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.
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.
“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.
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.
Free at home clinical-laboratory testing for COVID-19 has been provided in the past, but this time the federal government wants to manufacture as many tests as possible in the US
Pathologists and clinical laboratory managers may be interested to learn that the US market is about to be flooded with millions of at-home COVID-19 rapid tests. The federal government has contracted with 12 US-based test manufacturers to produce 200 million at-home self-tests aimed at detecting “currently circulating COVID-19 variants” through the end of this year, according to a US Department of Health and Human Services (HHS) news release.
Federal officials want to head off “supply chain issues” that developed in the past with reliance on tests made overseas, and to address a possible COVID-19 surge during the fall and winter, the Associated Press (AP) reported.
In fact, 500 million tests have already been distributed through US government channels to long-term care facilities, schools, and low-income senior housing.
“Manufacturing COVID-19 tests in the United States strengthens our preparedness for the upcoming fall and winter seasons, reduces our reliance on other countries, and provides good jobs to hardworking Americans,” said Assistant Secretary for Preparedness and Response Dawn O’Connell, JD (above), in an HHS news release. “ASPR’s investments in these domestic manufacturers will increase availability of tests in the future.” With the federal government preparing for what it expects to be a surge in demand for COVID-19 testing, clinical laboratories may want to track the CDC’s weekly reports on the number of positive COVID-19 cases as this year’s influenza season progresses. (Photo copyright: Administration for Strategic Preparedness and Response.)
In Vitro Diagnostics Test Makers Get Government Gigs
This is not the first time federal officials sent out free COVID-19 tests to consumers. According to the AP, more than 755 million tests went out to US households in previous efforts to fight the spread of infections. But unlike those tests, these tests will be manufactured entirely within the US.
The government’s latest wave of free tests is meant to “complement ASPR’s ongoing distribution of free COVID-19 tests to long-term care facilities, low-income senior housing, uninsured individuals, and underserved communities, with 500 million tests provided to date through these channels,” the HHS news release noted.
Both large and lesser-known in vitro diagnostics (IVD) manufacturers were selected by the federal government to receive funding. They include:
HHS advises people to take the test at the first sign of symptoms (fever, sore throat, runny nose, others), after coming into contact someone who has COVID-19, or prior to gathering with a group, as a preventative to spread of the coronavirus.
Reporting laboratories say existing antibodies work against the BA.2.86 variant.
The variant does not appear to be linked in the US with increasing infections or hospitalizations.
It is “unclear how easily BA.2.86 spreads” relative to other variants.
BA.2.86 has been detected in nine states: Colorado, Delaware, Michigan, Ohio, Pennsylvania, Virginia, Washington, and in wastewater in New York and Ohio, as well as in other countries.
For week ending Sept. 23, the CDC reported the following statistics compared to the prior week:
19,079 COVID-19 hospitalizations, down 3.1%.
Total hospitalizations: 6.3 million.
2.7% of total deaths were due to COVID-19, up 8%.
COVID-19 test positivity rate was 11.6%, down 1.1%.
1.8% of emergency department visits were diagnosed with COVID-19, down 11.7%.
According to Verywell Health, BA.2.86 carries more than 30 mutations.
“Even with a lot of mutations, there are a lot of spots in the virus that can be recognized by our immune system, and there are many shared mutations as well. There will be some protection from new vaccine booster as well as prior infections,” Rajendram Rajnarayanan, PhD, Assistant Dean of Research and Associate Professor, Basic Sciences, Arkansas State University, told Verywell Health.
It’s worth noting that the common cold, influenza, SARS, and SARS-CoV-2 are all in the coronavirus family, and thus closely related with similar symptoms. It would not be a surprise that SARS-CoV-2 joins those other viruses as an endemic virus with a similar yearly cycle of infection rates.
If that happens, and no surge in infections appears that would motivate orders for the new COVID-19 at-home tests, the government may find itself with a lot of unused tests at the end of the year. The US Food and Drug Administration (FDA) is aware of this possibility and provides a website where people can check to see if their test has an extended expiration date.
Plus, folks who are tired of the pandemic may not respond at all to the government’s insistence to prepare for possible surges in infection rates.
“Whether or not people are done with it, we know the virus is there, we know that it’s circulating. We know, if past is prologue, it’ll circulate to a higher degree and spread, and cases will go up in the fall and winter seasons,” said Assistant Secretary for Preparedness and Response Dawn O’Connell, JD, in the HHS new release. “Anticipating that that would be true again, or something similar, we want to make sure the American people have these tools.”
Clinical laboratories may want to prepare as well. Many people are not comfortable with at-home self-testing and prefer to have their local medical labs perform the tests.
