After normal colonoscopy, can you wait 15 years?
Volume 11, Issue 4 | January 23, 2025
ALSO IN THIS ISSUE
AI helps ultrasonographers image lungs
Cross-border collaboration helps diagnose rare diseases
A blood test for asthma?
Bird flu update: CDC updates risk assessment, turkeys must be tested
AI helps regular ultrasonographers tackle the tricky lungs
Ultrasound is very good at imaging lots of things - kidneys, livers, spleens, fetuses. But it has a hard time with lungs. That’s because air acts like a mirror for ultrasound waves, scattering them back at the probe. It’s not that ultrasound can’t be used to image the lungs - it can. But using it for that purpose is a very specialized skill that most ultrasonographers don’t have.
AI assistance could change that. In a study published in JAMA Cardiology, AI guidance allowed garden-variety ultrasonographers to perform lung exams that, 98% of the time, were just as good as those done by lung ultrasound experts. All they needed was a short training session.
COMMENTARY: Ultrasound is a great imaging tool. Most of the time it’s completely non-invasive, and it doesn’t carry the risks that X-rays (radiation) and MRIs (giant magnets that do scary things with metal) do. Plus it’s cheap compared to the others. We love to see ways in which it can be used more broadly.
Bird Flu Update
CDC updates H5N1 risk assessment
Turkeys in MN and SD must be tested before transport
Pet-food manufacturers must update food-safety plans
Last week, the CDC updated its risk assessment for H5N1. The agency stated that the risk to the public remains low, but several groups of people are now at increased risk: Farm workers who work with infected animals or their byproducts, backyard bird flock owners, animal-care workers such as veterinarians and zookeepers, and animal-health and public-health responders.
The USDA’s Animal and Plant Health Inspection Service is now requiring large commercial turkey farms in Minnesota and South Dakota to test birds for H5N1 before transporting them for slaughter. Genetic research indicated that cats had gotten infected as a result of eating raw turkey meat from those two states. The program may expand to other states if more outbreaks of bird flu happen in turkeys there. (Which it already has - outbreaks at four commercial turkey farms in Missouri were reported yesterday.)
This week USDA reported six more infections in domestic cats: two in California and one each in Kansas, Louisiana, Iowa, and South Dakota. The FDA is now requiring dog and cat food manufacturers that use uncooked or unpasteurized meat, milk, and eggs to reanalyze their food-safety plans with the goal of preventing H5N1 contamination. The requirement applies only to businesses that are covered by the Food Safety Modernization Act’s Preventive Control for Animal Food rule, but that includes everyone who sells retail pet food.
Ending the diagnostic odyssey for rare diseases takes collaboration
When it comes to diagnosing disease, clinicians are trained to “look for horses, not zebras.” In other words, when faced with a patient’s array of symptoms, the list of possible causes should start with diseases that are common, not ones that are rare. But 300 million people around the world (30 million in the US) have “zebra” diseases. Of these 7,000 diseases classified as rare, it is believed that 70% have a genetic cause.
A European consortium on rare diseases just announced the results of their recent work. The group, which brought together experts from 12 European countries, plus Canada, looked at the genomic data of almost 6,500 patients and unaffected family members. This multinational analysis was able to give definitive diagnoses to 506 patients. For the majority, the main benefit of these results was simply clarity for themselves and their family. But for 15%, the diagnosis gave their physicians a solid opportunity to change treatment.
This cross-border approach included the development of a unified framework for genetic analysis that was used by all the participating nations. Scientists hope to continue to expand the use of this approach across Europe.
After a normal colonoscopy, can you wait 15 years before recheck?
After you have a colonoscopy that finds nothing but normal bowel, the standard recommendation is to return in 10 years. This guideline was developed based on research from the 1950s that found colorectal cancer (CRC) to be very slow to progress.
Looks like it’s even slower than we thought - at least for people without major risk factors. Last year, two big studies published in JAMA Oncology found that waiting 15 years after a boring colonoscopy was very low risk. One of them tracked 110K Swedish individuals for 29 years, the other followed 195K US folks for 32 years.
The US study found that people who were already in the low-risk category (no family history of CRC, no/limited smoking, BMI below 25, physically active, healthy diet, low/moderate alcohol intake, etc.) could wait as long as 25 years before their next procedure. A wait of that duration put them at the same risk of CRC as high-risk individuals who waited the standard 10 years before a recheck.
COMMENTARY: Clearly one size does not fit all. Those at higher risk of CRC should start colonoscopy earlier than others. They should also repeat more frequently after each negative colonoscopy (every 3-5 years, based on these reports). An improved clinical screening program might reduce procedures for lower-risk individuals while doing more procedures for those at higher background risk.
It’s also worth noting that while the additional risk to lower-risk individuals delaying a repeat for 15 years is very low, it’s not zero. Colonoscopy is one of our most effective screening tests, with gold-standard predictive value combined with highly effective therapy if needed (polyp removal). It is moderately time-consuming, invasive, and expensive. But it saves many lives.
A blood test for asthma
Diagnosing asthma requires a lung-function test. It’s pretty simple, really - you take a breath, then blow out as hard as you can into a little tube. But good luck getting a baby or toddler to do that properly.
In a few years, you may not have to. Researchers have discovered a blood-based biomarker for asthma - it’s cyclic adenosine monophosphate (cAMP). In a study of 360 subjects, folks with asthma had cAMP levels in their blood that were consistently higher than those without the condition. Like up to 1000 times higher. And the level of cAMP correlated with the severity of disease, too.
The researchers are working with manufacturers to develop a point-of-care test to be used in clinicians’ offices.
Current off-the-shelf wearable devices, including watches and rings, may be able to predict IBD episodes. Research with 309 subjects who have Crohn’s disease or ulcerative colitis (the two major types of IBD) showed that several signs the devices measure were significantly changed up to seven weeks before flare-ups happened. The signs included heart-rate variability, heart rate, oxygenation, and number of daily steps taken.