In this feature, a panel of IDSA members identifies and critiques important new studies in the current literature that have a significant impact on the practice of infectious diseases medicine.
Click here for the previous edition of Journal Club. For a review of other recent research in the infectious diseases literature, see “In the Literature,” by Stanley Deresinski, MD, in each issue of Clinical Infectious Diseases.
Protease Inhibitor Therapy for Chronic HCV Infection
Reviewed by Jason Weinberg, MD
Chronic hepatitis C virus (HCV) infection is common worldwide, but outcomes are unsatisfactory with the current standard therapy of peginterferon and ribavirin. The addition of boceprevir, an HCV-specific protease inhibitor, was associated with improved sustained virologic response in two studies in the March 31 edition of The New England Journal of Medicine.
The first study examined the safety and efficacy of boceprevir when used in conjunction with peginterferon and ribavirin for patients with untreated chronic HCV infection. Following a four-week lead-in period in which all patients were treated with peginterferon and ribavirin, patients treated with 44 weeks of triple therapy had a significantly better rate of sustained virologic response (66 percent) than did patients treated with only peginterferon and ribavirin (38 percent). A similar rate of sustained virologic response (63 percent) was seen in a third group that received 24 weeks of triple therapy, after which all treatment was discontinued if HCV RNA was undetectable at weeks eight through 24 (response-guided therapy). A poor initial response to the four-week peginterferon-ribavirin lead-in period was associated with lower rates of sustained virologic response and higher rates of boceprevir resistance.
The second study describes the results of a trial with a similar design, using boceprevir in patients who previously failed standard therapy for chronic HCV infection. Boceprevir again improved outcomes, with overall sustained virologic response in 66 percent of patients receiving 44 weeks of triple therapy and 59 percent of patients receiving response-guided therapy compared to 21 percent of patients receiving 44 weeks of standard therapy. This benefit was seen in both patients who had not responded to previous therapy and patients who had had a relapse after previous therapy. Rates of sustained virologic response were again lower in patients who had a minimal response to a four-week peginterferon-ribavirin lead-in period, although boceprevir still provided some benefit.
In both studies, anemia was more common in patients receiving boceprevir, sometimes prompting dose reductions and the use of transfusions and erythropoietin in boceprevir recipients. It is also important to note that boceprevir is active only active against HCV genotype 1, limiting its usefulness to patients infected with that genotype. Despite caveats such as these, boceprevir and telaprevir, a similar HCV-specific protease inhibitor that has also been used in recent clinical trials, appear to provide welcome additions to otherwise limited treatment options for chronic HCV infection.
(Poordad et al. New Engl J Med. 2011;364:1195-206 and Bacon et al. New Engl J Med. 2011; 364:1207-17.)
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Bacterial Contamination of Physician Uniforms vs. Infrequently Washed White Coats
Reviewed by George R. Thompson III, MD
In recent years, British health officials have mandated that health care workers abandon their traditional white coats in favor of daily laundered short-sleeve uniforms. Although well intentioned, this attempt to reduce bacterial contamination of health care worker clothing has been based on supposition alone. A prospective, randomized controlled trial published in the April issue of the Journal of Hospital Medicine compared the extent of bacterial contamination of physicians’ white coats with that of newly laundered standardized short-sleeved uniforms.
One hundred physicians were randomized to the white coat group or the physician uniform group. Cultures were obtained using an imprint method of each participants’ breast pocket, sleeve cuff (long-sleeved for white coats, short-sleeved for uniforms) and from the volar surface of the wrist eight hours after beginning the workday. A subset additionally had cultures obtained two-and-a-half, five, and eight hours after they donned the uniforms.
No differences were found between total colony counts or the rate of methicillin-resistant Staphylococcus aureus (MRSA) positivity in cultures obtained from white coats versus newly laundered uniforms at eight hours. Additionally, despite the newly laundered uniforms demonstrating near sterility at the time they were put on, by two-and-a-half-hours hours, 50 percent of the total colonies counted at eight hours were already present.
