Rapid Diagnosis of Mucor and Aspergillus Co-Infection by Direct Microscopic Examination: A Case Report and Literature Review

Background: Mixed infections of Mucor and Aspergillus are very rare clinically and have a poor prognosis, primarily occurring in immunocompromised patients. Direct microscopic examination for early rapid diagnosis is of great significance in improving patient prognosis. Case Presentation: This report describes a 61-year-old male patient with a history of chronic obstructive pulmonary disease and rheumatoid arthritis who had been receiving long-term treatment with prednisone. The patient was admitted to the hospital due to aggravated fever, cough and shortness of breath. The initial diagnosis was pulmonary aspergillosis, and antifungal treatments such as voriconazole, caspofungin and posaconazole were administered successively. However, the patient's symptoms continued to worsen, with persistently high inflammatory markers. Chest X-ray indicated progression of pulmonary lesions, and ulceration of the nasal mucosa developed. The clinical diagnosis of a mixed infection of Mucor and Aspergillus was ultimately confirmed through direct microscopic examination of nasal ulceration mucosal secretions and bronchoalveolar lavage fluid smears. Despite timely treatment with amphotericin B, the patient died due to the severity of the condition and multiple organ failure. Conclusion: For patients with pulmonary aspergillosis undergoing immunosuppressive therapy who fail to respond to standard anti-aspergillosis treatment, the possibility of concurrent mucor infection should be highly suspected. Emphasize the advantages of direct microscopic examination in rapidly identifying pathogen infections, optimizing treatment strategies, and improving prognosis.