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FDA Grants Marketing Authorization to Diagnostic Tests for Chlamydia and Gonorrhea with At-Home Sample Collection

FDA says the move will make it easier to gain authorization for other clinical laboratory tests to utilize at-home collection kits

In another sign of how diagnostic testing is responding to changing consumer preferences, the US Food and Drug Administration (FDA) granted marketing authorization to LetsGetChecked for the company’s Simple 2 test for chlamydia and gonorrhea, which includes at-home collection of samples sent to the test developer’s clinical laboratories in the US and in Ireland.

This marks the first time the FDA has cleared a diagnostic test for either condition in which samples are collected at home. It’s also the first test with at-home sample collection to be authorized for any sexually transmitted infection (STI) other than HIV, the FDA said in a new release.

Simple 2 Home Collection Kits are available over the counter for anyone 18 or older. The kits employ Hologic’s Aptima collection devices, according to a company press release. A prepaid shipping label is also included to enable delivery to one of LetsGetChecked’s medical laboratories. The company performs the tests using the Hologic Aptima Combo 2 assay for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG).

Samples are collected through a vaginal swab or urine sample. “Results are delivered online in approximately 2-5 days with follow-up virtual consultations and treatment available if needed,” the company press release states.

Previously authorized tests for the conditions required sample collection at the point of care. The company also offers telehealth and online pharmacy services.

Jeff Shuren, MD, JD

“This authorization marks an important public health milestone, giving patients more information about their health from the privacy of their own home,” said Jeff Shuren, MD, JD (above), Director of the FDA’s Center for Devices and Radiological Health. “We are eager to continue supporting greater consumer access to diagnostic tests, which helps further our goal of bringing more healthcare into the home.” With this emphasis on at-home testing from the FDA, clinical laboratories in the US and Ireland will likely be processing more at-home collected samples. (Photo copyright: FDA.)

Simple 2 Process and Costs

Prior to collecting the sample, the user goes online to complete a questionnaire and activate the kit, the FDA news release notes.

LetsGetChecked, headquartered in New York City and Dublin, Ireland, says its US labs are CLIA– and CAP-certified. The company currently offers more than 30 at-home tests covering STIs, men’s health, women’s health, and COVID-19, at prices ranging from $89 to $249 per test.

The Simple 2 test costs $99, and is not covered by insurance, Verywell Health reported. Consumers can get discounts by subscribing to quarterly, semiannual, or annual tests.

New Regulatory Pathway

The FDA said it reviewed the test under its De Novo regulatory pathway, which is intended for “low- to moderate-risk devices of a new type,” according to the news release.

“Along with this De Novo authorization, the FDA is establishing special controls that define the requirements related to labeling and performance testing,” the agency stated. “When met, the special controls, in combination with general controls, provide a reasonable assurance of safety and effectiveness for tests of this type.”

This creates a new regulatory classification, the agency said, that will make it easier for similar devices to obtain marketing authorization.

Citing data from the federal Centers for Disease Control and Prevention (CDC), the FDA news release states that chlamydia and gonorrhea are the most common bacterial STIs in the US. The CDC estimates that there were 1.6 million cases of chlamydia and more than 700,000 cases of gonorrhea in 2021.

“Typically, both infections can be easily treated, but if left untreated, both infections can cause serious health complications for patients, including infertility,” the news release states. “Expanding the availability of STI testing can help patients get quicker results and access to the most appropriate treatment, ultimately helping to curb the rising rates of STIs.”

Experts Praise the FDA’s Authorization of the Lab Test

STI experts contacted by STAT said they welcomed the FDA’s move.

“There are many people who would like to be tested for STIs who may not know where to go or who have barriers to accessing medical care,” said Jodie Dionne, MD, Associate Professor of Medicine in the University of Alabama at Birmingham (UAB) Division of Infectious Diseases. “If we are going to do a better job of reaching more sexually active people for STIs … we need to be creative about how to get them tested and treated in a way that is highly effective and works for them.”

