What is mucormycosis?

Mucormycosis (sometimes called zygomycosis) is a serious but rare fungal infection caused by a group of molds called mucormycetes. These fungi live throughout the environment, particularly in soil and in decaying organic matter, such as leaves, compost piles, or rotten wood.

People get mucormycosis by coming in contact with the fungal spores in the environment. For example, the lung or sinus forms of the infection can occur after someone breathes in spores. These forms of mucormycosis usually occur in people who have health problems or take medicines that lower the body’s ability to fight germs and sickness. Mucormycosis can also develop on the skin after the fungus enters the skin through a cut, scrape, burn, or other type of skin trauma.

Types of mucormycosis

• Rhinocerebral (sinus and brain) mucormycosis is an infection in the sinuses that can spread to the brain. This form of mucormycosis is most common in people with uncontrolled diabetes and in people who have had a kidney transplant.
• Pulmonary (lung) mucormycosis is the most common type of mucormycosis in people with cancer and in people who have had an organ transplant or a stem cell transplant.
• Gastrointestinal mucormycosis is more common among young children than adults, especially premature and low birth weight infants less than 1 month of age, who have had antibiotics, surgery, or medications that lower the body’s ability to fight germs and sickness.
• Cutaneous (skin) mucormycosis: occurs after the fungi enter the body through a break in the skin (for example, after surgery, a burn, or other type of skin trauma). This is the most common form of mucormycosis among people who do not have weakened immune systems.
• Disseminated mucormycosis occurs when the infection spreads through the bloodstream to affect another part of the body. The infection most commonly affects the brain, but also can affect other organs such as the spleen, heart, and skin.

Types of fungi that most commonly cause mucormycosis

Examples are: Rhizopus species, Mucor species, Rhizomucor species, Syncephalastrum species, Cunninghamella bertholletiae, Apophysomyces species, and Lichtheimia (formerly Absidia) species.

The symptoms of mucormycosis depend on where in the body the fungus is growing. Contact your healthcare provider if you have symptoms that you think are related to mucormycosis.

Symptoms of rhinocerebral (sinus and brain) mucormycosis include:

• One-sided facial swelling
• Headache
• Nasal or sinus congestion
• Black lesions on nasal bridge or upper inside of mouth that quickly become more severe
• Fever

Symptoms of pulmonary (lung) mucormycosis include:

• Fever
• Cough
• Chest pain
• Shortness of breath

Cutaneous (skin) mucormycosis can look like blisters or ulcers, and the infected area may turn black. Other symptoms include pain, warmth, excessive redness, or swelling around a wound.

Symptoms of gastrointestinal mucormycosis include:

• Abdominal pain
• Nausea and vomiting
• Gastrointestinal bleeding

Disseminated mucormycosis typically occurs in people who are already sick from other medical conditions, so it can be difficult to know which symptoms are related to mucormycosis. Patients with disseminated infection in the brain can develop mental status changes or coma.

Who gets mucormycosis?

Mucormycosis is rare, but it’s more common among people who have health problems or take medicines that lower the body’s ability to fight germs and sickness. Certain groups of people are more likely to get mucormycosis, including people with:

• Diabetes, especially with diabetic ketoacidosis
• Cancer
• Organ transplant
• Stem cell transplant
• Neutropenia (low number of white blood cells)
• Long-term corticosteroid use
• Injection drug use
• Too much iron in the body (iron overload or hemochromatosis)
• Skin injury due to surgery, burns, or wounds
• Prematurity and low birthweight (for neonatal gastrointestinal mucormycosis)

How does someone get mucormycosis?

People get mucormycosis through contact with fungal spores in the environment. For example, the lung or sinus forms of the infection can occur after someone inhales the spores from the air. A skin infection can occur after the fungus enters the skin through a scrape, burn, or other type of skin injury.

Is mucormycosis contagious?

No. Mucormycosis can’t spread between people or between people and animals.

How can I lower the risk of mucormycosis?

It’s difficult to avoid breathing in fungal spores because the fungi that cause mucormycosis are common in the environment. There is no vaccine to prevent mucormycosis. For people who have weakened immune systems, there may be some ways to lower the chances of developing mucormycosis.

