Flu Scan for May 01, 2014

Flu vaccine and symptoms
;
Pandemrix-narcolepsy link
;
Flu hospitalizations
;
Flu B with strep A
;
H7N9 in China
;
H5N8 in South Korea

Study: Flu symptoms less severe in vaccinated elderly people

Health officials have been heard to say that even though influenza vaccine doesn't provide complete protection against flu, it may reduce symptoms if you do get sick. Now a study out of Wisconsin offers some evidence in support of that view.

In a 4-year-study reported in BMC Infectious Diseases, researchers found that elderly people who had received influenza vaccine but contracted flu anyway had less severe symptoms than did elderly flu patients who had not been vaccinated.

The team, led by Edward Belongia, MD, of the Marshfield Clinic as senior author, examined not only the effect of flu vaccination on flu severity but also whether flu was associated with more severe symptoms than other acute respiratory illnesses (ARIs).

From flu seasons 2007-08 through 2010-11, they prospectively enrolled patients with ARIs and tested them for flu using polymerase chain reaction. The patients were asked to rate each of eight symptoms on a scale of 0 to 3, yielding a severity score ranging from 1 to 24.

Of 2,374 patients enrolled, 324 tested positive for flu. The mean symptom severity score was 12.3 points, and the most common symptoms were cough (92%), fatigue (91%), and nasal congestion (84%), the report says.

For adults with flu, the association between influenza vaccination and symptom severity was affected by age: Among those 65 or older, symptom severity was 31% lower in those who were vaccinated than in those who were not vaccinated.

In the overall findings, flu was the strongest independent predictor of a higher severity score, with a mean increase of 1.7 points compared with those who tested negative (P < .001).

"Influenza is associated with more severe symptoms of acute respiratory illness," the authors conclude. "The association between influenza vaccination and reduced symptom severity in older adults should be confirmed and explored further in other populations and seasons."
May 1 BMC Infect Dis abstract

 

Report confirms Pandemrix link in Irish narcolepsy cases

Irish researchers today confirmed an increased risk of narcolepsy in Irish children and adolescents who received the Pandemrix 2009 H1N1 flu vaccine, adding to the list of European countries such as Sweden, Finland, England, France, and Norway that have reported similar findings.

The group reports its findings today in Eurosurveillance. Pandemrix, made by GlaxoSmithKline, contained the AS03 adjuvant.

The team conducted a retrospective population-based cohort study that included narcolepsy cases with onsets between Apr 1, 2009, and Dec 31, 2010. They looked at narcolepsy patients' medical records and obtained pandemic vaccination status from vaccine databases. Of 32 narcolepsy cases identified during that time period, 28 were in children and adolescents.

The narcolepsy incidence was 5.7 per 100,000 young people vaccinated with Pandemrix, versus 0.4 per 100,000 who weren't vaccinated. The authors said the narcolepsy risk was 13.9 fold higher in kids who received the pandemic vaccine, a significant increase. They noted that the finding is similar to that of a study in Finland, which found a 12.7-fold higher risk in those who got the pandemic vaccine.

The immunogenic mechanism of narcolepsy and how the vaccine might have contributed to it requires more study, the team said.

A recent study probing the relationship between narcolepsy and the vaccine suggested that an immune response to a protein on the 2009 H1N1 virus may play a role. Other possible causes that have been suggested include a genetic predisposition and manufacturing differences between Pandemrix and other similar vaccines.
May 1 Eurosurveill study
Dec 19, 2013, CIDRAP News item "Immune study yields clues in H1N1 vaccine-related narcolepsy"

 

Study finds differences in adult hospital cases of pandemic, seasonal flu

Compared with adults hospitalized with seasonal flu, those hospitalized with 2009 H1N1 infections were more likely to be younger and to have lower respiratory complications, shock or sepsis, or organ failure, according to a large study that explored the differences in impact between pandemic and seasonal flu.

The study, led by researchers from the US Centers for Disease Control and Prevention, included more than 9,000 adults whose hospitalization data were tracked through the Emerging Infections Program Influenza Surveillance Network from 2005 through 2010. Researchers published the findings yesterday in Clinical Infectious Diseases.

