Health experts are not sure what led to the high number of cases of Valley Fever in California last year, but believe it could be tied to an above average rainfall during the 2018-19 winter.

Valley Fever, also known as coccidioidomycosis, or “cocci,” is caused by breathing in the spores of a fungus that grows in the soil and dirt in some areas of California. The fungal spores are too small to see and may be present in dust that gets into the air when windy or when soil is disturbed, such as digging during construction. This fungus usually infects the lungs and can cause respiratory symptoms including cough, fever, chest pain and tiredness. In most people, the infection goes away but anyone with symptoms for more than a week should ask their healthcare provider if their symptoms could indicate Valley Fever.

The symptoms of Valley Fever are similar to those of the coronavirus, but unlike COVID-19, Valley Fever is not transmitted person to person. People who have Valley Fever or have had lingering effects from it, are more at risk to having a severe case of COVID-19 if the virus is contracted.

The California Department of Public Health reported 9,004 people were diagnosed with Valley Fever in 2019, the highest number of cases since health officials began tracking the virus in 1995.

Consistent with previous years, the highest incidence of Valley Fever in 2019 was reported in counties in the Valley and Central Coast regions.

«With the continued increase in Valley Fever cases, people living and working in the Central Valley and Central Coast regions of California should take steps to avoid breathing in dusty air outside,» said Dr. Erica Pan, CDPH Acting State Public Health Officer. “Although the symptoms of Valley Fever can be similar to those of COVID-19, it’s important that individuals with lingering cough and fatigue also talk to a healthcare provider about Valley Fever, especially if they have been outdoors in dusty air. People who work primarily outdoors such as construction workers and others that dig or disturb soil should especially learn more about the prevention of Valley Fever.”

While anyone can get Valley Fever, those most at-risk for severe disease include people who are black or Filipino, adults 60 years or older, pregnant women, and people with diabetes or conditions that weaken the immune system. In severe disease, the infection can spread to other parts of the body, and in these serious cases, prolonged antifungal medicine is required. 

A person can reduce their risk of Valley Fever by taking steps to avoid breathing in dust in areas where Valley Fever is common: When it is windy outside and the air is dusty, stay indoors and keep windows and doors closed; while driving, keep car windows closed and use recirculating air conditioning, if available; and if individuals must be outdoors in dusty areas, they should consider wearing a properly fitted N95 mask. 

Because of the high rate seen last year, the CDPH increased their awareness efforts. During 2019-2020, CDPH implemented a multimedia Valley Fever awareness campaign to reach more people and providers, including people living in areas with moderate to high rates of Valley Fever and those at risk for severe disease.