Stewardship / Resistance Scan for Jul 24, 2017

News brief

Study estimates $800,000 cost of an NDM-1 hospital outbreak

A new study in Emerging Infectious Diseases describes the physical and financial burden of a nosocomial outbreak caused by New Delhi metallo (NDM) beta-lactamase–containing Klebsiella pneumoniae.

The 2015 outbreak, which occurred at a tertiary teaching hospital in the Netherlands from Oct 1 to Dec 30, began when NDM-1–producing extended-spectrum beta lactamase (ESBL)-positive K pneumoniae bacteria were cultured and isolated from a patient in the surgical ward. Following that discovery, screening cultures of long-term admitted surgical patients revealed 2 more patients with NDM-producing K pneumoniae, and contact tracing and weekly screening rounds of all hospital patients revealed additional NDM carriers. A total of 29 patients were affected.

An assessment of outbreak-related expenses estimated the total costs of the 3-month outbreak at $804,263, corresponding to a cost of $27,770 per patient. The loss of revenue was mainly attributed to closure of beds during the outbreak. Other cost drivers were diagnostic tests and personnel time spent by laboratory employees and infection prevention experts.

"As shown in this study, the expansion of multidrug-resistant, gram-negative bacteria is of great concern; these bacteria both threaten patient safety and increase healthcare costs," the study authors write. "The intensive outbreak control measures of the hospital were costly and inconvenient for patients and staff."

The authors say that in countries where NDM-positive K pneumoniae is not endemic, early detection of colonized patients and adequate infection control strategies will be important factors in minimizing the spread of the multidrug-resistant bacteria.
Jul 21 Emerg Infect Dis dispatch

ASP associated with reduced mortality in patients treated with vancomycin

Mortality in older patients treated with vancomycin decreased by 7.1% after an antimicrobial stewardship program (ASP) was implemented, researchers at a Veteran Affairs hospital report in the American Journal of Infection Control.

In the retrospective quasi-experimental study, researchers at the Veterans Affairs Western New York Healthcare System in Buffalo, New York, aimed to evaluate the impact of an ASP on 30-day mortality rates in patients treated with intravenous (IV) vancomycin, which is the drug of choice for infections caused by methicillin-resistant Staphylococcus aureus but has been associated with nephrotoxicity. ASP interventions consisted of prospective audit and feedback, including appropriate antibiotic selection and dosing, microbiology, and duration of treatment. A secondary outcome was to determine risk factors for mortality associated with vancomycin.

Overall, 453 patients were treated with a minimum of 48 hours of IV vancomycin therapy during the study period—226 in the pre-ASP period (Oct 1, 2006 through Jul 31, 2008) and 227 during the ASP period (Aug 1, 2011 through Jul 31, 2014). Clinicians using the ASP made on average about four vancomycin recommendations per patient. Deaths occurred in 56 patients (12.4%), with 36 (64.3%) occurring during the pre-ASP period and 20 during the ASP period (P =.02). Patients in the ASP group also had less nephrotoxicity than those in the pre-ASP group (17 vs 31 patients).

Increased mortality was associated with pre-ASP years (odds ratio [OR]. 2.17), older age (OR, 1.08), nephroxicity (OR, 3.24), and hypotension (OR, 3.28). Treatment in the intensive care unit was also associated with higher mortality.

"Our prospective audit and feedback system was associated with improved mortality in an older population with a mean age of 68 years," the study authors write. "The process of comprehensive patient review, including culture data and imaging and close monitoring of any changes in renal function, may be necessary for the elderly patient beyond computerized support software to achieve improved rates of morality."
Jul 21 Am J Infect Control study

US data show increases in Campylobacter cases, outbreaks, resistance

The number of US Campylobacter outbreaks has doubled in recent years, and isolates have proved increasingly antibiotic resistant, according to a study last week in Clinical Infectious Diseases.

The researchers analyzed data on more than 300,000 Campylobacter infections from 2004 through 2012. The average annual incidence rate (IR) was 11.4 cases per 100,000 people, with the rate varying from 3.1 to 47.6 by state. IRs among preschool children were double the overall rate. Overall IRs increased 21%—from 10.5/100,000 in 2004-06 to 12.7/100,000 in 2010-12.

Over the study period, 347 Campylobacter outbreaks were reported. The annual median number of outbreaks doubled, from 28 in 2004-06 to 56 in 2010-12.

Antimicrobial susceptibility testing of isolates from 4,793 domestic and 1,070 travel-associated cases revealed that ciprofloxacin resistance increased among domestic infections from 12.8% in 2004-09 to 16.1% in 2010-12, a 26% increase.

The authors conclude, "These data provide baseline rates for monitoring change now that campylobacteriosis is a nationally notifiable disease," which occurred in 2015.
Jul 20 Clin Infect Dis study

News Scan for Jul 24, 2017

News brief

CDC updates Zika testing recommendations for pregnant women

The US Centers for Disease Control and Prevention (CDC) today updated its recommendations for testing pregnant women for Zika virus, mainly because one of the most frequently used tests—which detected immunoglobulin B (IgM) antibodies—is more likely to yield a false positive result, especially as incidence of the disease in the Americas decreases.

