Antimicrobial Resistance Scan for Aug 31, 2016

News brief

Study: Written reports help dentists reduce antibiotic prescribing

A new UK study has found that dentists prescribe fewer antibiotics to their patients after receiving a report on their past prescribing habits.

According to the study, published yesterday in PLoS Medicine, dentists prescribe roughly 10% of the antibiotics dispensed in UK community pharmacies, often in the absence of clinical need. Using dental prescribing and treatment claim data routinely collected by the UK National Health Service (NHS), researchers with the RAPiD (Reducing Antibiotic Prescribing in Dentistry) trial set out to determine whether an individualized audit and feedback intervention could have an impact on prescribing habits.

The trial included 795 dental practices in Scotland, with 632 practices in an intervention group and 163 in a control group. The intervention group was further subdivided into two groups: one that received a line graph showing an individual dentist's monthly prescribing rate, and another that received a line graph with a written "behavior change" message containing national guidelines for dental antibiotic prescribing.

At the start of trial, the rate of antibiotics prescribed per 100 NHS treatment claims was 8.3 in the control group and 8.5 in the intervention group. After 12 months, the researchers found that both groups were prescribing fewer antibiotics. But the drop in the prescribing rate in the intervention group—from 8.5 to 7.5—was 5.7% greater than it was for the control group. And the subset of dentists who received a written message saw their prescribing rate drop by an additional 6%.

The authors of the study wrote that the findings are significant because they indicate that a "relatively straightforward, low-cost public health and patient safety intervention" could help the entire healthcare system address antimicrobial resistance.
Aug 30 PLoS Med study

Review outlines economic incentives for antibiotic development

Limited commercial returns are considered a primary factor in why pharmaceutical companies are not investing in antibiotic development. That's why a "constellation of economic incentives" will be needed to promote antibacterial drug development going forward, according to an article published yesterday in Clinical Infectious Diseases.

The article, written by members of the Trans-Atlantic Task Force on Antimicrobial Resistance (TATFAR), is a review of the various economic incentives identified in policy documents, peer-reviewed publications, organization proposals, and government-sponsored reviews that have addressed the question of how to spur new antibiotic development. In October 2015, TATFAR agreed to make an informed recommendation on a package of economic incentives to be considered and implemented in the future.

In those documents, the authors found a consensus around the idea that economic incentives must contain both "push and pull" mechanisms that will guarantee return on investment. Push incentives include subsidies (in the form of grants, public-private partnerships, and tax credits) to fund early-stage development of antimicrobials, which is often risky and expensive. The idea is to provide incentives to academic institutions and companies by providing up-front money for research and development.

Pull incentives, on the other hand, are meant to encourage antibacterial drug development by promising a substantial financial reward to companies that successfully develop new antibiotics. Examples include large milestone or prize payments, patent buy-outs, advanced market commitments, and extended market exclusivity.

Pull incentives, the authors found, will be most successful if they rely on a "de-linkage" model that would remove the motivation for pharmaceutical companies to market and oversell their product. Negating the need for high product sales, they argue, would ensure that new antibiotics are not overused, thereby linking new antibiotic development to conservation and stewardship.

Finally, the authors found widespread agreement that global coordination will be needed to administer the funding of these incentive programs.
Aug 30 Clin Infect Dis literature review

Growing polymyxin resistance reported in CRE in Brazil

Brazilian researchers are reporting increasing resistance to polymyxin antibiotics in clinical Klebsiella Pneumoniae strains that are already resistant to carbapenem antibiotics.

In a letter to Emerging Infectious Diseases, the researchers report on an analysis of more than 3,000 K pneumoniae isolates recovered from patients at 10 private tertiary-care hospitals in Sao Paulo from January 2011 to December 2015.

The analysis showed a dramatic increase in carbapenem resistance in the K pneumoniae isolates—from 6.8% in 2011 to 35.5% in 2015. And among the carbapenem-resistant K pneumoniae isolates, polymyxin resistance rose from 0% in 2011 to 27.1% in 2015. Polymyxin resistance among carbapenem-susceptible K pneumoniae isolates also rose, from 0.7% in 2011 to 3.9% in 2015.

The authors said the findings are worrisome because carbapenem-resistant Enterobacteriaceae (CRE) are more deadly than carbapenem-susceptible strains, and carbapenem-resistant K Pneumoniae bacteria are endemic in Brazil. Furthermore, most resistant infections are treated with polymyxins.
Aug 30 Emerg Infect Dis letter

News Scan for Aug 31, 2016

News brief

In Liberian study, Ebola virus persisted in semen of 9% of male survivors

A study in Liberia has produced more evidence of persistence of the Ebola virus in semen after patients' recovery from the disease, with some of them still testing positive more than a year after recovery and greater age indicated as a possible risk factor.

The findings come from Liberia's Men's Health Screening Program, in which male Ebola survivor are offered semen testing and counseled about safe sex, according to a report yesterday in The Lancet Global Health.

In the study, men and boys ages 15 and older were tested for Ebola RNA by real-time reverse-transcriptase polymerase chain reaction (RT-PCR). They graduated from the program after receiving two consecutive negative semen test results. Data obtained between Jul 7, 2015, and May 6, 2016, were included in the study.

Of 429 participants, 38 (9%) had at least one positive semen test for Ebola RNA, and 24 (63%) of these tested positive a year or longer after their recovery. The longest interval between discharge from treatment and collection of a positive sample was 565 days.

Among participants who provided samples more than 90 days after recovery, those older than 40 were significantly more likely to have a positive test than were younger men (P = 0.0004), the report says.

