Candidiasis, a fungal infection caused by the Candida genus, remains a significant health issue, especially in hospital settings.
Candida spp. are typically found in the gastrointestinal microbiome and can inhabit the skin without causing harm; however, when they breach these barriers, they can lead to severe infections.
Among the various forms of candidiasis, candidemia, or Candida bloodstream infection, is particularly concerning.
In the United States, it ranks as one of the most prevalent healthcare-associated infections.
Candidemia incidents are associated with expensive hospitalizations, high morbidity, and alarming mortality rates that can reach about 25%.
The onset of candidemia often follows disruptions to bodily mucosal and skin barriers, making abdominal surgeries a notable risk factor.
Additionally, individuals with critical illnesses, immune system compromise, and those using indwelling medical devices are at heightened risk for this invasive infection.
Recent analyses show that Candidemia is increasingly associated with conditions such as malignancies, diabetes, and renal failure, along with the use of immunosuppressive medications, particularly corticosteroids.
Injection drug use has also emerged as a notable risk factor for non-healthcare-associated candidemia.
Historically, Candida albicans was the predominant cause of candidemia.
However, the incidence of non-C. albicans species has risen, with species like Candida glabrata, Candida parapsilosis, Candida tropicalis, and Candida krusei becoming more common.
Concerns are mounting as these species often display higher antifungal resistance rates and have been linked to increased patient mortality.
Moreover, Candida auris, known for its high transmissibility and multidrug resistance, has emerged as a critical player in healthcare-associated outbreaks.
While a population-based surveillance study from 2008 to 2013 indicated a decline in candidemia rates, more recent data from 2019 to 2021 reveal a concerning increase in hospitalizations and deaths associated with fungal infections, including invasive candidiasis.
This rise may be linked to COVID-19, where many critically ill patients faced compromised health, exacerbating the challenge of managing candidemia.
To address this growing concern, the Centers for Disease Control and Prevention (CDC) has been actively monitoring candidemia trends via the Emerging Infections Program (EIP).
What began as a surveillance program in two locations in 2008 has expanded to ten sites across the U.S., focusing on data collection regarding demographic characteristics, treatment practices, and antifungal resistance.
The recent report analyzing EIP data from 2017 to 2021 sheds light on candidemia incidence and risk factors, providing vital insights that can guide public health responses and clinical practices.
During the five-year period, the EIP documented a total of 7,381 candidemia cases from 6,235 patients.
Among those with multiple infections, many experienced recurrent cases: 32.9% had two cases, while 9.4% had as many as four or more.
Demographic analysis shows that age and racial disparities among patients shifted slightly over the years; for instance, a greater proportion of patients aged 65 and older were reported in 2021 compared to 2017.
By 2021, 45.6% of patients were in this age group, coinciding with a rise in Black or African American patients affected, increasing from 24.8% to 29.8%.
Conversely, the percentage of White patients decreased from 53.1% in 2017 to 44.8% in 2021, while there were increases in Asian and Hispanic or Latino patients over the same timeframe.
Overall, it was noted that a majority of cases—56.3%—were male, highlighting a trend seen in previous studies.
From a geographical perspective, Georgia recorded the highest number of cases at 1,828, followed by Maryland and Connecticut, illustrating regional variations in incidence.
The incidence of candidemia remained relatively stable across the years, at an average of 7.4 cases per 100,000 population but did exhibit a slight increase to 7.9 in 2021.
Demographic stratification revealed that candidemia incidents were notably higher among individuals aged ≥65 years (22.7 cases per 100,000) and infants under 1 year (8.0 cases per 100,000) in 2021.
Racial disparities persisted, with Black patients showing an incidence rate of 12.8 cases per 100,000 compared to 5.6 among non-Black patients.
Regional incidence was also notable, with Maryland having the highest rate of 14.5, underscoring the necessity for localized epidemiological understanding.
The classification of cases showed an increase in healthcare-associated incidences, rising from 52.2% in 2017 to 58.0% in 2021.
Consequently, the median time from patient hospital admission to the onset of candidemia was four days.
Data pointed to diabetes as the most common underlying health condition observed, particularly increasing from 32.1% to 38.0% between 2017 and 2021.
Additionally, other common underlying conditions included chronic kidney disease (25.6%), malignancies (24.3%), and chronic lung diseases (22.1%).
Interestingly, chronic liver disease showed a decrease in prevalence during this period.
Notably, between 2020 and 2021, there was a rise in candidemia cases coinciding with positive SARS-CoV-2 test results, reflecting the pandemic’s potential role in exacerbating health vulnerabilities.
In terms of treatment approaches, echinocandins were the most commonly administered antifungal agents, used in approximately 49.8% of cases, followed by azoles at 47.7%.
In 2021, a significant portion of cases (30.1%) involved a lack of antifungal treatment, which was attributed mostly to patient mortality before results became available.
Candidemia has a range of complications, which can lead to serious secondary conditions such as endocarditis (4.0%) and osteomyelitis.
Alarmingly, the overall rate of in-hospital death for candidemia patients rose from 26.8% in 2019 to 36.1% in 2021, emphasizing the need for improved clinical responses.
When examining species distribution, C. albicans remained the most commonly identified at 37.1%, although C. glabrata made notable gains, becoming the predominant species in certain states.
The emergence of C. auris, while low at 0.4%, warrants continuous vigilance due to its impact on healthcare.
Resistant strains remain a significant concern, with approximately 5.6% of tested isolates showing fluconazole resistance.
Given these findings, the CDC emphasizes the importance of rigorous surveillance to guide clinical guidelines and improve treatment outcomes.
The findings reiterate that candidemia remains a noteworthy public health challenge within the healthcare system, one that continually adapts to emerging risk factors and patient demographics.
As ongoing efforts focus on raising awareness and refining treatment protocols, the data gathered will support healthcare providers in tailoring preventative and therapeutic measures, ultimately helping to reduce the burden of this invasive fungal infection.
image source from：https://www.cdc.gov/mmwr/volumes/74/ss/ss7404a1.htm?s_cid=ss7404a1_w
