Study shows benefit of antivirals for hospital flu in elderly

Treatment with antiviral drugs early in the course of hospitalization for influenza in elderly patients is associated with a shorter hospital stay and a lower risk for extended care after discharge, according to a study yesterday in Clinical Infectious Diseases.

US researchers, including those from the Centers for Disease Control and Prevention (CDC), studied 6,593 adults 65 years and older who were hospitalized for flu and not from nursing homes; 18% required extended care after discharge.

Antiviral treatment within 4 days of illness onset was associated with a shorter hospital stay for those hospitalized 2 days or less after illness onset (adjusted hazard ratio [aHR], 1.81) and for those hospitalized more than 2 days after illness onset (aHR, 1.30).

Early antiviral treatment was also associated with patients being 25% to 60% less likely to need extended care after leaving the hospital.

"Flu can be extremely serious in older people, leading to hospitalization and in some cases long-term disability. This important study shows that people 65 and older should seek medical care early when they develop flu symptoms," said Dan Jernigan, MD, MPH, director of CDC's Influenza Division, in a CDC press release.
Sep 2 Clin Infect Dis study
Sep 2 CDC press release

Ivory Coast and Nigeria report more H5N1 in poultry

Veterinary officials in Ivory Coast and Nigeria are reporting several more H5N1 avian flu outbreaks at sites ranging from backyard holdings to commercial farms, according to separate reports from the World Organization for Animal Health (OIE).

Ivory Coast reported six new outbreaks, three in Bouake state that occurred in April and May and three in Abidjan state that began in August. Affected birds included backyard chickens, doves, ducks, and pigeons. Of 7,428 susceptible birds, the virus killed 4,001, and the remaining ones were stamped out.

Meanwhile, Nigeria reported five more outbreaks, mainly at farms, in two different states—Lagos, on the southwestern coast, and Delta, in the south central part of the country.

The outbreaks began between the middle and end of August, affecting layers and pullets. Of 5,913 vulnerable poultry, 1,056 deaths were reported. The survivors were culled to curb the spread of the virus.

The two countries are among a handful in Africa that have reported a reemergence of H5N1 in poultry after a several-year hiatus.
Sep 1 OIE report on Ivory Coast outbreaks
Sep 3 OIE report on Nigeria outbreaks

Experts devise potential high-yield flu vaccine approach

An international group led by scientists at the University of Wisconsin has developed a cell-culture–based method that could result in influenza vaccine yields double or higher the output seen with current vaccines, according to a study yesterday in Nature Communications.

The group screened libraries of mutated influenza A viruses to develop vaccine "backbones"—the six viral RNA segments that don't include hemagglutinin and neuraminidase. From that process they were able to develop a backbone that improved the immune response (measure in titers) of H1N1, H3N2, H5N1, and H7N9 vaccine viruses in African green monkey kidney cells and Madin-Darby canine kidney cells.

Technology to produce flu vaccines using mammalian cell cultures already exists, but in its current form is less efficient than making vaccines in eggs, according to a University of Wisconsin news release. Antigenic changes in vaccine virus grown in eggs was cited as one of the reasons for reduced effective of some vaccines made for the 2014-2015 flu season.

"Depending on the strain, we can get between a twofold and tenfold increase in production using mammalian cells," said Wisconsin's Yoshihiro Kawaoka, DVM, PhD. "Even a twofold increase is substantial for vaccine production."

The release noted that the technique was developed using a type of research that has now been paused by the federal government, which is devising regulations for how certain "dual-use research of concern" (DURC) can be safely undertaken. DURC involves studies that manipulate pathogens and can be used for either good or bad ends.
Sep 2 Nat Commun study
Sep 2 University of Wisconsin news release