Meningitis is an acute inflammatory disorder of the leptomeninges caused by invasion of various pathogenic microorganisms. As one of the most common neurological emergencies, this condition is associated with significant morbidity and mortality rates [8]. Clinically, the disease typically presents with fever, neck stiffness, and headache, often accompanied by nausea, vomiting, altered mental status, seizures, or even coma.
A. fumigatus, a ubiquitous saprophytic fungus, thrives in natural environments including soil, compost, and decaying vegetation. This opportunistic pathogen disseminates through airborne conidia, representing a significant fungal threat in clinical settings [9]. A. fumigatus infection typically initiates in the pulmonary system or paranasal sinuses following spore inhalation, with subsequent hematogenous dissemination or direct local invasion to adjacent anatomical structures [10]. Central nervous system infections caused by A. fumigatus carry a grave prognosis, demonstrating both high mortality rates and frequent treatment resistance. These infections most commonly manifest as cerebral abscesses, which represent the predominant clinical presentation [11, 12]. Neuroimaging findings (CT or MRI) typically demonstrate leptomeningeal thickening and enhancement, particularly at the skull base. Due to the fungus’s angioinvasive nature, associated vascular complications may include cerebral infarcts, hemorrhagic lesions, or abscesses following vascular distributions. Secondary manifestations such as hydrocephalus or local structural involvement may also be present in advanced cases [13].
Galactomannan, a key polysaccharide component of the Aspergillus cell wall, serves as the earliest detectable biomarker in circulation during Aspergillus infection. Serum galactomannan levels demonstrate a strong correlation with fungal burden, offering valuable quantitative insights into infection progression and severity [14]. 1-3-β-D-glucan, another essential and fungus-specific polysaccharide, constitutes a fundamental structural component of fungal cell walls. Together with galactomannan, these biomarkers provide valuable adjunctive diagnostic information for invasive fungal infections. However, while highly sensitive for fungal detection, neither biomarker offers species-level identification.
Accurate species-level identification of fungal pathogens is critical for precise diagnosis and targeted therapy in clinical practice. However, initial diagnostic approaches frequently rely on genus-level classification due to practical constraints. High-throughput gene sequencing overcomes this limitation by providing rapid, species-specific microbial identification directly from clinical specimens. While this technology’s enhanced sensitivity enables comprehensive pathogen detection, it may simultaneously identify multiple microorganisms in infected samples. Consequently, clinicians must exercise careful judgment when interpreting these results, as the detection of co-occurring pathogens may present diagnostic challenges.
A. fumigatus infection predominantly occurs in patients with compromised immune function [2]. The main feature of brain CT or MRI examination in A. fumigatus encephalopathy is mass shadows, which may also be accompanied by clinical features of meningitis. However, it is very rare for A. fumigatus to only cause meningitis. This case was ultimately diagnosed through high-throughput gene sequencing of pathogenic microorganisms. Subsequent brain MRI examinations have shown no imaging features of aspergillus in the brain parenchyma. The patient in this case has a medical history of multiple chronic diseases and thyroid malignant tumors, which are risk factors for A. fumigatus infection [15]. The patient experienced nasal congestion, runny nose, and nosebleeds two weeks before admission, suggesting the possibility of A. fumigatus infection. Although no obvious signs of A. fumigatus infection in the sinus were found on imaging, combined with medical history, it is considered that there is a high possibility of invasion of the brain through the sinus. After treatment with Voriconazole against A. fumigatus, the patient’s death remained unchanged. This case shows that A. fumigatus can cause meningitis without imaging features, and the patient’s condition is very critical. Aspergillus meningitis represents a rare but life-threatening infection characterized by substantial diagnostic difficulties and alarmingly high mortality rates. To minimize diagnostic errors, stringent clinical vigilance and comprehensive surveillance are essential. The PMseq-DR platform, with its capacity for cerebrospinal fluid-based high-throughput genomic analysis, emerges as a valuable tool for achieving timely and accurate diagnosis.