Study finds shifting disease burden following universal Hib vaccination

November 11, 2011

[EMBARGOED FOR NOV. 11, 2011] Vaccination against Haemophilus influenzae type b, or Hib, once the most common cause of bacterial meningitis in children, has dramatically reduced the incidence of Hib disease in young children over the past 20 years, according to a study published in Clinical Infectious Diseases and available online (http://www.oxfordjournals.com/our_journals/cid/prpaper1.pdf). However, other strains of the bacteria continue to cause substantial disease among the nation's youngest and oldest age groups.

"The Hib vaccine was successful in reducing disease among children 5 years and younger, and now the epidemiology has changed," said lead author Jessica MacNeil, MPH, of the Centers for Disease Control and Prevention, who, with colleagues, analyzed data for the current epidemiology and past trends in the invasive disease over the past two decades following the introduction of the Hib vaccine in the mid-1980s. Most H. influenzae disease in the United States is now caused by other, non-type b strains of the bacteria.

The study authors warn that the highest rates of disease from non-b type strains are in the oldest and youngest age groups, those 65 and older and infants less than a year old. Among children younger than 5 years old, young infants are the most likely to be diagnosed with the disease. Many of these cases occur during the first month of life, and among those, premature and low-birthweight babies are the most vulnerable.

The number of adults 65 and older who become ill due to H. influenzae is also high compared to the rest of the population, according to the study authors. Among those in this group who become sick, nearly 25 percent of the cases are fatal. Risk factors for this age group are harder to interpret, the authors note, as clinical outcomes may be due to underlying medical conditions.

American Indian and Alaska Native children continue to have a disproportionately large burden of both Hib and non-b type disease compared to others, the study found, but the reasons behind this are not fully understood. "Why these groups continue to be at a higher risk than other populations should be the focus of future studies," MacNeil said. Understanding risk factors for H. influenzae disease in this population, such as household crowding, poverty, and poor air quality, could potentially help prevent transmission.

The study authors found that no substantial serotype replacement has been observed among young children in the U.S., which suggests the current Hib vaccine has been effective in preventing H. influenzae illness in this age group. However, the authors note, the burden of disease seen in older adults is an opportunity that could be addressed in the future with an H. influenzae vaccine for adults.
-end-
NOTE: The study is available online. It is embargoed until 12:01 a.m. EST on Friday, Nov. 11, 2011. Current Epidemiology and Trends in Invasive Haemophilus influenzae Disease--United States, 1989 http://www.oxfordjournals.com/our_journals/cid/prpaper1.pdf

Clinical Infectious Diseases is a leading journal in the field of infectious disease with a broad international readership. The journal publishes articles on a variety of subjects of interest to practitioners and researchers. Topics range from clinical descriptions of infections, public health, microbiology, and immunology to the prevention of infection, the evaluation of current and novel treatments, and the promotion of optimal practices for diagnosis and treatment. The journal publishes original research, editorial commentaries, review articles, and practice guidelines and is among the most highly cited journals in the field of infectious diseases. Clinical Infectious Diseases is an official publication of the Infectious Diseases Society of America (IDSA). Based in Arlington, Va., IDSA is a professional society representing more than 9,000 physicians and scientists who specialize in infectious diseases. For more information, visit www.idsociety.org.

Infectious Diseases Society of America

Related Children Articles from Brightsurf:

Black and Hispanic children in the US have more severe eczema than white children
A presentation at this year's virtual American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting reveals the disparities that exist for Black and Hispanic children when it comes to Atopic Dermatitis (AD), commonly known as eczema.

Black children with cancer three times less likely to receive proton radiotherapy than White children
A retrospective analysis led by investigators from Brigham and Women's Hospital has found racial disparities in the use of the therapy for patients enrolled in trials.

The Lancet Child & Adolescent Health: First Europe-wide study of children confirms COVID-19 predominately causes mild disease in children and fatalities are very rare
Children with COVID-19 generally experience a mild disease and fatalities are very rare, according to a study of 582 patients from across Europe published today in The Lancet Child & Adolescent Health journal.

Children not immune to coronavirus; new study from pandemic epicenter describes severe COVID-19 response in children
- While most children infected with the novel coronavirus have mild symptoms, a subset requires hospitalization and a small number require intensive care.

How many children is enough?
Most Russians would like to have two children: a boy and a girl.

Preterm children have similar temperament to children who were institutionally deprived
A child's temperament is affected by the early stages of their life.

Only-children more likely to be obese than children with siblings
Families with multiple children tend to make more healthy eating decisions than families with a single child.

Children living in countryside outperform children living in metropolitan area in motor skills
Residential density is related to children's motor skills, engagement in outdoor play and organised sports. that Finnish children living in the countryside spent more time outdoors and had better motor skills than their age peers in the metropolitan area.

Hispanic and black children more likely to miss school due to eczema than white children
In a study that highlights racial disparities in the everyday impact of eczema, new research shows Hispanic and black children are more likely than white children to miss school due to the chronic skin disease.

Children, their parents, and health professionals often underestimate children's higher weight status
More than half of parents underestimated their children's classification as overweight or obese -- children themselves and health professionals also share this misperception, according to new research being presented at this year's European Congress on Obesity (ECO) in Glasgow, UK (April 28-May 1).

Read More: Children News and Children Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.