Infection PreventioneBug Bytes

December 2014

Airport Exit and Entry Screening for Ebola August–November 10, 2014

• In response to the Ebola epidemic, CDC, the World Health Organization, and other international organizations collaborated in August to screen for Ebola persons at airports who were exiting countries with widespread transmission.

• Since the program began, an estimated 80,000 travelers have departed by air from the three countries with widespread Ebola transmission.

• In October, an enhanced U.S. entry screening program was begun at five U.S. airports as an added measure. Of 1,993 travelers screened, a total of 86 (4.3%) were referred to CDC for additional evaluation, and seven (8.1%) were symptomatic and referred for medical evaluation. None of the seven were diagnosed with Ebola.

• Source: Clive M Brown, MBBS, Aaron E Aranas, MPH, Gabrielle A Benenson, MPH, et al. MMWR Morb Mortal Wkly Rep 2014;63(Early Release):1-6

Research on farmers' markets shows presence of Salmonella, E. coliThe study focused on farmers' markets in Los Angeles and Orange counties in California, as well as in the Seattle, Washington, area. Specifically tested were samples of the herbs cilantro, basil and parsley. Of the 133 samples tested from 13 farmers' markets, 24.1 percent tested positive for E. coli and one sample tested positive for Salmonella. A total of 16 samples had average E. coli counts considered to be unsatisfactory according to guidelines established by the Public Health Laboratory Service. When tested for Salmonella, 15 samples had suspicious growth but only one tested positive -- a parsley sample from a Los Angeles County farmers' market. Orange County farmers' markets had the highest percentage of samples with E. coli growth followed by farmers' markets in the greater Seattle area and Los Angeles County.Salmonella symptoms include diarrhea, abdominal cramps and fever around 12 to 72 hours after consumption that can last four to seven days. Symptoms for pathogenic forms of E. coli include severe stomach cramps, diarrhea that often becomes bloody, and vomiting.

Source: Donna J Levy, Nicola K Beck, Alexandra L Kossik, Taylor Patti, J Scott Meschke, Melissa Calicchia, Rosalee S Hellberg. Microbial safety and quality of fresh herbs from Los Angeles, Orange County and Seattle farmers' markets. Journal of the Science of Food and Agriculture, 2014

Kitchens are source of multi-drug resistant bacteria

• Researchers from University Hospital in Basel, Switzerland collected and examined 298 cutting boards (154 from University Hospital and 144 from private households) after preparation of various meats (i.e., poultry, beef/veal, pork, lamb, game and fish) and before being cleaned. They also collected 20 pairs of gloves from hospital kitchen employees after they handled raw poultry. These samples were tested for the presence of ESBL-producing Enterobacteriaceae, a family of gram-negative bacteria that includes Salmonella, E. coli and Klebsiella.

• In testing the cutting boards, researchers found that 6.5 percent of hospital cutting boards used in preparation of poultry were contaminated with ESBL-producing E. coli. For boards used in households, researchers found ESBL-producing E. coli on 3.5 percent of these surfaces. They also found that 50 percent of the hospital kitchen gloves were contaminated with this drug-resistant E. coli. The researchers found that none of the cutting boards used in preparing beef/veal, pork, lamb, game or fish were contaminated with any ESBL-producing bacteria. They also found that the meat's country of origin did not play a factor in the presence of bacteria on any of the surfaces.

• Source: Sarah Tschudin-Sutter, Reno Frei, Roger Stephan, Herbert Hächler, Danica Nogarth, Andreas F. Widmer. Extended-Spectrum β-Lactamase (ESBL)–Producing Enterobacteriaceae: A Threat from the Kitchen. Infection Control and Hospital Epidemiology, 2014; 35 (5): 581

Five dead, dozens ill from bacteria linked to caramel apples

• Dec 19 2014: Five people have died and 21 others have been hospitalized in recent weeks in a listeria outbreak linked to caramel apples. A total of 28 people infected with listeria have been reported from 10 states. The CDC warned consumers not to eat any pre-packaged, commercially-produced caramel apples, including those with other toppings such as nuts, chocolate or sprinkles, until more information is available.