Family physician Alan Katz, MD, a professor at the University of Hawaii John A Burns School of Medicine, told STAT that the Hologic assay is also used by clinicians who treat people in remote locations to diagnose STIs and is regarded as being highly accurate.

“This option is exceptionally useful for individuals who live in rural areas or are geographically distanced from a clinic where STI testing can be done and there is no telehealth option available,” he told STAT.

With this latest move, the FDA is recognizing that it is time to give consumers more control over their healthcare. This is a signal to clinical laboratories that they should be developing their own strategies and offerings that serve consumers who want to order their own tests. Of course, many states still require a physician’s signature on lab test orders, but that is likely to change over time.

—Stephen Beale

Related Information:

FDA Grants Marketing Authorization of First Test for Chlamydia and Gonorrhea with At-Home Sample Collection

LetsGetChecked Receives US Food and Drug Administration (FDA) De Novo Authorization for At-Home Chlamydia and Gonorrhea Testing System

FDA Grants Approval for First Time to a Home Test for Chlamydia and Gonorrhea

FDA Authorizes First Home Test for Chlamydia and Gonorrhea

You Can Now Test for Chlamydia and Gonorrhea with an At-Home Kit FDA Approves Home Test for Chlamydia and Gonorrhea

University of Oxford Researchers Use Spectroscopy and Artificial Intelligence to Create a Blood Test for Chronic Fatigue Syndrome

Spectroscopic technique was 91% accurate in identifying the notoriously difficult-to-diagnose disease suggesting a clinical diagnostic test for CFS may be possible

Most clinical pathologists know that, despite their best efforts, scientists have failed to come up with a reliable clinical laboratory blood test for diagnosing myalgic encephalomyelitis (ME), the condition commonly known as chronic fatigue syndrome (CFS)—at least not one that’s ready for clinical use.

But now an international team of researchers at the University of Oxford has developed an experimental non-invasive test for CFS using a simple blood draw, artificial intelligence (AI), and a spectroscopic technique known as Raman spectroscopy.

The approach uses a laser to identify unique cellular “fingerprints” associated with the disease, according to an Oxford news release.

“When Raman was added to a panel of potentially diagnostic outputs, we improved the ability of the model to identify the ME/CFS patients and controls,” Karl Morten, PhD, Director of Graduate Studies and Principal Investigator at Oxford University, told Advanced Science News. Morton led the research team along with Wei Huang, PhD, Professor of Biological Engineering at Oxford.

The researchers claim the test is 91% accurate in differentiating between healthy people, disease controls, and ME/CFS patients, and 84% accurate in differentiating between mild, moderate, and severe cases, the new release states.

The researchers published their paper in the journal Advanced Science titled, “Developing a Blood Cell-Based Diagnostic Test for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Peripheral Blood Mononuclear Cells.”

Karl Morten, PhD

“This could be a game changer as we are unsure what causes [ME/CFS] and diagnosis occurs perhaps 10 to 20 years after the condition has started to develop,” said Karl Morten, PhD, Director of Graduate Studies and Principal Investigator at Oxford University. “An early diagnosis might allow us to identify what is going wrong with the potential to fix it before the more long-term degenerative changes are observed.” Though this research may not lead to a simple clinical laboratory blood test for CFS, any non-invasive diagnostic test would enable doctors to help many people. (Photo copyright: Oxford University.)

Need for an ME/CFS Test

The federal Centers for Disease Control and Prevention (CDC) describes ME/CFS as “a serious, long-term illness that affects many body systems,” with symptoms that include severe fatigue and sleep difficulties. Citing an Institute of Medicine (IoM) report, the agency estimates that 836,000 to 2.5 million Americans suffer from the condition but notes that most cases have not been diagnosed.

“One of the difficulties is the complexity of the disease,” said Jonas Bergquist, MD, PhD, Director of the ME/CFS Research Center of Uppsala University in Sweden, told Advanced Science News. “Because it’s a multi-organ disorder, you get symptoms from many different regions of the body with different onsets, though it’s common with post viral syndrome to have different overlapping [symptoms] that disguise the diagnosis.” Bergquist was not involved with the Oxford study.

