Study: Kids, Underlying Conditions, And The 2009 Pandemic Flu

Credit CDC FluView

 

# 6522

 

The chart above illustrates the sharp rise in pediatric deaths from flu-related complications during the 2009-2010 H1N1 pandemic seasons in the United States.  As grim as this charts is, it probably doesn’t fully represent the burden the 2009 pandemic placed on the pediatric community.

 

In another chart, again from the CDC, we get an estimate of deaths related to the 2009 pandemic, broken down by age groups through April of 2010.

 

 

While just over 300 pediatric deaths were recorded during this time period, the CDC estimates that 4 times (n=1280) that many children likely died from flu-related illness in the United States.

 

Globally, the number was undoubtedly many times higher than that (see Lancet: Estimating Global 2009 Pandemic Mortality).

 

 

All of which serves as prelude to a new study that appears today in the journal  Pediatrics, that looks at 336 documented pH1N1-associated deaths, and finds a high number of kids with underlying neurologic conditions.

 

Two-thirds of all deaths in children under the age of 17 occurred in kids with at least 1 underlying medical condition (n=227), and just under half of all cases (n=146) involved neurological disorders, such as cerebral palsy, epilepsy, or intellectual disability.

 

 

Neurologic Disorders Among Pediatric Deaths Associated With the 2009 Pandemic Influenza

Lenee Blanton, MPH^a,Georgina Peacock, MD, MPH, FAAP^b, Chad Cox, MD, MPH^a, Michael Jhung, MD, MPH^a, Lyn Finelli, DrPH^a, and Cynthia Moore, MD, PhD^b

ABSTRACT (Excerpts)

RESULTS: Of 336 pH1N1-associated pediatric deaths with information on underlying conditions, 227 (68%) children had at least 1 underlying condition that conferred an increased risk of complications of influenza. Neurologic disorders were most frequently reported (146 of 227 [64%]), and, of those disorders, neurodevelopmental disorders such as cerebral palsy and intellectual disability were most common.

CONCLUSIONS: Neurologic disorders were reported in nearly two-thirds of pH1N1-associated pediatric deaths with an underlying medical condition. Because of the potential for severe outcomes, children with underlying neurologic disorders should receive influenza vaccine and be treated early and aggressively if they develop influenza-like illness.

 

According to a statement released last night by the CDC:

 

Of the children with neurologic disorders for whom information on vaccination status was available, only 21 (23 percent) had received the seasonal influenza vaccine and 2 (3 percent) were fully vaccinated for 2009 H1N1.

 

 

With September just around the corner, the annual push for flu vaccinations is upon us, and today’s study will hopefully help inspire parents to get all kids – regardless of underlying conditions - vaccinated against influenza.

 

While the effectiveness of flu vaccines vary from year-to-year, and indeed, from one person to the next, they remain the single most important preventative step you can take to avoid getting the flu each year.

 

Despite the hyperbolic anti-vaccine rhetoric often found on the Internet, the truth is, serious adverse reactions to the vaccine are exceedingly rare (see the CDC’s  Influenza Vaccine Safety).

 

With two new strains of seasonal flu expected to be in circulation this winter (Yamagata B, and the Victoria H3N2) – ones that will be covered by this year’s vaccine – getting the flu shot this year is doubly important.

 

CDC recommends that just about everyone aged 6 months and older get an annual influenza vaccination, and stresses their importance for those who are at greater risk of serious complications.

 

For more on vaccine safety and effectiveness, the CDC maintains extensive web pages, and resources, on seasonal flu vaccines, including:

 

What You Should Know for the 2012-2013 Influenza Season

 

Preventing Seasonal Flu With Vaccination

 

Children, the Flu, and the Flu Vaccine

Morbid Obesity And H1N1 Flu

 

 

# 4442

 

 

Very early on in the pandemic of 2009 it was suggested that obesity might be a risk factor for complications from the H1N1 virus.   This was based on anecdotal observations of ICU patients with flu related illness, many of whom were seriously overweight.

 

The earliest reference I can find in my blogging to an obesity connection was on May 25th (H1N1 Morbidity And Previously Existing Conditions), although the idea wasn’t fully fleshed out (sorry about that) until early July (see Obesity Seen As Major Risk Factor For Flu Complications).

 

Over the summer and fall we saw conflicting reports on the matter, with no firm conclusions.   

 

Until now. 

The CDC, following the publication of a study in PLoS One, has issued guidance on morbid obesity and influenza complications in the form of a Q&A page.   

 

First, the PLoS One research article,  then a few snippets from the CDC page.

 

 

 

Morbid Obesity as a Risk Factor for Hospitalization and Death Due to 2009 Pandemic Influenza A(H1N1) Disease

Morgan OW, Bramley A, Fowlkes A, Freedman DS, Taylor TH, et al. 2010 Morbid Obesity as a Risk Factor for Hospitalization and Death Due to 2009 Pandemic Influenza A(H1N1) Disease. PLoS ONE 5(3): e9694. doi:10.1371/journal.pone.0009694

Severe illness due to 2009 pandemic A(H1N1) infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1), independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP) to increase the risk of influenza-related complications.

