Fungus Among Us: Three Fungal Diseases that Cause Pneumonia in the United States

August 22, 2019|11:42 a.m.| Tom Chiller, MD, MPHTM, chief of the Mycotic Diseases Branch, CDC

Tom ChillerWith Fungal Disease Awareness Week beginning next month, on Sept. 23, it is critical that we educate the public about endemic fungal diseases and work to better understand these diseases. Many people are familiar with common fungal diseases like ringworm and athlete’s foot. These are usually mild illnesses that improve with treatment. Our small but mighty team at CDC works on the fungal diseases that can cause severe disease and even death. In the United States, three main types of fungi—coccidioidomycosis, histoplasmosis, and blastomycosis—can cause lung infections like pneumonia when people breathe in fungal spores from the air. Depending on where you live, you may be more likely to come in contact with one of these fungi.

If you live in the western United States, for instance, you may be familiar with Valley fever (or coccidioidomycosis). Thousands of Valley fever infections are reported to health departments every year. Southern Arizona and the San Joaquin Valley in California have the highest number of infections in the country. These fungal lung infections have similar symptoms to the more common bacterial or viral lung infections, resulting in a lot of misdiagnosis and underreporting. Many people who get Valley fever were exposed to large amounts of dust in areas where the fungus is commonly found. Recently a group of U.S. volunteers got sick after building houses near Tijuana, Mexico.

If you’re in central or eastern United States, you are likelier to be affected by the fungus that causes histoplasmosis. It tends to grow in areas with large amounts of bird or bat droppings, such as chicken coops or caves. A recent outbreak among campers in Louisiana was linked to bat droppings from a hollowed tree. We recommend that people with weakened immune systems avoid activities that disrupt large amounts of bird or bat droppings, such as cleaning chicken coops, exploring caves, or participating in demolition or construction of a building where bird or bat droppings are present. Throughout Latin America and the Caribbean, histoplasmosis is one of the most common infections in people living with HIV/AIDS. At CDC, we are working with partners to develop new tools to help diagnose histoplasmosis earlier and set up laboratory-based surveillance in Latin America and the Caribbean to help prevent severe illness and death.

If you live in the midwestern, south-central, or southeastern states, you are more likely to come in contact with the fungus that causes blastomycosis. It particularly likes to live in areas surrounding the Ohio and Mississippi River valleys, the Great Lakes, and the Saint Lawrence River. But it probably lives in other places too. For example, physicians have recently detected cases in upstate New York. Based on cases reported to health departments, infections are most common in areas of northern Michigan, Minnesota, and Wisconsin, as well as some other parts of the southeastern United States. In these areas, people with weakened immune systems may want to avoid activities that involve disturbing soil in wooded areas or near bodies of water.

Surveillance for these three fungal diseases is critical to understand how many people get infected. It is also important to monitor trends, develop prevention methods, and help healthcare providers and laboratories better detect and treat these diseases. Health departments in about half of the United States collect information about Valley fever and send it to CDC through the National Notifiable Diseases Surveillance System. But the information collected in the reports is minimal. We need more detailed information about where a person was most likely infected with Valley fever, how strains are related, and which areas could pose a risk.

Histoplasmosis and blastomycosis are not nationally notifiable, but state health departments can voluntarily send information on cases to CDC. Thirteen states require reporting of histoplasmosis and five states require reporting of blastomycosis. The more information we have at a national level, the better we can understand these fungi and educate public health officials, healthcare providers, and the public about the risk of disease.

The public needs to know: No matter where you live, if you have pneumonia that isn’t getting better with treatment, ask your healthcare provider about the possibility of a fungal infection. We all have a role to play in identifying these diseases earlier, reporting them faster, and raising awareness so that we can save lives and protect the populations we serve.