Flu Scan for Mar 05, 2015

News brief

Using 3 years of data, CDC places annual flu deaths at 5,000 to 27,000

Using a new method to estimate influenza-related hospitalizations and deaths, the Centers for Disease Control and Prevention (CDC) calculates that somewhere between 5,000 and 27,000 Americans died of flu-related causes during each of the three flu seasons from 2010-11 through 2012-13.

Writing yesterday in PLoS One, the authors noted that flu-related hospitalizations and deaths are undercounted because some people who contract flu don't seek medical care or get tested. During the 2009 H1N1 flu pandemic, they said, the CDC developed a multiplier method to provide more timely estimates of flu hospitalizations and deaths than were possible with older methods.

The authors said they adapted this method for use during non-pandemic seasons, when flu awareness may be lower. Five sites in the CDC's Influenza Hospitalization Surveillance Network (FluSurv-NET) collected data on the frequency and sensitivity of flu testing over two seasons to estimate under-detection of cases.

Using population-based rates of flu-related hospitalizations and intensive care unit (ICU) admissions for 2010-13 from FluSurv-NET, the authors extrapolated them to the US population and corrected them for under-detection. Flu deaths were calculated using a ratio of deaths to hospitalizations.

The team estimated that annual hospitalizations for the three seasons ranged from 114,192 to 624,435, ICU admissions ranged from 18,491 to 95,390, and deaths ranged from 4,915 to 27,174. The burden fell mainly on elderly people, who accounted for 54% to 70% of hospital cases and 71% to 85% of deaths.

"After accounting for the under-detection of influenza, our estimates represented 2.0–5.6 times the level of influenza morbidity as reported by influenza hospitalization surveillance," depending on the age-group, with under-detection greatest in the elderly, the report says.

The authors say their estimates are similar to previous CDC estimates of 86,494 to 544,909 hospitalizations per year from 1979 to 2001 and 3,349 to 48,614 deaths per year from 1976 to 2007, which were based on models of excess flu-related morbidity and mortality.
Mar 4 PLoS One report
Aug 26, 2010, CIDRAP News story on earlier CDC estimates

Guillain-Barre syndrome linked to influenza illness

Being hospitalized for influenza and pneumonia (P&I) was associated with hospitalization for the neurologic disorder Guillain-Barre syndrome (GBS), but influenza vaccine was not, according to an ecological study that used nationally representative data and was reported yesterday in Vaccine.

CDC researchers analyzed monthly hospitalization data for GBS and P&I from 2000 through 2009, as well as data on seasonal flu vaccination coverage from the 2004-05 through 2008-09 seasons.

The authors determined GBS seasonality using Poisson regression and GBS and P&I temporal clusters using scan statistics. They examined the association between P&I and GBS hospitalizations in the same and the following month using negative binomial regression.

The investigators found that vaccine coverage increased from 19.7% to 35.5% in the study period, but GBS did not follow a similar pattern. They also noted a seasonal GBS pattern, with winter months having higher rates.

They found a significant correlation between monthly P&I and GBS hospitalizations that held true for the current month but not the following month. Monthly vaccine coverage, however, was not associated with GBS hospitalization in adjusted models.
Mar 4 Vaccine abstract

News Scan for Mar 05, 2015

News brief

Saudi Arabia reports 3 new MERS cases, 1 fatal

Saudi Arabia's Ministry of Health (MOH) today reported three new MERS-CoV cases in separate cities, one of which was fatal.

The newly reported fatality involved a 73-year-old Saudi man in Riyadh. Potential exposure to MERS-CoV (Middle East respiratory syndrome coronavirus) in a healthcare setting is under investigation. He had no recent contact with animals or with MERS cases in the community.

The second patient is a 30-year-old male expatriate in Unayzah, which lies northwest of Riyadh in Al-Qassim region. He is in critical condition. He reported no recent contact with another MERS patient, but possible animal contact is being investigated.

