Flu Scan for Oct 25, 2013

News brief

CDC: Flu vaccine uptake increased in recent years

The US Centers for Disease Control and Prevention (CDC) today published a broad look at flu vaccine coverage patterns over five recent seasons—based on an analysis of eight different surveillance tools—that showed significant gains in both kids and adults. Coverage levels for all age and risk groups, however, are well below the Healthy People (HP) 2020 goal of 70% for children and adults and 90% for healthcare providers.

According to the report, the tools the CDC uses to gauge flu vaccine uptake range from the National Health Interview Survey (NHIS), which is designed to track progress on HP 2020 goals, to Internet panel surveys. The analysis, in Morbidity and Mortality Weekly Report (MMWR), includes data from the 2007-08 to 2011-12 seasons.

For children, coverage rose significantly over the five seasons, from 31.1% in 2007-08 to 56.7% in 2011-12 as measured by NHIS

For adults, flu vaccine coverage remained low but increased slightly, from 33.0% in 2007-08 to 38.3% in 2011-12 as measured by NHIS. Among adults, seniors had the highest vaccination levels—69.4% in 2011-12 according to NHIS data.

Coverage declined by age in kids but rose by age in adults. Coverage varied by state for both adults and children.

The investigators found that uptake in health providers is increasing but, at 62% in 2011-12, is still well below targets. Likewise, vaccination in pregnant women is on the rise, but only about half receive the flu shot.

The authors say that the results point to a need for more strategies to improve flu vaccine coverage, such as expanding the use of standing orders and increasing awareness in public health officials of the strengths and limitations of various methods used to gauge uptake.
Oct 25 MMWR report

Study: Uncommon H5N1 mutations may transmit in mammals

A study assessing H5N1 avian flu mutations as the virus spreads in ferrets found that mutations that were present in as few as 5.9% of the viruses infecting one ferret could be transmitted to another, according to data published this week in Nature Communications.

US and Japanese researchers, including Yoshihiro Kawaoka, DVM, PhD, of the University of Wisconsin, used data from transmission studies already conducted by Kawaoka in 2011 on engineered H5N1 strains. Publication of that controversial work was originally halted but later allowed by US biosecurity experts.

The team used deep sequencing to identify genetic mutations that happened as the virus replicated in and transmitted between ferrets. They found that during transmission natural selection acts strongly on hemagglutinin (HA), the protein the virus uses to attach to host cells.

They found that within-host genetic diversity in HA increases during replication but is dramatically reduced upon transmission via respiratory droplets—to only one or two distinct HA segments, a small portion of the viral genome.

However, the discovery that mutations present in only 5.9% of the viruses infecting one ferret could be transmitted to another suggests that even rare mutations could be transmitted if they have an evolutionary advantage, according to a Science Daily story on the study.

"Fully avian viruses may act differently in nature," said lead author Thomas Friedrich, PhD, from the University of Wisconsin. "But the data suggest to us that it wouldn't take many viruses from a chicken to infect a person, if the right mutations were there—even if they were a tiny minority of the overall virus population."
Oct 23 Nature Comm abstract
Oct 23 Science Daily story

H7N2 strikes another farm in New South Wales

An H7N2 strain of avian flu has killed 620 chickens on a farm in New South Wales, Australia, that houses 55,000 layer hens near where an outbreak occurred last week, according to a report today from the World Organization for Animal Health (OIE).

The farm listed in today's report was under surveillance because of the previous H7N2 outbreak, which the OIE confirmed on Oct 16. It houses caged layer hens 45 to 84 weeks old. Authorities will cull the remainder of the flock and disinfect the property to prevent further disease spread, the report said.

Last week's outbreak killed 18,000 of 435,000 chickens on a separate farm, and the remaining birds were subsequently culled, the OIE said.
Oct 25 OIE report
Oct 16 CIDRAP News Scan on previous outbreak

News Scan for Oct 25, 2013

News brief

FDA proposes FSMA rule on safety of animal food

The US Food and Drug Administration (FDA) today issued a proposed rule under the 2011 FDA Food Safety Modernization Act (FSMA) for improving the safety of food for animals. The proposed rule is open for public comment for 120 days, the agency said in a press release.

The rule would require producers of animal feed and pet food to develop formal plans and establish procedures to prevent foodborne illness in both animals and people. They would also need plans for correcting any problems that might arise.

"The proposed rule would also require animal food facilities to, for the first time, follow proposed current good manufacturing practices that address areas such as sanitation," the FDA said in the release.

"This proposed rule on animal food complements proposed rules published in January 2013 for produce safety and facilities that manufacture food for humans to set modern, prevention-based standards for food safety," said FDA Deputy Commissioner for Foods and Veterinary Medicine Michael R. Taylor, JD. "They also work in concert with standards proposed in July 2013 to help ensure that imported foods are as safe as those produced domestically."

The FDA will hold three public meetings on the rule:

Nov 21 at the FDA Center for Food Safety and Applied Nutrition, College Park, Md.
Nov 25 at the Ralph H. Metcalfe Federal Building, Chicago
Dec 6 at the John E. Moss Federal Building, Sacramento, Calif.

Oct 25 FDA press release

North Dakota warns of possible church hepatitis A exposure

A Catholic bishop in North Dakota who has hepatitis A may have inadvertently exposed hundreds of people to the virus at three masses and a priest convention in late September and early October, according to the North Dakota Department of Health (NDDH) and an Associated Press (AP) report.

The NDPH said in a statement yesterday that people who received communion at the four events in Fargo and Jamestown might have been exposed to the virus. The AP story said Bishop John Folda of the Diocese of Fargo, who attended the masses and convention, contracted hepatitis from contaminated food while attending a conference in Italy in September.

"The risk of people getting hepatitis A in this situation is low, but the Department of Health felt it was important for people to know about the possible exposure," NDDH Immunization Program Manager Molly Howell said in the statement. She said those who received communion at the events should be tested for hepatitis A only if they have symptoms.

A diocesan spokeswoman said Folda has been taking time off work since Oct 10 because of his illness and has improved greatly, according to the AP story.

The NDDH statement noted that hepatitis A is found in the stool of infected persons and can spread when people do not wash their hands thoroughly after using the toilet or changing a diaper or soiled sheets. An infected person is most likely to spread the virus during the first 2 weeks before symptoms begin, it said.
Oct 24 NDDH statement
Oct 25 AP story