Jennifer Head, University of Michigan; Alexandra K. Heaney, University of California, San Diego, and Simon Camponuri, University of California, Berkeley

As the climate warms, the southwestern U.S. is increasingly experiencing weather whiplash as the region swings from drought to flooding and back again. As a result, the public is hearing more about little-known infectious diseases, such as valley fever.

In May 2024, about 20,000 people attended a music festival in Buena Vista Lake, California. In the months that followed, at least 19 developed valley fever, and eight were hospitalized from their infection. This outbreak follows a dramatic increase of more than 800% in valley fever infections in California between 2000 and 2018.

In 2023, California reported the second-highest number of valley fever cases on record, with more than 9,000 cases reported statewide. And between April 2023 and March 2024, California provisionally reported 10,593 cases – 40% more than during the same period the prior year.

The Conversation U.S. asked Jennifer Head, Simon Camponuri and Alexandra Heaney – researchers specializing in the epidemiology of valley fever – to explain what valley fever is, and what might explain its rise in recent years.

What is valley fever, and how do you get infected?

Valley fever is the common name for a disease called coccidioidomycosis, which is an infection caused by pathogenic fungi from the Coccidioides genus. The fungi are primarily found in arid soils of the southwestern United States, as well as parts of Central and South America.

When the fungus has access to moisture and nutrients, it grows long, branching fungal chains throughout the soil. When the soil dries out, these chains fragment to form fungal spores, which can be stirred up into the air when the soil is disturbed, such as by wind or digging. Airborne spores can then be inhaled and cause a respiratory infection.

Cases of valley fever are typically highest in California’s southern San Joaquin Valley and southern Arizona, but they have been increasing outside of these regions. Between 2000 and 2018, the incidence of valley fever cases increased fifteenfold in the northern San Joaquin Valley and eightfold along the Southern California coast. And between 2014 and 2018, incidence increased by more than eightfold along the central coast.

Because of these trends and the virulence of the pathogen that causes valley fever, it is listed as a priority pathogen by the World Health Organization. Historically, fungal infections have received very little attention and resources. By creating this list, the WHO is hoping to galvanize action surrounding listed pathogens, including getting more resources for research as well as the development of new treatments.

What are the symptoms, and what should people be looking for?

After inhaling fungal spores from the environment, Coccidioides initially infects the lungs, causing symptoms like mild to severe cough, fever, difficulty breathing, chest pain and tiredness. Valley fever symptoms can resemble other common respiratory infections, so it’s important for people to get checked by a doctor if they’ve experienced prolonged symptoms, particularly if they have been given antibiotics that they are not responding to.

In California and Arizona, an estimated one-third of community-acquired pneumonia cases – or pneumonia acquired outside of the hospital – are caused by valley fever. However, only a fraction of community-acquired pneumonia cases get tested for it, so it’s likely the number of valley fever cases is significantly higher. Among diagnosed cases, half experienced symptoms for two months or more before being diagnosed.

In 5% to 10% of cases, the fungus can spread from the lungs to other parts of the body, such as the central nervous system, liver and bones, causing meningitis or arthritis-like symptoms. These cases can be severe and possibly fatal.

Antifungal treatment is available, and early diagnosis and treatment is critical for better outcomes.

What time of year should you be most concerned?

Valley fever cases can occur year-round, but in California, cases reported via surveillance systems tend to increase starting in August and September, peak in November and return to background levels in January and February.

Researchers believe that patients are likely exposed to the fungus in the summer and early fall months, typically one to three months prior to their diagnosis. This delay accounts for time between when patients are exposed, develop symptoms and are diagnosed with the disease. While cases peak in the fall on average, seasonal strength and timing varies regionally.

Our research shows that this seasonal surge in the fall is especially strong following wetter winters and that alternation between dry and wet conditions is associated with increased incidence in fall months.

Valley fever cases in California nearly doubled following wet winters that occurred one and two years after the 2007-2009 and 2012-2015 droughts.

In 2023, California experienced a similar transition, with an extreme drought occurring between 2020-2022 followed by heavy precipitation in the winter of 2022-2023.

