Release: May 12, 2000
Contact: Kenneth Satterfield, 407-238-4161 (as of 5/12/2000)
Recurrent Acute Otitis Media in Infants Linked to Lack of Antibodies Against Streptococcus Pneumoniae
A Minnesota study states low level of antibodies to newborns may lead
to increased incidence of acute otitis media in a child's first 12 months. Maternal and infant immunization may act to reduce episodes of infant ear infections.
Orlando, FL -- A new study from a University of Minnesota medical team has established a relationship between cord blood (blood found in the vessels of the umbilical cord during birth) pneumococcal anti-PS IgG antibody levels and the number of otitis media episodes during the first 12 months of life.
Background: Infants with otitis media during the first 6 months of life are at a greater risk for recurrence of chronic ear infections with effusion than children of the same age with later onset of the disorder. This high-risk period for otitis media coincides with a period of infant immunodeficiency. An infant's immature immune system responds poorly to certain antigenic challenges and must rely on a declining concentration of antibodies received from the birth mother.
Previous studies show that children with recurrent otitis media do not exhibit total immunoglobin G, M, or A deficiencies as compared to healthy children. Other studies have demonstrated that low concentrations of pneumococcal anti-PS immunoglobin G antibodies correlate with increased susceptibility to recurrent otitis media. Further, infants with low cord blood antibody against S. pneumoniae serotypes 14 and 19F incur ear infections at an age younger than infants with higher levels.
Therefore, this prospective study set out to determine if cord blood anti-capsular polysaccharide (PS) pneumococcal immunoglobin G antibody concentration was related to the number of otitis media and acute otitis media episodes during the first year of life.
The authors of the study are Kathleen Daly, PhD and G. Scott Giebink, MD from the Otitis Media Research Center and University of Minnesota Health Center; Mary H. Meland, MD from HealthPartners, Inc., Minneapolis, MN; Eric T. Becken from the University of Minnesota Medical School; and Bruce R. Lindgren, MS from the Division of Biostatistics, University of Minnesota School of Public Health. There findings were presented at a meeting of the American Society of Pediatric Otolaryngology on May 18, 2000 in Orlando, Florida.
Their research was supported in part by NIH grants from the National Institute on Deafness and Other Communication Disorders, the Minnesota Medical Foundation, the Deafness Research Foundation, and the Lions Multiple District 5M Hearing Foundation.
"¢Methodology: The study population consisted of 592 infants born to women from separate medical facilities observed by the same Minneapolis-Saint Paul health maintenance organization (HMO). One group of women, between the ages of 18 and 35, was enrolled during the third trimester of pregnancy. The second group in the study consisted of women 18 years of age who received obstetric care at the same HMO as those in the first group. Women were excluded for conditions known to interfere with their pregnancy or infant birth weight, a terminated pregnancy within 1 year, or a history of infertility.
Study subjects completed questionnaires during the third trimester of pregnancy and monthly for six months after birth. The surveys were designed to measure demographic and environmental variables such as maternal and paternal age, household income, ethnicity, maternal education, passive smoking exposure, day care attendance, and infant feeding methods. The questions also addressed family history of otitis media (three or more episodes of otitis media in a 12-month period, tympanostomy tubes, chronic otorrhea, or persistent middle ear effusion).
Infants ears were examined by pneumatic otoscopy and tympanometry at scheduled two, four, and six month well-child visits, and with pneumatic otoscopy at two weeks, 9-12,15, and 24 month well-child visits and all illness visits through 24 months of age. Pediatricians, pediatric nurse practitioners, and family practitioners performed examinations. At each visit, an ear examination form was filled out listing symptoms, tympanic membrane (TM) position, color, mobility, appearance, and middle ear diagnosis. Diagnostic consistency was evaluated by comparing recorded signs and symptoms and a middle ear algorithm.
Results: Key findings focused on the relationship between antibody levels and otitis media episodes. They are:
(1) Between 0-12 months of age, children with the lowest quartile of antibody against serotype 3 had
significantly more AOM episodes than those with antibody levels in the upper three quartiles (p = 0.04) and the relationship between 19F and number of AOM episodes was of borderline significance (p = 0.05)
(2) Similarly, between 0-12 months infants with the lowest quartile of antibody against serotype 19F had significantly more OM episodes (p = 0.04) and the relationship between 23F and number of OM episodes was of borderline significance (p = 0.05) (Table 3). Serotypes 3, 19F and 23F, with p values of < 0.1 for both AOM and OM episodes, were entered into the Poisson regression model predicting number of episodes in first 12 months.
(3) Only low levels of serotype 19F remained significantly related to number of OM episodes in the first 12 months, with a 23% increase in the average number of episodes.
Therefore, infants with low levels of cord blood antibodies to specific serotypes have more episodes of otitis media.
Conclusion: The authors state their research endorses the potential benefit of maternal immunization to delay the onset of otitis media and to also reduce the subsequent episodes during the child's first 12 months. Doing so may reduce the need for tympanostomy tube placement at a later date.
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