Research already shows that germicidal UV can effectively inactivate airborne microbes that transmit measles, tuberculosis and SARS-CoV-1, a close relative of the novel coronavirus.

This article was first published on Wednesday, July 22, 2020 in Kaiser Health News.

By Will Stone July 22, 2020

High up near the ceiling, in the dining room of his Seattle-area restaurant, Musa Firat recently installed a "killing zone" — a place where swaths of invisible electromagnetic energy penetrate the air, ready to disarm the coronavirus and other dangerous pathogens that drift upward in tiny, airborne particles.

Firat's new system draws on a century-old technology for fending off infectious diseases: Energetic waves of ultraviolet light — known as germicidal UV, or GUV — are delivered in the right dose to wipe out viruses, bacteria and other microorganisms.

Research already shows that germicidal UV can effectively inactivate airborne microbes that transmit measles, tuberculosis and SARS-CoV-1, a close relative of the novel coronavirus. Now, with concern mounting that the coronavirus that causes COVID-19 may be easily transmitted through microscopic floating particles known as aerosols, some researchers and physicians hope the technology can be recruited yet again to help disinfect high-risk indoor settings.

"I thought it was a great idea, and I want my customers to be safe," said Firat whose casual eatery, Marlaina's Mediterranean Kitchen, is 20 minutes south of downtown Seattle.

As the U.S. grapples with how to interrupt the spread of the highly infectious virus, UV is being used to decontaminate surfaces on public transit and in hospitals where infectious droplets may have landed, as well as to disinfect N95 masks for reuse. But so far using this technology to provide continuous air disinfection has remained outside of most mainstream, policy-setting conversations about the coronavirus.

Experts attribute this to a combination of factors: misconceptions about UV's safety, a lack of public awareness and technical know-how, concerns about the costs of installing the technology, and a general reluctance to consider the role of aerosols in the spread of the coronavirus.

Aerosols are microdroplets expelled when someone exhales, speaks or coughs. Unlike the larger and heavier respiratory droplets that fall quickly to the ground, aerosols can linger in the air a long time and travel through indoor spaces. When someone catches a virus this way, the process is called "airborne transmission."

It's already recognized that the coronavirus can spread by means of aerosols during medical procedures, which is why healthcare workers are advised to wear respirators, such as N95 masks, that filter out these tiny particles. Yet there is still considerable debate over how likely the virus is to spread in other settings via aerosols.

Recently, the question of airborne transmission gained new urgency when a group of 239 scientists called on the World Health Organization to take the threat of infectious aerosols more seriously, arguing that the "lack of clear recommendations on the control measures against the airborne virus will have significant consequences."

WHO officials conceded that more research is needed but maintained that most infections do not happen this way.

As the science continues to evolve, UV could emerge as an attractive safeguard against airborne transmission — one with a track record against pathogens — that can be deployed to reduce the risk of infectious aerosols accumulating in indoor settings such as schools and businesses.

Welcome to the 'Killing Zone'

At Marlaina's restaurant, there are just two visible clues of the new UV disinfection system — a subtle glow of blue light above the black grates of the drop ceiling, and a hand-chalked sign at the door, proudly announcing to diners: "Coronavirus Disinfected Here!"

The system was installed while the restaurant was closed during Washington state's lockdown. The setup is known as "upper-room germicidal UV" because the UV fixtures are mounted high and angled away from humans below.

Ceiling fans circulate the air, eventually pushing any suspended viral particles that have accumulated in the dining space through the grated drop ceiling, to the area where UV lights, positioned horizontally, blast them with radiant energy.

The inspiration and technical assistance for Marlaina's owner came from customer Bruce Davidson, a pulmonary physician who was Philadelphia's "tuberculosis czar" in the mid-'90s. Back then, the U.S. was grappling with a new outbreak of TB that included strains resistant to existing drugs.

"Preventing transmission was the most important part, because we had no drugs, no vaccine," recalled Davidson, who now lives outside Seattle. UV light proved to be a key strategy back then, and Davidson thinks it can help again: "It really ought to be in most indoor public spaces now."

To demonstrate the concept, Davidson lit a cigar inside Marlaina's and showed how the smoke danced upward, collecting in the ceiling space with the UV fixtures.

"If somebody has undetected coronavirus and doesn't eat with a mask and is talking and so on, the vast majority of their particles are going to get pulled up there into the killing zone and circulate and bounce around," Davidson said. "Statistically, the risk to other people is going to be very low."