This transition was followed by a near-record spike in cases in 2023. The state experienced another wet winter during the 2023-2024 wet season, furthering concern about continued high risk for valley fever in 2024.

Our research team recently developed a model to forecast valley fever cases that will occur between April 2024 and March 2025 in California. We forecast that the state is likely to see another spike in cases during the fall and winter of 2024, on par with the spike in 2023.

During high-risk periods, clinicians should consider valley fever as a potential diagnosis. This is especially true when evaluating a patient presenting with valley fever symptoms or a respiratory illness who lives in, works in or traveled to an endemic or emerging region.

We are currently working to characterize seasonal disease patterns in Arizona as well, which are different from California’s. This is likely because Arizona has two rainy seasons.

Are some people at greater risk than others?

Those who spend time or work outdoors in areas where valley fever is common, especially where they may be exposed to dirt and dust, are more likely to get it.

While healthy people are still at risk of infection, certain factors can increase the likelihood of developing severe disease from valley fever. These include being an adult 60 years or older, having diabetes, HIV or another condition that weakens the immune system, or being pregnant. People who are Black or Filipino also have been noted to have a higher risk of severe disease, which may relate to more exposure to the fungal spores, underlying health conditions, inequities in accessing care or other possible predispositions.

How can you protect yourself from getting valley fever?

People who live and work in the regions where the fungus is found should avoid exposure to dust as much as possible. When it is windy outside and the air is dusty, stay indoors and keep windows and doors closed.

When driving through a dusty area, limit vehicle speed, keep car windows closed and recirculate the air, if possible. When working outdoors, use dust suppression techniques, including wetting soil before digging to prevent stirring up dust, and installing fencing, windbreaks and vegetation where possible.

For those who must directly stir up soil or be in dusty conditions, such as while doing construction or gardening work, consider using an N95 mask to limit dust inhalation.

Jennifer Head, Assistant Professor of Epidemiology, University of Michigan; Alexandra K. Heaney, Assistant Professor in Climate and Health Epidemiology , University of California, San Diego, and Simon Camponuri, PhD Candidate in Environmental Health Sciences, University of California, Berkeley

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Claire Therese Hemingway, University of Tennessee

Just like people confronted with a sea of options at the grocery store, bees foraging in meadows encounter many different flowers at once. They must decide which ones to visit for food, but it isn’t always a straightforward choice.

Flowers offer two types of food: nectar and pollen, which can vary in important ways. Nectar, for instance, can fluctuate in concentration, volume, refill rate and accessibility. It also contains secondary metabolites, such as caffeine and nicotine, which can be either disagreeable or appealing, depending on how much is present. Similarly, pollen contains proteins and lipids, which affect nutritional quality.

When confronted with these choices, you’d think bees would always pick the flowers with the most accessible, highest-quality nectar and pollen. But they don’t. Instead, just like human grocery shoppers, their decisions about which flowers to visit depend on their recent experience with similar flowers and what other flowers are available.

I find these behaviors fascinating. My research looks at how animals make daily choices – especially when looking for food. It turns out that bees and other pollinators make the same kinds of irrational “shopping” decisions humans make.

Predictably irrational

Humans are sometimes illogical. For instance, someone who wins $5 on a scratch ticket immediately after winning $1 on one will be thrilled – whereas that same person winning $5 on a ticket might be disappointed if they’re coming off a $10 win. Even though the outcome is the same, perception changes depending on what came before.

Perceptions are also at play when people assess product labels. For instance, a person may expect an expensive bottle of wine with a fancy French label to be better than a cheap, generic-looking one. But if there’s a mismatch between how good something is and how good someone expects it to be, they may feel disproportionately disappointed or delighted.

Humans are also very sensitive to the context of their choice. For example, people are more likely to pay a higher price for a television when a smaller, more expensive one is also available.

These irrational behaviors are so predictable, companies have devised clever ways to exploit these tendencies when pricing and packaging goods, creating commercials, stocking shelves, and designing websites and apps. Even outside of a consumer setting, these behaviors are so common that they influence how politicians design public policy and attempt to influence voting behavior.