One key to the Oxford researchers’ technique is the use of multiple artificial intelligence models to analyze the spectral profiles. “These signatures are complex and by eye there are not necessarily clear features that separate ME/CFS patients from other groups,” Morten told Advanced Science News.

“The AI looks at this data and attempts to find features which can separate the groups,” he continued. “Different AI methods find different features in the data. Individually, each method is not that successful at assigning an unknown sample to the correct group. However, when we combine the different methods, we produce a model which can assign the subjects to the different groups very accurately.”

Without a reliable test, “diagnosis of the condition is difficult, with most patients relying on self-report, questionnaires, and subjective measures to receive a diagnosis,” the Oxford press release noted.

But developing such a test has been challenging, Advanced Science News noted.

How Oxford’s Raman Technique Works

Raman spectroscopy uses a laser to determine the “vibrational modes of molecules,” according to the Oxford press release.

“When a laser beam is directed at a cell, some of the scattered photons undergo frequency shifts due to energy exchanges with the cell’s molecular components,” the press release stated. “Raman micro-spectroscopy detects these shifted photons, providing a non-invasive method for single cell analysis. The resulting single cell Raman spectra serve as a unique fingerprint, revealing the intrinsic and biochemical properties and indicating the physiological and metabolic state of the cell.”

The researchers employed the technique on blood samples from 98 subjects, including 61 ME/CFS patients, 16 healthy controls, and 21 controls with multiple sclerosis (MS), Advanced Science reported.

The Oxford scientists focused their attention on peripheral blood mononuclear cells (PBMCs), as previous studies found that these cells showed “reduced energetic function” in ME/CFS patients. “With this evidence, the team proposed that single-cell analysis of PBMCs might reveal differences in the structure and morphology in ME/CFS patients compared to healthy controls and other disease groups such as multiple sclerosis,” the press release states.

Clinical Laboratory Blood Processing and the Oxford Raman Technique

Oxford’s Raman spectroscopic technique “only requires a small blood sample which could be developed as a point-of-care test perhaps from one drop of blood,” the researchers wrote. However, Advanced Science News pointed out that required laser microscopy equipment costs more than $250,000.

In their Advanced Science paper, the researchers note that the test could be made more widely available by transferring blood samples collected by local clinical laboratories to diagnostic centers that have the needed hardware.

“Alternatively, a compact system containing portable Raman instruments could be developed, which would be much cheaper than a standard Raman microscope, and [which] incorporated with microfluidic systems to stream cells through a Raman laser for detection, eliminating the need for lengthy blood sample processing,” the researchers wrote.

They noted that the technique could be adapted to test for other chronic conditions as well, such as MS, fibromyalgia, Lyme disease, and long COVID.

“Our paper is very much a starting point for future research,” Morten told Advanced Science News. “Larger cohorts need to be studied, and if Raman proves useful, we need to think carefully about how a test might be developed.”

Bergquist agreed, stating it’s “not necessarily something you would see in a doctor’s office. It requires a lot of advanced data analysis to use—I still see it as a research methodology. But in the long run, it could be developed into a tool that could be used in a more simplistic way.”

Though a useable diagnostic test may be far off, clinical laboratories should consider how they can aid in ME/CFS research.

—Stephen Beale

Related Information:

First Steps Towards Developing a New Diagnostic Test to Accurately Identify Hallmarks of Chronic Fatigue Syndrome in Blood Cells

First Ever Diagnostic Test for Chronic Fatigue Syndrome Sparks Hope

Developing a Blood Cell-Based Diagnostic Test for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Peripheral Blood Mononuclear Cells

Blood Test for Chronic Fatigue Syndrome Found to Be 91% Accurate

Scientists Develop Blood Test for Chronic Fatigue Syndrome

Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): A Systematic Review

Biomarker for Chronic Fatigue Syndrome Identified

Wastewater Analysis Continues to be an Effective Tool for Tracking Deadly Infectious Diseases in Human Communities

In addition to viruses, wastewater analysis can also be used to detect the presence of chemical substances such as opioids

Wastewater surveillance and analysis continues to be a useful tool for detecting the prevalence of viruses such as SARS-CoV-2, influenza, and respiratory syncytial virus (RSV) in a community. Perhaps more importantly, wastewater surveillance can fill in gaps where clinical laboratory testing data may be days or weeks behind the true spread of viral infections.

