Fusarium solani Endophthalmitis in the Absence of Identifiable Risk Factors: A Case Report and Literature Review

Han Wang,1,2 Jinhan Yu,1 Meifen Zhang,3 Ying Zhao1 1Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China; 2Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 3Department of Ophthalmology, Peking Union Medical College Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of ChinaCorrespondence: Ying Zhao, Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China, Email [email protected]: Fusarium solani (F. solani) is a rare cause of endophthalmitis, most commonly occurring after ocular trauma, surgery, or in immunocompromised individuals. Fungal endophthalmitis carries a distinctly poor prognosis. Among published cases of Fusarium endophthalmitis, enucleation rates exceed 20%. Mortality in disseminated infections among immunocompromised hosts approaches 50– 80%, reaching nearly 100% in persistently neutropenic patients. Even among patients who retain the eye, significant visual impairment is nearly universal. To our knowledge, cases arising spontaneously in immunocompetent individuals without any identifiable risk factors have not been previously documented.Case: We report a case of endophthalmitis in an otherwise healthy woman with no apparent risk factors. Initial conventional cultures of ocular samples yielded negative results. However, F. solani was ultimately identified through three consecutive next-generation sequencing (NGS) analyses and by inoculating aqueous humor into blood culture bottles. The patient was treated with vitrectomy, intravitreal injection of amphotericin B and oral voriconazole. Despite aggressive antifungal therapy, the infection progressed rapidly, ultimately necessitating evisceration of the affected eye. We report a case of endophthalmitis in a 67-year-old immunocompetent woman with no history of ocular breach or systemic immunosuppression. Initial conventional cultures of aqueous humor were negative. The pathogen was ultimately identified through repeated NGS and by inoculating aqueous humor into blood culture bottles. The isolate was confirmed as Fusarium solani by ITS and TEF-1α sequencing. Antifungal susceptibility testing showed MICs of 1 μg/mL for both amphotericin B and voriconazole, values well within the wild-type range. Despite guideline-adherent combination therapy (amphotericin B and voriconazole) and early vitrectomy, the infection progressed relentlessly and ultimately necessitating evisceration.Conclusion: To our knowledge, this represents the first documented case of F. solani endophthalmitis occurring in the absence of identifiable risk factors in an immunocompetent host. This case underscores the diagnostic value of NGS in detecting rare ocular pathogens, and the potential utility of blood culture bottle inoculation for pathogen recovery. Besides, this case report also reminds us that in vitro antifungal susceptibility does not guarantee in vivo efficacy in Fusarium endophthalmitis. It also highlights the importance of considering filamentous fungi in the differential diagnosis of unexplained intraocular infections, even in patients without classical risk factors.Keywords: Fusarium solani, endophthalmitis, voriconazole, amphotericin B, next-generation sequencing (NGS)