Weekly Digest: New treatment for C. difficile could reduce recurrence; Concern grows for FDA guidance on antibiotics in agriculture

28 Jan 2017
Author: Ellyse Stauffer

A weekly roundup of news on drug resistance and other topics in global health.   

What should countries like Kenya be doing to minimize the risk of antibiotic resistance? In an interview with The Conversation U.S., Dr. Samuel Kariuki, microbiologist, and chair of the Global Antibiotic Resistance Partnership (GARP)-Kenya points to a number of national and county-level solutions, including the enforcement of legislation for responsible use of antibiotics in agriculture, and improved surveillance through increased collaboration between laboratories, hospitals, and research institutions. [The Conversation]

Modern contrast media and practices with CT scans may not increase the risk of kidney injuries. CDDEP Fellow Eili Klein and colleagues studied the relationship between CT contrast media and kidney damage, using emergency department records for a large urban hospital over five years (2009 to 2014). Their analysis included nearly 18,000 patients: 7,200 who had a CT scan with contrast, 5,500 who had a CT scan without contrast, and 5,200 who did not have a CT scan. The study, published in the Annals of Emergency Medicine, found no increase in acute or delayed kidney damage for patients with initial creatinine levels below 4.0 mg/dL(which includes people with some, but not severe, kidney impairment).The authors caution against changes in practice that could harm patients, however. They write, “It is likely that nephroprotective treatment patterns are at least partially responsible for the observed lack of increased acute kidney injury incidence after contrast media administration.” According to Dr. Klein, the findings bolster the case for randomized trials of contrast media, which have heretofore been considered unethical because of the widely-held belief that contrast media is a definite cause of acute and chronic kidney damage. [Annals of Emergency Medicine]

Concern grows for FDA guidance on antibiotics in agriculture. Earlier this month, the U.S. Food and Drug Administration (FDA) announced the full implementation of Guidance for Industry (GFI) #213, which aims to reduce inappropriate use of antibiotics in agriculture by the voluntary removal of pharmaceutical company indications for production purposes from all labels of medically important antibiotics. The FDA guidelines also require veterinary oversight for continued use of these antibiotics for disease prevention and control. Approximately 70 percent of all medically important antibiotics sold in the U.S. are used in animals, and experts are skeptical that Guidance #213 will have a significant impact on their use. This article from the Center for Infectious Disease Research and Policy highlights experts’ concerns over the effectiveness of the new guidance. [CIDRAP]

Antibiotic use restrictions found effective in reducing Clostridium difficile. In England, the incidence of Clostridium difficile dropped by 80 percent from 2006 through 2016, spurred by national control policies implemented in 2007 restricting the use of fluoroquinolones. In a study published in The Lancet Infectious Diseases, researchers analyzed regional and national data for incidence of C. difficile, along with antimicrobial prescribing data to determine whether the decline could be attributed to a decline in use of fluoroquinolones (indicated by resistant isolates declining faster than susceptible isolates) or by improvements in hospital infection control (indicated by similar declines regardless of susceptibility). They found a significant decline in fluoroquinolone-resistant infections and no significant change in fluoroquinolone-susceptible infections, indicating that restrictions in the use of fluoroquinolones are largely responsible for the decline in C. difficile infections. [Lancet ID, CIDRAP].

New treatment for C. difficile could reduce recurrence. Findings reported in The New England Journal of Medicine demonstrate that the addition of bezlotoxumab, a human monoclonal antibody against C. difficile toxin B, to standard antibiotic treatment can reduce the risk of a repeat infection by 37 percent. The addition of actoxumab, a human monoclonal antibody against C. difficile toxin A, did not improve efficacy. The results of two phase-3 trials indicate that the rate of sustained cure (protection against recurrent C. difficile infection for up to 12 weeks) was 64 percent with bezlotoxumab, 58 percent with bezlotoxumab in combination with actoxumab, and 54 percent with a placebo. [NEJM, CIDRAP]

Self-medication with antibiotics in the Middle East common. A review of 22 cross-sectional surveys that included populations in 11 countries in the Middle East found high and variable rates of self-medication with antibiotics (SMA) among adults, similar to levels in other low- and middle-income countries, and far higher than in Europe or other high-income countries. The surveys were published between January 2000 and June 2016. The review, published in the International Journal of Infectious Diseases, also reported on correlates of SMA, which is more common among less educated and poorer individuals. The most common indications for SMA were coughs, colds, and other upper respiratory tract problems, and the antibiotic most commonly used was penicillin. Antibiotics were obtained from stored left-over drugs, over-the-counter in pharmacies, and from friends or relatives. The authors point to a need for stronger controls on antibiotics, as well as better access to health care, especially for lower income groups. [IJID]

First study of antibiotic consumption and costs in Iraq. A study in the International Journal of Pharmacy Practice evaluated antibiotic source, consumption and total cost in the public and private sectors in Al-Najaf Province, Iraq, in 2012. More than 21 million defined daily doses (DDDs) were dispensed in Al-Najaf in one year, amounting to 45 DDDs per 1,000 inhabitants per day. More than half were dispensed by government healthcare institutions. Extended-spectrum (35 percent) and combined penicillins (26 percent) were the most frequently dispensed antibiotics and meropenem the least used (0.02 percent). The total cost of antibiotics consumed exceeded US$9 million for one year. [IJPP]

“Completing the Development of Ebola Vaccines,” third report from Ebola Vaccine Team B, a partnership between The Wellcome Trust and The Center for Infectious Disease Research and Policy (CIDRAP). The report recognizes the impressive achievement of a successfully completed field efficacy trial of Merck's rVSV-ZEBOV vaccine, but points out remaining challenges in getting a vaccine to the point of use. The authors call for a “reinvented global leadership” to better complete the task of “licensing and delivering safe, effective, and durable multi-strain Ebola vaccines for preventing outbreaks and quickly stopping future outbreaks when they occur.” This report follows two earlier reports, which detailed 1) qualities to seek in Ebola vaccines, and 2) four areas key to their development. [CIDRAP]

Image via CDC