Like minds

Research shows bumblebees and humans share many of these behaviors. A 2005 study found bees evaluate the quality of nectar relative to their most recent feeding experience: Bees trained to visit a feeder with medium-quality nectar accepted it readily, whereas bees trained to visit a feeder with high-quality nectar often rejected medium-quality nectar.

My team and I wanted to explore whether floral traits such as scents, colors and patterns might serve as product labels for bees. In the lab, we trained groups of bees to associate certain artificial flower colors with high-quality “nectar” – actually a sugar solution we could manipulate.

For example, we trained one group to associate blue flowers with high-quality nectar. We then offered that group medium-quality nectar in either blue or yellow flowers.

We found the bees were more willing to accept the medium-quality nectar from yellow flowers than they were from blue. Their expectations mattered.

In another recent experiment, we gave bumblebees a choice between two equally attractive flowers – one high in sugar concentration but slower to refill and one quick to refill but containing less sugar. We measured their preference between the two, which was similar.

We then expanded the choice by including a third flower that was even lower in sugar concentration or even slower to refill. We found that the presence of the new low-reward flower made the intermediate one appear relatively better.

These results are intriguing and suggest, for both bees and other animals, available choices may guide foraging decisions.

Potential uses

Understanding these behaviors in bumblebees and other pollinators may have important consequences for people. Honeybees and bumblebees are used commercially to support billions of dollars of crop production annually.

If bees visit certain flowers more in the presence of other flowers, farmers could use this tendency strategically. Just as stores stock shelves to present unattractive options alongside attractive ones, farmers could plant certain flower species in or near crop plants to increase visitation to the target crops.

Claire Therese HemingwayUniversity of Tennessee

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Selma Hedlund, Boston University

The COVID-19 pandemic exposed a pressing issue: The U.S. health care system is increasingly dependent on immigrant physicians, but it’s becoming harder for aspiring ones to work and settle in the U.S.

Today, 1 in 4 doctors are foreign-born, international medical graduates. Their numbers are even larger in underserved areas – essentially, low-income, more rural parts of the country where many American doctors don’t want to work.

This immigrant workforce is key to offsetting a dire physician shortage. The need for more doctors is due, in part, to America’s growing and aging population; U.S.-born doctors’ unwillingness to move to poorer and more rural areas; and U.S.-born doctors’ lack of interest in going into primary care, which can be less lucrative and prestigious than other areas of medicine.

As a result, immigrant doctors have become indispensable in hospitals and clinics across the nation. But while they’re in demand, more and more foreign doctors are starting to see the immigration process as a risky endeavor.

During the COVID-19 pandemic, I wrote my dissertation about how immigrant physicians navigate the U.S. immigration system and foreign licensing procedures. My interviewees described how a combination of stricter immigration policies and more competition for residency spots have made the U.S. a less feasible destination.

Visa vicissitudes

U.S. visas can be categorized into two categories: immigrant and nonimmigrant. Nonimmigrant visas, such as tourist, student or exchange visitors visas, prohibit holders from having what’s called “immigrant intent,” meaning that they don’t plan to use their visas to permanently stay in the U.S.

In order for immigrant doctors to be licensed to practice in the U.S., they need to complete licensing exams. They also need to obtain clinical experience in the U.S. This can be completed while on a tourist visa or a student visa, which are relatively easy to obtain.

However, all immigrant physicians – even if they’re certified specialists in their home country – need to get accepted into and complete a U.S. residency program in order to practice in the U.S. as specialists. These are intensive, supervised training programs that can last up to seven years.

Nonetheless, a majority of immigrant doctors in the U.S. will complete their American residencies on nonimmigrant visas, even though by this point in the process they quite clearly have immigrant intent.

It wasn’t always this way.

There’s a special work visa called the H-1B that allows for both immigrant and nonimmigrant intent. A few decades ago, many immigrant physicians entered residency programs that sponsored H-1B visas, which served as stepping stones to green cards.