From point-of-care diagnostic tests to ancestral DNA home-testing, this company’s spit tubes are used by more medical laboratories than any other brand
Most clinical laboratory specialists know that OraSure Technologies of Bethlehem, Pa., was the first company to develop a rapid point-of-care DNA diagnostic test for HIV back in the 1990s. This was a big deal. It meant physicians could test patients during office visits and receive the results while the patients were still in the office. Since many patients fail to follow through on doctors’ test orders, this also meant physicians were diagnosing more patients with HIV than ever before.
Today, OraSure is the dominant company in the spit tube
industry. OraSure claims its tubes contain patented chemical preservatives that
can maintain the specimen’s integrity for up to two years at room temperature.
That’s a long time. And this one feature has made OraSure popular with
direct-to-consumer (DTC) genetic home-test developers.
OraSure provides nearly all of the specimen receptacles used
by individuals searching for their ancestral roots. It’s estimated that about
90% of the DTC genetic-testing market uses the company’s spit tubes. This is
partly because OraSure makes the only tubes approved by the US Food and Drug
Administration (FDA) for home DNA-testing purposes.
“The FDA approval gives customers confidence,” Mark Massaro, Managing Director, Senior Equity Analyst at investment bank Canaccord Genuity Group, told Bloomberg. “That, and they can preserve saliva for a long time.”
The OraSure spit tube above contains a patented mix of chemicals that can maintain saliva’s integrity for up to two years at room temperature. This is critical for ensuring specimens arrive at medical laboratories in usable condition to produce accurate test results. (Photo copyright: Zhongjia Sun/Bloomberg Businessweek.)
Spit, Close, Recap, Send
To use the saliva-testing DNA kits, an individual first
spits into the tube and then snaps the cap on the tube shut. This action
perforates a membrane which contains a patented, chemical mix of preservatives.
These chemicals help preserve the sample and minimize contamination from
non-human DNA that may be present.
“You’ve got to make it as easy as possible for a person to
spit in the tube, close the tube, recap the tube, and send it to you without
any variation,” Stephen
Tang, PhD, President and Chief Executive Officer at OraSure, told Bloomberg.
Saliva samples are very susceptible to environmental factors
like temperature and are extremely time sensitive. They need to be properly
handled and stored to prevent any degradation and ensure the most accurate test
results. Once in the spit tube, a saliva sample can last more than two years at
room temperature, according to the company.
“That’s the secret,” Tang stated. “Saliva is not pure. It’s
got a lot of bacteria and other stuff swimming in it.”
OraSure reported the company made $182 million in revenue in
2018, with about $20 million of that amount being profit. DNA Genotek, Inc., a subsidiary of OraSure
designed the T-shaped spit tubes being used for consumer-DNA testing kits.
Other Clinical Laboratory Uses for Specimen-Collection Devices
In addition to the consumer-DNA industry, OraSure’s tube technology is used in clinical and academic laboratory situations as well as in veterinary DNA testing. The company is focused on expanding the uses for their specimen-collection technology. They have recently begun using their technology to collect urine specimens for diagnosing sexually transmitted diseases and other conditions. OraSure also has added devices for feces collection, to better compete in the developing field of microbiome for gut bacteria analysis.
“We are all about the integrity of the sample collection,”
Tang says. “It’s a wide-open field.”
Ancestry Sued by OraSure
In 2017, Ancestry.com agreed to pay OraSure $12.5 million to
settle a lawsuit which alleged the company had copied OraSure’s patented DNA
testing technology to produce their own saliva-based DNA test.
According to the lawsuit, Ancestry.com purchased saliva test
kits from DNA Genotek in 2012 and 2013 for the purpose of collecting saliva
samples from their customers. In 2013, Ancestry.com filed for a patent of their
own for an improved variation of the kits reportedly without DNA Genotek’s
consent.
OraSure also has devices for substance abuse testing,
cryosurgical kits for the testing of skin lesions, and kits for forensic
toxicology.
Maintaining specimen integrity is critical to ensure lab
test results are accurate and reproducible. OraSure’s spit tube technology
solves the problem of preserving specimens while they are transported to
clinical laboratories and other pathology facilities.
Sensitivity and specificity of test kit for over-the-counter sale does not equal that of HIV assays performed in licensed and accredited clinical laboratories
Despite concerns about the potential for false positive results, an in-home rapid HIV test kit designed to be sold to consumers in pharmacies and other retail outlets cleared one more hurdle on the path to winning clearance by the Food and Drug Administration (FDA) to come to market.
On May 15, the 17 voting members of FDA’s Blood Products Advisory Committee (BPAC), concluded that the benefits of the OraQuick in-home HIV test outweigh the potential risks for consumers, according to a story published at cbsnews.com. The FDA advisory panel’s decision came despite earlier reported concerns regarding decreased accuracy of the OTC test when performed by consumers as compared to results from the professional-use version. (more…)
