News Scan for Jun 21, 2017

News brief

Study suggests prior dengue infection doesn't increase Zika viral load

An analysis of blood samples from Brazilian patients seen in an emergency department for acute febrile illness found no sign of antibody-dependent enhancement (ADE) in those with Zika infection who had previously been exposed to dengue virus.

Both viruses are flaviviruses, which are known for enhancing immune response. As part of their work on Zika virus vaccines, scientists have been trying to tease out how and if ADE impacts Zika severity and if cross-infection with dengue or other flaviviruses worsens the disease.

A Brazil-based research team examined samples from 65 patients who were evaluated at a hospital in Sao Paulo state during the first half of 2016, when the area was experiencing a Zika outbreak. To explore any connection between ADE and both dengue and Zika, the researchers examined patients' viral loads and their cytokine profiles during acute infection. They published their findings yesterday in Clinical Infectious Diseases.

For patients diagnosed as having acute dengue or Zika infections, the researchers didn't see higher viremia levels in those who had previously been infected with dengue, but they noted that the study had only enough power to detect the difference with Zika virus.

In the cytokine analysis part of the study, the investigators looked at patterns with 10 cytokines, finding a significant difference in only one: IL-1-beta, which was lower in patients with acute dengue infections who had been infected with dengue previously. Again, the researchers said the power to detect differences between the groups was low, but in the Zika patients they did see a significant positive association between IL-1-beta and viral load.

The authors said they will continue to evaluate the group of patients to assess if earlier dengue infection protects against future Zika infections or illnesses involving other dengue serotypes. They also said they will explore other immunoglobulin subclasses and different immune cell subsets to better understand the mechanisms of the findings they observed in the patients.
Jun 20 Clin Infect Dis abstract

New MERS case reported in Riyadh

Saudi Arabia's Ministry of Health (MOH) reported one new MERS-CoV case yesterday in an update dated Jun 19.

The patient is a 42-year-old male expatriate from Riyadh. He did not have any symptoms of MERS-CoV (Middle East respiratory syndrome coronavirus) infection and is in stable condition. He's listed as a secondary household contact of a previously reported case.

The MOH reported no new cases in an update dated yesterday and of this writing had not issued a Jun 21 report. Before yesterday, the agency reported new cases on 19 straight days.

As of yesterday, Saudi Arabia's MERS-CoV cases since 2012 total 1,656, including 676 deaths. Seventeen people are still being treated for their infections.
Jun 19 MOH report

Nonmedical vaccine exemptions linked to pertussis outbreaks

A study yesterday in Proceedings of the National Academy of Sciences used geospacial data to show that US counties with more kindergartners with nonmedical vaccine exemption status have higher rates of pertussis outbreaks in the United States.

The data come from 2012, when the national incidence rate for pertussis was 15.4 per 100,000 people, the highest since 1955. The researchers compared reports of nonmedical vaccine exemption statuses of kindergarteners during the 2011-12 and 2012-13 academic years with statistically significant geographic clusters of pertussis cases in 2012 for two different age-groups (5 years and younger and 10 to 14 years), reported at the county level.

They found that relative risk for pertussis outbreaks increased in counties that had more unvaccinated kindergartners. On average, the proportion of kindergarteners with nonmedical vaccine exemptions was 2.8 times larger in counties reporting a pertussis vaccine cluster.

"Although we recognize that correlation does not establish causation, the findings from this investigation are consistent with previous suggestions that geographic clusters of nonmedical vaccine exemptions and waning immunity may have been two of several factors that contributed to community-level pertussis outbreaks," the authors concluded.
Jun 20 Proc Natl Acad Sci study

Ricin vaccine candidate received more funding

The National Institute of Allergy and Infectious Diseases (NIAID) is providing, additional money for animal testing of the novel ricin poison treatment and vaccine, RiVax, according to a company news release.

The NIAID will provide Soligenix, the maker of RiVax, with approximately $2 million in additional funding, bringing the total amount awarded to date under this contract to $18.7 million, according to the release.

The company specializes in making products that treat rare diseases. If all contract options are exercised, the total award of up to $24.7 million will support preclinical, manufacturing, and clinical development.

Ricin is a toxin that could be weaponized. The plant-derived poison is lethal in doses as small as a grain of salt and can be dissolved in water. There are no current treatments for ricin poisoning, but RiVax acts as a medical countermeasure to prevent the effects of ricin exposure.
Jun 21 Soligenix press release

Stewardship / Resistance Scan for Jun 21, 2017

News brief

Review identifies factors to boost stewardship in long-term care

A literature review of antimicrobial stewardship activities at long-term care facilities (LTCFs) that focused on workflow systems identified factors that were effective and possibly complementary, researchers reported yesterday in Clinical Infectious Diseases.