• Of the 28 victims, 26 were hospitalized and five of those people died, the CDC said, adding that listeriosis contributed to at least four of the deaths. Nine of the cases involved a pregnant woman or her newborn infant. Listeriosis is an infection that primarily affects older adults, pregnant women, newborns and people with weakened immune symptoms. Symptoms include fever, muscle aches, headache, confusion and convulsions.

• No illnesses related to the outbreak have been linked to apples that are not caramel-coated and are not prepackaged, or to caramel candy. The cases were diagnosed in late October and November.

• Source: http://www.cdc.gov/listeria/

Bacterial infections differ based on geography, healthcare spending

• Where you live affects the type of bacteria that cause bloodstream infections, according to researchers at Rhode Island Hospital and an international team of investigators. The closer you live to the equator, the greater the likelihood of a bloodstream infection caused by a group of bacteria called Gram-negative bacteria, which thrive in warm and moist environments, compared to another group of bacteria referred to as Gram-positive bacteria. The study also found that the proportion of a country's GDP spent on health care impacted the type of bacteria causing such infections.

• A five-member international steering committee that collected and studied data from 2007-2011 from 23 medical centers (with two hospitals participating from Sao Paolo, Brazil) including in the U.S., Greece, Egypt, Israel, Australia, Canada, Japan, Italy, Netherlands, Thailand, Switzerland and Argentina. For each site, data was obtained regarding latitude, longitude, mean annual precipitation, mean daily temperature, population density, per-capita gross domestic product and the percentage of GDP in that country allocated for health care.

• Source: David Fisman, Eleni Patrozou, Yehuda Carmeli, Eli Perencevich, Ashleigh R. Tuite, Leonard A. Mermel. Geographical Variability in the Likelihood of Bloodstream Infections Due to Gram-Negative Bacteria: Correlation with Proximity to the Equator and Health Care Expenditure. PLoS ONE, 2014; 9 (12): e114548 DOI: 10.1371/journal.pone.0114548

Addition of Vancomycin to Cefazolin Prophylaxis Is Associated With Acute Kidney Injury After Primary Joint Arthroplasty• Researchers studied 1828 patients undergoing primary hip and knee arthroplasty over a 2-year

period who received either cefazolin (n = 500) or cefazolin and vancomycin (n = 1328) as perioperative antibiotic prophylaxis. During the study period, a perceived high prevalence of MRSA infections led some surgeons to add vancomycin to the prophylactic antibiotic regimen. The patient characteristics, case mix, and preoperative renal function and baseline creatinine clearance were similar between the two groups. AKI was defined according to the published Acute Kidney Injury Network (AKIN) criteria, and the risk of AKI in both groups was compared. Patients receiving dual antibiotics were more likely to develop AKI compared with those receiving cefazolin alone (13% versus 8%, p = 0.002). Dual-antibiotic prophylaxis also was associated with greater severity; patients in the dual antibiotic group had higher rates of Grade II and III acute kidney injury (3% versus 0%, p = 0.003). Without a clear advantage in reducing surgical site infections, the utility and safety of routine addition of vancomycin to the prophylactic regimen in all patients undergoing primary hip and knee arthroplasty should be avoided. Further prospective studies should look at the efficacy of preoperative MRSA screening, decolonization, and selective use of vancomycin in high-risk patients.

