Rapid malaria diagnostic tests linked to increased antibiotic prescribing
A review of 10 linked studies yesterday in the American Journal of Tropical Medicine and Hygiene indicates that introduction of rapid diagnostic tests for malaria in Africa and Afghanistan curbed use of anti-malaria drugs but was also linked to increased antibiotic prescribing.
The 10 related studies, which analyzed drug prescriptions written from 2007 to 2013 for 562,368 patients in malaria-endemic regions of Africa (Ghana, Cameroon, Tanzania, Nigeria, and Uganda) and Afghanistan, were conducted by the ACT Consortium, a research partnership created to investigate delivery of artemisinin-based combination therapies (ACTs) for malaria treatment. The studies looked at the impact of malaria rapid diagnostic testing (mRDT) on fever case management across a range of clinical settings, and included a comparison group without mRDT intervention.
Overall, mRDTs were associated with lower ACT prescribing, with mRDT interventions in most settings (10 African settings, 4 Afghanistan settings) producing statistically significant reductions in ACT prescribing compared to scenarios without mRDT intervention. Lower prescribing was mostly due to malaria test-negative patients not receiving ACTs. However, mRDT interventions were also associated with significantly more systemic prescribing of antibiotics in seven settings (5 in Africa, 2 in Afghanistan), with antibiotics being prescribed to 40% to 80% of patients who tested negative.
Across most settings, either an antimalarial or an antimicrobial was prescribed for more than 75% of patients. The studies also showed that prescribing did not always adhere to malaria test results. In many settings, ACTs were prescribed to more than 30% of test-negative patients; in other settings, more than 20% of the patients who tested positive were not given ACTs.
The findings echo those from a Mar 29 BMJ analysis of nine of the studies, which found that the risk of antibiotic prescription was 21% higher in places where mRDT was introduced. The authors say the results "highlight issues that warrant particular attention in future work on point-of-care diagnosis and fever and malaria case management.
Aug 7 Am J Trop Med Hyg abstract
Related Mar 29 CIDRAP News story
Study: Carbapenem restriction reduces resistance in P aeruginosa
A new study in Clinical Infectious Diseases suggests that restricting carbapenem antibiotics, even for a short time, may be an effective strategy for managing carbapenem resistance in Pseudomonas aeruginosa.
In the study, researchers at King Saud Medical City, a public hospital in Riyadh, Saudi Arabia, conducted a two-phase retrospective study to investigate to compare the antimicrobial susceptibility pattern of P aeruginosa before and after implementation of a carbapenem restriction program. The program was in response to the identification of a new strain of P aeruginosa in the hospital's intensive care unit that was susceptible to many antipseudomonals but resistant to imipenem and meropenem.
The program restricted use of imipenem and meropenem except in three cases: culture-based carbapenem therapy, empirical carbapenem therapy after failure of other antibiotics, and carbapenem therapy prescribed by an infectious disease consultant. The first phase of the study was from May 2016 to July 2016 (before carbapenem restriction) and the second phase was September 2016 to November 2016 (after carbapenem restriction).
The results showed that after implementing carbapenem restriction, overall carbapenem consumption fell from 28.44 to 11.67 defined daily doses (DDD) per 1,000 patient days, and the percentage of P aeruginosa isolates that were resistant to imipenem and meropenem decreased significantly, from 76% to 38.5% (P=0.019) and from 74.1% to 30% (P=0.012), respectively. Susceptibility of P aeruginosa to other antibiotics was not affected by carbapenem restriction. The study did not investigate clinical outcomes before and after carbapenem restriction.
The authors write, "Although some investigatorsargued that a long period of time is required for a change in antibiotic prescribing practice to show an effect on the antimicrobial susceptibility pattern, the present study proved that even a short duration of change in antibiotic prescribing habits might cause a change in the antimicrobial susceptibility pattern."
Aug 4 Clin Infect Dis study
Study shows clinical impact of an educational ASP in Spain
A new study by researchers in Spain reports that an education-based antimicrobial stewardship program (ASP) at a large teaching hospital produced a sustained reduction in antibiotic use and decreased the incidence and mortality of hospital-acquired candidemia and multidrug-resistant bloodstream infections (MDR-BSI).
The quasi-experimental study, published yesterday in Clinical Infectious Diseases, investigated to impact of a multifaceted educational intervention at a tertiary-care teaching hospital in Sevilla, Spain, over a 5-year period. The main intervention was weekly peer-to-peer educational interviews, in which counselors selected one antibiotic prescription per week and interviewed the prescribers about the case. The researchers recorded data on antibiotic consumption over five years, calculated as DDD per 1,000 occupied bed days (OBD), and analyzed the incident density per 1,000 OBD of hospital-acquired BSI caused by the six most frequent microorganisms—Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, P aeruginosa, Staphylococcus aureus, and Candida SPP. They also assessed crude death rate per 1,000 OBD.
The results showed that implementation of the ASP was followed by a significant drop in antibiotic consumption that was sustained during the following years, with the median consumption dropping from 1,008 DDD/1,000 OBD in the first year to 774 DDD/1,000 OBD in the last year. The reduction was observed in all classes of antibiotics.
In addition, the incidence density and mortality of hospital-acquired candidemia and MDR-BSI decreased parallel to the reduction in antibiotic pressure. The increasing trend observed in the pre-intervention period for incidence of candidemia and MDR-BSI (+0.018 cases per 1,000 OBD per quarter) reverted toward a decreasing trend with a change in slope of -0.029 cases/1,000 OBD per quarter, while the increasing trend in the crude death rate in the pre-intervention period (+0.011 deaths/1,000 OBD per quarter) reverted toward a decreasing trend with a change in slope of -0.015deaths/1,000 OBD per quarter.
The authors of the study say they believe this is the first ASP to demonstrate that reducing antibiotic pressure can reduce the incidence and mortality of hospital-acquired MDR-BSI, an important finding given that the evidence supporting the clinical benefits of ASPs has to date been insufficient. "Our results prove that educational interventions can be successful when based on active learning targeted towards real clinical problems of interest to specialists of all departments," they write.
Aug 7 Clin Infect Dis abstract