They noted that LTCFs face different antimicrobial stewardship challenges than hospitals do, and identifying the useful interventions is especially important, given Centers for Medicare and Medicaid Services (CMS) rule changes requiring antimicrobial stewardship activities in LTCFs.

Of 20 studies on antimicrobial stewardship interventions at LTCFs that met the research criteria, 5 were randomized controlled trials and 15 were quasi-experimental analyses.

The effective approaches they found included multidisciplinary education supported by enduring material, integrating pre-prescription data collection tools into nurses' workflow, integrating post-prescription recommendations into prescribers' workflow, and using infectious disease experts as external consultants.

Structured education that involves nurses, nurse assistants, and prescribers may be a feasible and practical strategy, especially when combined with comprehensive approaches, such as incorporating actionable items into pocket guides and posting educational materials in common areas, the team concluded. They noted that education alone might be enough to start antimicrobial stewardship, but it isn't enough to sustain it.

Communication between people with different roles at LTCFs seems vital, the experts wrote, and, ideally, tools supporting antimicrobial stewardship, especially gathering relevant clinical information before prescribing and fostering communication among staff, will become embedded in electronic medical record systems.
Jun 20 Clin Infect Dis abstract

Scientists, medical experts warn of antimicrobial chemical hazards

A statement signed by more than 200 scientists and medical professionals is calling on the international community to limit the production and use of triclosan and triclocarban, two antimicrobial ingredients widely used in over-the-counter antibacterial soaps and thousands of other consumer products.

The Florence Statement on Triclosan and Triclocarban, written in 2016 and published yesterday in Environmental Health Perspectives, says that continued use of the chemicals is concerning because peer-reviewed research has concluded that they are environmentally persistent endocrine disruptors that bioaccumulate in aquatic plants and organisms and have been associated with reproductive and developmental harm in animals. The authors also say there's no evidence that use of triclosan and triclocarban improves consumer health or prevents disease, and that overuse may contribute to antimicrobial resistance and may modify the microbiome.

"We therefore call on the international community to limit the production and use of triclosan and triclocarban and to question the use of other antimicrobials," the authors write.

In September 2016, the US Food and Drug Administration (FDA) banned triclosan and triclocarban, along with 17 other active antimicrobial agents used in consumer antiseptic washes, saying that manufacturers had not demonstrated that the ingredients are safe for long-term daily use or are more effective than plain soap and water in preventing illness or infection. The FDA gave manufacturers 1 year to phase out or reformulate products using the chemicals.

The FDA ban, however, does not apply to hand sanitizing gels, foams, or wipes and doesn't limit use of the chemicals in healthcare settings. In addition, the statement notes that many of the chemicals are still used in other consumer and building products. The authors of the statement say the narrow scope of the FDA's ruling indicates that "existing regulatory practices are not sufficient to protect human and ecosystem health from adverse impacts of antimicrobial chemicals."

The statement urges governments, chemical and product manufacturers, and consumers to avoid use of triclosan, triclocarban, and other antimicrobial chemicals except where they provide an evidence-based health benefit, and to use safer alternatives that pose no risk to humans or ecosystems.
Jun 20 Environ Health Perspect statement

Study finds higher antibiotic prescribing in docs who dismiss risks

Physicians who perceive the risks posed by antibiotics as low are more likely to prescribe them than those who consider potential side effects to be a concern and understand the problem posed by antibiotic resistance, according to a study yesterday in the Journal of General Internal Medicine.

US investigators analyzed data on 2,874 patient visits involving an antibiotic prescription for pneumonia or upper respiratory tract infection in 2014 and 2015. The prescriptions were written by 69 emergency department clinicians, and prescribing rates ranged from 7% to 91%.

Clinicians who framed prescribing decisions as a choice between continued illness and possible benefit (a "why not take a risk?" gist) had higher rates of prescribing (odds ratio [OR], 1.28). In contrast, those who tended to agree with the "antibiotics may be harmful" gist were associated with about a 50% lower prescribing rate (OR, 0.81). (Using the "gist" approach to categorizing prescribers is based on what researchers call "fuzzy-trace theory.")

Study author Eili Klein, PhD, a fellow with the Center for Disease Dynamics, Economics & Policy (CDDEP) said in a CDDEP news release, "What's needed are interventions that change the mental calculus of clinicians. The 'just to be safe' mentality of many clinicians doesn't recognize the potential harms of antibiotic treatment or consider the further development of antimicrobial resistance."

"Interventions that explicitly focus on changing providers' gists, such as by emphasizing that even rare side effects can happen eventually, or that antibiotic resistance may hurt the patient in the event of a future illness, are more likely to be effective," added co-author David Broniatowski, PhD.
Jun 20 J Gen Intern Med study
Jun 21 CDDEP news release