amoebic liver abscess (ALA) caused by Entamoeba histolytica (Eh) constitute the two predominant varieties, whilst other infective aetiologies such as tubercular and fungal LA are reported uncommonly. The true frequency of ALA often remains underestimated, owing to constraints related to the poor sensitivity of conventional methods. Hence, we performed this study to explore the usefulness of various diagnostic modalities for detection of ALA to select optimal strategies for incorporation in our routine diagnostic repertoire. The co-occurrence of other infective aetiologies of LA was also investigated.

METHODS

This observational, cross-sectional study conducted from August 2021 to July 2023 included provisionally diagnosed cases of LA whose pus samples obtained under relevant radio-imaging guidance were subjected to various conventional and molecular tests primarily for detection of amoebic aetiology, including microscopy, antigen detection, serology and nested multiplex polymerase chain reaction (PCR). Cultures and cartridge-based nucleic acid amplification test were performed for detection of pyogenic/fungal and tubercular aetiology, respectively.

RESULTS

Of 82 samples, a positive microbial yield was obtained in 69 patients (84.1%) with, ALA in 31 (44.9%), PLA in 26 (37.7%), ALA with superimposed bacterial co-infection in 10 (14.5%), tubercular in one (1.4%) and fungal in one (1.4%). Maximum number of ALA cases were detected by nested-multiplex PCR (41/82, 50.0%) followed by amoebic serology (28, 34.1%). Further, 45 bacterial isolates were obtained from 36 culture-positive specimens, with Escherichia coli as the predominant isolate followed by Klebsiella pneumoniae and Burkholderia pseudomallei.

CONCLUSIONS

Molecular investigations are useful tests for the diagnosis of ALA and need to be incorporated in routine clinical practise for maximum detection of cases. Amoebic serology can serve as an alternative option.