• Protect yourself from the environment. It’s important to note that although these actions are recommended, they haven’t been proven to prevent mucormycosis.
  • Try to avoid areas with a lot of dust like construction or excavation sites. If you can’t avoid these areas, wear an N95 respirator (a type of face mask) while you’re there. Click here for more information about respirators.
  • Avoid direct contact with water-damaged buildings and flood water after hurricanes and natural disasters.
  • Avoid activities that involve close contact to soil or dust, such as yard work or gardening. If this isn’t possible,
    • Wear shoes, long pants, and a long-sleeved shirt when doing outdoor activities such as gardening, yard work, or visiting wooded areas.
    • Wear gloves when handling materials such as soil, moss, or manure.
    • To reduce the chances of developing a skin infection, clean skin injuries well with soap and water, especially if they have been exposed to soil or dust.
• Antifungal medication. If you are at high risk for developing mucormycosis (for example, if you’ve had an organ transplant or a stem cell transplant), your healthcare provider may prescribe medication to prevent mucormycosis and other mold infections. Doctors and scientists are still learning about which transplant patients are at highest risk and how to best prevent fungal infections.

The fungi that cause mucormycosis live in the environment

Mucormycetes, the group of fungi that cause mucormycosis, are present throughout the environment, particularly in soil and in association with decaying organic matter, such as leaves, compost piles, and animal dung. They are more common in soil than in air, and in summer and fall than in winter or spring.Most people come in contact with microscopic fungal spores every day, so it’s probably impossible to completely avoid coming in contact with mucormycetes. These fungi aren’t harmful to most people. However, for people who have weakened immune systems, breathing in mucormycete spores can cause an infection in the lungs or sinuses which can spread to other parts of the body.

Types of fungi that cause mucormycosis

Several different types of fungi can cause mucormycosis. These fungi are called mucormycetes and belong to the scientific order Mucorales. The most common types that cause mucormycosis are Rhizopus species and Mucor species. Other examples include Rhizomucor species, Syncephalastrum species, Cunninghamellabertholletiae, Apophysomyces, Lichtheimia (formerly Absidia), Saksenaea, and Rhizomucor.

How is mucormycosis diagnosed?

Healthcare providers consider your medical history, symptoms, physical examinations, and laboratory tests when diagnosing mucormycosis. Healthcare providers who suspect that you have mucormycosis in your lungs or sinuses might collect a sample of fluid from your respiratory system to send to a laboratory. Your healthcare provider may perform a tissue biopsy, in which a small sample of affected tissue is analyzed in a laboratory for evidence of mucormycosis under a microscope or in a fungal culture. You may also need imaging tests such as a CT scan of your lungs, sinuses, or other parts of your body, depending on the location of the suspected infection.

How is mucormycosis treated?

Mucormycosis is a serious infection and needs to be treated with prescription antifungal medicine, usually amphotericin B, posaconazole, or isavuconazole. These medicines are given through a vein (amphotericin B, posaconazole, isavuconazole) or by mouth (posaconazole, isavuconazole). Other medicines, including fluconazole, voriconazole, and echinocandins, do not work against fungi that cause mucormycosis. Often, mucormycosis requires surgery to cut away the infected tissue.

How common is mucormycosis?

Mucormycosis is rare, but the exact number of cases is difficult to determine because no national surveillance exists in the United States. Population-based incidence estimates for mucormycosis were obtained from laboratory surveillance in the San Francisco Bay Area during 1992–1993 and suggested a yearly rate of 1.7 cases per 1 million population.

Prospective surveillance among 16,808 transplant recipients performed in 23 institutions during 2001–2006 found that mucormycosis was the third most common type of invasive fungal infection in stem cell transplant recipients and accounted for 8% of all invasive fungal infections (77 mucormycete cases occurred among 983 stem cell transplant recipients who developed any fungal infection). Among solid organ transplant recipients, mucormycosis accounted for 2% of all invasive fungal infections (28 mucormycete cases occurred among 1,208 solid organ transplant recipients who developed any fungal infection). The number of cases varied widely across participating institutions.

Mucormycosis outbreaks

Healthcare providers who are concerned about an unusual number of new cases should contact their state or local public health agency.

Although most cases of mucormycosis are sporadic (not part of an outbreak), outbreaks of mucormycosis have occured. In healthcare settings, it can be difficult to determine whether mucormycosis is healthcare-associated or whether the infections were acquired somewhere else. Some examples of sources implicated in healthcare-associated mucormycosis outbreaks include adhesive bandages, wooden tongue depressors, hospital linens, negative pressure rooms, water leaks, poor air filtration, non-sterile medical devices, and building construction.Community-onset outbreaks have been associated with trauma sustained during natural disasters.

Deaths due to mucormycosis

Mucormycosis is frequently a life-threatening infection. A review of published mucormycosis cases found an overall all-cause mortality rate of 54%. The mortality rate varied depending on underlying patient condition, type of fungus, and body site affected (for example, the mortality rate was 46% among people with sinus infections, 76% for pulmonary infections, and 96% for disseminated mucormycosis).