The flamingo diagnostic
Volume 10, Issue 19 | November 14, 2024
ALSO IN THIS ISSUE
RADx®Tech Maternal Health Challenge winners
Pandemic preparedness against Marburg
Bird flu: Humans can get it without symptoms; teen hospitalized
CRC screening followup: Younger folks and FIT
RADx®Tech announces Maternal Health Challenge winners
Two years ago, NIH’s RADx®Tech launched the Maternal Health Challenge: A competition that would award “up to $8 million in prizes to accelerate the development of maternal health diagnostic devices, wearables, or other remote sensing technologies for use in maternity care deserts.” Last month, the agency announced the six grand-prize winners and two runners-up. They include:
A rapid home test for the detection of urinary tract infections
An app that uses photos of the user’s nail beds to check for anemia
An ultrasound benchtop blood test to measure clotting time
A virtual companion that provides online mental-health monitoring and support
The remaining four are wearables, all of which use proprietary algorithms to assess important clinical signs including blood pressure, pulse, respiration, and more. None of the proposals involve anything that could really be termed generalized AI.
COMMENTARY: As a way to fund innovation, challenge.gov is relatively novel. Multiple proposals are evaluated in parallel (versus the traditional one-at-a-time grant-approval process), and all funds are awarded with no strings or reporting attached. Changing the ground rules alone can be motivational, but just how much public funding should be assigned this way is controversial (it makes up a very small proportion today).
Because significant work has to be done before competitors even know how much funding they will get (if any), entrants tend to be limited to those already in the early commercial phase. Only two of the 15 groups that got through the viability stage of this challenge were from academic institutions, and neither made it to the final round.
Pandemic preparedness against Marburg disease
Rwanda’s outbreak of Marburg virus (related to Ebola) may be close to its end. The last patient in the nation with the disease was discharged on November 8, the WHO reported, “kicking off the mandatory 42-day countdown to declare the end of the outbreak.”
COMMENTARY: Though the risk to people in the US has remained low, we were happy to see that HHS has taken the threat seriously. The agency worked with experts from Mass General Brigham to create a toolkit to help frontline health-care facilities quickly and safely test people for Marburg. Among other guidance, it outlines how to collect, process, and report laboratory test results, as well as how to prevent and control infection, deal with waste management, and implement good occupational health practices.
Bird Flu: Humans can get it without symptoms; Canadian teen very sick
In British Columbia, a teen with no underlying conditions has been hospitalized with H5N1 and is in critical condition due to acute respiratory distress. Dr. Bonnie Henry, British Columbia’s health officer, noted that this strain of flu might be worse in young people as compared to adults who have been exposed to H1N1 flu viruses in the past. (This was also the case during the 1918 pandemic.) Of note: the patient is infected with the version of the virus that affects wild birds, not the one that affects dairy cows.
Cases of bird flu in humans continue to pop up in Washington state and California (five each). All have been linked to exposure to infected poultry or cattle.
CDC tests in Michigan and Colorado have shown that some dairy workers have gotten infected with bird flu without getting symptoms. Because of these results, the agency now recommends that everyone who works directly with infected cattle get tested for the disease. It also recommends treatment with Tamiflu for anyone “with high-risk exposure, especially those who didn’t wear adequate PPE,” as CIDRAP reported.
The diagnostic value of standing on one leg
Sometimes you need sophisticated equipment to evaluate someone’s health problems. Other times, you just need to see whether your patient can act like a flamingo.
A report in PLOS ONE looked at age-related changes in subjects’ ability to complete various tasks that require strength and balance. After testing hand grip, knee strength, and gait across a level surface in a group of 40 adults ages 50 and older, they concluded that standing on one leg is the task that most reliably gets harder and harder to do as a person ages. Because of that reliability, it can be used as a metric to determine how a patient’s neuromuscular systems are aging.
COMMENTARY: Unlike flamingo-ing, gait has been extensively studied for many years as an indicator of specific sensory/motor difficulties. (In June, Nature Communications published the results of a successful machine-learning contest to develop a model that could objectively evaluate freezing of gait, a common issue in two thirds of Parkinson’s disease cases.) Standing on one leg also requires the coordination of many different body systems, so it makes sense that it should work as a metric. However, this result does not imply that practicing this one skill will actually reduce frailty.
CRC screening follow-up: What happens when you get younger folks to use FIT?
Last week we summarized a paper that modeled the relative costs and benefits of all the less-invasive colorectal cancer (CRC) screening tests. The standout result was that an annual $18 fecal immunochemical test (FIT) was as good as other stool tests done every three years and substantially better than the new blood tests. It reduced deaths by 90% - as much as colonoscopy, and at a much lower cost. But with screening stuck at about 60% of the population, the great hope for less-invasive tests is to grow the number of people getting screened.
This week Kaiser reported what happened when they distributed nearly half a million FIT home kits to their newly screening-eligible 45- to 50-year-old members. In this observational study, 39% of the kits were used, and of the 3.6% who tested positive, 65% received a follow-up colonoscopy within three months. Of those, 59% had an adenoma detected. Most were minor and removed, but 13.2% of patients had more advanced diagnoses, and 2.8% had full-blown CRC.
COMMENTARY: While Kaiser promoted the test quite extensively, that promotion varied among locations. The 39% who returned the test might have a richer mix of concerns than the other 61%, which could have meant they were more likely to have disease.
Overall, FIT’s positive predictive value (PPV; the probability that a patient with a positive (abnormal) test result actually has the disease) was 59% – a very effective level for a screening test. (For comparison, mammography first-image PPV is just 2.3%.) Of course, there is no way to know (yet) how many of the negative FIT results were false - that would take years of follow-up and analysis.
Bottom line: This was a very successful campaign that will have saved many lives. FIT is a bargain (about 50 cents per life saved), but if you can afford it, colonoscopy is even better. Blood tests (as currently published) are far less effective and more expensive. But if the alternative is no test at all, please take advantage of them.