Although this study evaluated only total colony counts and the presence of MRSA, and did not include an assessment of Gram-negatives or other drug-resistant pathogens, it cautions against hospital policy changes in the absence of supportive data. In fact the authors suggest that work clothes would have to be changed every few hours if the intent were solely to reduce bacterial contamination. Their data does not support discarding long-sleeved white coats for short-sleeve uniforms changed on a daily basis.
(Burden et al. J Hosp Med. 2011;6:177-182.)
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Alcohol Prep Pads Contaminated with Bacillus
Reviewed by Kathryn E. Stephenson, MD, MPH
The Centers for Disease Control and Prevention (CDC) reported in March that two cases of Bacillus cereus bacteremia and sepsis in children in Colorado in 2010 were most likely due to the use of contaminated alcohol prep pads during the insertion of vascular catheters.
An investigation of the two cases revealed that 40 out of 60 alcohol prep pads sampled at a Colorado children’s hospital yielded B. cereus or Bacillus spp., and that the pads were not labeled as either sterile or nonsterile on the outside of the package. The pads were supplied by a single manufacturer that subsequently recalled the product in January 2011 because of potential contamination.
It is important to be aware that not all alcohol prep pads are sterile, and that B. cereus group and Bacillus species are resistant to killing by alcohol. Contamination of the pads with Bacillus spp. can lead to health-care associated outbreaks of invasive disease as well as pseudoinfections from contaminated tissue samples. As a result of the investigation, the Food and Drug Administration warned health care providers in a news release that nonsterile alcohol prep pads should not be used to prepare the skin of patients for surgery or for sterile procedures, including catheter insertion. In addition, FDA advised that nonsterile pads not be used on patients with a depressed immune system. CDC also recommended that manufacturers do a better job of labeling their products sterile or nonsterile to avoid misuse by health care facilities and providers.
(Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report. March 25, 2011:60(11):347.)
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Update on Tuberculosis in the United States
Reviewed by Jonathan Li, MD
While tuberculosis (TB) continues to be one of the leading causes of death worldwide from an infectious disease, the rates of new TB cases continue to decline in the United States. A report from the Centers for Disease Control and Prevention (CDC), published in the March 25 issue of the Morbidity and Mortality Weekly Report, provides the latest update.
In 2010, 11,181 TB cases were reported in the U.S., an incidence of 3.6 cases per 100,000 people (compared to a rate of 340 per 100,000 people in Africa). Of these cases, 40 percent were born in the U.S., a 3.7 percent decrease compared to 2009 and a 75 percent decrease compared to 1993. The 6,707 TB cases (60 percent) from foreign-born individuals represent a 4 percent decrease since 2009 and a 47 percent decrease since 1993. In 2010, four countries accounted for half of all TB cases from foreign-born individuals: Mexico (23 percent), the Philippines (11 percent), India (9 percent), and Vietnam (8 percent). In 2010, Hispanics accounted for more TB cases than any other ethnic group, but Asians had the highest TB case rate (22.5 per 100,000 persons).
A total of 113 cases of multidrug-resistant TB (1.3 percent) were identified that were resistant to at least isoniazid and rifampin (compared to a 3.6 percent rate globally in 2008). Only one case of extensively drug-resistant (XDR) TB was reported in the U.S. in 2010. (XDR TB is defined as resistance to isoniazid, rifampin, fluoroquinolone, and at least one second-line injectable drug.) Based on the latest data from 2007, 94 percent of those who started treatment eventually completed treatment.
This CDC update highlights the progress that has been made in the control of the TB epidemic in the United States. However, further progress will be hindered by the headwind of a persistent worldwide epidemic, which will likely lead to a growing gap in the rates of TB incidence between U.S.-born and foreign-born individuals.
(Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report. March 25, 2011 / 60(11);333-337.)
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For a review of other recent research in the infectious diseases literature, see “In the Literature,” by Stanley Deresinski, MD, in each issue of Clinical Infectious Diseases:
- Antibiotic Resistance and Bacterial Altruism
- The Viral Portion of Our Microbiome: The Gastrointestinal Virome
- Persisting Alteration of Gastrointestinal Bacterial Flora
- CRP, ESR, or both?
- Intracellular Pathogens are not Protected from Antibody
- Anaplasma and Ixodes: Keeping warm with Snuggling and Antifreeze
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