Updates

By Carol A. Kemper, MD, FACP, Clinical Associate Professor of Medicine, Stanford University, Division of Infectious Diseases; Santa Clara Valley Medical Center, Section Editor, Updates; Section Editor, HIV, is Associate Editor for Infectious Disease Alert.

Anthrax-laced Heroin

Source: A ProMED-mail post, January 6, 2010, www.promedmail.org

Eleven heroin users in Northern England and Scotland, as well as a possible twelfth, have been diagnosed with anthrax infection; five have died. Although details of the investigation are not yet forthcoming, the outbreak, thus far, points to contaminated heroin — or contamination of an agent used to cut heroin. Most of the heroin entering the United Kingdom originates in Afghanistan, where anthrax is endemic. If this is the case, then contamination of the original product with anthrax spores could result in a much wider outbreak. On the other hand, one of the more common agents used to cut heroin nowadays is bone meal. Since anthrax has not been reported in livestock within the United Kingdom for many years, this would also suggest that possible contamination of product occurred prior to entry into the U.K. market, potentially resulting in a larger number of cases.

Users have been warned to avoid heroin for the present, and anyone with swelling or infection at an injection site is urged to seek medical care. Physicians in the United Kingdom are on the alert for additional possible cases.

Supersize My Bugs

Source: White AS, et al. Beverages obtained from soda fountain machines in the U.S. contain microorganisms, including coliform bacteriaInt J Food Microbiol. 2009 (Epub ahead of print).

This engaging epidemiologic survey assessed microbial contamination of soda-fountain drinks, dispensed from nine different fountain machines, relative to current U.S. drinking water standards. Ninety drinks, including diet soda, regular soda, water, and ice were cultured. A follow-up survey examined the concentration of bacteria and other organisms found in an additional 27 drinks collected either in the morning or the afternoon. The beverages were self-dispensed or dispensed by a server.

Nearly half (48%) of the beverages contained coliforms, and one in ten had bacterial-colony counts > 500 colony-forming units per mL. The most common pathogen identified was Chryseobacterium meningosepticum, found in 17% of the beverages, followed by E. coli in 11%. Other microbes isolated included Klebsiella, Staphylococcus, Serratia, Stenotro-phomonas, and Candida spp. Ice alone did not exceed U.S. drinking water standards. No difference was observed in rates of bacterial contamination between self-dis-pensed drinks and those dispensed by a server, suggesting the machines are the source of the contamination.

Community-acquired ESBLs on the Rise

Source: Ben-Ami R, et al. A multinational survey of risk factors for infection with extended-spectrum beta-lactamase-producing Enterobacteriaceae in non-hospitalized patients. Clin Infect Dis. 2009,49:682-690.

At our local hospital and clinic facility, we've been seeing a number of cases of community-onset, ESBL-containing infections (mostly urinary), in younger persons, without apparent risk factors for resistant bacterial infection. Many of these patients have been in their 20s or 30s, several have been from India, and many were female and/or pregnant. There is a growing concern that as ESBLs diffuse into the general population, these highly-resistant infections will be occurring with greater frequency, even in persons with no apparent risk factors.

These authors assessed risk factors for infection with ESBL-containing Enterobacteriaceae in non-hospitalized patients based on a recent finding reported in epidemiologic surveys from six different centers in Europe, Asia, and North America. A total of 983 patient-specific Enterobacteriaceae isolates were included in the survey, 90.5% of which were E. coli, 6.9% Klebsiella spp, and 2.5% were Proteus mirabilitis; of these, 339 (34.5%) isolates contained ESBLs.

Despite the broad geographic diversity in the center populations, similar risk factors were observed between the centers. In univariate analysis, risk factors for community onset of ESBL-producing infection included multiple indicators of contact with the health care system, including hospitalization or surgery within the previous three months, residence in a long-term care facility, and bladder catheterization, as well use of antibiotics within the previous three months, presence of comorbidities (cardiovascular disease, renal disease, malignancy), and poor functional status. However, in multivariate analysis, five independent risk factors were identified, all of which were fairly consistent across the six centers, including male sex, older age (> 65 years), recent antibiotic use, recent hospitalization, and stay at a long-term care facility. The authors assert that this "multivariate risk model" provides a good predictive model for assessing risk in this group.

However, 221 of 339 patients (65%) infected with ESBL-producing organisms had no evidence of recent contact with the health care system. Compared with those patients described above, these patients were generally healthier and younger, and the above risk model was poorly predictive.

The source for most of the ESBL-containing isolates was urinary. About 60% of the ESBL-containing isolates contained CTX-M genes, which do not hydrolyze carbapenems, suggesting that molecular-based technologies (if affordable) may be used to more rapidly identify these isolates, facilitating infection control measures. Resistance to non-β-lactam agents was analyzed, and was fairly similar between the six centers. Rates of fluoroquinolone resistance were 17%-29% in all areas except Spain, where resistance to ciprofloxacin was found in two-thirds of isolates. Gentamicin resistance was high (~70%) in Tel Aviv, but lower in France (43%) and Canada (10%). Rates of resistance to trimethoprim-sulfamethoxazole were high (71-78%) in isolates from France, Tel Aviv, and Spain, but lower in Canada (36%). Isolates containing CTX-M genes were more likely to be resistant to fluoroquinolones.

Community-onset infection with ESBL-containing organisms appears to be increasing. Measures should be undertaken to identify non-healthcare facility sources for colonization and infection with these organisms.

Mandatory Influenza Vaccination of Health care Workers

By Stan Deresinski, MD, FACP

Source: Babcock HM et al. Mandatory Influenza vaccination of health care workers: Translating policy to practice. Clin Infect Dis. 2010 Jan 11. [Epub ahead of print]

In past years, the acceptance of personal seasonal influenza vaccination by health care workers (HCW) could only be described as pitiful, with fewer than one-half receiving the yearly vaccine. This represents a danger to the HCW and, more importantly, to the patients in their care, making it, as a result, ethically unacceptable. Vaccination rates for 2009-2010 are likely to be higher because of the wild-card introduction of pandemic influenza H1N1 2009.

One approach to dealing with the recalcitrance of some HCWs, which has been implemented in a limited number of institutions, is a policy of mandatory vaccination, as described by Babcock et al at BJC Healthcare. It includes, among other things, 11 acute-care hospitals, which has made annual influenza vaccination a condition of employment for all 26,000 employees, regardless of job function (non-employee physicians were excluded). This resulted in 98.4% of employees being vaccinated.

Religious exemptions were granted to 90 (0.3%), and medical exemptions (reviewed by occupational health nurses and their medical directors) were granted to 321 (1.2%). Requests for exemption often reflected misinformation regarding the vaccine and influenza and, in a number of cases, this misinformation came from employees' physicians.

It is likely that mandatory influenza vaccination will likely be adopted with increasing frequency in the future. Get ready for it!