Flu Scan for Oct 27, 2016

News brief

Swedish study finds good flu vaccine protection in older people

A "real-world" analysis of flu vaccine effectiveness (VE) today in Eurosurveillance that included 2 million Stockholm County, Sweden, residents each season found low flu VE in general but surprisingly robust results in two of the four seasons in adults 65 years and older who had chronic conditions.

The seasonal flu immunization program in Stockholm offers vaccination for free to people aged 65 and older, pregnant women, and anyone else with certain underlying risk factors like chronic disease. A total of 2 million to 2.2 million people were included per season from 2011-12 to 2014-15 so as to gauge VE in all people in the county who were hospitalized for influenza and pneumonia or had primary care flu cases. Flu was defined as a clinical diagnosis.

The number of patients diagnosed as having flu was highest in 2011-12 and in 2014-15, seasons dominated by the H3N2 strain, but hospitalization rates were about three times higher in 2014-15 than in 2011-12.

Protection against flu in all people studied was 19% in 2011-12, 40% in 2012-13, 37% in 2013-14, and 15% in 2014-15. For all people 65 and older it was 10%, 49%, 46%, and 18% for those seasons, respectively.

When the authors looked at only people who had chronic disease, they found that flu VE was 10%, 50%, 48%, and 15% for the four seasons, respectively, among all age-groups. For those 65 and older who had chronic conditions, the rates were 17%, 53%, 55%, and 18%. The flu VE rates below 18% were not significant.
Oct 27 Eurosurveill study

H5N8 found in Hungarian swan

A dead swan in Hungary has tested positive for H5N8, an avian flu that recently made headlines for shutting down an Indian zoo, according to the infectious disease blog Avian Flu Diary.

Hungary's Department of Animal Health and Animal Welfare reported yesterday that a dead swan in Csongrad County tested positive for the highly pathogenic avian flu strain, which has destroyed thousands of poultry worldwide in the last 2 years.

Waterfowl and migratory birds are at the greatest risk for H5N8, especially during the current fall migration season. Hungarian officials warned that European countries need to be on high alert for H5N8 in the coming weeks.
Oct 27 Avian Flu Diary post

Study: Poultry market intervention fails to deter H7N9 avian flu

A study today in Emerging Infectious Diseases shows that live-poultry market intervention failed to halt an H7N9 avian flu epidemic in Guangdong province, China.

Since March of 2013, H7N9 has caused four waves of human infections in China involving more than 800 cases and at least 320 deaths. One of the major risk factors for contracting the virus is exposure to live poultry or poultry environments. To stop disease spread, several markets were closed in epicenter cities during the outbreaks, and advanced surveillance measures were put into place.

In this retrospective study, researchers used epidemiologic and genomic data to analyze the second and third waves of human infection, to understand if heightened surveillance and poultry market control led to a disruption of the virus. They found no evidence it did, and instead concluded that "…the H7N9 circulating during the second wave probably persisted in targeted cities and/or their neighboring areas until the third epidemic wave."

Viral persistence, and not novel introduction of poultry strains, likely caused the continued epidemic in China, the authors said.
Oct 27 Emerg Infect Dis study

News Scan for Oct 27, 2016

News brief

Tortilla chips blamed for GI illness outbreak at Wyoming prison

In today's Morbidity and Mortality Weekly Report, the Centers for Disease Control and Prevention (CDC) and local health officials said rancid tortilla chips were to blame for an outbreak of gastrointestinal illness that sickened 79 workers and inmates at a correctional facility in Wyoming a year ago.

The patients fell ill 1 to 3 hours after eating lunch on Oct 11, 2015, and reported gas, bloating, and diarrhea (70% of patients) and vomiting (21%). Within 3 weeks of the outbreak, the Wyoming Department of Health and county health department conducted a case-control study to identify the outbreak source.

Epidemiologic investigation pointed to tortilla chips as the only food associated with the illness, and markers for rancidity (hexanal and peroxide) were found in the chips through composite food samples. There was no evidence of an infectious source or chemical agent. Very few case-control studies exist that prove that rancidity, caused by the decomposition of oils and fats, can lead to gastrointestinal illness.

"This outbreak serves as a reminder to consider alternative food testing methods during outbreaks of unusual gastrointestinal illness when typical foodborne pathogens are not identified," the authors said.
Oct 27 MMWR study

WHO: 1 million successfully treated for hepatitis C with new drugs

The World Health Organization (WHO) in a report today titled, Global Report on Access to Hepatitis C Treatment: Focus on Overcoming Barriers, said 1 million people in low and middle-income countries have been successfully treated for hepatitis C with a new class of drugs, direct-acting antivirals (DAAs).

When the drugs were introduced in 2013, many critics feared DAAs were too expensive for poorer countries, and would fail to reach the 80 million people who have chronic hepatitis C worldwide. Through cost-lowering strategies, such as competition from generic medicines through licensing agreements, local production, and price negotiations, the WHO said some member states were able to offer wider access to the drug.

Costs for the drug vary greatly: Some countries, such as Romania, price a 3-month course of DAAs at almost $80,000. But other countries, such as Egypt, used local production and dropped their cost from $900 in 2014 to less than $200 in 2016, the report said.

Hepatic C kills 700,000 people each year. DAAs have a cure rate of 95%, but their high costs have led to restricted use in even high-income countries. Earlier this year, the World Health Assembly said that its goal for viral hepatitis was to treat 80% of infected people by 2030.
Oct 27 WHO press release

C Diff DNA found on hospital surfaces during outbreak

In a study today in the American Journal of Infection Control, the authors found Clostridium difficile DNA on 71% of hospital surfaces during a C difficile outbreak, and on 28% of the surfaces 2 years after the outbreak ended.

The disease is easily spread in hospitals because its spores are resistant to most disinfectants. The bacteria can also live on inert surfaces and is one of the leading causes of diarrhea in elderly hospital patients.

From January through July 2009, a C difficile outbreak linked to a mortality rate of 11% occurred in a Costa Rican general hospital. Twenty-four surface samples were collected during the outbreak, with another 54 surface samples collected 2 years later. Overall, C difficile DNAwas detected in 40% of the 75 environmental samples, with a 2.5-fold increase during the outbreak.

About 67% of bedrails and walls were C difficile–positive during the outbreak.

"These results reinforce the relevance of strict hygiene procedures and cleaning measures in the control of C difficile infections in hospitals, even in the absence of outbreaks," the authors concluded.
Oct 27 Am J Infect Control study