Research shows close to 90% of airborne particles from a previous coronavirus (SARS-CoV-1) can be inactivated in about 16 seconds when exposed to the same strength of UV as in the restaurant's ceiling. Other viruses, such as the adenovirus, are more resistant and require a higher dose of UV.

"Although it's not perfect, it probably offers the best solution for direct air disinfection" in the current pandemic, said David Sliney, a faculty member at Johns Hopkins University and longtime researcher on germicidal UV.

When used with proper ventilation, upper-room GUV is about 80% effective against the spread of airborne tuberculosis, according to several studies. This is equivalent to replacing the air in a room up to 24 times an hour.

But widespread adoption of UV systems could be an uphill battle, Sliney said, because in the U.S., interest in using UV for air disinfection has waned in recent decades as scientists focused their attention on powerful vaccines and drugs to deal with infectious diseases.

Understanding Aerosols and Airborne Transmission

UV can be a powerful weapon against an airborne virus, but it can go only so far toward preventing infection. People can still get sick from the larger, heavier droplets ejected via coughs and sneezes. They can directly inhale those droplets or touch a surface contaminated with them, and then touch their eyes, nose or mouth.

UV also does not prevent someone from being exposed to infectious aerosols that have just emerged from an infected person — and are lingering quite near his or her body — what researcher Richard Corsi called the "near field."

"In that scenario, you're inhaling a very concentrated cloud of these tiny particles that you can't see," said Corsi, dean of the Maseeh College of Engineering & Computer Science at Portland State University. "You're getting a pretty significant dose in your respiratory system."

So, even if there is upper-room UV in a building, Corsi said, face masks and social distancing are still necessary to block larger respiratory droplets and remove some of the aerosols in the near field. But Corsi said there's now enough evidence to show that coronavirus aerosols can hang in the air and spread throughout a room ("the far field"), and it's time to take that airborne spread seriously.

One example of far-field transmission is documented in a study of a restaurant in China at which some diners seated at neighboring tables contracted the COVID-19 virus despite never coming into close contact with the "index case-patient." Another piece of evidence came from a March 10 choir practice in Mount Vernon, Washington, after which the majority of singers contracted the coronavirus, even though members of the group took precautions to use hand sanitizer and avoid hugs and handshakes.

In their letter to WHO, scientists note that the coronavirus that causes MERS can spread through aerosols, and "there is every reason to expect that [the COVID virus] behaves similarly."

Understanding the Technology and Safety

Germicidal UV harnesses a portion of the electromagnetic spectrum that contains short waves of radiant energy, called UV-C. This wavelength is further away from the visible spectrum than other forms of UV light.

Think of it as giving the virus a lethal sunburn.

"We have very little practical experience to show how effective it can be [in a pandemic] since it's been out of use in this country and in Western Europe," said Sliney of Johns Hopkins, who chairs a committee with the Illuminating Engineering Society, which recently released new guidance on GUV.

Sliney recommends installing UV in big-box stores, restaurants and grocery stores, which typically have high ceilings. "There needs to be vertical air exchange," he said, as with ceiling fans, so "it's not just sterilizing the air in the upper space of the room."

"No one doubts the efficacy of germicidal UV in killing small microorganisms and pathogens. I think the bigger controversy, if there is any, is misperceptions around safety," said Dr. Edward Nardell, a professor at Harvard Medical School who researches GUV.

Low-dose germicidal UV can damage the eyes and skin, but Nardell said those risks can be avoided by following the appropriate guidelines. While international guidelines warn against directly exposing humans to UV-C, the risks of skin cancer are considered negligible, especially compared with longer wavelengths of UV that can penetrate more deeply.

Could UV Make a Comeback?

With interest in UV climbing, there is concern about shoddy products on the market and exaggerated claims about their effectiveness against the virus, said Jim Malley, a professor at the University of New Hampshire who studies public health and disinfection.

Consumers should be wary of marketing claims about "UV wands" that can be waved quickly over surfaces or special "portals" that people walk through, he said, because those are probably not correctly calibrated to inactivate the virus and could be dangerous.

Malley said he does not think there's much of a viable market for upper-room GUV outside healthcare settings, but he supports installing the technology in the most high-risk settings, such as meatpacking plants and nursing facilities.