The third patient is a 44-year-old male expatriate in Shaqra, a town midway between Unayzah and Riyadh in Riyadh region. He had recent camel exposure but no contact with other MERS patients.

None of the three patients was a healthcare worker (HCW) or had preexisting disease.

The MOH also reported the recoveries of two expatriates in Riyadh, a 50-year-old male HCW and a 76-year-old woman. A 34-year-old male expatriate HCW in Buraydah also recovered from MERS-CoV, the MOH said.

The country has now confirmed 936 MERS cases, including 402 deaths. It noted that 507 patients have recovered, while 27 are still receiving treatment.
Mar 5 MOH update

University of Oregon infections trigger meningitis B campaign

A type B meningococcal disease outbreak at the University of Oregon that sickened four freshmen, one of them fatally, since the middle of January has prompted a mass vaccination campaign with the vaccine against the subtype, according to an update yesterday from the Oregon Health Authority (OHA).

The fatality occurred on Feb 17, and the Lane County Health Department has been identifying contacts to assess who should receive antibiotic prophylaxis.

The 4-day vaccination campaign started on Mar 2, targeting all undergraduates at the University of Oregon, Eugene, campus, graduate students who live on campus, and any students with certain high-risk medical conditions. Last week the university said more than 3,000 students had already been vaccinated.

For the campus campaign, students are receiving Trumenba, made by Wyeth, which targets Neisseria meningitides serogroup B. Trumenba is given in three doses, with the second 2 months later and the final dose 6 months later. The school will hold follow-up vaccination clinics in May and September.

As part of the campaign, the US Centers for Disease Control and Prevention (CDC) and the OHA will be asking students to voluntarily provide throat swabs as a measure to look for asymptomatic carriage.

The Oregon outbreak is the second to occur at a US college this year. In February officials at Providence College, based in Providence, R.I., said meningitis B infections hospitalized two students since Feb 1, triggering a vaccination campaign that began on Feb 8.

The Food and Drug Administration (FDA) recently approved two type B meningococcal vaccines, Trumenba in October and Bexsero, a Novartis product, on Jan 23. Approvals for both vaccines had been fast-tracked, because type B has become the most prevalent of the serogroups that can cause meningococcal disease in the United States. Federal officials cleared Bexsero for emergency use in two college outbreaks in 2013, one at Princeton University and the other at the University of California, Santa Barbara.

On Feb 26 the Advisory Committee on Immunization Practices (ACIP) of the CDC voted unanimously to recommend the type B vaccine to high-risk groups, such as those with low immunity and college students in outbreak settings.
Mar 4 OHA update
Feb 28 University of Oregon report
Feb 13 Providence College meningitis update
Feb 26 CIDRAP News scan "ACIP recommends meningitis B vaccine for high-risk groups"

Two more hospitals report scope-related 'superbug' infections

A second Los Angeles hospital and one in Hartford, Conn., reported drug-resistant "superbug" infections linked to contaminated duodenoscopes, Reuters reported yesterday.

Cedars-Sinai Medical Center in Los Angeles reported four infections with carbapenem-resistant Enterobacteriaceae (CRE) and said 67 more patients were at risk. Two weeks ago the UCLA Ronald Reagan Medical Center in Los Angeles reported seven CRE infections, two of them fatal, linked to the fiber-optic instrument.

A hospital in Hartford, meanwhile, reported at least five duodenoscope-linked infections involving drug-resistant Escherichia coli. A Hartford Courant story yesterday identified the hospital as Hartford Hospital and said officials were notifying 281 additional patients of possible exposure.

Rocco Orlando III, MD, chief medical officer of Hartford HealthCare, said that the endoscopies that led to potential exposures in the past several months are of a type reserved for very ill patients and were not general endoscopies, the Courant reported.

The FDA, meanwhile, updated its alert on the type of duodenoscopes involved in the outbreak.
Mar 4 Reuters report
Mar 4 Hartford Courant story
Mar 4 FDA updated alert