The CDC detailed the new guidance today in an early online edition of Morbidity and Mortality Weekly Report (MMWR).

Health officials emphasized that health providers should continue to ask pregnant women at each prenatal visit about possible Zika exposure and possible symptoms of the illness before and during the current pregnancy. Nucleic acid and serologic testing are still recommended for symptomatic pregnant women within 12 weeks of illness onset.

However, for asymptomatic women with ongoing possible exposure, the CDC no longer routinely recommends routine IgM testing, due to the test's limitations and difficulty interpreting results. Recent studies have down that Zika IgM antibodies might be detected for months after infection, limiting the ability to tell if the infection occurred before or during pregnancy.

However, they note that in areas with ongoing possible Zika transmission, nucleic acid testing should be offered at the start of prenatal care, with follow-up testing based on local Zika transmission trends.

The CDC will host a Clinician Outreach and Communication Activity (COCA) call to explain and field questions about the new guidance on Jul 27 at 2 pm eastern time.
Jul 24 MMWR early release report
CDC COCA call information

Ebola RNA detected in semen more than 2 years after symptom onset

In about 8% of men, Ebola virus RNA can be detected in semen samples more than 2 years after symptom onset, according to a new study published in Open Forum Infectious Diseases.

The study was based on samples donated by 137 men diagnosed as having Ebola virus disease (EVD). Previous research has shown that within approximately 3 months of acute EVD, as many as 28% to 100% have Ebola RNA in semen, and sexual transmission of Ebola has taken place up to 6 months after infection. This was the first study to measure prevalence of Ebola RNA through the 2-year mark, when 11 of the men, or 8%, had detectable Ebola RNA in their semen.

Volunteers were recruited in Monrovia, Liberia, and donated semen samples every 90 days for the duration of the study. The longest time from EVD onset to detectable Ebola in semen was 965 days. The men who had Ebola RNA in their semen the longest were on average older and more likely to report vision problems than men who cleared the RNA earlier.

Currently, the World Health Organization recommends that men who've been diagnosed as having EVD practice abstinence or use condoms for 12 months after recovery. The study authors suggest their work should prompt a revised discussion of the timeline for sexual transmission of Ebola.
Jul 22 Open Forum Infect Dis study

In other research news, investigators who published a study in PLoS Neglected Tropical Diseases said that young children, the elderly, and rural patients were more likely to die from Ebola infections, and there was a decreasing trend in the case-fatality rate during Liberia's 2014-16 Ebola outbreak.

The researchers used 16,370 lab samples from Liberia, and identified 3,897 confirmed EVD cases and 3,975 Ebola RNA–negative suspected cases. Patients with Ebola who were 6 to 30 years old were more likely to survive the infection, as were urban versus rural patients. The case-fatality rate dropped from 80% in 2014 among confirmed cases to 63% at the study's end.
Jul 21 PLoS Negl Trop Dis study

More H5N8 outbreaks reported in Italy, South Africa

Italy and South Africa recently reported more highly pathogenic H5N8 avian flu outbreaks, according to separate updates from the World Organization for Animal Health (OIE).

In Italy, two events were reported in Lombardy region in the north central part of the country, and both began on Jul 19. One occurred at a commercial turkey farm and the other was detected in backyard birds. Between the two locations, the virus sickened 18,874 of 20,563 birds, killing 1,692 of them. Culling was planned for the remaining poultry, along with disinfection of the bands, movement controls, and enhanced screening.

Italy was among several countries to report several H5N8 outbreaks over the winter and spring, and its last outbreak was reported in May, also affecting poultry in Lombardy region.

South Africa reported two more H5N8 outbreak, both affecting wild birds, the country's agriculture officials said in a notification today to the OIE. Both detections occurred in provinces that have already reported the virus in poultry. In the new events, tests on two southern masked weavers—a type of perching bird—found dead in Mpumalanga province on Jun 30 tested positive for the virus.

Also, the virus turned up in tests on birds from two locations Gauteng province. The outbreaks there began between Jul 11 and Jul 13, affecting a yellow-billed duck and an Egyptian found dead in the city of Tshwane and in hobby geese at a backyard holding in the city of Emfuleni.
Jul 21 OIE report on H5N8 in Italy
Jul 24 OIE report on H5N8 in South Africa

New polio case confirmed in Afghanistan

The Global Polio Eradication Initiative (GPEI) last week confirmed another case of wild polio virus type 1 in Afghanistan. The nation, along with Pakistan and Nigeria, is one of three in the world in which wild polio is still transmitted.

Afghanistan now has 5 confirmed polio cases in 2017. The most recent case reported an onset of paralysis on Jun 19 in Kandahar.

On Jun 21, officials reported an environmental sample collected in Nangarhar tested positive for wild polio virus type 1. This is the seventh positive environmental sample collected in the country this year.

GPEI also noted the four cases of vaccine-derived poliovirus type 2 detected last week in Syria. That country has seen 27 vaccine-derived polio cases this year. On Saturday, a vaccination campaign targeting 448,000 children younger than 5 years began in Syria.
Jul 19 GPEI update