"My gut feeling is we should do anything we can in those places, because we have a horrendous fatality record" with the coronavirus, he said.

At Marlaina's restaurant, the installation was relatively straightforward.

The owner, Firat, purchased four UV fixtures (at $165 each), hired an electrician to install the fans and bought black gridded plastic panels to enclose the ceiling space where the UV is mounted.

Firat still encourages his customers to wear masks and maintain social distance. But he said the UV has become part of the ambiance.

"It's more modern and clean, and the response is great, absolutely great," he said.

This story is part of a partnership that includes NPR and Kaiser Health News.

Public health officials are trying to find a common thread among the four cases identified so far in Colorado.

This article was first published on Monday, July 20, 2020 in Kaiser Health News.

By Markian Hawryluk   

DENVER — Dr. Michelle Barron, medical director of infection prevention and control at UCHealth University of Colorado Hospital, received an unusual call last month from the microbiology lab: confirmation of the third case this year of trench fever, a rare condition transmitted by body lice that plagued soldiers during World War I.

Barron's epidemiological training kicked in.

"Two is always an outbreak, and then when we found a third — OK, we clearly have something going on," Barron recalled thinking.

Barron, who said she'd never before seen a case in her 20 years here, contacted state public health officials, who issued an advisory Thursday and said a fourth person with a suspected case had been identified. They asked physicians to be on the lookout for additional cases.

Trench fever is characterized by relapsing fever, bone pain (particularly in the shins), headache, nausea, vomiting and malaise. Some of those infected can develop skin lesions or a life-threatening infection of their heart valves.

The condition is caused by the bacterium Bartonella quintana, a close relative of the bug that causes cat scratch fever. Colonies of it live in the digestive systems of body lice and are excreted in their feces. The bugs can enter the body through a scratch in the skin or through the eyes or nose. Dried lice feces can be infectious for up to 12 months.

Trench fever is most commonly diagnosed among people experiencing homelessness or living in conditions where good hygiene is difficult. Those with compromised immune systems are particularly at risk.

Public health officials are trying to find a common thread among the four cases identified so far in Colorado. They occurred months apart, and the patients appear to have no connection other than having been homeless in the Denver area.

Other cases of the disease may have been overlooked. This outbreak comes, after all, at a time when much attention is being diverted to the coronavirus pandemic. But the economic fallout of that crisis could be fueling the outbreak of an illness that thrives on hardship.

Trench fever can be an easy diagnosis to miss, Barron said. Patients often have other health problems that could explain their symptoms, and doctors will try to rule out the more common causes before considering a rare one.

Moreover, the bacteria grow very slowly in lab cultures — it can take up to 21 days, and labs usually discard cultures after seven days. Barron said the bacteria in two of the confirmed cases grew just before the cell cultures were due to be thrown out.

Doctors will often treat the symptoms of a disease like trench fever with antibiotics. If the patient heals, it's possible no tests will be pursued to determine the organism causing the illness, said Dr. Kristy Murray, an infectious disease specialist with Baylor College of Medicine and Texas Children's Hospital in Houston.

"With this particular disease, unless you work in a setting where you're with the homeless all the time, you're not thinking about it or looking for it," she said. "It is very rare."

Nonetheless, in recent years, outbreaks have occurred in San Francisco and Seattle homeless camps.

Barry Pittendrigh, a Michigan State University entomologist who was part of an international collaborative studying the lice that cause trench fever, said head lice can also carry the bacteria, but their immune systems are strong enough to keep it in check. Body lice live in clothing, coming on and off to feed on the body. Their immune systems aren't as strong, he said, so the bacteria can flourish.

"We see scenarios when social crises are occurring — wars, economic downturn, displacement of people — when there is this chance that we'll have problems around hygiene that, in turn, these louse populations take off and you get these diseases," Pittendrigh said.

A spike in body lice occurred during the 2008 recession, he said, and before that, during the Great Depression and the two world wars. The current economic and health disruption caused by the COVID-19 pandemic could lead to another increase.

As public health agencies struggle with the coronavirus, fewer resources are left to track down outbreaks of other infectious diseases.

Colorado is committed to battling both issues, said state health department spokesperson Deanna Herbert. "We are continuing to grow the COVID-19 response staff, which allows us to balance other outbreaks and needs with responding to the global pandemic," she wrote in an email. "Scaling to the size we have is a tremendous undertaking, but we have a staff that is absolutely committed to being as responsive as possible to the needs of all Coloradans."