But drastic restrictions to the number of people admitted into this visa program, coupled with cuts in graduate medical education funding, have directed most foreign-born doctors to what’s called a J-1 exchange visitors visa.

Challenges of working in underserved areas

The J-1 not only explicitly prohibits immigration intent, it also requires that doctors return to their home country for at least two years upon completing American residency training.

Foreign-born doctors nonetheless pursue the J-1 because there’s the opportunity to obtain a waiver, with limited slots that will allow them to remain in the U.S. and adjust to an H-1B visa. If selected for the waiver program, they must commit to a minimum of three years of service in a designated medically underserved area in the U.S.

While this system can offer short-term relief to physician shortages, it can also lead to exploitation.

As one interviewee told me, “We hear very scary things about the J-1 waiver. The employers can take advantage and make you work more and pay less.”

For the duration of the waiver program, immigrant physicians have minimal ability to change employers without violating the conditions of the waiver – and their path to immigration. Underserved areas are often understaffed and underresourced, which can make for stressful working conditions.

Forced to go above and beyond

The challenges don’t end with the visa process. There are financial burdens as well.

International medical graduates often spend tens of thousands of dollars to pay for U.S. medical licensing exams, multiple visa applications, international travel and lodging, residency and green card applications.

They also spend months in unpaid positions in hospital settings to gain the U.S. clinical experience that’s required to apply for residency. Then, in order to match into residency, immigrant physicians typically need to outperform their American peers on exams. They also need to have more prestigious research qualifications and stronger recommendation letters. Still, immigrant doctors are more likely to match into less competitive residency programs.

While interviewing immigrant physicians, many testified to the competition getting steeper in recent years.

“I told a friend, if you don’t have scores in upper 90s in all the exams and you’re not a green card holder, don’t even bother,” an Indian physician who immigrated 20 years ago explained to me. “It’s so tough.”

Stuck in limbo

Over the course of my research I noticed a trend: Many international medical graduates will come to the U.S. on student visas to pursue U.S. graduate degrees in health-related fields, such as public health, before they even start the licensing process. This helps them get their foot in the door into a very complicated immigration system and build a stronger resume as they prepare for residency applications. It’s also another expensive investment.

But even those who match into and complete residency won’t necessarily be able to stay and work in America.

Those with positive experiences from working in underserved communities often struggle to remain in their positions after their waiver contracts are fulfilled because of the green card backlog.

The average immigrant’s wait time for a green card has doubled since the national quota system was introduced in the early 1990s.

By 2018, an applicant had to wait an average of 18 months to get approved for their green card and another five years and eight months to receive it. The COVID-19 pandemic introduced new barriers and delays.

Indians, one of the biggest nationalities among immigrant physicians, have the longest wait times under the current system, sometimes waiting up to a decade to obtain the security of permanent residence. Among the 1.8 million cases currently stuck in the employment-based green card backlog, 63% are Indian nationals.

A pending green card application is often formally considered abandoned if the applicant leaves the country, preventing people from visiting loved ones abroad for years.

No fix on the horizon

Despite frequent calls for change and reform, these bottlenecks continue to adversely affect both patients and doctors.

While the current model has its benefits, it also reflects a trend in which much-needed immigrant professionals live in prolonged, demoralizing uncertainty. Work visas have been subject to increasing cuts and restrictions in recent years under both the Trump and Biden administrations. Conditions will likely worsen if Trump returns to office: The “Muslim ban” he enacted in 2017 adversely affected many immigrant doctors and their patients, and his calls for increased vetting will likely exacerbate existing barriers to legal immigration.

A paradox has emerged: While the U.S. says it wants to attract and retain world class talent, its byzantine immigration system continually discourages potential hires.

The doctors I interviewed gave a variety of reasons for wanting to work in the U.S., including better lifestyles and opportunities for professional development. But the complexity and sheer unwieldiness of the U.S. visa regime is causing the nation to lose skilled professionals to other countries with more streamlined processes.

Selma Hedlund, Postdoctoral Associate at Center of Forced Displacement, Boston University

This article is republished from The Conversation under a Creative Commons license. Read the original article.