Scope of CDC Surveillance on Invasive Mold Disease
Over a five-year period from 2020 through 2024, researchers conducted active, laboratory-based surveillance at two Atlanta-area academic hospitals and associated outpatient clinics. The investigation identified 968 patients with potential IMD. Of those, 449 individuals—accounting for 46% of the suspected cases—were determined to have an actual infection. This confirmed group included 89 confirmed cases, 142 probable cases, and 218 surveillance cases, which involved patients presumptively treated for the condition.
Invasive mold disease occurs when specific types of mold enter the human body. This can happen through the inhalation of mold spores from the environment, exposure to contaminated medical devices, tainted healthcare linens, or as part of broader healthcare-associated outbreaks. Once inside, the mold spores travel deep into the body, damaging tissues and organs. The infections can impact a wide range of body systems, including the lungs, sinuses, skin, and the central nervous system.
A Shift in Traditional Risk Factors
Historically, invasive mold disease primarily affected individuals with weakened or compromised immune systems. However, the new CDC data reveals a troubling shift. Approximately 35% of patients infected with invasive mold disease had none of the classic risk factors used to identify people predisposed to these infections. The researchers emphasized that this statistic underscores a pressing need for clinicians and surveillance efforts to consider the possibility of fungal infections among patients who lack traditional host risk factors.
Lung infections were by far the most common manifestation of the disease, accounting for 68% of all cases. Skin or deep-tissue infections made up 11% of cases, while sinus or nasal infections accounted for 10%. Central nervous system infections represented 9% of the total. A much smaller percentage of infections occurred in non-skin soft tissues, which accounted for 2% of cases. Blood, bone, and eye infections were the rarest, each representing just 1% of the documented infections.
Severe Viral Illness as a Catalyst
The surveillance period overlapped heavily with the COVID-19 pandemic, providing crucial insights into how severe respiratory viruses interact with fungal pathogens. Fifty-eight patients, representing 13% of the study group, had a current or recent COVID-19 infection. The CDC researchers noted that critical illness—particularly severe cases of COVID-19 and influenza—is increasingly recognized as a significant risk factor for developing invasive mold infections.
The data showed that patients with a concurrent or recent COVID-19 infection experienced significantly worse outcomes compared to those without the viral infection. Among these patients, 66% required admission to an intensive care unit. In contrast, only 39% of patients without a COVID-19 infection required ICU care. The disparity in mortality was equally stark. The 90-day all-cause mortality rate among patients with a current or recent COVID-19 infection reached 66%, compared to 41% for those without a recent viral infection.
Burden on ICU Care Resources
Across the entire study cohort, invasive mold disease was associated with substantial morbidity and an extreme burden on critical care infrastructure. In total, 43% of all patients with confirmed mold infections were admitted to an intensive care unit. Half of the patients required intubation and mechanical ventilation to survive. For the patients for whom complete mortality data were available, 45% died within 90 days of their diagnosis.
Treating these infections presents significant clinical challenges. The fungi responsible are notoriously difficult to eradicate once they invade tissue. Treatment typically requires prolonged courses of intravenous antifungal medications, which can carry severe side effects, including kidney and liver damage. In some cases, surgical intervention is necessary to physically remove infected tissue, particularly in sinus or deep-tissue infections. The complexity of these treatments contributes to the prolonged ICU care stays observed in the CDC surveillance data.
What Happens Next
The high mortality rates and the surprising prevalence of invasive mold disease in patients without traditional risk factors demand a shift in clinical awareness. Healthcare providers must maintain a high index of suspicion for mold infections even in low-risk patients, particularly those presenting with severe respiratory distress or those recovering from severe viral infections like influenza or a COVID-19 infection.
To improve patient outcomes, the CDC researchers call for earlier and more accurate case detection. Rapid diagnostic tools are essential for initiating timely antifungal therapy. Furthermore, the medical community must prioritize the development of improved antifungal treatments, as current options are often limited by toxicity and emerging drug resistance. Hospitals will also need to strengthen infection control protocols to prevent healthcare-associated outbreaks linked to contaminated devices or linens. As severe respiratory viruses continue to circulate, monitoring for secondary fungal infections will remain a critical component of intensive care management.
— Aisha Mensah, health desk, AXO News