Murray said an outbreak often can be interrupted with outreach to homeless shelters and other groups that provide services to those living on the street. Mobile showers or offering to launder or replace their clothes can help. Body lice can be killed by washing and drying clothes at high temperatures — at least 130 degrees Fahrenheit.

The pesticide permethrin can also be used to treat clothing, bedding and backpacks to prevent lice infestation. Most people don't need to worry, though: According to the federal Centers for Disease Control and Prevention, infestation is unlikely to persist on anyone who bathes regularly and switches to clean clothes and bedding every week.

Still, trench fever has been considered a reemerging disease since the 1990s.

"Old infectious diseases always still have the potential to come back," Barron said. "Even though we live in a society that we consider very modern and very safe on so many levels, these organisms, at the end of the day, have been here longer than us and plan to survive."

Markian Hawryluk: MarkianH@kff.org, @MarkianHawryluk

Promises made early on in the coronavirus pandemic that testing would be free are being rolled back in ways that are creating turmoil for consumers.

This article was first published on Monday, July 20, 2020 in Kaiser Health News.

By Julie Appleby

In advance of an upcoming road trip with her elderly parents, Wendy Epstein's physician agreed it would be "prudent" for her and her kids to get tested for COVID-19.

Seeing the tests as a "medical need," the doctor said insurance would likely pay for them, with no out-of-pocket cost to Epstein. But her children's pediatrician said the test would count as a screening test — since the children were not showing symptoms — and she would probably have to foot the bill herself.

It made no sense. "That's two different responses for the exact same scenario," said Epstein, a health law professor at DePaul University in Chicago, who deferred the tests as she clarified the options.

Early on in the coronavirus pandemic — when scarce COVID testing was limited to those with serious symptoms or serious exposure — the government and insurers vowed that tests would be dispensed for free (with no copays, deductibles or other out-of-pocket expense) to ensure that those in need had ready access.

Now, those promises are being rolled back in ways that are creating turmoil for consumers, even as testing has become more plentiful and more people — like Epstein — are being advised to get them.

Late last month, the Trump administration issued guidance saying insurers had to waive patient costs only for "medically appropriate" tests "primarily intended for individualized diagnosis or treatment of COVID-19." It made clear that insurers do not have to fully waive cost sharing for screening tests, even when required for employees returning to work or for assisting in public health surveillance efforts.

Left unclear are situations like that faced by Epstein — and others who seek a test to clear a child for summer camp or day care. Public health officials have been unanimous in the opinion that widespread, readily available testing is crucial for getting businesses and schools open again, and society back on its feet.

But who should bear the costs of that testing — or a share of them — is an unresolved question.

Who pays when all employees are required to have a negative COVID test in order to return to work? Or if a factory tests workers every two weeks? Or just because someone wants to know for their own peace of mind?

The questions may be compounded in some cities and states where tests are widely available at clinics or drive-thru centers. In New York, CityMD clinics bill insurers $300 for the service, according to an explanation-of-benefits document given to KHN by a patient. The related charge from the lab that processed the test, according to the same patient's insurance statement, was $55. Most patients don't have to pay a share of those amounts.

The clinic has a partnership with the city allowing anyone who wants a test for the virus to get one. Still, no test is truly free, as labs bill insurers or submit for reimbursement from government programs.

Until a recent spike in virus cases created long delays in many areas, some other regions also took a test-everyone-who-wants-a-test approach. While that is one way to get a picture of where the virus is spreading, it can also become a cash cow providing income to clinics and labs, as residents seek multiple "free" tests after each potential exposure.

In an email, a spokesperson for CityMD would not say how much the clinic is reimbursed for testing. The clinics do not bill for lab testing, she wrote, referring questions about those costs to the laboratories that process them.

Insurers will be making judgment calls — likely on a case-by-case basis — about how they will handle cost sharing for screening tests under the new Trump administration guidance.

What is clear: Insurers have argued against requirements that they waive all cost sharing for workplace COVID testing, noting they don't do that for other screening efforts, such as drug-testing programs. For now, insurers will "continue to pay for tests recommended by a doctor," Kristine Grow, spokesperson for AHIP, an industry group, wrote in an email to KHN.

