Diagnosed by App: Medical Testing in the Palm of Your Hand
Urinary tract infections aren't life-threatening, but they can be excruciatingly painful and debilitating.
"Overnight, I'd be gripped by this searing pain and I can barely walk," says Ling Koh, a Los Angeles-based bioengineer. But short of going to the ER or urgent care, she'd have to suffer for a few days until she could get in to see her family doctor for an antibiotic prescription.
Smartphones are now able to do on-the-spot diagnostic tests that were previously only able to be performed in a lab.
No longer. Koh, who works for Scanwell Health, was instrumental in the development of the company's smartphone app that is FDA-cleared for urinary tract infection screening. It allows someone to test urine at home using a paper test strip — the same one used by doctors in ERs and labs. The phone app reads a scan card from the test kit that can analyze what's on the strip and then connect the patient to a physician who can make a virtual diagnosis.
Test strips cost $15 for a three-pack and consultation with a doc is about the same as an average co-pay -- $25, and the app matches the quality of clinical laboratory tests, according to the company. Right now, you can get a referral to a telehealth visit with a doctor in California and get a prescription. A national rollout is in the works within the next couple of months.
"It's so easy to use them at home and eliminate the inefficiencies in the process," says Koh. "A telemedicine doctor can look at the test results and prescribe directly to the pharmacy instead of women waiting at home, miserable, and crying in the bathtub."
Scanwell is now involved in an ongoing National Institutes of Health- sponsored study of chronic kidney disease to test a version of the app to identify patients who have the disease, which affects more than 30 million Americans. "Because kidney disease has virtually no symptoms, by the time people realize they're sick, their illness is advanced and they're ready for dialysis," says Koh. "If we can catch it sooner, early intervention can help them avoid kidney failure."
Smartphones have changed society — and now they may change medical care, too. Thanks to the incredible processing capabilities of our smartphones, which come equipped with a camera, access to the internet and are thousands of times faster than the 1960s era NASA computers that ran the Apollo Moon Mission, these pocket-sized powerhouses have become an invaluable tool for managing our health and are even able to do on-the-spot diagnostic tests that were previously only able to be performed in a lab.
This shift to in-home testing is the wave of the future, promising to ease some of the medical care bottlenecks in which patients can have two- to three-week waits to see their family doctors and lift some of the burdens on overworked physicians.
"This is really the democratization of medicine because a lot of the things we used to rely on doctors, hospitals, or labs to do we'll be able to do ourselves," says Dr. Eric Topol, an eminent cardiologist and digital health pioneer at the Scripps Clinic and Research Institute in La Jolla.
But troubling questions remain. Aside from the obvious convenience, are these tests truly as accurate as ones in a doctor's office? And with all this medical information stored and collected by smartphones, will privacy be sacrificed? Will friends, family members, and employers suddenly have access to personal medical information we'd rather keep to ourselves?
The range of what these DIY health care apps can do is mind-boggling, and even more complex tests are on the way.
"I'm really worried about that because we've let our guard down," says Topol. "Data stored on servers is a target for cyber thieves — and data is being breached, hacked, brokered, and sold, and we're complacent."
Still, the apps have come a long way since 2011 when Topol whipped out an experimental smartphone electro-cardiogram that he had been testing on his patients when a fellow passenger on a flight from Washington D.C. was seized with severe chest pains. At 35,000 feet in the air, the app, which uses fingertip sensors to detect heart rate, showed the man was having a heart attack. After an emergency landing, the passenger was rushed to the closest hospital and survived. These days, even the Apple Watch has an FDA-approved app that can monitor your electro-cardiogram readings.
The range of what these DIY health care apps can do is mind-boggling, and even more complex tests are on the way. Phone apps can now monitor sleep quality to detect sleep apnea, blood pressure, weight and temperature. In the future, rapid diagnostic tests for infectious diseases, like flu, Dengue or Zika, and urinalysis will become common.
"There is virtually no limit to the kinds of testing that can be done using a smartphone," says Dr. John Halamka, Executive Director of the Health Technology Exploration Center at Beth Israel Lahey Health. "No one wants to drive to a clinician's office or lab if that same quality testing can be achieved at a lower cost without leaving home."
SkinVision's skin cancer screening tool, for instance, can tell if a suspicious mole is cancerous. Users take three photos, which are then run through the app's algorithm that compares their lesions with more than three million pictures, evaluating such elements as asymmetry, color, and shape, and spits out an assessment within thirty seconds. A team of in-house experts provide a review regardless of whether the mole is high or low risk, and the app encourages users to see their doctors. The Dutch-based company's app has been used by more than a million people globally in the EU, and in New Zealand and Australia, where skin cancer is rampant and early detection can save lives. The company has plans to enter the U.S. market, according to a spokesperson.