The study also suggests that the counseling part of the program has been effective, as 84 of 113 men who reported not using condoms at enrollment reported using them at their first follow-up visit. Also, 176 of 385 participants who initially said they were sexually active reported abstinence at the first follow-up.

In an accompanying commentary, two experts said the findings must be interpreted cautiously, since the authors could not do cell culture isolation to confirm the presence of viable Ebola virus, as opposed to just residual viral RNA.

But the commentators, Daniel Bausch, MD, MPH&TM, of the Tulane School of Public Health and Tropical Medicine in New Orleans, and Ebola survivor Ian Crozier, MD, of the Infectious Diseases Institute in Kampala, Uganda, added that sexual transmission more than 6 months after recovery has been documented in Liberia. Therefore, they advise that male Ebola survivors should continue to follow advice to abstain from sex or use condoms until RT-PCR semen testing is repeatedly negative.
Aug 30 Lancet Glob Health report
Aug 30 Lancet Glob Health commentary

First case of MERS confirmed in Saudi Arabia in 6 days

The Saudi Arabia Ministry of Health (MOH) reported a case of MERS-CoV infection today after 5 days of no new cases. In the last 6 weeks, there's been a slowdown of MERS diagnoses in the country, which has been battling an outbreak of the respiratory disease since 2012.

According to the MOH, a 40-year-old man from Al Hofuf is in critical condition after presenting with symptoms of MERS-CoV (Middle East respiratory syndrome coronavirus). The MOH described the expatriate as having contact with camels.

Direct and indirect contact with camels is a known risk factor for contracting MERS, but researchers do not yet know how the animals pass the disease to humans.

Saudi Arabia's MERS case count has now reached 1,449, including 610 deaths and 3 patients still being treated, according to the MOH.
Aug 31 MOH update

PAHO reports 1,428 more chikungunya cases in Central, South America

In its most recent weekly update late last week, the Pan American Health Organization (PAHO) reported 1,428 new suspected or confirmed chikungunya cases, lifting the total in the Americas this year to 252,154.

Weekly increases have varied, and some countries report several weeks worth of cases at a time, while some go several weeks with reporting any. For comparison, in the previous 2 weeks PAHO reported increases of 32,492 and 3,100 cases, respectively.

Most of the newly reported cases were from Costa Rica, El Salvador, Honduras, Colombia, and Venezuela. One more death was reported, putting that total for the year at 55.
Aug 26 PAHO update

In other chikungunya developments, researchers from the Philippines, where the disease is endemic, yesterday reported that in an outbreak, rising antibodies approaching 50% seem to signal the end of the event. Their observation came from active febrile illness surveillance in the city of Cebu during 2012 to 2014.

They made weekly telephone calls, made home visits, and collected blood samples. They reported their findings in Emerging Infectious Diseases.

Overall chickungunya incidence during the second year was significantly lower than the first year: 2.84 cases per 100 person years, compared with 12.32 cases per 100 person years. The authors said the change was driven by a drop in subclinical infections across all age-groups. Prevalence of neutralizing antibodies rose significantly, from 28% at the beginning of the first surveillance year to 42% at the start of the second year.

The investigators said the seroprevalence level was higher than the 10% to 30% reported at the end of a major outbreak on St. Martin in the Caribbean, but they said the neutralizing test they used in the Philippines was more sensitive and might account for the difference.
Aug 30 Emerg Infect Dis report

Commercial farm in China reports H5N6 avian flu

A commercial farm in TaijiangCounty, China, today reported an outbreak of H5N6 avian flu, according to the World Organization for Animal Health (OIE). TaijiangCounty is located in Guizhou province, in the southwestern part of the country.

More than 16,000 birds were destroyed after 7,167 poultry on the farm died from the disease and 10,113 were infected, for a total loss of 23,884 birds. The outbreak is continuing, and officials will provide updates after an investigation is completed. The outbreak appears to have a 30% mortality rate and a 71% case-fatality rate.

H5N6 is a highly pathogenic avian flu virus that has caused 15 human infections in China, including 8 deaths, the most recent in January.
Aug 31 OIE report
Jan 11 CIDRAP news story on most recent case

Seqirus reports FDA approval of its second quadrivalent flu vaccine

The vaccine manufacturer Seqirus announced this week that it has gained US Food and Drug Administration (FDA) approval of its second quadrivalent (four-strain) influenza vaccine, Afluria Quadrivalent, for use in adults.

Seqirus is offering both Afluria Quadrivalent and Flucelvax Quadrivalent, a cell-based vaccine that won FDA approval in May, for use in the 2016-17 flu season in the United States, according to a press release. Seqirus was formed to combine the flu vaccine operations of CSL and Novartis when CSL bought Novartis's US flu vaccine business in 2015.

Afluria Quadrivalent is an inactivated vaccine that contains two influenza A and two influenza B strains, the company noted. It comes in single-dose, preservative-free pre-filled syringes. In a randomized controlled trial with 3,449 participants, the vaccine was shown to be non-inferior to two trivalent inactivated flu vaccines for all flu strains targeted, the company said.

Trivalent flu vaccines contain two type A strains and one type B. Several flu vaccine makers have added quadrivalent products to their lines in recent years because of the difficulty of predicting which of the two influenza B lineages will be more common in any given season.

Seqirus offers a trivalent formulation of Afluria that is available in a needle-free injector. The company announcement does not mention a needle-free version of Afluria Quadrivalent.
Aug 29 Seqirus press release