Surging fatal fungal infections led by atmospheric rivers in California

The recent atmospheric river storms in California are fueling public health concerns as cases of Valley Fever, a fungus-induced disease, have surged following heavy rainfalls in the state of the U.S.

Valley Fever is caused by breathing in dust from outdoor air that contains spores of the Coccidioides fungus. It usually affects the lungs and can cause prolonged symptoms, including cough, fever, chest pain and fatigue. It can also lead to severe diseases, such as meningitis which basically refers to inflammation of the brain membranes, and even death, according to the California Department of Public Health (CDPH).

The department issued an advisory to healthcare providers last month, as the cases of Valley Fever broke records last year following several back-to-back atmospheric rivers that delivered powerful rainstorms in California.

Valley Fever and rainfalls

A total of 9,280 new cases of Valley Fever with onset dates in 2023 have been recorded in California to date, higher than any other year on record, according to the CDPH.

Record storms in California lead to surging deadly fungal infections. The department blamed the heavy rainfall in the winter following years of drought for the increase in the disease.

Based on last year's climate and disease pattern, "we expect to continue to receive a higher number of case reports than usual throughout the winter months of 2024," said the CDPH in the advisory.

New research by the University of California, Berkeley and the CDPH showed that during drought, the fungus that causes Valley Fever can become less active. However, when the rains return, the fungus can grow, leading to increases in infection.

According to the Centers for Disease Control and Prevention, approximately 200 people die from Valley Fever every year in the country.

Valley Fever is named for California's San Joaquin Valley, where the disease was discovered. The progression of the illness depends on the strength of the individual's immune system.

Health experts are worried that Valley Fever could become a much bigger public health problem as increasing human activities, such as farming practices and construction, as well as climate change create ever more favorable conditions for the fungus.

Atmospheric rivers

Early in February, atmospheric rivers, a long corridor of concentrated moisture in the atmosphere, brought record-breaking rainfall and severe winds to California, unleashing mudslides, flooding roadways and knocking out power.

Another round of atmospheric rivers is poised to slam the state again over the next few days. The first of the storms is expected to begin Saturday morning and last into Sunday morning, and the second round is expected to begin affecting the state Sunday afternoon and will last through the middle of next week, the New York Times reported.

The risk of flooding is increasing because the heavy rainfall make it harder for the ground to absorb rain during the second storm. Also, winds are expected to be strong with the second one.

(With input from Xinhua)