Apps like Instant Heart Rate analyze blood flow, which can indicate whether your heart is functioning normally, while uChek examines urine samples for up to 10 markers for conditions like diabetes and urinary tract infections. Some behavioral apps even have sensors that can spot suicide risks if users are less active, indicating they may be suffering from a bout of the blues.
Even more complex tests are in the research pipeline. Apps like ResAppDX could eventually replace x-rays, CT scans, and blood tests in diagnosing severe respiratory infections in kids, while an EU-funded project called i-Prognosis can track a variety of clues — voice changes, facial expressions, hand steadiness — that indicate the onset of Parkinson's disease.
These hand-held testing devices can be especially helpful in developing countries, and there are pilot programs to use smartphone technology to diagnose malaria and HIV infections in remote outposts in Africa.
"In a lot of these places, there's no infrastructure but everyone has a smartphone," says Scanwell's Koh. "We need to leverage the smartphone in a clinically relevant way."
However, patient privacy is an ongoing concern. A 2019 review in the Journal of the American Medical Association conducted by Australian and American researchers looked at three dozen behavioral health apps, mainly for depression and smoking cessation. They found that about 70 percent shared data with third parties, like Facebook and Google, but only one third of them disclosed this in a privacy policy.
"Patients just blindly accept the end user agreements without understanding the implications."
Users need to be vigilant, too. "Patients just blindly accept the end user agreements without understanding the implications," says Hamalka, who is also the Chief Information Officer and Dean for Technology at Harvard Medical School.
And quality control is an issue. Right now, the diagnostic tools currently available have been vetted by the FDA, and overseas companies like Skin Vision have been scrutinized by the U.K.'s National Health Service and the EU. But the danger is that a lot of apps are going to be popping up soon that haven't been properly tested, due to loopholes in the regulations.
"All we want," says Topol, "are rigorous studies to make sure what consumers are using is validated."
[Correction, August 19th, 2019: An earlier version of this story misstated the specifics of SkinVision's service. A team of in-house experts reviews users' submissions, not in-house dermatologists, and the service is not free.]
Indigenous wisdom plus honeypot ants could provide new antibiotics
For generations, the Indigenous Tjupan people of Australia enjoyed the sweet treat of honey made by honeypot ants. As a favorite pastime, entire families would go searching for the underground colonies, first spotting a worker ant and then tracing it to its home. The ants, which belong to the species called Camponotus inflatus, usually build their subterranean homes near the mulga trees, Acacia aneura. Having traced an ant to its tree, it would be the women who carefully dug a pit next to a colony, cautious not to destroy the entire structure. Once the ant chambers were exposed, the women would harvest a small amount to avoid devastating the colony’s stocks—and the family would share the treat.
The Tjupan people also knew that the honey had antimicrobial properties. “You could use it for a sore throat,” says Danny Ulrich, a member of the Tjupan nation. “You could also use it topically, on cuts and things like that.”
These hunts have become rarer, as many of the Tjupan people have moved away and, up until now, the exact antimicrobial properties of the ant honey remained unknown. But recently, scientists Andrew Dong and Kenya Fernandes from the University of Sydney, joined Ulrich, who runs the Honeypot Ants tours in Kalgoorlie, a city in Western Australia, on a honey-gathering expedition. Afterwards, they ran a series of experiments analyzing the honey’s antimicrobial activity—and confirmed that the Indigenous wisdom was true. The honey was effective against Staphylococcus aureus, a common pathogen responsible for sore throats, skin infections like boils and sores, and also sepsis, which can result in death. Moreover, the honey also worked against two species of fungi, Cryptococcus and Aspergillus, which can be pathogenic to humans, especially those with suppressed immune systems.
In the era of growing antibiotic resistance and the rising threat of pathogenic fungi, these findings may help scientists identify and make new antimicrobial compounds. “Natural products have been honed over thousands and millions of years by nature and evolution,” says Fernandes. “And some of them have complex and intricate properties that make them really important as potential new antibiotics. “
In an era of growing resistance to antibiotics and new threats of fungi infections, the latest findings about honeypot ants are helping scientists identify new antimicrobial drugs.
Danny Ulrich
Bee honey is also known for its antimicrobial properties, but bees produce it very differently than the ants. Bees collect nectar from flowers, which they regurgitate at the hive and pack into the hexagonal honeycombs they build for storage. As they do so, they also add into the mix an enzyme called glucose oxidase produced by their glands. The enzyme converts atmospheric oxygen into hydrogen peroxide, a reactive molecule that destroys bacteria and acts as a natural preservative. After the bees pack the honey into the honeycombs, they fan it with their wings to evaporate the water. Once a honeycomb is full, the bees put a beeswax cover on it, where it stays well-preserved thanks to the enzymatic action, until the bees need it.
