Disseminated candidiasis is a severe fungal infection that spreads throughout the body. It occurs when Candida species, a yeast commonly found on human skin and mucous membranes, proliferate. While usually harmless, Candida becomes a serious threat if it enters the bloodstream and reaches internal organs, potentially leading to life-threatening complications.
What is Disseminated Candidiasis?
Disseminated candidiasis, also known as invasive candidiasis or Candida septicemia, occurs when Candida fungi spread from their typical sites of colonization to the bloodstream and then to various organs. The infection can range in severity from a mild presentation to a more widespread disease involving multiple organ systems, potentially leading to sepsis and shock. While Candida albicans traditionally caused most cases, non-albicans Candida species are increasingly prevalent, especially in hospitalized individuals.
Candida species are opportunistic pathogens, meaning they take advantage of changes in the host’s defenses to cause infection. When conditions allow, such as a weakened immune system or breaches in natural barriers, these fungi can invade the bloodstream and disseminate, causing deep-seated infections in organs like the kidneys, brain, eyes, liver, and spleen.
Who is at Risk and How Does it Develop?
Disseminated candidiasis primarily affects individuals with compromised immune systems or those in specific healthcare settings. Patients with conditions such as cancer, HIV/AIDS, or those who have undergone organ transplantation are at increased risk due to their weakened defenses. Individuals receiving chemotherapy or immunosuppressive medications are also more susceptible to this fungal spread.
The presence of medical devices also plays a significant role in the development of this infection. Central venous catheters provide a direct pathway for Candida to enter the bloodstream, as the fungi can form biofilms on these devices. Prolonged stays in intensive care units (ICUs) and the use of broad-spectrum antibiotics are additional factors that disrupt the body’s natural microbial balance, allowing Candida to overgrow and potentially invade.
Recognizing the Signs and Symptoms
The signs and symptoms of disseminated candidiasis can be non-specific, making early recognition challenging. Patients often experience persistent fever and chills that do not respond to typical antibiotic treatments. This lack of response should prompt consideration of a fungal infection.
Beyond generalized symptoms, the infection can manifest differently depending on the organs affected. For example, kidney involvement, seen in over half of patients, may lead to candiduria (Candida in urine), hypertension, or even renal failure. Central nervous system involvement, occurring in about one-third of cases, can result in abscess formation, while nearly half of all cases show endophthalmitis, an infection of the eye. Skin lesions, ranging from discrete pustules and red papules to nodules, may also appear.
Diagnosis and Treatment Approaches
Diagnosing disseminated candidiasis involves laboratory tests, imaging, and sometimes tissue biopsies. Blood cultures are a common method, though they yield positive results in only about 50-60% of cases. Newer, more rapid blood tests, such as the T2Candida Panel, can identify five common Candida species within 3-5 hours, significantly faster than the traditional 6-day culture process.
Other diagnostic tools include the detection of specific fungal markers like (1,3)-beta-D-glucan in the blood, which can suggest invasive fungal infection. Imaging studies, such as CT scans, can help identify organ involvement, revealing abnormalities like pulmonary nodules or renal microabscesses. If a medical device, such as a central venous catheter, is suspected as the source, its removal is generally recommended.
Treatment for disseminated candidiasis typically involves intravenous antifungal medications. Echinocandins, such as micafungin, caspofungin, or anidulafungin, are often the initial choice for most adult patients with candidemia. Fluconazole is another antifungal option, particularly for patients who are not severely ill and when fluconazole resistance is unlikely. Amphotericin B, including lipid formulations, is also used, especially for more severe cases or when other treatments are not tolerated. Treatment duration usually extends for at least 14 days after the last positive blood culture and resolution of symptoms.
Preventing Disseminated Candidiasis
Preventing disseminated candidiasis, particularly in healthcare settings, involves several focused strategies. Adhering to strict hand hygiene protocols among healthcare personnel is a primary measure to prevent the spread of Candida species. Proper placement and maintenance of central venous catheters are also important, as these devices can serve as entry points for the fungus.
Antimicrobial stewardship, which promotes the appropriate use of antibiotics, helps to avoid disrupting the body’s normal flora, reducing opportunities for Candida overgrowth. For high-risk patients, such as those undergoing intensive chemotherapy or stem cell transplantation, antifungal prophylaxis may be considered to prevent invasive disease. Close monitoring of these vulnerable individuals for any signs of infection is also a preventative action.