But AHIP also sent a clear signal that it would not embrace cost sharing waivers for workplace or public health screening efforts. Earlier this month, the organization lobbied federal lawmakers to include funding in the next stimulus package for public health surveillance and workplace testing programs — a cost estimated between $6 billion and $25 billion annually in an earlier study commissioned by the group.

The Evolving Rules for Free Testing

The coronavirus relief legislation passed by Congress in March, and April guidance from the Trump administration implementing it, agreed that patients should not be burdened with payments for COVID testing and treatment that is "medically appropriate."

But as the pandemic has evolved and grown, the definition of that term has both broadened and become fuzzier.

The Centers for Disease Control and Prevention says testing is appropriate for people who fall into five broad categories, including those with suspected exposure and those required to be tested for "purposes of public health surveillance," which it defines as checking for disease hot spots or trends.

"There's definitely a disconnect between what public health experts are recommending for testing and how it's going to be paid for," said Sabrina Corlette, co-director of the Center on Health Insurance Reforms at Georgetown University.

And tension is mounting among insurers, employers and consumers over who should pay. While insurers say employers should cover the cost for back-to-work testing, many employers are struggling financially and may not be able to do so. At the same time, workers, especially those in lower-wage jobs, also cannot afford out-of-pocket costs for testing, particularly if it is required regularly.

Among those waiting to hear if their insurance will cover the test is Enna Allen of Glencoe, Illinois, who urged her au pair to get a test after the young woman traveled to New Orleans. She had been on a plane, after all, and New Orleans has its share of COVID cases.

"I wanted her to have a test before she returned to work with my kids," said Allen.

As Allen called around to find a testing site, she explained the test was needed for employment — for someone with no symptoms. After some effort, she found a clinic that, for $275, offered a 15-minute rapid test and said it would accept her au pair's insurance.

"I'm assuming they [the insurer] will cover it unless I get a bill weeks from now," said Allen, who said she would pay the bill for her employee if that happens.

There is also a great gray area in deciding who should qualify for free testing after "suspected" exposure. What is suspected exposure? Sharing a small office with an infected co-worker? Participating in a protest? Or simply living in or visiting the Sun Belt, where community spread is accelerating?

"If the au pair went to a clinic and said she was just in New Orleans, and the doctor said that's enough of a risk to order a test, even though she doesn't have symptoms, my read of the guidance is the health plan has to cover it 100%," said Corlette.

Yet a child who's mainly been sheltering at home who needs a test before being admitted to summer camp probably would not meet the definition.

"That's a different story because it's harder to argue there's been exposure or potential exposure," said Corlette. "At the end of the day, there's many ways to interpret the guidance."

Congressional Democrats have accused the Trump administration in its new guidance of "giving insurance companies loopholes instead of getting people the free testing they need."

Insurers, patients and politicians have locked horns before when screening tests were billed differently than those same tests for diagnostic purposes, since the boundary is often unclear. Under the Affordable Care Act, for example, colonoscopy screening for cancer is "free," meaning no patient copayment. But if a polyp is found, doctors sometimes code the procedure as a diagnostic test, which can lead to hundreds or even thousands of dollars in copayments.

While vital, testing is costly — or can be. Medicare reimburses up to $100 for the COVID test. On top of that, there may also be costs associated with the office or clinic visit. And the price is widely variable in the private market, according to a report out last week by KFF, the Kaiser Family Foundation. Prices ranged from $20 to $850 for a single test. (KHN is an editorially independent program of the foundation.)

Media reports have shown tests average $100, but some labs bill insurers for thousands of dollars for each one.

Without a copay, many patients never learn how much their tests actually cost their insurers, which could lead to overuse.

Also, when patients are entirely shielded from the cost, test makers, labs and medical providers are more likely to seek price increases, said Heather Meade, a principal at Washington Council Ernst & Young.

In the end, consumers may still feel a resulting pinch in the form of higher premiums.

Wondering about the sharply different views of her doctors on whether her insurance would fully cover the cost, law professor Epstein called her insurer, which assured her the tests would be covered 100% at in-network providers with no copay or deductible, as long as they were coded correctly. The family will be tested soon, and it appears she's dodged a financial bullet. But Epstein cautioned in an email: "It's unclear to me how many insurers will maintain this policy."

Julie Appleby: jappleby@kff.org, @Julie_Appleby

As public health workers scramble to summon enough of a workforce to address a once-in-a-generation pandemic, they're being pulled from normal mosquito-related tasks.