Less is known about the chemistry of ants’ honey-making. Similarly to bees, they collect nectar. They also collect the sweet sap of the mulga tree. Additionally, they also “milk” the aphids—small sap-sucking insects that live on the tree. When ants tickle the aphids with their antennae, the latter release a sweet substance, which the former also transfer to their colonies. That’s where the honey management difference becomes really pronounced. The ants don’t build any kind of structures to store their honey. Instead, they store it in themselves.
The workers feed their harvest to their fellow ants called repletes, stuffing them up to the point that their swollen bellies outgrow the ants themselves, looking like amber-colored honeypots—hence the name. Because of their size, repletes don’t move, but hang down from the chamber’s ceiling, acting as living feedstocks. When food becomes scarce, they regurgitate their reserves to their colony’s brethren. It’s not clear whether the repletes die afterwards or can be restuffed again. “That's a good question,” Dong says. “After they've been stretched, they can't really return to exactly the same shape.”
These replete ants are the “treat” the Tjupan women dug for. Once they saw the round-belly ants inside the chambers, they would reach in carefully and get a few scoops of them. “You see a lot of honeypot ants just hanging on the roof of the little openings,” says Ulrich’s mother, Edie Ulrich. The women would share the ants with family members who would eat them one by one. “They're very delicate,” shares Edie Ulrich—you have to take them out carefully, so they don’t accidentally pop and become a wasted resource. “Because you’d lose all this precious honey.”
Dong stumbled upon the honeypot ants phenomenon because he was interested in Indigenous foods and went on Ulrich’s tour. He quickly became fascinated with the insects and their role in the Indigenous culture. “The honeypot ants are culturally revered by the Indigenous people,” he says. Eventually he decided to test out the honey’s medicinal qualities.
The researchers were surprised to see that even the smallest, eight percent concentration of honey was able to arrest the growth of S. aureus.
To do this, the two scientists first diluted the ant honey with water. “We used something called doubling dilutions, which means that we made 32 percent dilutions, and then we halve that to 16 percent and then we half that to eight percent,” explains Fernandes. The goal was to obtain as much results as possible with the meager honey they had. “We had very, very little of the honeypot ant honey so we wanted to maximize the spectrum of results we can get without wasting too much of the sample.”
After that, the researchers grew different microbes inside a nutrient rich broth. They added the broth to the different honey dilutions and incubated the mixes for a day or two at the temperature favorable to the germs’ growth. If the resulting solution turned turbid, it was a sign that the bugs proliferated. If it stayed clear, it meant that the honey destroyed them. The researchers were surprised to see that even the smallest, eight percent concentration of honey was able to arrest the growth of S. aureus. “It was really quite amazing,” Fernandes says. “Eight milliliters of honey in 92 milliliters of water is a really tiny amount of honey compared to the amount of water.”
Similar to bee honey, the ants’ honey exhibited some peroxide antimicrobial activity, researchers found, but given how little peroxide was in the solution, they think the honey also kills germs by a different mechanism. “When we measured, we found that [the solution] did have some hydrogen peroxide, but it didn't have as much of it as we would expect based on how active it was,” Fernandes says. “Whether this hydrogen peroxide also comes from glucose oxidase or whether it's produced by another source, we don't really know,” she adds. The research team does have some hypotheses about the identity of this other germ-killing agent. “We think it is most likely some kind of antimicrobial peptide that is actually coming from the ant itself.”
The honey also has a very strong activity against the two types of fungi, Cryptococcus and Aspergillus. Both fungi are associated with trees and decaying leaves, as well as in the soils where ants live, so the insects likely have evolved some natural defense compounds, which end up inside the honey.
It wouldn’t be the first time when modern medicines take their origin from the natural world or from the indigenous people’s knowledge. The bark of the cinchona tree native to South America contains quinine, a substance that treats malaria. The Indigenous people of the Andes used the bark to quell fever and chills for generations, and when Europeans began to fall ill with malaria in the Amazon rainforest, they learned to use that medicine from the Andean people.
The wonder drug aspirin similarly takes its origin from a bark of a tree—in this case a willow.
Even some anticancer compounds originated from nature. A chemotherapy drug called Paclitaxel, was originally extracted from the Pacific yew trees, Taxus brevifolia. The samples of the Pacific yew bark were first collected in 1962 by researchers from the United States Department of Agriculture who were looking for natural compounds that might have anti-tumor activity. In December 1992, the FDA approved Paclitaxel (brand name Taxol) for the treatment of ovarian cancer and two years later for breast cancer.
In the era when the world is struggling to find new medicines fast enough to subvert a fungal or bacterial pandemic, these discoveries can pave the way to new therapeutics. “I think it's really important to listen to indigenous cultures and to take their knowledge because they have been using these sources for a really, really long time,” Fernandes says. Now we know it works, so science can elucidate the molecular mechanisms behind it, she adds. “And maybe it can even provide a lead for us to develop some kind of new treatments in the future.”
