The effect of influenza on hospitalizations, outpatient
visits, and courses of antibiotics in children.
Neuzil KM, Mellen BG, Wright PF, Mitchel EF Jr, Griffin MR.
Department of Medicine, University of Washington School of Medicine, Seattle,
USA. kneuzil@u.washington.edu
BACKGROUND: Despite high annual rates of influenza in children, influenza
vaccines are given to children infrequently. We measured the disease burden of
influenza in a large cohort of healthy children in the Tennessee Medicaid
program who were younger than 15 years of age. METHODS: We determined the rates
of hospitalization for acute cardiopulmonary conditions, outpatient visits, and
courses of antibiotics over a period of 19 consecutive years. Using the
differences in the rates of these events when influenzavirus was circulating and
the rates from November through April when there was no influenza in the
community, we calculated morbidity attributable to influenza. There was a total
of 2,035,143 person-years of observation. RESULTS: During periods when
influenzavirus was circulating, the average number of hospitalizations for
cardiopulmonary conditions in excess of the expected number was 104 per 10,000
children per year for children younger than 6 months of age, 50 per 10,000 per
year for those 6 months to less than 12 months, 19 per 10,000 per year for those
1 year to less than 3 years, 9 per 10,000 per year for those 3 years to less
than 5 years, and 4 per 10,000 per year for those 5 years to less than 15 years.
For every 100 children, an annual average of 6 to 15 outpatient visits and 3 to
9 courses of antibiotics were attributable to influenza. In winter, 10 to 30
percent of the excess number of courses of antibiotics occurred during periods
when influenzavirus was circulating. CONCLUSIONS: Healthy children younger than
one year of age are hospitalized for illness attributable to influenza at rates
similar to those for adults at high risk for influenza. The rate of
hospitalization decreases markedly with age. Influenza accounts for a
substantial number of outpatient visits and courses of antibiotics in children
of all ages.
Influenza and the rates of hospitalization for respiratory
disease among infants and young children.
Izurieta HS, Thompson WW, Kramarz P, Shay DK, Davis RL, DeStefano F, Black S,
Shinefield H, Fukuda K.
Division of Viral and Rickettsial Diseases, National Center for Infectious
Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
BACKGROUND: Young children may be at increased risk for serious complications
from influenzavirus infection. However, in population-based studies it has been
difficult to separate the effects of influenzavirus from those of respiratory
syncytial virus. Respiratory syncytial virus often circulates with
influenzaviruses and is the most frequent cause of hospitalization for lower
respiratory tract infections in infants and young children. We studied the rates
of hospitalization for acute respiratory-disease among infants and children
during periods when the circulation of influenzaviruses predominated over the
circulation of respiratory syncytial virus. METHODS: For each season from
October to May during the period from 1992 to 1997, we used local viral
surveillance data to define periods in Washington State and northern California
when the circulation of influenzaviruses predominated over that of respiratory
syncytial virus. We calculated the rates of hospitalization for acute
respiratory disease, excess rates attributable to influenzavirus, and
incidence-rate ratios for all infants and children younger than 18 years of age
who were enrolled in either the Kaiser Permanente Medical Care Program of
Northern California or the Group Health Cooperative of Puget Sound. RESULTS: The
rates of hospitalization for acute respiratory disease among children who did
not have conditions that put them at high risk for complications of influenza
(e.g., asthma, cardiovascular diseases, or premature birth) and who were younger
than two years of age were 231 per 100,000 person-months at Northern California
Kaiser sites (from 1993 to 1997) and 193 per 100,000 person-months at Group
Health Cooperative sites (from 1992 to 1997). These rates were approximately 12
times as high as the rates among children without high-risk conditions who were
5 to 17 years of age (19 per 100,000 person-months at Northern California Kaiser
sites and 16 per 100,000 person-months at Group Health Cooperative sites) and
approached the rates among children with chronic health conditions who were 5 to
17 years of age (386 per 100,000 person-months and 216 per 100,000
person-months, respectively). CONCLUSIONS: Infants and young children without
chronic or serious medical conditions are at increased risk for hospitalization
during influenza seasons. Routine influenza vaccination should be considered in
these children.
Is it time to give influenza vaccine to healthy infants?
McIntosh K, Lieu T.
From the article:
"Both studies, but particularly that
of Izurieta and colleagues, leave considerable uncertainty about whether
influenza is responsible for all, or even most, of the excess morbidity that is
attributed to it."
"To justify routine influenza
vaccination of infants and toddlers, however, the benefit-risk ratio would need
to be very high, given the relatively small proportion of cases of severe
respiratory illness that would be prevented, the probable need for more than one
does, the uncertainties and unpredictability of antigenic variability, and need
to immunize during a period when many other vaccines are given."
ALL INFORMATION, DATA, AND
MATERIAL CONTAINED, PRESENTED, OR PROVIDED HERE IS FOR GENERAL INFORMATION
PURPOSES ONLY AND IS NOT TO BE CONSTRUED AS REFLECTING THE KNOWLEDGE OR OPINIONS
OF THE PUBLISHER, AND IS NOT TO BE CONSTRUED OR INTENDED AS PROVIDING MEDICAL OR
LEGAL ADVICE. THE DECISION WHETHER OR NOT TO VACCINATE IS AN IMPORTANT AND
COMPLEX ISSUE AND SHOULD BE MADE BY YOU, AND YOU ALONE, IN CONSULTATION WITH
YOUR HEALTH CARE PROVIDER.