The median age for adults hospitalized with the 2009 H1N1 virus during the pandemic period was 47, versus 68 for those with seasonal flu, according to the study. Those hospitalized during the pandemic were only slightly less likely to have an underlying medical condition, but the profiles of chronic illness were different for the two types of flu.

For example, adults with severe 2009 H1N1 infections were more likely to have asthma or be pregnant, but less likely than their seasonal flu counterparts to have COPD or other chronic lung diseases, cardiovascular disease, or metabolic disease. Some of the less frequent complications in the pandemic patients were acute respiratory distress syndrome, acute heart failure, hemoptysis, and encephalopathy.

Adults with severe pandemic flu were more likely to require intensive care unit treatment or mechanical ventilation or to die during hospitalization.

The team concluded that though the 2009 pandemic is viewed as generally mild compared with other pandemics, many serious complications occurred in those with severe infections. They said the findings can help guide clinicians toward the most effective clinical management and help them know what to expect from the virus in the future.
Apr 29 Clin Infect Dis abstract

 

Tests in suspected hantavirus cluster reveal influenza B, strep A

Virginia health officials yesterday said lab tests in the wake of unexplained deaths of a Pulaski County woman and her teenage daughter were positive for influenza B and invasive Streptococcus group A, not hantavirus or other pathogens, according to a New River Health District (NRHD) statement e-mailed to journalists.

The illness also hospitalized three other family members and a close family contact, the Roanoke Times reported yesterday. The family and local officials originally suspected hantavirus, because the mother and daughter had cleaned out a mouse-infested trailer 2 weeks before they died.

Molly O'Dell, MD, director of the NRHD, said in the statement, "This type of co-infection is exceedingly rare, and it doesn't appear to pose a threat to the community at large." She said flu and strep are common illnesses that continue to circulate in the area this season.

Tests also ruled out Legionella and tularemia, according to the NRHD statement.

Some states on the East Coast have reported a late-season spike in influenza B infections, a pattern that isn't unusual. Invasive bacterial infections involving influenza B have been reported in the medical literature. For example, a case series of 19 strep A coinfections in southern England during the 2010-11 flu season included four that involved influenza B, three of which were fatal.
Apr 30 Times story
Feb 3, 2011, Eurosurveillance report

 

H7N9 sickens two more in China

Chinese media outlets, citing provincial officials, reported two new H7N9 influenza cases today, in a 74-year-old woman from Hunan province and a 23-year-old man from Jiangxi province. The reports in Chinese were translated and posted by FluTrackers, an infectious disease news message board.

Both patients are hospitalized, and the man is listed in stable condition. FluTrackers noted that official notices had not yet appeared on provincial health ministry Web sites. Once the notices are posted, the FluTrackers' outbreak count would rise to 435 cases, with 299 reported in the second wave of activity, compared to 136 in the first.

In other developments, the World Health Organization (WHO) today provided more details about three H7N9 reports it received from China on Apr 25 and 28. They include a 51-year-old man from Jiangsu province, a 75-year-old woman from Jiangxi province, and a 55-year-old man from Anhui province. All three are hospitalized, two of them in critical condition. Illness onset dates ranged from Apr 12 to 15.

Investigations revealed that two of the patients had been exposed to poultry before they got sick, but exposure history wasn't available for the third patient.
May 1 FluTrackers thread
May 1 WHO update

 

H5N8 outbreaks affect 100,000 more South Korean poultry

Officials yesterday confirmed three outbreaks of H5N8 avian flu in March and April that affected more than 100,000 domestic chickens and geese in central South Korea, according to a report filed with the World Organization for Animal Health (OIE).

In the first outbreak, in the southern region of Gyeonggi province, the virus killed 370 birds on a farm housing 30,000 breeding chickens. The remaining birds were destroyed to control the outbreak, which began on Mar 6.

The second outbreak began Mar 10 on a farm with 70,000 breeding chickens near Sejong city in North Chungcheong province. H5N8 killed 100 of the poultry, and the rest were culled to prevent disease spread.

In the third outbreak, which began on Apr 21, the virus killed 300 geese on a small farm in North Chungcheong province north of Sejong. The remaining 400 geese were culled.

All told, 770 poultry were killed by the virus and 99,930 were culled, for a total of 100,700 affected birds. The country has culled more than 10 million poultry because of H5N8 outbreaks this year.
Apr 30 OIE report

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