One sign of the value of testing wastewater for infectious diseases is the fact that government officials are financing a continuing program of wastewater testing. In September, the federal Centers for Disease Control and Prevention (CDC) awarded a contract to conduct wastewater surveillance/analysis worth millions of dollars to Verily Life Sciences, a Google company, rather than renewing its contract with Biobot Analytics, which had been doing the work since 2020. One interesting twist in the award of this contract is how an ensuing dispute pulled the plug on a significant portion of the wastewater analysis in this country.

In their September Morbidity and Mortality Weekly Report (MMWR), the CDC highlighted a CDC study during which wastewater samples were taken from 40 wastewater treatment plants located in Wisconsin’s three largest cities. The samples were collected weekly and tested for influenza and RSV. The findings were then compared with data regarding emergency department (ED) visits for those diseases.

The CDC found that higher detections of flu and RSV were associated with higher rates of ED visits for both illnesses. The study also suggests that wastewater might detect the spread of these viruses earlier than ED visit data alone.

Peter DeJonge, PhD

“During the COVID-19 pandemic, wastewater surveillance for SARS-CoV-2 provided valuable insight into community incidence of COVID-19,” said Peter DeJonge, PhD (above), a CDC Career Epidemiology Field Officer, in an interview with Infectious Disease Special Edition. “[The CDC’s] report supports the idea that wastewater surveillance also has the potential to serve as a useful method with which to track community spread of influenza and RSV.” Local clinical laboratories are also involved in the CDC’s wastewater surveillance programs. (Photo copyright: CDC.)


Keeping Communities Informed about Spread of Viral Infections

The CDC’s study was conducted from August 2022 to March 2023. The wastewater samples from all three cities tested positive for the viruses in advance of increases in ED visits. After the ED visits for those viruses had subsided, the viral material remained in sewersheds for up to three months. 

“Both influenza and RSV can cause substantial amounts of illness, hospitalization, and even death during annual epidemics, which often occur during winter months in the US,” Peter DeJonge, PhD, a CDC Career Epidemiology Field Officer assigned to the Chicago Department of Public Health, told Infectious Disease Special Edition (IDSE). “Clinical providers and public health officials benefit from surveillance data to understand when and where these diseases are spreading in a community each year. This type of data can help prepare clinics [and clinical laboratories] for anticipated cases, tailor public health messaging, and encourage timely vaccination.”

“The collective burden from these respiratory viruses is staggering. With these viruses circulating simultaneously and potentially shifting in seasonality and severity, communities must be able to understand the full impact of each of these illnesses to inform awareness and public health responses that can prevent infections, hospitalizations, and even deaths,” said Mariana Matus, PhD, CEO and cofounder of Biobot Analytics, in an August press release announcing the launch of a “Respiratory Illnesses Panel” that will monitor wastewater for Influenzas A and B (seasonal flu), Respiratory Syncytial Virus (RSV), and SARS-CoV-2 (COVID-19).

“Traditional testing methods for these illnesses do not provide a comprehensive picture of the number of people infected due to inaccurate reporting, as well as asymptomatic or misdiagnosed cases,” Matus continued. “By monitoring wastewater concurrently for influenza, RSV, and SARS-CoV-2, we can fill in these gaps and provide important information to communities.”

CDC Moves to Change Wastewater Surveillance Contractor Mid-stream

As new variants of SARS-CoV-2 emerge, a recent contract dispute may be the cause of a time delay in efforts to perform wastewater surveillance for the disease, as well as for other viral infections, according to Politico.

The CDC’s move to replace Biobot Analytics with Verily Life Sciences to do wastewater surveillance has led to Biobot filing a protest with the Government Accountability Office (GAO).