This article was first published on Thursday, July 16, 2020 in Kaiser Health News.

By Anna Maria Barry-Jester and Lauren Weber 

Bug spray, swollen welts, citronella. It's mosquito season.

The U.S. public health system has been starved for decades and lacks the resources necessary to confront the worst health crisis in a century. Read the investigation from KHN and The Associated Press.

And in a normal year, the health department serving Ohio's Delaware County would be setting out more than 90 mosquito traps a week — black tubs of stagnant water with nets designed to ensnare the little buggers.

But this year, because of COVID-19, the mosquitoes will fly free.

The coronavirus has pulled the staffers away, so they haven't set a single trap yet this year, according to Dustin Kent, the program manager of the residential services unit. Even if workers had the time, the state lab that typically tests the insects for viruses that infect humans isn't able to take the samples because it also is too busy with COVID-19.

That means the surrounding community, just north of Columbus, Ohio, has to wait until potentially deadly mosquito-borne illnesses such as that caused by the West Nile virus sicken humans to find out if the insects are carrying disease.

"It's frustrating knowing that we can do a more preventative approach," Kent said. "But we're stuck reacting."

In Washtenaw County, Michigan, mosquito samples aren't being collected because the health department didn't have the staff or ability to hire and train summer interns who would typically perform the work. In Houston, a COVID-19 hot spot, a third of mosquito control staffers are working the COVID call center, stocking warehouses and preparing coronavirus testing materials. And across Florida, public health officials couldn't test chicken blood for exposure to mosquito-borne viruses — chickens get bitten by the insects, too, so that can serve as a warning — at the overwhelmed state lab until mid-June, a task that normally begins in the spring.

Monitoring and killing mosquitoes is a key public health task used to curb the spread of deadly disease. In recent years, top mosquito-borne illnesses have killed some 200 people annually in the U.S. But that relatively low toll is due in part to the efforts of public health departments to keep the spread at bay, unlike in other countries where hundreds of thousands are sickened and die each year.

"Mosquitoes are the biggest nuisance and pest on this planet. Hands down," said Ary Faraji, president of the American Mosquito Control Association, a nonprofit that supports public agencies dedicated to mosquito control. "They are responsible for more deaths than any other organism on this planet, including humans."

This is a physical job that can't be done by telecommuting from home. Keeping track of mosquitoes and the diseases they carry requires setting up traps, and searching backyards and commercial lots. Public health workers patrol irrigation ditches and overturn the backyard tires, plastic bins and garbage that can hold standing water where mosquitoes breed.

Around the U.S., more than half of public health departments combat mosquitoes. In some states, including Florida and California, specific departments are dedicated to tracking and preventing their spread. The goal is to find infected mosquito populations and kill them before they get to humans, or at least warn the community about their presence as mosquito-borne epidemics are happening more frequently nationally as temperatures rise.

But a joint investigation published this month by KHN and The Associated Press detailed how state and local public health departments across the U.S. have been starved for decades, leaving them underfunded and without adequate resources to confront the coronavirus pandemic, let alone perform the other work like mosquito control they are tasked to handle at the same time. Over 38,000 public health worker jobs have been lost since 2008. Per capita spending on local health departments has been cut by 18% since 2010.

So as public health workers scramble to summon enough of a workforce to address a once-in-a-generation pandemic, they're being pulled from normal mosquito-related tasks. The short staffing is leaving many localities — especially those without separate, dedicated control districts — flying blind on potential mosquito threats.

The Centers for Disease Control and Prevention has stepped in to help and is now running mosquito testing for at least nine states, including Florida, Arizona and the Carolinas, said Roxanne Connelly, entomology and ecology team lead for the CDC's National Center for Emerging and Zoonotic Infectious Diseases, as well as evaluating human blood samples for mosquito-borne disease for 40 states. Concerned about the disruptions, the CDC issued a policy brief with the Environmental Protection Agency on Thursday, stressing that mosquito prevention and spraying of insecticides was an essential service that needs to continue even in a national health emergency.

"Mosquitoes are still going to be around, and still causing diseases, no matter what sort of pandemic is going on," Connelly said.

