Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans

Study finds benefits for antibiotic de-escalation in pneumonia patients

A new study out of Spain has found that antibiotic de-escalation in adult patients with community-acquired pneumonia appears safe and effective and does not adversely affect outcomes.

The study, published yesterday in the Journal of Antimicrobial Chemotherapy, is a retrospective analysis of all adult patients with community-acquired pneumococcal pneumonia (CAPP) admitted to a public hospital in Barcelona, Spain from 1995 to 2014. The aim of the investigation was to determine whether antibiotic de-escalation therapy—in which the initial broad-spectrum antibiotic therapy was narrowed to penicillin, amoxicillin, or amoxicillin/clavulanate within 72 hours of admission—had any impact on clinical outcomes in CAPP patients. The primary outcomes measured were 30-day mortality and length of hospital stay (LOS).

Of the 1,410 episodes of CAPP, antibiotic de-escalation within the first 72 hours after admission was performed on 166 patients. Those patients, it was observed, had a less severe presentation at admission than the non-de-escalation group. After adjustment for confounding factors in multivariate and propensity score analyses, investigators found that antibiotic de-escalation was not associated with an increased risk of 30-day mortality but was associated with a shorter LOS and duration of intravenous (IV) antibiotic therapy. Similar results were observed in a subgroup of patients who had high-risk pneumonia, were clinically unstable within 72 hour of admission, or had bacteremia.

The authors say that the results of their study suggest that de-escalation strategies should be more widely implemented in the management of hospitalized adults with CAPP. 
Oct 20 J Antimicrob Chemother study 

Romanian authorities identify 4 cases of XDR TB

Originally published by CIDRAP News Oct 20

Cases of extensively drug-resistant tuberculosis (XDR-TB) have been identified in three students at a university in Romania and in a family contact, according to a report yesterday from the European Centre for Disease Prevention and Control (ECDC).

The cluster of cases involves three students attending the University of Medicine and Pharmacy in Oradea Municipality, Bihor County, Romania, and a family member of one of the students. The presumed index case is a student from Israel who was diagnosed in 2015, and the other two students are UK citizens. All three students were in contact with each other at the university. The family contact is a brother of one of the UK students.

Romanian authorities have identified 87 contacts who were exposed to the students and are following up to test for XDR-TB as well as latent TB infection. More cases in association with this cluster are expected.

XDR-TB is a rare type of TB that is resistant to first-line antibiotics (isoniazid and rifampicin), any fluoroquinolone, and at least one of three second-line drugs (amikacin, kanamycin, or capreomycin). While it is possible to treat patients diagnosed with XDR-TB, the remaining treatment options are less effective and have more side effects.
Oct 19 ECDC Rapid Risk Assessment 

Dutch study finds incidence of pediatric C diff stable

Originally published by CIDRAP News Oct 20

A study by Dutch researchers yesterday finds that the incidence of pediatric Clostridium difficile infection (CDI) has been stable over the previous 6 years.

The surveillance study, published in Clinical Infectious Diseases, included all CDIs reported from May 2009 to May 2015 by 26 Dutch hospitals participating in a national sentinel surveillance study. Infected children were 2 and older. Investigators distinguished between healthcare-onset CDI (in which symptoms began in a hospital or long-term care facility) and community-onset CDI (when symptoms began at home).

Overall, 4,691 CDIs were included in the study, with a total of 135 pediatric CDIs (3%) being reported at 17 hospitals. The investigators did not observe an increase in the monthly number of reported pediatric CDIs during the study period. The median age of the children with CDI was 10 years.

Of the 135 pediatric CDI cases, 55% were community-onset, and 31% met the criteria for severe CDI. Although severe CDI was more likely to occur in children, it resulted in fewer complications than adult CDI. In contrast to adults, there was no CDI-related mortality. Pediatric CDI cases were more likely to occur in university hospitals than non-university hospitals.

The investigators also found that, of the 36 C difficile PCR ribotypes identified, ribotype 265 was most prevalent in children (15%) but rarely found in adults.

The authors note that the findings are in contrast to several studies in recent years that have shown an increase in the incidence of pediatric CDI in community settings and hospitals in the United States.
Oct 19 Clin Infect Dis abstract        

Significant overtreatment, undertreatment found in young people's STIs

Originally published by CIDRAP News Oct 20

A study yesterday suggests a significant number of adolescents and young adults are overtreated, and even more are undertreated, for chlamydia and gonorrhea.

The retrospective study, published in the International Journal of Infectious Diseases, looked at 797 patients aged 13 to 24 who were screened for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) in the pediatric emergency department of an urban safety-net hospital in Chicago from July 2014 to June 2015. Cook County, where the hospital is located, has the second highest rate of CT and GC infections in the United States, after Los Angeles County.

Overall, the investigators found that 21.6% of the patients tested positive for a sexually transmitted infection (STI), with 19.1% testing positive for CT, 5.5% for GC, and 3.1% testing positive for both. Most of the infected were black and female. Of the 171 patients with an STI, 21.6% were overtreated and 43.4% were undertreated.