According to World Socialist Web Site (WSWS), “The scope of the [Biobot] contract [to provide extended data for the public health agency’s National Wastewater Surveillance System (NWSS)] included data from more than 400 locations from over 250 counties across the entire United States, covering 60 million people. On top of this, Biobot also conducted genomic sequencing to identify the latest variants in circulation.” 

About one quarter of the wastewater testing sites in the country have been shut down due to Biobot’s contract being suspended in September. The remaining 1,200 sites that are not covered under the original contract will continue wastewater testing, Politico reported. 

The GAO hopes to have a decision on the contract dispute in January. Verily says it is ready to proceed with testing in all locations and already has its infrastructure in place. 

“We are committed to working with the CDC to advance the goals of the … testing program, initiate testing on the samples already delivered when allowed to resume work, and make wastewater data available as quickly as possible,” Bradley White, PhD, Principal Scientist/Director at Verily, told Politico.

Under the terms of Verily’s contract, the company will collect samples from wastewater treatment centers cross the county and analyze the samples for COVID-19 and the mpox (monkey pox) virus.

This contract marks the first agreement between the CDC and Verily.

The CDC has not disclosed why it decided to change contractors, but it is probable that cost may have been played a role in the decision. Verily’s contract is for $38 million over the course of five years and Biobot’s most recent contract was for around $31 million for a period of less than 18 months, Politico reported. 

In a LinkedIn post, Matus reported that Biobot had already laid off 35% of its staff due to the contract decision by the CDC. 

Competition in Wastewater Surveillance Market

When seeking viruses in wastewater, scientists use gene-based detection methods to locate and amplify genetic signs of pathogens. But public health officials are just beginning to tap into the potential opportunities that may exist in the analysis of data present in wastewater.

Wastewater surveillance is also being looked at as a way to combat America’s opioid epidemic.

“Wastewater surveillance is becoming more mature and more mainstream month after month, year over year,” Matus told Time

Thus, regardless of which companies end up working with the CDC, it appears that wastewater surveillance and analysis, which requires a great deal of clinical laboratory testing, will continue to help fight the spread of deadly viral infections, as well as possibly the nation’s drug epidemic.

—JP Schlingman

Related Information:

Wastewater Shows COVID Levels Dipping as Hospitalizations Tick Up

How Wastewater Testing Can Help Tackle America’s Opioid Crisis

Wastewater Surveillance May Help Detect Flu, RSV Outbreaks

The Respiratory Illnesses Panel Will Include Monitoring for Influenza A and B, RSV, and SARS-CoV-2

Wastewater Surveillance Data as a Complement to Emergency Department Visit Data for Tracking Incidence of Influenza A and Respiratory Syncytial Virus—Wisconsin, August 2022–March 2023

Biobot Analytics Files Protest against CDC Issuing Wastewater Surveillance Contract to Verily

Biobot Analytics Awarded NIDA Funding for Nationwide Wastewater-based Monitoring Program for High Risk Substance and Others Associated with Health Risks

Wastewater Signals Upswing in Flu, RSV

Biobot Analytics Launches Respiratory Illness Panel

Detecting COVID Surges is Getting Harder, Thanks to a Contract Dispute

Verily Lands $38 Million Deal with CDC for Wastewater Surveillance

Genetic Testing of Wastewater Now Common in Detecting New Strains of COVID-19 and Other Infectious Diseases

San Francisco International Airport First in the Nation to Test Wastewater for SARS-CoV-2 Coronavirus

In Early Weeks of Flu Season, COVID-19 Patients Show Milder Symptoms as SARS-CoV-2 Continues to Evolve

Doctors report difficulty differentiating COVID-19 from other viral infections, impacting clinical laboratory test orders

Because the SARS-CoV-2 coronavirus is in the same family of viruses that cause the common cold and influenza, virologists expected this virus—which caused the global COVID-19 pandemic—would evolve and mutate into a milder form of infection. Early evidence from this influenza season seems consistent with these expectations in ways that will influence how clinical laboratories offer tests for different respiratory viruses.