Even with relatively low rates of disease, in part because of limited testing to measure the problem so far this year, there are worrying signs. Fourteen people in the Florida Keys have come down with locally acquired dengue, which can cause fever, severe body aches and vomiting. Massachusetts has found its first mosquito carrying Eastern equine encephalitis, which kills approximately a third of people infected, according to the CDC. West Nile virus has been found in mosquitoes, birds or other species in at least 18 states and has infected people in nine.

"This year it's more of a wild card; we're not getting the surveillance we'd normally get," said David Brown, the technical adviser for the American Mosquito Control Association.

The flu-like symptoms of diseases like West Nile — fever, body aches — especially worry Nina Dacko, who supervises the mosquito control program for Tarrant County Public Health in Fort Worth, Texas.

"I wonder which cases are going to be missed as everyone is going to expect COVID and then move on when they test negative," she said.

Budget cuts are coming in waves as tax shortfalls rock local health departments. Three municipalities in Texas, including Watauga, Saginaw and Lake Worth, haven't sent any mosquitoes in for testing this year — they don't have the time, or have lost staffing and money due to revenue shortfalls from COVID-19, Dacko said.

Smaller health departments appear to be bearing the brunt of the problems, North Carolina state public health entomologist Michael Doyle said in an email, as they have fewer staffers to fight the coronavirus. Some larger departments and programs — like those covering Houston, California's Central Valley or Maricopa County, Arizona — say they've been able to operate close to normal.

And while public health officials say small outdoor gatherings are safest when it comes to avoiding exposure to the coronavirus, some worry that the risk of acquiring mosquito-borne diseases could rise.

"Everyone knows, if you're outdoors, that's where you're actually going to get exposed," said Chelsea Gridley-Smith, director of environmental health for the National Association of County and City Health Officials.

Labs swamped by COVID tests may be increasing that risk. Local governments often rely on the same public health labs to test whether mosquitoes are carrying diseases like West Nile, dengue or Eastern equine encephalitis that they do to test humans for infectious diseases, like COVID-19. As a result, much of the country is weeks behind where they would typically be in testing mosquitoes for the presence of dangerous diseases, Brown said.   

Stopping mosquitoes requires getting information in real time. If a mosquito is carrying West Nile virus, "you want to know that today, not two weeks from now," Brown said.

When the COVID pandemic hit Salt Lake City, which has its own labs to test mosquitoes, the mosquito department shared its materials with the labs testing for COVID-19 and donated N95 masks that its staff uses when spraying mosquito-killing chemicals, according to Faraji, who is also the executive director of the Salt Lake City Mosquito Abatement District. Utah has done about 5% of the mosquito testing it would usually do by this point, he said.

"Our underlying concern is that one public health emergency doesn't lead into another," Faraji said.

Any grand fix to the hole in the nation's current mosquito netting is going to require some serious cash, Gridley-Smith said, to allow for dedicated staffing, instead of expecting public health workers to juggle it alongside multiple other programs.

The Southern Nevada Health District — which includes Las Vegas — doesn't have a dedicated mosquito department. From April to October, workers there trap, collect and test mosquitoes for viruses, said Vivek Raman, who oversees the efforts. The rest of the year, the same team is in charge of sanitation for all the area hotels and mobile home parks, including those on the casino strip. But restaurant inspections, permitting and sanitation help pay their way.

"One of the challenges with mosquitoes is they don't pay permit fees," he said.

Several bills to support mosquito control efforts, including the Strengthening Mosquito Abatement for Safety and Health Act, have passed through Congress with bipartisan support in recent years but haven't been funded.

For the CDC's Connelly, the lack of dollars is just another part of the boom-bust nature of funding for health departments and mosquito control programs nationally. Infusions of cash after bouts with mosquito-borne Zika or hurricanes aren't enough to fully maintain robust programs, she said, and they often have to start over when the next crisis hits.

Raman and his colleagues did have plans this year to work with the CDC on a project to reduce the population of Aedes aegypti, an invasive mosquito species that can carry a range of deadly viruses, including Zika, and which first showed up in southern Nevada around 2017. That project is on hold until next year.

AP journalists Mike Householder in Canton Township, Michigan, Juan A. Lozano in Houston and Jeannie Ohm in Arlington, Virginia, contributed to this report.

This story is a collaboration between The Associated Press and KHN. To reach the AP's investigative team, email investigative@ap.org.

Anna Maria Barry-Jester: annab@kff.org, @annabarryjester

Lauren Weber: LaurenW@kff.org, @LaurenWeberHP