ID Update

ID Update™: Sanford Guide News

  • ID Update™ is the Sanford Guide infectious diseases news page.
  • Each month, we summarize new or updated practice guidelines, recent clinical trials, new reviews, relevant drug safety notices, new drug approvals, new dosage forms, new treatment indications and other current developments.

JULY 2014

New HIV laboratory testing recommendations from CDC

  • The CDC has issued updated recommendations for laboratory testing for HIV infection. Testing begins with a combination immunoassay that detects HIV-1 and HIV-2 antibodies and HIV-1 p24 antigen; positive specimens undergo supplemental testing with an immunoassay that differentiates HIV-1 from HIV-2 antibodies. The new algorithm allows diagnosis up to 3-4 weeks earlier than the previously recommended sequence of tests using the Western blot.

Recent Literature

  • There were more cases of pertussis in the US in 2012 than in any year in the last half-century. Antibiotics are used mainly to prevent spread. The authors review advances in the epidemiology, diagnosis, treatment, and prevention of this ancient disease (Chest 146:205, 2014).
  • Human infection caused by Bartonella spp. (mainly B. henselae, B. quintana, and B. bacilliformis) presents a treatment challenge. Relapses occur frequently due to an intraerythrocytic phase that provides a protective niche for the microbe. This review summarizes recent data and treatment recommendations based on pathogenicity (Int J Antimicrob Agents 44:16, 2014).
  • Successful treatment of mold infection of the central nervous system involves early diagnosis, appropriate antifungal therapy, neurosurgical assessment and intervention, and management of host immunologic impairment. The epidemiology, microbiology, clinical manifestations, and therapy of infection caused by Aspergillus, Fusarium, Scedosporium, Mucorales, and dematiaceous fungi are reviewed (N Engl J Med 371:150, 2014).
  • Significant interpatient variability in voriconazole plasma concentrations results from genetic polymorphism of the major metabolizing enzyme CYP2C19 as well as nonlinear pharmacokinetics, drug interactions, and the effect of concomitant liver disease. Is it time for initial dose selection to be guided by CYP2C19 genotype? (Pharmacotherapy 34:703, 2014.)

JUNE 2014

All New App Versions Coming Summer 2014

  • All new versions of the Sanford Guide Apps are coming in summer 2014. The current app (Gold App icon) will be replaced* by three (3) separate apps: Sanford Guide to Antimicrobial Therapy ($29.99/yr), Sanford Guide to HIV/AIDS Therapy ($29.99/yr), and Sanford Guide to Hepatitis Therapy ($9.99/yr). *Existing subscriptions will receive content updates for the remainder of the subscription period.
  • The new Apps will feature Full Text Search, numerous user interface enhancements, faster launch and access to content and simplified purchase and account management. Content will be updated on the same schedule as the Web Edition. Subscriptions will be for one year.

Ebola outbreak, West Africa: update

  • The ongoing Ebola viral disease (EVD) outbreak in West Africa is now the largest outbreak ever documented. As of June 18 there have been 528 cases (laboratory-confirmed, probable, and suspected) and 337 deaths reported in Guinea, Liberia, and Sierra Leone. More information can be found on the CDC MMWR homepage.

New Drug Approvals

  • Efinaconazole (Jublia) 10% solution is the first triazole approved for the topical treatment of toenail onychomycosis due to T. rubrum and T. mentagrophytes.
  • Tedizolid (Sivextro), an oxazolidinone, has been approved for oral and IV treatment of skin and skin structure infections including those caused by MRSA. Its 12 hour elimination half-life allows for once-daily dosing.

Recent Literature

  • Published information on daptomycin bone penetration is scant. Limited data obtained from 16 patients undergoing knee or hip replacement suggest clinically useful penetration of bone and synovial fluid (Antimicrob Agents Chemother 58:3991, 2014).
  • Colistin and polymyxin B have essentially identical antibacterial spectra, with cross-resistance existing between the two drugs. However, polymyxin B has superior pharmacological properties. Nation, et al, summarize the key differences (Clin Infect Dis 59:88, 2014).
  • Dalbavancin and oritavancin are lipoglycopeptides with concentration-dependent killing and terminal half-lives >2 weeks, properties that allow for convenient dosing. In separate trials, dalbavancin administered in two weekly doses and oritavancin given as a single dose were non-inferior to twice-daily vancomycin for skin and skin structure infections (N Engl J Med 370:2169, 2014; N Engl J Med 370:2180, 2014; editorial: N Engl J Med 370:2238, 2014).

