Friday, September 16, 2011

MMWR: Influenza-Associated Pediatric Deaths 2010-2011

 

 

# 5844

 

 

The CDC’s MMWR yesterday contained an in-depth look at 115 flu-related pediatric deaths over the past 12 months (Sept 2010-Aug 2011). Notification of pediatric flu-related deaths has been nationally required since 2004.

 

Case criteria is defined as: `death from a clinically compatible illness confirmed to be influenza by a diagnostic test in a U.S. resident aged <18 years, with no period of complete recovery between illness and death’.

 

Despite being a reportable event, the number of flu-related pediatric deaths is likely under stated since only those patients who are tested for influenza, test positive, and then are subsequently reported to the CDC are counted.

 

Since reporting became mandatory, yearly pediatric influenza deaths have ranged from a low of 46 during the 2005-2006 flu season to a high of 282 during the 2009—2010 pandemic.

 

Making this past year’s total of 115 a bit higher than we’ve generally seen in a non-pandemic year.

 

FIGURE 1. Number of influenza-associated pediatric deaths (N = 115), by week of death and type of influenza virus --- United States, September 1, 2010--August 31, 2011

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Despite surveillance numbers that showed that only 26% of the influenza viruses in circulation last year were influenza B, a disproportionately high 38% of these pediatric fatalities were attributed to the B virus.

 

Just under half (49%) of these pediatric deaths occurred in children who had no ACIP defined high risk medical conditions. These children also saw a shorter interval between illness onset and death (4 days versus 7 days), and were more likely to die at home or in the emergency department.

 

Statistics that reinforce the need for all parents to closely monitor their children when they have signs of influenza.  The CDC provides a parent’s guide with information on the danger signs in children, and advice on vaccination.

 

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Of the 57 cases that met at least one of ACIP’s high-risk definitions, the report lists: `31 (54%) had a neurologic disorder, 17 (30%) had pulmonary disease, 14 (25%) had a chromosomal abnormality or genetic disorder, 11 (19%) had congenital heart disease or other cardiac disease, and 11 (19%) had asthma or reactive airway disease. Obesity was reported in two (4%) of the 57 children’.

 

Vaccination coverage in this age cohort (6 mos – 17yrs) during the 2010-2011 flu season was estimated to be about 49%. 

 

Of the 74 children whose vaccination status could be established, only 23% had received influenza vaccine in at least 14 days before illness onset. Among children with at least one ACIP-defined high risk condition, 31% had been vaccinated.

 

Leading the authors to conclude:

 

These findings emphasize the need to improve vaccination coverage among all children, especially those at increased risk for influenza-related complications.

To protect infants aged <6 months who are too young to be vaccinated, ACIP recommends that pregnant women (3) and household contacts and out-of-home caregivers of such infants receive vaccination against influenza (1).

Because influenza vaccination of women during pregnancy has been shown to be effective in reducing hospitalizations (1) and deaths among infants aged <6 months (3), improving vaccination rates among pregnant women is a priority.

 

 

The complete and very detailed report may be viewed at:

 

Influenza-Associated Pediatric Deaths --- United States, September 2010--August 2011

Weekly

September 16, 2011 / 60(36);1233-1238

 

The editor’s summary states:

 

What is already known on this topic?

Since influenza-associated pediatric deaths became a nationally notifiable condition in 2004, the number of deaths reported to CDC has ranged from 46 during the 2005--06 influenza season to 282 during the 2009--10 season.

 

What is added by this report?

A total of 115 influenza-associated pediatric deaths were reported to CDC that occurred from September 1, 2010 to August 31, 2011. Fifty-six (49%) children who died from influenza virus infections during the 2010--11 influenza season had no reported Advisory Committee on Immunization Practices (ACIP)--defined high-risk medical conditions. Children without high-risk conditions had a shorter interval between illness onset and death (4 days versus 7 days), were more likely to die at home or in the emergency department, and were more likely to have a positive bacterial culture from a sterile site. Among children who died from influenza, few (23%) were vaccinated, and 50% received antiviral therapy.

 

What are the implications for public health practice?

Continued efforts are needed to ensure annual influenza vaccination in all persons aged ≥6 months, and children with high-risk medical conditions should be specially targeted for vaccination. Health-care providers should be aware that severe complications of influenza can occur in children without high-risk medical conditions. Early and aggressive treatment with oseltamivir or zanamivir is recommended as soon as possible after symptom onset in patients with confirmed or suspected influenza who are hospitalized; who have severe, complicated, or progressive illness; or who are at a higher risk for influenza complications.