News Scan for Mar 30, 2020

News brief

Review supports oral step-down antibiotics for heart infections

A review of published research going back nearly 70 years suggests oral antibiotic step-down therapy is at least as effective as intravenous (IV)-only antibiotics for treating infective endocarditis (IE), US researchers reported today in JAMA Internal Medicine.

The review identified 21 observational or quasi-experimental studies and three randomized controlled trials (RCTs) that focused on the effectiveness of antibiotics administered orally for part of the therapeutic course in patients with IE. None of the observational studies found oral step-down therapy to be inferior to IV-only therapy, with patients on oral step-down therapy achieving cure rates of 77% to 100%. Three observational studies in particular found that patients treated with oral step-down therapy had lower mortality rates than those treated with IV-only therapy.

Results were similar in the three RCTs, which showed that oral step-down therapy was at least as effective as IV-only therapy in left-sided, right-sided, and prosthetic valve IE. The largest of the three trials found that, after 3.5 years of follow up, rates of treatment failure (26% vs 38%; hazard ratio [HR], 0.64; 95% confidence interval [CI], 0.45 to 0.91) and mortality (16% vs 27%; HR, 0.57; 95% CI, 0.37 to 0.87) were significantly lower in patients who received oral step-down antibiotics compared with those received IV-only therapy.

The authors say the findings challenge the long-held dogma that treatment of IE requires IV antibiotic strategies and indicate that oral step-down therapy should be incorporated into clinical practice, especially since prolonged IV therapy is associated with higher risk of adverse events.

"Oral antibiotic step-down therapy is intrinsically safer than prolonged intravenous therapy owing to the elimination of the risk of complications from the indwelling line," they write. "Thus, absent any data suggesting the superiority of intravenous therapy, any meaningful data supporting the efficacy of modern oral antibiotic therapy for IE creates equipoise, which allows for a reasonable consideration of oral therapy for this disease in well-selected patients."
Mar 30 JAMA Intern Med abstract


Study finds high carriage of MDR bacteria in Ghanaian infants

A study of two neonatal intensive care units (NICUs) in Ghana found that half of the newborn babies screened were carrying multidrug-resistant gram-negative (MDR GN) bacteria, researchers reported last week in Open Forum Infectious Diseases.

As part of an ongoing study of infection control interventions against neonatal sepsis and MDR GN carriage, a team of researchers from Ghana, Sweden, and Denmark conducted a cross-sectional study of two NICUs in Accra from September 2017 through January 2018. To determine the prevalence of MDR GN carriage, they cultured swabs collected from newborns and the hospital environment and performed antibiotic susceptibility testing. They also obtained blood cultures isolates from infants who had sepsis, and performed molecular analysis of those isolates, to determine the proportion and source of GN bloodstream infections (BSIs).

A total of 276 GN isolates were collected from 175 of 228 (76.8%) screened newborns. The three most common organisms isolated were Klebsiella spp. (41.7%, 115/276), Escherichia coli (26.4%, 73/276), and Enterobacter spp. (12.3%, 34/276). The carriage rate of MDR GN bacteria among screened neonates was 49.6% (113/228), while 46.1% (105/228) carried third-generation cephalosporin-resistant organisms. Among Klebsiella species, 75.6% (87/115) expressed extended-spectrum beta-lactamase (ESBL) enzymes and 15.6% (18/115) expressed carbapenemase enzymes. The carriage rate MDR GN bacteria increased with duration of hospitalization and was strongly associated with antibiotic use.

Overall, 7% (16/228) of the screened neonates developed GN BSIs, 13 of which were MDR. Whole-genome sequencing of isolates from two infants who had ESBL-producing K pneumoniae BSIs showed similarity between the carriage and the bloodstream isolates, and further analysis also found similarities with K pneumoniae isolates from the hospital environment.

The authors of the study say the findings highlight the need to improve antibiotic use and infection prevention and control practices in NICUs in low-resource settings.
Mar 28 Open Forum Infect Dis abstract


Avian flu outbreaks strike poultry in Vietnam and Taiwan

Animal health officials in Vietnam reported five more highly pathogenic H5N6 avian flu outbreaks in poultry, according to a Mar 28 notification from the World Organization for Animal Health (OIE).

The outbreaks began from Feb 2 to Feb 25, affecting village birds in separate locations in two provinces, Ha Noi and Tranh Hoa, both located in the north. Taken together, the virus killed 465 of 4,753 susceptible birds. The remaining ones were culled as part of the outbreak response.

Earlier this year, the country reported several other similar outbreaks, including in Ha Noi and Tranh Hoa. H5N6 is one of the avian flu strains known to infect people. Though poultry outbreaks have been reported in a handful of Asian countries, China is the only country to report human cases.
Mar 28 OIE report on H5N6 in Vietnam

Elsewhere, Taiwan reported two more highly pathogenic H5N2 outbreaks, part of activity involving the strain that has been under way there since 2015.

The latest events both occurred in Yunlin County and began on Mar 5 and Mar 8, one at a facility housing native chickens and the other housing turkeys. Between the two events, the virus killed 1,819 of 9,578 birds. Authorities destroyed the surviving birds to help contain the outbreaks.
Mar 27 OIE report on H5N2 in Taiwan

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