While new variants of the SARS-CoV-2 virus continue to appear, indications are that early in this flu season individuals infected with the more recent variants are experiencing milder symptoms when compared to the last few years. Doctors report they find it increasingly difficult to distinguish COVID-19 infections from allergies or the common cold because patients’ symptoms are less severe, according to NBC News.

This, of course, makes it challenging for doctors to know the most appropriate clinical laboratory tests to order to help them make accurate diagnoses.

Erick Eiting, MD

“It isn’t the same typical symptoms that we were seeing before. It’s a lot of congestion, sometimes sneezing, usually a mild sore throat,” Erick Eiting, MD, Vice Chair of Operations for Emergency Medicine at Mount Sinai Hospital in New York City, told NBC News. “Just about everyone who I’ve seen has had really mild symptoms. The only way that we knew that it was COVID was because we happened to be testing them.” Knowing which tests for respiratory viruses that clinical laboratories need to perform may soon be the challenge for doctors. (Photo copyright: Mt. Sinai.)

Milder COVID-19 Symptoms Follow a Pattern

Previous hallmarks of a COVID-19 infection included:

  • Loss of taste,
  • loss of smell,
  • dry cough,
  • fever,
  • sore throat,
  • diarrhea,
  • body aches,
  • headaches.

However, physicians now observe milder symptoms of the infection that follow a distinct pattern and which are mostly concentrated in the upper respiratory tract

Grace McComsey, MD, Vice President of Research and Associate Chief Scientific Officer at University Hospitals Health System (UH) in Cleveland, Ohio, told NBC News that some patients have described their throat pain as “a burning sensation like they never had, even with Strep in the past.”

“Then, as soon as the congestion happens, it seems like the throat gets better,” she added.

In addition to the congestion, some patients are experiencing:

  • headache,
  • fever,
  • chills,
  • fatigue,
  • muscle aches,
  • post-nasal drip. 

McComsey noted that fatigue and muscle aches usually only last a couple of days, but that the congestion can sometimes last a few weeks. She also estimated that only around 10-20% of her newest COVID patients are losing their sense of smell or taste, whereas early in the pandemic that number was closer to 60-70% of her patients. 

Doctors also noted that fewer patients are requiring hospitalization and that many recover without the use of antivirals or other treatments.

“Especially since July, when this recent mini-surge started, younger people that have upper respiratory symptoms—cough, runny nose, sore throat, fever and chills—99% of the time they go home with supportive care,” said Michael Daignault, MD, an emergency physician at Providence Saint Joseph Medical Center in Burbank, California.

Milder SARS-CoV-2 Variants Should Still be Taken Seriously

Doctors have varying opinions regarding why the current COVID-19 variants are milder. Some believe the recent variants simply aren’t as good at infecting the lungs as previous variants.

“Overall, the severity of COVID-19 is much lower than it was a year ago and two years ago,” Dan Barouch, MD, PhD, Director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, told NBC News. “That’s not because the variants are less robust. It’s because the immune responses are higher.”

McComsey added that she doesn’t think mild cases should be ignored as she is still seeing new cases of long COVID with rapid heart rate and exercise intolerance being among the most common lingering symptoms. Re-infections also add to the risks associated with long COVID.

“What we’re seeing in long COVID clinics is not just the older strains that continue to be symptomatic and not getting better—we’re adding to that number with the new strain as well,” McComsey said. “That’s why I’m not taking this new wave any less seriously.”

Clinical Laboratory COVID-19 Testing May Decrease

According to Andrew Read, PhD, Interim Senior Vice President for Research and Evan Pugh University Professor of Biology and Entomology at Pennsylvania State University, there is nothing unexpected or startling about the coronavirus acquiring new mutations.

“When a mutation confers an interesting new trick that’s got an advantage, it’s going to be popping up in many different places,” Read told the New York Times. “Everything we see is just consistent with how you imagine virus evolution proceeding in a situation where a new virus has jumped into a novel host population.”

