Deep Tissue, Blood, Lung and Systemic Fungal Infections
A variety of fungi can cause deep tissue and lung infections that have the potential to spread to the blood or the rest of the body (systemic). Some of these fungi are found throughout the U.S., while others are found in specific regions of the country. People frequently become infected when they come in contact with infected soil.
Lung infections typically start with the inhalation of fungal spores. With lung infections, as with fungal infections that have spread below the surface of the skin, the invading fungi have the potential to spread from the original infection location and move to the blood (septicemia) and/or spread throughout the body to other organs, tissues, bone, and sometimes into the meninges that cover the spinal cord and into the brain, causing meningitis.
In many people with competent immune systems, fungal lung infections may cause only mild to moderate flu-like symptoms such as coughing, fever, muscle aches, headaches, and rashes. In these people, the infection may remain localized the the lungs and not spread (the organisms are walled off in granulomas). However, people with localized infections may, at some point in their life, become immunocompromised and the silent, chronic fungal infection may then become an active, acute infection.
Some lung infections caused by fungi may take months to years to cause symptoms, slowly and progressively growing worse and disseminating throughout the body, causing night sweats, chest pain, weight loss, and enlarged lymph nodes. Others may progress rapidly, causing pneumonia and/or septicemia.
Fungal lung infections are more likely to be severe in people who have underlying lung disease and/or a weakened immune system, such as those with HIV/AIDS or cancer, organ or stem cell transplant patients, hospitalized patients, and those who take medications that weaken the immune system. Both acute and chronic fungal infections can cause permanent lung, organ, and bone damage and can be fatal.
Some common fungal lung infections that have the potential to become systemic include:
- Aspergillosis, caused by Aspergillus fumigatus or several other Aspergillus species. Tese fungi are commonly found in soil, plants, and house dust. They can cause fungal masses in the sinuses and lungs and, in some cases, can spread to the brain and bones.
- Blastomycosis, caused by Blastomyces dermatitidis found in moist, organic-rich soil, particularly in woodland areas of the southeastern and south-central United States. Although most people who breathe in the spores don't get sick, some of those who do may develop flu-like symptoms. The infection can become severe in people with compromised immune systems, especially if it spreads from the lungs to other organs.
- Coccidioidomycosis, also called Valley fever, caused primarily by Coccidioides immitis, which is found in the arid soil of the southwestern U.S., Mexico, and South America. Recently, the fungus was found in south-central Washington state. The term "Valley fever" usually refers to Coccidioides infection of the lungs, but the infection can spread to other parts of the body in severe cases (this is called "disseminated coccidioidomycosis").
- Cryptococcosis, caused by Cryptococcus neoformans or, rarely, by another Cryptococcus species found in soil and are associated with bird droppings. Anyone may become infected, but the highest prevalence in the U.S. is in people who have HIV/AIDS. An emerging infection, Cryptococcus gatti, has been identified in the Pacific Northwest and is thought to pose a threat to individuals in that area. Cryptococcosis usually affects the lungs or the central nervous system, but it can also affect other parts of the body. Brain infections are called cryptococcal meningitis.
- Histoplasmosis, caused by Histoplasma capsulatum found primarily in the east and central U.S. in soil that contains large amounts of bird and bat droppings. Those who become ill after breathing in Histoplasma spores may have a fever, cough, and fatigue. The infection can become severe in those with weakened immune systems, especially if it spreads from the lungs to other organs.
- Candidiasis, caused by Candida species, which are part of the normal human flora, and are found worldwide. Infections occur in the moist mucous membranes but can occur in other parts of the body as well. Systemic—or invasive—candidiasis can affect the blood, heart, brain, eyes, bones, and other parts of the body. Candida bloodstream infection, which is the most common form of invasive candidiasis, is called candidemia. Candidemia is currently the fourth most common cause of hospital-acquired septicemia in the United States.
- Pneumocystis pneumonia (PCP) is a serious lung infection caused by Pneumocystis jiroveci (formerly known as Pneumocystis carinii), which is found worldwide. PCP most commonly affects those with compromised immune systems, including those with HIV/AIDS, organ transplant recipients, and those undergoing treatment for cancer. Although people with HIV/AIDS are less likely to acquire PCP today than in years past, it is still a significant public health problem.