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.
Blood Test Can Detect Lymphoma Cells Before a Tumor Grows Back
When David M. Kurtz was doing his clinical fellowship at Stanford University Medical Center in 2009, specializing in lymphoma treatments, he found himself grappling with a question no one could answer. A typical regimen for these blood cancers prescribed six cycles of chemotherapy, but no one knew why. "The number seemed to be drawn out of a hat," Kurtz says. Some patients felt much better after just two doses, but had to endure the toxic effects of the entire course. For some elderly patients, the side effects of chemo are so harsh, they alone can kill. Others appeared to be cancer-free on the CT scans after the requisite six but then succumbed to it months later.
"Anecdotally, one patient decided to stop therapy after one dose because he felt it was so toxic that he opted for hospice instead," says Kurtz, now an oncologist at the center. "Five years down the road, he was alive and well. For him, just one dose was enough." Others would return for their one-year check up and find that their tumors grew back. Kurtz felt that while CT scans and MRIs were powerful tools, they weren't perfect ones. They couldn't tell him if there were any cancer cells left, stealthily waiting to germinate again. The scans only showed the tumor once it was back.
Blood cancers claim about 68,000 people a year, with a new diagnosis made about every three minutes, according to the Leukemia Research Foundation. For patients with B-cell lymphoma, which Kurtz focuses on, the survival chances are better than for some others. About 60 percent are cured, but the remaining 40 percent will relapse—possibly because they will have a negative CT scan, but still harbor malignant cells. "You can't see this on imaging," says Michael Green, who also treats blood cancers at University of Texas MD Anderson Medical Center.
The new blood test is sensitive enough to spot one cancerous perpetrator amongst one million other DNA molecules.
Kurtz wanted a better diagnostic tool, so he started working on a blood test that could capture the circulating tumor DNA or ctDNA. For that, he needed to identify the specific mutations typical for B-cell lymphomas. Working together with another fellow PhD student Jake Chabon, Kurtz finally zeroed-in on the tumor's genetic "appearance" in 2017—a pair of specific mutations sitting in close proximity to each other—a rare and telling sign. The human genome contains about 3 billion base pairs of nucleotides—molecules that compose genes—and in case of the B-cell lymphoma cells these two mutations were only a few base pairs apart. "That was the moment when the light bulb went on," Kurtz says.
The duo formed a company named Foresight Diagnostics, focusing on taking the blood test to the clinic. But knowing the tumor's mutational signature was only half the process. The other was fishing the tumor's DNA out of patients' bloodstream that contains millions of other DNA molecules, explains Chabon, now Foresight's CEO. It would be like looking for an escaped criminal in a large crowd. Kurtz and Chabon solved the problem by taking the tumor's "mug shot" first. Doctors would take the biopsy pre-treatment and sequence the tumor, as if taking the criminal's photo. After treatments, they would match the "mug shot" to all DNA molecules derived from the patient's blood sample to see if any molecular criminals managed to escape the chemo.
Foresight isn't the only company working on blood-based tumor detection tests, which are dubbed liquid biopsies—other companies such as Natera or ArcherDx developed their own. But in a recent study, the Foresight team showed that their method is significantly more sensitive in "fishing out" the cancer molecules than existing tests. Chabon says that this test can detect circulating tumor DNA in concentrations that are nearly 100 times lower than other methods. Put another way, it's sensitive enough to spot one cancerous perpetrator amongst one million other DNA molecules.
They also aim to extend their test to detect other malignancies such as lung, breast or colorectal cancers.
"It increases the sensitivity of detection and really catches most patients who are going to progress," says Green, the University of Texas oncologist who wasn't involved in the study, but is familiar with the method. It would also allow monitoring patients during treatment and making better-informed decisions about which therapy regimens would be most effective. "It's a minimally invasive test," Green says, and "it gives you a very high confidence about what's going on."
Having shown that the test works well, Kurtz and Chabon are planning a new trial in which oncologists would rely on their method to decide when to stop or continue chemo. They also aim to extend their test to detect other malignancies such as lung, breast or colorectal cancers. The latest genome sequencing technologies have sequenced and catalogued over 2,500 different tumor specimens and the Foresight team is analyzing this data, says Chabon, which gives the team the opportunity to create more molecular "mug shots."
The team hopes that that their blood cancer test will become available to patients within about five years, making doctors' job easier, and not only at the biological level. "When I tell patients, "good news, your cancer is in remission', they ask me, 'does it mean I'm cured?'" Kurtz says. "Right now I can't answer this question because I don't know—but I would like to." His company's test, he hopes, will enable him to reply with certainty. He'd very much like to have the power of that foresight.
This article is republished from our archives to coincide with Blood Cancer Awareness Month, which highlights progress in cancer diagnostics and treatment.
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.