Data from the Centers for Disease Control and Prevention’s COVID-19 Data Tracker—which reports weekly hospitalizations, deaths, emergency department (ED) visits, and COVID-19 test positivity results—shows infection trends fluctuating, but overall, they are decreasing.

  • For the week of October 21, 2023, there were 16,186 hospitalizations due to COVID-19 compared to the highest week recorded (January 15, 2022) with 150,674 hospitalizations nationwide.
  • The highest number of deaths reported in a single week were 25,974 for the week of January 8, 2021, while 637 patients perished from COVID-19 during the week of October 21, 2023.
  • In January of 2021, COVID accounted for 13.8% of all ED visits and in October 2023, COVID-19 was responsible for 1.3% of ED visits. 

“What I think we’re seeing is the virus continuing to evolve, and then leading to waves of infection, hopefully mostly mild in severity,” Barouch told The New York Times.

As severity of COVID-19 infections continues to fall, so, presumably, will demand for COVID-19 testing which has been a source of revenue for clinical laboratories for several years.

—JP Schlingman

Related Information:

Sore Throat, Then Congestion: Common COVID Symptoms Follow a Pattern Now, Doctors Say

COVID Continues to Rise, but Experts Remain Optimistic

What Is the Order of COVID Symptoms This Fall?

COVID Symptoms Now Follow a Distinct Pattern, Doctors Report

How are COVID-19 Symptoms Changing?

What Are the Mild Symptoms of COVID-19, and When Should You See a Doctor?

Doctors Admit They Can’t Tell COVID Apart from Allergies or the Common Cold Anymore—Highlighting How Mild Virus has Become

The Evolution of SARS-CoV-2

UCSF Researchers Identify Genetic Mutation That Promotes an Asymptomatic Response in Humans to COVID-19 Infection

Researchers Use Whole Genome Sequencing to Make Surprising Discovery about Hospital-Acquired C. Diff Infections

By analyzing strains of the bacterium from a hospital ICU, the scientists learned that most infections were triggered within patients, not from cross-transmission

Tracking the source of Hospital-acquired infections (HAI) has long been centered around the assumption that most HAIs originate from cross-transmission within the hospital or healthcare setting. And prevention measures are costly for hospitals and medical laboratories. However, new research puts a surprising new angle on a different source for some proportion of these infections.

The study suggests that most infections caused by Clostridioides difficile (C. Diff), the bacterium most responsible for HAIs, arise not from cross-transmission in the hospital, but within patients who already carry the bacterium.

The research team, led by immunologist Evan Snitkin, PhD, and microbiologist Vincent Young, MD, PhD, both from the University of Michigan (UM), and epidemiologist Mary Hayden, MD, of Rush University Medical Center in Chicago, analyzed fecal samples from more than 1,100 patients in Rush Medical Center’s intensive care unit over a nine-month period.

A researcher performed whole genome sequencing on 425 strains of the bacterium isolated from the samples and found “very little evidence that the strains of C. diff from one patient to the next were the same, which would imply in-hospital acquisition,” according to a UM news story.

“In fact, there were only six genomically supported transmissions over the study period. Instead, people who were already colonized were at greater risk of transitioning to infection,” UM stated.

Arianna Miles-Jay, PhD, a postdoctoral fellow in The Snitkin Lab at the University of Michigan and Manager of the Genomic Analysis Unit at the Michigan Department of Health and Human Services, performed the genomic sequencing. “By systematically culturing every patient, we thought we could understand how transmission was happening. The surprise was that, based on the genomics, there was very little transmission,” she said in the UM news story.

The researchers published their findings in the journal Nature Medicine titled, “Longitudinal Genomic Surveillance of Carriage and Transmission of Clostridioides Difficile in an Intensive Care Unit.”

