What’s New in ID? April 2019 / Travanj 2019.

Novel tetracyclines for drug-resistant organisms

Two novel tetracyclines are promising options for treatment of certain drug-resistant organisms in adults. Eravacycline, an intravenous agent, resulted in similar clinical cure rates as carbapenems for complicated intra-abdominal infections, even among patients with infections caused by extended-spectrum beta-lactamase-producing organisms. Omadacycline, available orally and intravenously, was as effective as linezolid for bacterial skin and skin structure infections, including those caused by methicillin-resistant Staphylococcus aureus; it can also be used for the treatment of community-acquired pneumonia. Both are approved by the Food and Drug Administration in the United States; eravacycline is also approved by the European Medicines Agency. Contraindications and adverse reactions are similar to the tetracycline class of antimicrobials.

Solomkin J, Evans D, Slepavicius A, et al. Assessing the Efficacy and Safety of Eravacycline vs Ertapenem in Complicated Intra-abdominal Infections in the Investigating Gram-Negative Infections Treated With Eravacycline (IGNITE 1) Trial: A Randomized Clinical Trial. JAMA Surg 2017; 152:224.

Newman J, Izmailyan S, Fyfe C, Tsai, L. Microbiological Efficacy of Eravacycline against Enterobacteriaceae And Acinetobacter, Including Mdr Isolates: A Pooled Analysis from Ignite1 and Ignite4, Two Phase 3 Trials of Complicated Intra-Abdominal Infection. Presented at ASM Microbe 2018, June 7-11 2018, Atlanta GA.

O’Riordan W, Green S, Overcash JS, et al. Omadacycline for Acute Bacterial Skin and Skin-Structure Infections. N Engl J Med 2019; 380:528.

Stets R, Popescu M, Gonong JR, et al. Omadacycline for Community-Acquired Bacterial Pneumonia. N Engl J Med 2019; 380:517.

Primary prophylaxis against Mycobacterium avium complex not required in most patients with HIV

In patients with HIV and a CD4 count <50 cells/microL, antimicrobial prophylaxis to prevent Mycobacterium avium complex (MAC) was common before the introduction of potent antiretroviral therapy (ART). However, the risk of MAC infection appears to be low in patients receiving potent ART, and observational data do not support a clear benefit from prophylaxis in this setting. This approach is consistent with updated recommendations from the International Antiviral Society-USA (IAS-USA) panel and the United States Department of Health and Human Services.

Panel on Opportunistic Infections in HIV-Infected Adults and Adolescents. Guidelines for the prevention and treatment of opportunistic infections in HIV-infected adults and adolescents: Recommendations from the Centers for Disease Control and Prevention, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. http://aidsinfo.nih.gov/contentfiles/lvguidelines/adult_oi.pdf (Accessed on February 15, 2019).

Targeted MRSA decolonization at time of hospital discharge

Colonization with methicillin-resistant Staphylococcus aureus (MRSA) increases the risk of a subsequent MRSA infection, but whether targeted decolonization can durably reduce that risk has been uncertain. In a randomized trial including more than 2000 hospitalized patients with MRSA colonization or infection, education at the time of discharge plus decolonization (daily bathing or showering with chlorhexidine, chlorhexidine mouthwash, and nasal mupirocin for five days twice per month for six months) was associated with a 30 percent reduction in the rate of MRSA infection over the year following discharge compared with education alone; the number needed to treat to prevent one MRSA infection was 30. However, adherence to the six-month regimen outside the context of a clinical trial may be difficult; it is uncertain whether less intensive regimens would have comparable efficacy.

Huang SS, Singh R, McKinnell JA, et al. Decolonization to Reduce Postdischarge Infection Risk among MRSA Carriers. N Engl J Med 2019; 380:638.

Health advisory about H3N2 influenza A activity in the United States

In late March 2019, the Centers for Disease Control and Prevention (CDC) released a health advisory stating that influenza activity remains high in the United States, with an increasing proportion of influenza activity being due to the influenza A subtype, H3N2. The increase in influenza A H3N2 cases is important because this subtype has been associated with an increase in hospitalizations and deaths in patients ≥65 years of age. In addition, influenza vaccines are frequently less effective against influenza A H3N2 viruses than against influenza A H1N1 and influenza B viruses. Influenza should be considered as a possible diagnosis for patients with respiratory illness while local influenza activity remains elevated, with early empiric antiviral therapy for hospitalized and high-risk patients. Additional details can be found on the CDC’s website.

Centers for Disease Control and Prevention. Health Alert Network. Influenza season continues with an increase in influenza A(H3N2) activity. https://emergency.cdc.gov/han/han00419.asp

Source: Uptodate, 2019.