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Not only are clinicians failing to order CDI tests for hospitalized patients with diarrhea, but more than half of European hospital labs still use inaccurate CDI testing methods

Once again, the bar on the quality of care is being raised. This time it involves hospitals in Europe. A recently published study shows that hospitals across the continent are not properly diagnosing all the cases of Clostridium difficile associated with patients having diarrhea.

Failure to diagnose or inadequate use of medical laboratory tests were cited by researchers as contributing to this situation. The European, multi-center, prospective, bi-annual point prevalence study of Clostridium difficile in hospitalized patients with diarrhea revealed that more than 39,000 cases of the hospital bug C. difficile go undetected each year.

This international study was presented in May at the 24th European Congress of Clinical Microbiology and Infectious Diseases in Barcelona. The study was funded by the pharmaceutical company Astellas Pharma Europe Ltd.

Nearly 40,000 C. diff Cases Are Missed by European Hospitals Yearly

This study involved C. difficile incidence (CDI) data from 482 European hospitals. The data indicated that every day, an average 109 cases of CDI are missed due to lack of clinical suspicion or inadequate lab testing. This has the potential to add up to more than 39,000 cases annually, noted a University of Leeds press release.

The CDI data was captured on two different days in two different seasons. One sampling day was during the winter of 2012/13. The second sampling day was in the summer of 2013. A total of 7,181 fecal samples were submitted by participating hospitals to 20 EUCLID national coordinating laboratories (NCL).

Rate of False-Positive CDI Dropped With Improved Testing Policies

After the first sampling day, shifts in CDI testing policy and methodology across Europe were implemented. The data showed that false-positive rates decreased between the two study days in those countries where testing procedures and methods had improved.

Lead researcher Mark Wilcox, M.D., is the Professor of Medical Microbiology at the United Kingdom’s University of Leeds. He stated, “Countries with increased awareness of CDI have been able to improve early diagnosis and reduce outbreaks associated with the most virulent strains of CDI. This study highlights that it is essential that we improve the implementation of testing in hospitals in order to tackle the issue of the increasing incidence of the bug across Europe.”

Mark Wilcox MD

Mark Wilcox, M.D. (pictured above), is a Professor of Medical Microbiology at the United Kingdom’s University of Leeds. He led the recent study that found that more than 39,000 cases of C. difficile infection are missed each year in hospitals throughout Europe. (Photo copyright University of Leeds)

Half of Europe’s Hospitals Do Not Use Accurate CDI Test Procedures

Despite the new guidelines and improvements shown by many hospitals, more than 50% of European hospitals have not yet adopted the more accurate CDI testing procedures, noted the University of Leeds press release, pointing out that more than one in five (22.8%) fecal samples tested at NCL are found positive for C. difficile. Furthermore, the EUCLID study found that more than half (52.1%) of hospitals in Europe only tested for CDI at the request of a physician.

Wilcox told Dark Daily  that clinicians often fail to order clinical laboratory tests at the proper time because diarrhea is a very common symptom, especially in hospitalized patients. “There are many causes of diarrhea, including underlying illness, medications, and infections (including CDI),” he pointed out.

“Clinicians may be unaware of the risk of CDI and/or often assume that the symptoms are not due to an infection.”

Wilcox said that existing guidelines recommend hospitals test for CDI in all unformed stools in which the cause is undetermined, but “we are still seeing an issue with both a lack of clinical suspicion and lack of testing for CDI.

“CDI… causes considerable suffering for patients and is a huge economic burden to hospitals across Europe,” he added. “These results reveal that there is still more to be done in order to optimize CDI management and prevention.”

What Clinicians and Lab Professionals Need to Know about CDI Testing

Wilcox, therefore, recommended, “Mandatory testing for CDI of all diarrheal samples received in the microbiology laboratory would ensure that failure to request CDI testing is not the main reason for missing this diagnosis.”

He also stressed that clinicians and clinical laboratory professionals should be educated about CDI and, most importantly, which are the most accurate medical laboratory tests for this infection. “Some C. difficile tests have poor sensitivity and/or poor specificity for CDI,” he explained. “The optimized way of testing for CDI is to use a highly sensitive screening test (e.g. GDH or PCR for toxin gene), followed by a toxin test,” Wilcox stressed.

In a previous study, published in the journal Lancet Infectious Diseases, Wilcox had led a team of researchers to establish the best method for diagnosing C. difficile, noted another University of Leeds press release. This study found that patients with fecal samples positive for cytotoxin assay were twice as likely to die within 30 days as those patients with samples only positive by the alternative “gold-standard” method (16.6% vs. 9.7%). This finding means that pathology laboratory tests that detect the presence of toxin in fecal samples—the cytotoxin assay—are the most reliable indicators of C. difficile.

How Published Studies Can Contribute to Raising the Bar on Quality

On the subject of “raising the bar” on clinical quality, the example presented above shows how published studies are drawing the curtain back on patient outcomes. With increasing frequency, clinical studies are addressing two specific issues and their causes. One is failure to diagnose and the other is failure to order the right medical laboratory test that would be appropriate, given a patient’s symptoms. On both of these issues, pathologists and clinical lab scientists are well positioned to help clinicians achieve better patient outcomes.

—By Patricia Kirk

Related Information:

Nearly 40,000 hospital bug cases missed each year

Level playing field for Clostridium difficile diagnosis

Differences in outcome according to Clostridium difficile testing method: a prospective multicentre diagnostic validation study of C difficile infection