When the investigators looked at the factors involved in overtreatment and undertreatment, they found that male and female patients who were overtreated were more likely to present with STI exposure or genitourinary (GU) symptoms. In addition, female patients who were overtreated were likely to be 18 to 19 years old and have a history of STIs. Patients were more likely to be undertreated if they were female and less likely to be undertreated if they presented with STI exposure, had a history of STIs, and had GU symptoms.

Both overtreatment and undertreatment of STIs are problematic. Overtreatment can cause unnecessary emotional trauma, the authors write, and potentially increase the risk of antibiotic resistance, particularly in gonorrhea. Undertreatment, meanwhile, can lead to other conditions and create a pool of young adults and adolescents who are at risk of spreading their infections. The authors suggest that point-of-care testing for CT and GC, as well as use of more modern methods of patient communication to ensure follow-up, could substantially reduce over- and undertreatment.
Oct 19 Int J Infect Dis study

HHS gives Johns Hopkins $16 million to improve antibiotic use in US healthcare

Originally published by CIDRAP News Oct 19

The US Department of Health and Human Services (HHS) on Tuesday awarded $16 million to Johns Hopkins University to help reduce unnecessary antibiotic use and fight antibiotic resistance in the healthcare system.

The contract awarded to the Johns Hopkins Armstrong Institute for Patient Safety and Quality will be spread out over 5 years and will fund the development of tools and educational modules to help healthcare providers make better decisions about antibiotic treatment. Johns Hopkins researchers will also be developing tools to help educate patients about antibiotics and when they are—and aren't—necessary.

"It's important for everyone, from health care providers to patients and families, to understand the importance of properly prescribing antibiotics," Johns Hopkins University assistant professor of pediatrics Pranita Tamma, MD, said in a news release. "We want to ensure each person involved in the care process is aware that antibiotics are essential for certain infections, but they can actually do more harm than good if they are improperly prescribed."
 Oct 18 Johns Hopkins University press release

ASP in rehab facility reduces antibiotic use and resistance

Originally published by CIDRAP News Oct 19

The results of a small, single-center study suggest that implementing an antibiotic stewardship program (ASP) based on infectious disease (ID) consultation in a rehabilitation facility can reduce antibiotic use and antimicrobial resistance without affecting patient outcomes.

The quasi-experimental study, reported in Infection Control and Hospital Epidemiology, compared the periods before and after an ASP was implemented at a 150-bed rehabilitation facility in northern Italy specializing in spinal cord injuries (SCI). The authors note that patients cared for in SCI rehab hospitals are prone to infections dues to several factors—including bladder catheterization, invasive procedures, and pressure sores—and that antibiotic over-prescribing in these facilities is a recognized problem.

The ASP, which was implemented in July 2012, had two elements: Systematic bedside ID consultation with a dedicated ID consultant who visited patients and discussed antibiotic prescribing with their doctors, and regular structural interventions. The interventions included revisions of internal protocol for antibiotic prophylaxis and educational sessions on the appropriateness of antibiotic treatment.

During the study period (January 2011 to December 2014), overall antibiotic consumption at the facility decreased by 48%, dropping from 42 defined daily doses (DDD) per 100 patient days in 2011 to 22 DDD in 2014. Specifically, the use of carbapenems dropped by 97% and fluoroquinolone use dropped by 92%. The use of aminoglycosides, tetracycline, clindamycin, and macrolides also declined. The consumption of third-generation cephalosporins remained stable.

At the same time, the researchers found that the incidence of C difficile fell from 3.6 cases per 10,000 patient days in 2011 to 1.2 cases in 2014. In addition, they observed a significant decrease in drug-resistant bacteria. The prevalence of extensively drug-resistant (XDR) strains declined from 55% to 12% in Pseudomonas aeruginosa and from 96% to 73% in Acinetobacter baumanni; the prevalence of extended-spectrum beta-lactamase (ESBL) producing strains dropped from 42% to 17% in Escherichia coli and from 62% to 15% in Proteus mirabilis; carbapenem-resistant strains fell from 42% to 17% in Klebsiella pneumoniae; and methicillin-resistant strains of Staphylococcus aureus decreased from 77% to 40%.

The authors note that while their study is limited by the single-center design and long-term monitoring is needed, the results suggest that an ASP based on systematic ID consultation can be effective outside of acute-care hospitals.
Oct 17 Infect Control Hosp Epidemiol study 

Children of hog workers have more drug-resistant S aureus

Originally published by CIDRAP News Oct 18

 A study today conducted by the Johns Hopkins Bloomberg School of Public Health suggests children in the households of workers at large industrial hog farms may be more vulnerable to drug-resistant forms of S aureus.

Large hog farms commonly administer small doses of antibiotics for growth promotion and disease prevention, which can promote antibiotic resistance. In addition, evidence has begun to emerge in Europe of swine workers and their families being infected with livestock-associated antibiotic-resistant S aureus. With that in mind, the researchers wanted to investigate the nasal carriage of resistant S aureus in children in the homes of US hog workers.

