Right now, the attention of the United States and the world is focused on coronavirus disease 2019 (COVID-19). However, as summer approaches and with it the monsoon season, those in Arizona and other parts of the Southwest will have another respiratory illness to contend with – Valley fever.
Unlike COVID-19, a viral infection, Valley fever is caused by a fungus, medically known as Coccidioides. Valley fever is transmitted by breathing in Coccidioides spores that arise from the dirt, not by person to person spread as with COVID-19. In highly endemic areas such as Phoenix and Tucson metropolitan areas, it is estimated that one in 100 persons become ill from Valley fever each year.
The Risk of Contracting Both Infections
With so many people affected by both COVID-19 and Valley fever, what are the risks of contracting both at the same time? And if you have had Valley fever, are you at higher risk of contracting COVID-19?
According to John Galgiani, MD, an infectious disease specialist with Banner – University Medical Center Tucson and medical director for the Valley Fever Center, it is theoretically possible to contract both COVID-19 and Valley fever at the same time. However, the odds of this happening are very low. And although it makes sense that having two infections at once would be worse than having only one alone, thus far we have no experience on which to judge how bad simultaneous infections would be.
“On the other hand, for those who have had Valley fever in the past, there is no reason to believe they are at higher risk for contracting COVID-19, as Valley fever does not interfere with or weaken a person’s immune system”, said Dr. Galgiani.
How Are the Two Illnesses Similar?
Although very different in nature and cause, there are several similarities between COVID-19 and Valley fever according to Dr. Galgiani. Both illnesses are acquired through the respiratory track and share similar symptoms—fever, cough, shortness of breath, as well as fatigue in some instances. These symptoms can range from mild to life-threatening, while for many people the infection can be completely asymptomatic. Thus, many cases of both COVID-19 and Valley fever go undiagnosed.
What Makes Them Different?
With so many similarities, how can you tell them apart? “Strictly speaking, you cannot,” said Dr. Galgiani. “However, their general patterns are different and can provide you clues.”
- COVID-19 is an emerging epidemic. The number of confirmed cases is on the rise and based on current projections, it is expected to peak in Arizona in the next couple of weeks. “The risk for Valley fever is ever-present with seasonal fluctuations each year,” said Dr. Galgiani. “So, while COVID-19 cases hopefully decline in the coming months, the number of Valley fever cases are expected to increase into the summer.”
- COVID-19 causes a more acute illness. Chronic COVID-19 illnesses have not been evident. In contrast, while Valley fever sometimes starts abruptly, it typically continues for weeks to several months before symptoms completely resolve.
- The primary complication of COVID-19 is respiratory failure. While Valley fever can result in respiratory failure in rare cases, the infection can also spread to other parts of the body, causing destruction in bones, skin, the brain or elsewhere.
Ultimately, control and reduction of both COVID-19 and Valley fever could come from a vaccine. While work is underway for a COVID-19 vaccine, a vaccine candidate already exists for Valley fever and is in the development and testing stages for dogs.
For more information about Valley fever, visit the Valley Fever Center for Excellence website.