Evan Snitkin, PhD

“Something happened to these patients that we still don’t understand to trigger the transition from C. diff hanging out in the gut to the organism causing diarrhea and the other complications resulting from infection,” said Evan Snitkin, PhD (above), Associate Professor of Microbiology and Immunology, and Associate Professor of Internal Medicine, Division of Infectious Diseases at University of Michigan, in a UM news story. Medical laboratories involved in hospital-acquired infection prevention understand the importance of this research and its effect on patient safety. (Photo copyright: University of Michigan.)

Only a Fraction of HAIs Are Through Cross-Transmission

In the study abstract, the researchers wrote that “despite enhanced infection prevention efforts, Clostridioides difficile remains the leading cause of healthcare-associated infections in the United States.”

Citing data from the US Centers for Disease Control and Prevention (CDC), HealthDay reported that “nearly half a million C. diff infections occur in the United States each year. Between 13,000 and 16,000 people die from the bacterium, which causes watery diarrhea and inflammation of the colon. Many of these infections and deaths have been blamed on transmission between hospitalized patients.”

The new study, however, notes that 9.3% of the patients admitted to the ICU carried toxigenic (produces toxins) C. diff, but only 1% acquired it via cross-transmission. The carriers, the study authors wrote, “posed minimal risk to others,” but were 24 times more likely to develop a C. diff infection than non-carriers.

“Our findings suggest that measures in place in the ICU at the time of the study—high rates of compliance with hand hygiene among healthcare personnel, routine environmental disinfection with an agent active against C. diff, and single patient rooms —were effective in preventing C. diff transmission,” Snitkin told HealthDay. “This indicates that to make further progress in protecting patients from developing C. diff infections will require improving our understanding of the triggers that lead patients asymptomatically carrying C. diff to transition to having infections.”

Recognizing Risk Factors

Despite the finding that infections were largely triggered within the patients, the researchers still emphasized the importance of taking measures to prevent hospital-acquired infections.

“In fact, the measures in place in the Rush ICU at the time of the study—high rates of compliance with hand hygiene among healthcare personnel, routine environmental disinfection with an agent active against C. diff, and single patient rooms—were likely responsible for the low transmission rate,” the UM news story noted.

One expert not involved with the study suggested that hospitals’ use of antibiotics may be a factor in causing C. diff carriers to develop infections.

“These findings suggest that while we should continue our current infection prevention strategies, attention should also be given to identifying the individuals who are asymptomatic carriers and finding ways to reduce their risk of developing an infection, like carefully optimizing antibiotic usage and recognizing other risk factors,” Hannah Newman, Senior Director of Infection Prevention at Lenox Hill Hospital in New York City, told HealthDay.

Snitkin, however, told HealthDay that other factors are likely at play. “There is support for antibiotic disruption of the microbiota being one type of trigger event, but there is certainly more to it than that, as not every patient who carries C. diff and receives antibiotics will develop an infection.”

Another expert not involved with the study told HealthDay that “many patients are already colonized,” especially older ones or those who have been previously hospitalized.

“A lot of their normal flora in their GI tract can be altered either through surgery or antibiotics or some other mechanism, and then symptoms occur, and that’s when they are treated with antibiotics,” said Donna Armellino, RN, Senior VP of Infection Prevention at Northwell Health in Manhasset, New York.

Whatever is taking place, hospital-acquired infections kill thousands of people every years. It’s on the federal Centers for Medicare and Medicaid Services’ (CMS) “never event” list of hospital-acquired conditions (HOC) that should never happen to hospital patients. This affects reimbursement to hospitals for treatment of infections under Medicare’s Hospital-Acquired Condition Reduction Program

This research also demonstrates the value of faster, cheaper, more accurate gene sequencing for researching life-threatening conditions. Microbiologists, Clinical laboratory scientists, and pathologists will want monitor further developments involving these findings as researchers from University of Michigan and Rush University Medical Center continue to learn more about the source of C. diff infections.

—Stephen Beale

Related Information:

The Surprising Origin of a Deadly Hospital Infection

Patient-to-Patient Transmission Not to Blame for Most C. Difficile Infections in Hospitals

Longitudinal Genomic Surveillance of Carriage and Transmission of Clostridioides difficile in an Intensive Care Unit

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