 

<BIG SNIP>

Our findings support observations that morbid obesity may be associated with hospitalization and possibly death due to 2009 pandemic H1N1 infection. These complications could be prevented by early antiviral therapy and vaccination.

(Continue . . . )

 

 

The CDC’s  Q&A  Page is lengthy, so just a few excerpts.   Follow the link to read it in its entirety.  

 

2009 H1N1 Flu In The News

March 16, 2010 10:30 AM ET

Morbid Obesity as a Risk Factor for Hospitalization and Death due to 2009 H1N1

This document provides updated information on obesity and morbid obesity as risk factors for serious 2009 H1N1-related complications based on findings from recent studies.

How are obesity and morbid obesity defined?

Body mass index (BMI) is a measure of body fat based on height and weight. Obesity is defined as a BMI of greater than or equal to 30 kilos per meter squared and morbid obesity is defined as a BMI greater than or equal to 40 kilos per meter squared. Among Americans 20 years and older, 28% are obese and 5% are morbidly obese.

Have obesity or morbid obesity been considered risk factors for serious flu-related complications in the past?

The Advisory Committee on Immunization Practices considers that certain chronic health conditions place persons at higher risk of serious flu related complications, including asthma, diabetes and heart disease, and emphasizes the importance of vaccination in people with these health conditions. In the past, neither obesity or morbid obesity have been considered independent risk factors that would place people at higher risk for serious flu-related complications.

What has been learned from the 2009 H1N1 pandemic about obesity and risk of serious influenza disease death?

During the 2009 H1N1 pandemic, early reports from the United States and abroad suggested that obesity was more frequent among persons hospitalized with 2009 H1N1 disease or who died following 2009 H1N1 infection.

Since that time, a number of studies have suggested that many 2009 H1N1patients tend to be morbidly obese. The study “Morbid Obesity as a Risk Factor for hospitalization and Death due to 2009 Pandemic Influenza A (H1N1) Disease,” published in PLoS ONE, sought to determine whether or not obesity or morbid obesity were in fact independent risk factors for serious 2009 H1N1-related complications, including death.  This study found that morbidly obesity persons have a higher risk of hospitalization for 2009 H1N1 infection compared to persons with normal weight. Data from this study also suggest that the risk of death following H1N1 infection may be higher for morbidly obese individuals.

 

 

Other than losing weight, and living a generally more active lifestyle, the CDC’s main recommendation is to take advantage of the flu vaccination.   This year, and every year.

CDC Q&A On H1N1 And Underlying Conditions

 

 

# 4383

 

 

The CDC has maintained, and refined over time, a list of those underlying medical conditions they believe predispose some people to more serious complications from the H1N1 pandemic virus.  

 

Here is their list as of early December:

 

People at High Risk for Developing Flu-Related Complications

• Children younger than 5, but especially children younger than 2 years old
• Adults 65 years of age and older
• Pregnant women
• People who have medical conditions including:
  • Asthma
  • Neurological and neurodevelopmental conditions [including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy, epilepsy (seizure disorders), stroke, intellectual disability (mental retardation), moderate to severe developmental delay, muscular dystrophy, or spinal cord injury].
  • Chronic lung disease (such as chronic obstructive pulmonary disease [COPD] and cystic fibrosis
  • Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)
  • Blood disorders (such as sickle cell disease)
  • Endocrine disorders (such as diabetes mellitus)
  • Kidney disorders
  • Liver disorders
  • Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders)
  • Weakened immune system due to disease or medication (such as people with HIV or AIDs, or cancer, or those on chronic steroids)
  • People younger than 19 years of age who are receiving long-term aspirin therapy

 

Tuesday night the CDC posted an overview and Q&A on the most commonly seen underlying conditions in patients hospitalized from the H1N1 flu over the past 10 months.   

 

This  update reflects data gather from roughly 60 counties, and 13 metro areas around the country, and is covers the time span April 15, 2009 – February 16, 2010. I’ll not post the whole thing, since you can follow this link to read it in its entirety. 

 

Since very early in this pandemic it has been apparent that people with certain types of underlying conditions were being hospitalized with serious complications.    Pregnancy and Asthma were both identified very early as potential complicating factors.

 

According to EIP data collected from April 2009 to February 16, 2010, 85% of hospitalized adults and 58% of hospitalized children with 2009 H1N1 virus infections have had one or more medical conditions. 

 

The two charts below show the most commonly reported underlying conditions in adults and children.  For both cohorts, Asthma was the number one complicating factor, showing up in more than 30% of each group.

 

After that, developmental and neurological disorders weighed heavily among children, and chronic metabolic, cardiac, and pulmonary disorders impacted adults the greatest.

 

 

 

 

 

Other blogs that have dealt with this subject in the past few months include:

 

CMAJ: Asthma As A Pandemic Risk Factor In Children

Australian Study: H1N1 Hospitalized Patients

Study: H1N1 Hospitalization Profiles

Study: H1N1 A Threat To All Age Groups