Presumed Candida tropicalis endogenous endophthalmitis with multifocal systemic Candida albicans abscesses: a case report

Endophthalmitis is a kind of infectious diseases that seriously threatens vision; Endogenous fungal endophthalmitis (EFE) accounts for 2% to 8% of all endophthalmitis, and is rare and often misdiagnosed in clinical practice. Different strains of Candida may have organ orientation differences, and mixed infections have also been reported in literature.

A 72 year old male patient was admitted to the hospital due to fever for 5 months and decreased vision in both eyes. The patient's left vitreous fluid underwent metagenomic next-generation sequencing (mNGS), which revealed the presence of Candida tropicalis (1 sequence detected); The fungal culture of vitreous humor and the blood culture sent for testing at the same time was negative. Candida albicans was detected in the culture of surgical specimens for renal and lumbar lesions. The core clinical feature of this case is the inconsistency of pathogen detection between the whole body and the eyes. Due to mNGS only detected one Candida tropicalis sequence and the vitreous fungal culture was negative, this case should be considered as a suspected Candida tropicalis endophthalmitis clinically diagnosed. It may be a mixed invasive infection of Candida albicans and Candida tropicalis, and there may be differences in organ orientation between the two strains (Candida albicans prefers kidney and bone tissues, while Candida tropicalis is invasive to intraocular tissues), forming a zoning colonization pattern. However, this explanation still lacks conclusive microbiological evidence. The patient received local and systemic antifungal treatment in both eyes, and underwent bilateral vitrectomy. The systemic infection was controlled, and the left eye vision improved from near blindness to 0.25 (8 months) with some recovery in visual function.

EFE is prone to misdiagnosis, and high-risk individuals should undergo pathogen testing as soon as possible. mNGS is a rapid identification tool, but caution should be exercised when single sequence detection and negative culture occur. When the pathogens are inconsistent, alternative explanations such as contamination and sequential infection should be excluded. The combination of comprehensive antifungal therapy and surgical treatment is effective,Clinical physicians need to establish a global mindset and pay attention to the intrinsic relationship between systemic lesions and eye damage.