MAY 2014

CDC Health Advisory: MERS-CoV

  • CDC has confirmed the first US case of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection, identified in a traveler (details here). Clinicians should be vigilant for MERS-CoV in patients with respiratory disease returning from the Middle East.

New Drug Approval

  • Dalbavancin (Dalvance) has been approved for the treatment of adults with Gram-positive skin and skin structure infections, including MRSA.

Recent Literature

  • Macrolide antibiotics are known to cause ventricular arrhythmias by prolonging the QT interval. A review of recent literature suggests that the risk of arrhythmias in the absence of other risk factors is very low. Taking a thorough history and performing an EKG before and during therapy should allow for safe use of chronic macrolides in most patients for whom they are recommended (Am J Respir Crit Care Med 189:1174, 2014).
  • Published data assessing cross-reactivity between penicillins and cephalosporins for non-IgE-mediated hypersensitivity reactions (HSR) are scant. Retrospective data from an outpatient parenteral antimicrobial program suggest that cefazolin is well tolerated in patients who have experienced a non-IgE-mediated HSR to nafcillin (Antimicrob Agents Chemother 58:3137, 2014).
  • The pathogenesis, clinical manifestation, diagnosis, and treatment of antibiotic hypersensitivity reactions are reviewed, as well as basic principles of desensitization (Clin Infect Dis 58:1140, 2014).
  • Brazil will host the 2014 FIFA World Cup and the 2016 Olympic and Paralympic Games. Data (primarily about infectious diseases) collected from ill travelers returning from Brazil in 1997-2013 is presented to 1) assist clinicians who are advising prospective travelers to these events regarding pretravel preparation, and 2) help focus posttravel illness workup (Clin Infect Dis 58:1347, 2014).

Updated Practice Guidelines

  • The DHHS Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents have been updated and are available at the AIDSinfo clinical guidelines portal.

APRIL 2014

Ebola outbreak, West Africa

  • There is currently an outbreak of Ebola viral disease in Guinea and Liberia. A summary of the situation from the US CDC can be found here. Advice for travelers from the European CDC can be found here.

Updated Practice Guidelines

Hepatitis C News

  • Three large trials (ION-1, ION-2, ION-3) of a ledipasvir/sofosbuvir fixed dose combination tablet, with or without ribavirin, for chronic hepatitis C (genotype 1) have been published in the New England Journal of Medicine. Sofosbuvir, a nucleotide analog inhibitor of the HCV NS5B RNA polymerase, was FDA-approved late last year. Approval of the combination of sofosbuvir plus ledipasvir, a potent HCV NS5A inhibitor, is expected by fall (ION-2: N Engl J Med 370:1483, 2014; ION-1 and ION-3 are published online).

Other Recent Literature

  • Drawz et al review recent advances in beta-lactamase inhibitors including avibactam and MK-7655 (effective against ESBLs, AmpC, and KPC enzymes). Avibactam will likely be the first inhibitor introduced in the US since piperacillin-tazobactam in 1993 (Antimicrob Agents Chemother 58:1835, 2014).
  • Current literature supports an association between voriconazole exposure and cutaneous squamous cell carcinoma in lung transplant recipients. The mechanism is unestablished but may involve the drug's primary metabolite, voriconazole N-oxide (Clin Infect Dis 58:997, 2014).
  • The incidence of skin abscesses has increased, and MRSA is a dominant cause. Management of abscesses is reviewed (N Engl J Med 370:1039, 2014).

New Drug Approvals

  • Miltefosine (Impavido) has been approved for treatment of visceral, cutaneous, and mucosal leishmaniasis in patients ≥12 years of age.

New Dosage Forms

  • Metronidazole 1.3% vaginal gel is a new single-dose option for bacterial vaginosis (BV). Metronidazole 0.75% gel, one applicator-full at bedtime x 5 days, has been the CDC recommendation for topical treatment of BV.
  • Posaconazole, previously marketed as delayed-release tablets and oral suspension, is now available in an intravenous formulation (300 mg/vial). The approved indication is prophylaxis of invasive Aspergillus and Candida infections, and the dose is 300 mg IV bid on day 1, then 300 mg IV qd.