• Source: Courtney PM et al. Clinical Orthopaedics and Related Research 11/2014

Portable UV light as an alternative for decontamination

• Targeted surface disinfection is a key infection control measure. Usually, decontamination of surfaces is performed by wiping the surface with some kind of disinfecting agent or, in the case of auxiliary devices, submerging the entire product in a disinfecting solution. In all of these cases, the success of surface disinfection depends mainly on the type of pathogen, the type and concentration of the active chemical substances, and the overall duration of the disinfection process. Ultraviolet (UV) irradiation, which inactivates microorganisms by the formation of DNA/RNA dimers, is widely used for the decontamination of safety cabinets, for water decontamination, and in the food processing industry. This study evaluated the capability of a new hand-held UV device to provide surface decontamination

• The following species were tested: spores of Geobacillus stearothermophilus Bacillus pumilus, Bacillus atropheaus and Clostridium difficile, and vegetative cells from Staphylococcus aureus, Enterococcus faecium, Escherichia coli and Acinetobacter baumannii. A minimum 90% reduction of viable organisms was achieved within 40 seconds for all 4 spore species. In contrast, reproducible total (100%) inactivation of the 4 non-spore-producing species occurred in less than 5 seconds. Source: Peterssen LP et al: American Journal of Infection Control 42 (2014) 1334-6

Buffer zone guidelines may be inadequate to protect produce from feedlot contamination• The pathogen Escherichia coli O157:H7 can spread, likely airborne, more than one tenth mile downwind

from a cattle feedlot onto nearby produce. The high percentages of leafy greens contaminated with E. coli suggest great risk for planting fresh produce 180 m [590 feet] or less from a feedlot. That suggests that current buffer zone guidelines of 120 meters [400 feet] from a feedlot may be inadequate. In the study, the investigators sampled leafy greens growing in nine plots; three each at 60, 120, and 180 meters downwind from the cattle feedlot at the research center, over a two year period. The rate of contamination with the pathogenic E. coli O157:H7 declined with distance from an average of 3.5 percent of samples per plot at 60 meters to 1.8 percent at 180 meters. The researchers sampled the produce six times between June and September of each year. They also sampled the feedlot surface manure in 10 feedlot pens for E. coli O157:H7, finding it in an average of 71.7 to 73.3 percent of samples in 2012 and 2011, respectively. Moreover, the study's long-term nature enabled sampling under a greater diversity of weather conditions. A variety of conditions can affect the level of contamination. For example, following a period of high cattle management activity when the feedlot was dry and dusty, including removal of around 300 head of cattle for shipping, the rate of total non-pathogenic E. coli-contaminated samples per plot at 180 meters shot up to 92.2 percent. Conversely, total E. coli-positive leafy green samples were notably lower on one August sample date than on any other date, a finding the investigators attribute to cleaning and removal of feedlot surface manure from the nearby pens a few weeks earlier. The highest levels of contamination found on leafy greens, in August and September of 2012. Source: American Society for Microbiology December 2014

Trial confirms Ebola vaccine candidate safe, equally immunogenic in Africa

• Two experimental DNA vaccines to prevent Ebola virus and the closely related Marburg virus are safe, and generated a similar immune response in healthy Ugandan adults as reported in healthy US adults earlier this year. Scientists from the NIAID developed the DNA vaccines that code for Ebola virus proteins from the Zaire and Sudan strains and the Marburg virus protein.

• In this phase 1 trial, the Makerere University Walter Reed Program enrolled 108 healthy adults aged between 18 and 50 from Kampala, Uganda between November, 2009 and April, 2010. Each volunteer was randomly assigned to receive an intramuscular injection of either the Ebola vaccine (30 volunteers), Marburg vaccine (30), both vaccines (30), or placebo (18) at the start of the study, and again 4 weeks and 8 weeks later. The vaccines given separately and together were safe and stimulated an immune response in the form of neutralising antibodies and T-cells against the virus proteins. Four weeks after the third injection, just over half of the volunteers (57%; 17 of 30) had an antibody response to the Ebola Zaire protein as did 14 of 30 participants who received both the Ebola and Marburg vaccines. However, the antibodies were not long-lasting and returned to undetectable levels within 11 months of vaccination. Both DNA vaccines were well tolerated in Ugandan adults with similar numbers of local and systemic reactions reported in all groups. Only one serious adverse event (neutropenia; low white blood cell count) was reported in a Marburg vaccine only recipient, but was not thought to be vaccine related.

• Source: The Lancet, December 2014