Chronic Pulmonary Aspergillosis in a Patient With AIDS

Aspergillus fumigatus escape mechanisms from its harsh survival environments

Aspergillus fumigatus is a ubiquitous pathogenic mold and causes several diseases, including mycotoxicosis, allergic reactions, and systemic diseases (invasive aspergillosis), with high mortality rates. In its ecological niche, the fungus has evolved and mastered many reply strategies to resist and survive against negative threats, including harsh environmental stress and deficiency of essential nutrients from natural environments, immunity responses and drug treatments in host, and competition from symbiotic microorganisms. Hence, treating A. fumigatus infection is a growing challenge. In this review, we summarized A. fumigatus reply strategies and escape mechanisms and clarified the main competitive or symbiotic relationships between A. fumigatus, viruses, bacteria, or fungi in host microecology. Additionally, we discussed the contemporary drug repertoire used to treat A. fumigatus and the latest evidence of potential resistance mechanisms. This review provides valuable knowledge which will stimulate further investigations and clinical applications for treating and preventing A. fumigatus infections. KEY POINTS: • Harsh living environment was a great challenge for A. fumigatus survival. • A. fumigatus has evolved multiple strategies to escape host immune responses. • A. fumigatus withstands antifungal drugs via intrinsic escape mechanisms.

HIV-infected patients rarely develop invasive fungal diseases under good immune reconstitution after ART regardless high prevalence of pathogenic filamentous fungi carriage in nasopharynx/oropharynx

PURPOSE

We aimed to investigate the prevalence and risk factors of filamentous fungi (FF) carriage in human immunodeficiency virus (HIV)-infected patients in Guangdong province, along with its subsequent incidence of invasive fungal disease (IFD).

METHODS

Seven hundred and sixteen HIV-infected individuals from the outpatient clinic and 293 sex-matched healthy controls were recruited prospectively from May 1 to August 31, 2017. Fungi were isolated from oropharyngeal and nasopharyngeal swabs, then identified by morphological and molecular biological techniques. Logistic regression analysis was used to identify risk factors of pathogenic FF carriage. Pathogenic FF carriers were followed up through the end of 2019.

RESULTS

Of the 716 included HIV-infected patients, 602 (84.1%) were male, the median age was 34 (27-42) years, and the median CD4+ count was 385 (254-542) cells/μl. Pathogenic FF were isolated in 119 (16.6%) cases with HIV infection and 40 (13.7%) healthy controls. Mucorales were found in 3 HIV-infected individuals and Talaromyces marneffei in 2 HIV-infected individuals, but not in healthy controls. History of cured opportunistic infections (OIs; OR, 1.97; 95% CI, 1.23-3.13, p = 0.004), and smoking (OR, 1.55; 95%CI, 1.03-2.32, p = 0.035) were independent risk factors of pathogenic FF carriage in HIV-infected individuals. A total of 119 pathogenic FF carriers with HIV infection were followed. During follow-up, 119 (100%) cases received antiretroviral therapy (ART) for at least 28 months, 107 (90%) cases had CD4+ counts>200 cells/μl, and none developed IFD.

DISCUSSION

Pathogenic FF carriage is common in HIV-infected individuals but may not develop IFD in those who achieved immune reconstitution. Smoking and cured OIs history increase the risk of pathogenic FF carriage. Smoking abstinence and ART adherence are especially important for these patients.