New diagnostic methods and treatments – including faecal transplantation – will help improve the care of patients with Clostridium difficile (C. diff.), a deadly bacterial infection that can occur after antibiotic use, according to updated guidelines released by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA).
C. diff. sickens nearly 500,000 Americans annually, a rate that plateaued in 2010 after reaching historic highs, but has yet to decline in the US as it has in England and parts of Europe. The most common bug acquired in the hospital, C. diff. kills 15,000 to 30,000 people every year and costs more than $4.8bn a year in hospitalisations alone.
C. diff. has become a significant problem due to the excessive use of antibiotics, which disturb the balance of bacteria in the gastrointestinal system, wiping out good bacteria and allowing the C. diff. bacteria to flourish and cause cramps and diarrhoea. Some patients suffer from repeated recurrence despite standard antibiotic treatment.
Diagnosis and treatment of C. diff. has evolved significantly since the last guidelines were published in 2010.
“We can better control this epidemic by learning how to use new treatments and diagnostics,” said Dr L Clifford McDonald, co-chair of the guidelines panel and associate director for science in the division of healthcare quality promotion for the US Centres for Disease Control and Prevention (CDC). “The role of the infectious disease specialist is critical, not only in providing expert diagnosis and treatment of C. diff. infections, but also in helping set institutional policies that will lead to their prevention – including reducing the inappropriate use of antibiotics through good stewardship.”
C. diff. is diagnosed based on a patient’s medical history, signs and symptoms, combined with test results. The optimal method for laboratory diagnosis of C. diff. is the subject of debate and depends on how carefully patients are selected for testing. The guidelines recommend only testing patients with new onset and unexplained diarrhoea (three or more unformed stools in 24 hours).
While immunoassays were the most common diagnostics employed previously, molecular testing – which has its pros and cons – is now used by more than 70% of hospital labs. Molecular tests can help rule out C. diff. infection, as well as reduce transmission by detecting C. diff. colonisation in patients with diarrhea from other causes. But because they are very sensitive and can lead to over diagnosis, when there are no pre-agreed institutional criteria that limit testing to patients with significant unexplained diarrhoea of three or more unformed stools in 24 hours, the guidelines recommend that a C. diff. common antigen test and a stool toxin test (such as an immunoassay) be used as part of a two- or three-step test process.
Further, not everyone diagnosed with C. diff. requires treatment, notes McDonald. “We often find people get better on their own if they stop taking the offending antibiotic,” he said.
The guidelines include new recommendations for treatment when warranted, including: – Vancomycin or fidaxomicin – antibiotics vancomycin or fidaxomicin should be used for initial treatment of even mild C. diff., rather than metronidazole, which the previous guidelines recommended as first-line therapy. Research shows the cure rates are higher for vancomycin and fidaxomicin than for metronidazole.
Faecal microbiota transplantation (FMT) – The guidelines recommend FMT for treatment of people with two or more recurrences of C. diff. and for whom traditional antibiotic treatment has not worked. FMT is a new treatment since the last guidelines were published but is not approved by the US Food and Drug Administration (FDA).
However, FDA has issued Guidance for Industry regarding the use of FMT to treat C. diff. infection not responsive to standard therapies (https://www.fda.gov/ucm/groups/fdagov-public/@fdagov-bio-gen/documents/document/ucm361393.pdf). FMT involves transferring faecal bacteria from a healthy person’s stool to the gut of a person with recurrent C. diff., to replenish the good bacteria and control the disease-causing bacteria.
The guidelines include the same suggestions for preventing the spread of C. diff. as the 2010 guidelines – including isolating infected patients and ensuring healthcare workers and visitors use gloves and gowns – but also call for increased attention to antibiotic stewardship to reduce the unwarranted use of the drugs. While nearly all antibiotics predispose people to C. diff., some are of particular concern, including the fluoroquinolones, cephalosporins and clindamycin.
The guidelines make no recommendation for the use of probiotics. “We tell patients that for the most part they won’t hurt, but at this point we can’t make a recommendation for which ones to use and specifically how to use them,” said McDonald.
The new guidelines also include recommendations for epidemiologic surveillance, diagnosis, and treatment of C. diff. in children, which the 2010 guidelines did not address.
The IDSA/SHEA guidelines panel includes experts who specialise in epidemiology, diagnosis, infection control and clinical management of adult and paediatric patients.
Standard treatment is yet another antibiotic, but the IDSA has changed its guidance on which drug to use and how, reports STAT News. It urges “antibiotic stewardship” to reduce resistance to the drugs that fight infections yet in some people destroy healthy microbes, too. The society also encourages “diagnostic stewardship” – testing the right people so carriers for whom the bacterium is harmless aren’t needlessly given antibiotics just because they have diarrhoea.
C. diff releases spores that people can easily spread to one another. Healthy people develop antibodies to the toxin released by the bacteria so they don’t get sick, but they can be colonized by C. diff without being infected.
“If you change a diaper, you probably get spores in your mouth but you don’t get C. diff infection. Health care workers do not appear to have C. diff infection, yet they are around it all the time,” said McDonald.
The ones who are vulnerable are patients taking antibiotics for another illness, leaving them without healthy gut microbes.
C. diff is so insidious because the chances of it coming back again and again get higher and higher. The risk of having a repeat infection is 20% to 30% after the first bout, rising to 40% after a second, and 60% after a third.
The misery of severe diarrhoea can disrupt people’s lives, whether they live at home or in nursing homes. One study cited by the IDSA found that C. diff infections outnumber MRSA infections, a type of antibiotic-resistant staph infection, in long-term care facilities.
Abstract
A panel of experts was convened by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) to update the 2010 clinical practice guideline on Clostridium difficile infection (CDI) in adults. The update, which has incorporated recommendations for children (following the adult recommendations for epidemiology, diagnosis, and treatment), includes significant changes in the management of this infection and reflects the evolving controversy over best methods for diagnosis. Clostridium difficile remains the most important cause of healthcare-associated diarrhea and has become the most commonly identified cause of healthcare-associated infection in adults in the United States. Moreover, C. difficile has established itself as an important community pathogen. Although the prevalence of the epidemic and virulent ribotype 027 strain has declined markedly along with overall CDI rates in parts of Europe, it remains one of the most commonly identified strains in the United States where it causes a sizable minority of CDIs, especially healthcare-associated CDIs. This guideline updates recommendations regarding epidemiology, diagnosis, treatment, infection prevention, and environmental management.
Authors
L Clifford McDonald, Dale N Gerding, Stuart Johnson, Johan S Bakken, Karen C Carroll, Susan E Coffin, Erik R Dubberke, Kevin W Garey, Carolyn V Gould, Ciaran Kelly, Vivian Loo, Julia Shaklee Sammons, Thomas J Sandora, Mark H Wilcox
[link url="http://www.infectioncontroltoday.com/guidelines/fecal-transplantation-molecular-testing-among-new-recommendations-c-diff-guidelines"]Infection Control Today material[/link]
[link url="https://academic.oup.com/cid/advance-article/doi/10.1093/cid/cix1085/4855916?searchresult=1"]Clinical Infectious Diseases abstract[/link]
[link url="https://www.statnews.com/2018/02/15/fecal-transplants-c-diff-idsa/"]Stat News report[/link]