For the study, published in Environmental Health Perspectives, researchers collected and compared data on 400 adult-child pairs in the top-ten hog-producing counties in North Carolina, the second-largest hog-producing state in the nation. One set of 198 pairs included a parent who was employed full time at an industrial hog operation (IHO) and a child under the age of 7 years in the same household. The 202 community referent (CR) pairs included a parent from the community who did not work on a hog farm and a child under the age of seven.

The participants filled out a questionnaire and provided investigators with a nasal swab, which was analyzed for the presence of S aureus, MRSA, and multidrug-resistant S aureus (MDRSA).

Among the adults in the study, the investigators found that S aureus nasal carriage prevalence was higher in the hog workers than in the CR parents (53% vs 31%), MRSA prevalence was low in both groups (2% vs 4%), and MDRSA prevalence was similar (12% vs 8%). But among the children, the differences were much starker, especially for drug-resistant S aureus. While nasal carriage of S aureus was higher among children of hog workers than those in the CR household (49% vs 31%), so was nasal carriage of MRSA (14% vs 6%) and MDRSA (23% vs 8%).

The investigators also found evidence suggesting that S aureus, MRSA, and MDRSA prevalence was higher in the children of hog workers who brought home personal protective equipment than it was in the children of hog workers who didn't bring this equipment home.

The authors of the study say the findings need to be confirmed in other populations, and that potential pathways and mechanisms of exposure should be more closely studied. And while none of the children in the study became sick, the investigators also say further studies should be done to determine whether the nasal carriage prevalence of drug-resistant S aureus in children of hog workers represents a risk for infection.

"Before this study, we didn't know how common it was for children living with industrial hog operation workers in North Carolina to carry antibiotic-resistant S. aureus in their noses," study leader Christopher Heaney, PhD, MS, said in a Johns Hopkins press release. "Now that we know how prevalent MRSA and MDRSA are, important next steps are to learn how children are becoming exposed and whether there are implications for their health."
Oct 18 Environ Health Perspect study
Oct 18 Johns Hopkins press release

MRSA acquisition low in those exposed to index patients, study finds

Originally published by CIDRAP News Oct 18

 The rate of MRSA acquisition is low among contacts of patients colonized or infected with methicillin-resistant S aureus (MRSA), according to a study yesterday in the American Journal of Infection Control.

In the single-center study, researchers at the Sunnybrook Health Sciences Centre in Toronto obtained surveillance cultures from 2,133 patients who had been exposed to780 index patients from 2004 to 2014. The index patients had been colonized or infected with MRSA, and their contacts were either roommates of in an adjacent bed space to the index patient for at least 24 hours. Surveillance cultures were obtained from the contact patients 0, 3, 6, and 9 days after exposure from 2004 to 2008, and then 0, 5, and 10 days after exposure from 2008 to 2015.

At the end of the study period, the researchers found that of the 1,389 contact patients who had completed the surveillance screening, only 79 (5.7%) had acquired MRSA. But the rate of acquisition was higher (8.8%) in the group that completed the screening in the hospital than in those who were diagnosed as having MRSA post-discharge (2.5%). This indicates, the authors said, that the positivity rate for MRSA contacts decreases over time from exposure.

The authors said the results suggest it may be appropriate to reassess the need to flag MRSA contacts at hospital discharge.
Oct 17 Am J Infect Control study

International travelers can spread antibiotic-resistant bacteria, study finds

Originally published by CIDRAP News on Oct 17

International travel can contribute to the spread of antimicrobial resistance, according to a new study published in The Lancet Infectious Diseases.

For the large-scale, longitudinal cohort study, Dutch researchers collected fecal samples from 2,001 Dutch travelers and 215 non-travelling household members, along with questionnaires on demographics and illnesses that were filled out before and after travel. The median travel duration was 20 days, and the sub-regions most frequently visited were Southeast Asia, eastern Africa, South America, and southern Asia. Fecal samples were screened for the presence of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E), which can be resistant to a range of frequently used antibiotics.

Of the 1,847 participants who were ESBL-E negative before travel and submitted fecal samples after return, 633 were found to have acquired at least one ESBL-E during their journey, for an acquisition rate of 34.3%. The participants most likely to get sick were those who had traveled to Southeast Asia (75% incidence).

Researchers found that antibiotic use during travel was the strongest predictor for ESBL-E acquisition. Other independent predictors included diarrhea during travel, traveler's diarrhea that persisted after return, and pre-existing chronic bowel disease.

While the rate ESBL-E acquisition observed in travelers to Southeast Asia was similar to other studies, the researchers also found that the study participants continued to carry ESBL-E bacteria longer than those in previous studies. The median duration of colonization after travel was 30 days, but more than 11% remained colonized after 12 months. In addition, the possibility of transmitting ESBL-E to a household member was 12%.

"Our findings support the substantial contribution of international travel to the spread of ESBL-E and antimicrobial resistance worldwide," the authors wrote.

An accompanying commentary argues that the findings strengthen the message that the risk of antibiotic-resistant bacteria must be taken into account when evaluating travelers with infections, especially those who have traveled to Southeast Asia. 
Oct 14 Lancet Infect Dis study
Oct 14 Lancet Infect Dis commentary