Reuters Health Information
By Frederik Joelving
NEW YORK (Reuters Health) May 18 - Maternal measles antibodies wane earlier than previously thought, leaving infants susceptible to the virus for several months under current immunization guidelines, Belgian researchers report in a May 18th online paper in BMJ.
While not recommending an overhaul of general vaccination age -- currently 12 months in both Belgium and the US -- they said infants with special exposure to measles may need to be immunized at six months.
"We could recommend to vaccinate earlier, but because of good coverage here in Belgium we do not want to lose people" by adding an extra trip to the doctor, said lead author Dr. Elke Leuridan of the University of Antwerp in Wilrijk, Belgium.
Dr. Leuridan and colleagues studied 207 healthy mother-child infant pairs. Eighty-seven of the mothers had been vaccinated against measles and 120 had natural immunity.
The researchers collected venous blood during pregnancy (week 36, 10 ml), at birth (cord blood, 10 ml) and in infants at 1, 3 and 12 months (2 ml). In addition, they took samples randomly at either 6 or 9 months.
They used an enzyme-linked immunosorbent assay to measure the amount of measles immunoglobulin G (IgG) in the blood, calibrating the assay against the international reference preparation of measles antigen. The samples were considered positive if the corrected optical density was greater than 0.2, and negative if it was less than 0.1.
Overall, vaccinated women had lower IgG titers than naturally immune women (779 vs. 2687 milli-International Units per milliliter, or mIU/mL; p<0.001). The same pattern was seen for the infants at all ages (p<0.001).
Maternal antibodies persisted for a median of 3.8 months in infants of naturally immune mothers and for 1 month in babies of vaccinated women. In a linear mixed model, 99% of babies of vaccinated mothers had lost their maternal antibodies after six months, compared to 95% of babies of naturally immune women. Breast feeding, parity, gestational age, birth weight, educational level, day care attendance and cesarean section were not significant in the model.
The findings are consistent with earlier studies showing that measles susceptibility is growing every year, Dr. Leuridan said. Yet, she added, "it is quite new that it is such a large gap."
Part of the reason for the expanding gap, she said, could be the increasing age of mothers and the general success of immunization in lowering overall exposure to the virus.
Dr. Archana Chatterjee, of Creighton University School of Medicine in Omaha, Nebraska, said current immunization practice is based on the theoretical assumption that maternal antibodies might interfere with the necessary replication of the vaccine virus.
She called the new study "food for thought," noting that larger studies are needed before considering guideline changes. For instance, small amounts of maternal antibodies that went undetected in the study in principle might interfere with the vaccine, she said.
Still, Dr. Chatterjee said, "it certainly is something that gives us pause."
http://www.bmj.com/cgi/content/abstract/340/may18_2/c1626
BMJ 2010.
Monday, February 28, 2011
Tuesday, February 15, 2011
Periconceptional Fever/Influenza Linked to Specific Congenital Birth Defects
From Reuters Health Information CME
News Author: Megan Brooks
CME Author: Désirée Lie, MD, MSEd
NEW YORK (Reuters Health) February 4, 2011 — New research confirms that women who develop influenza or a fever of 101°F or higher during the periconceptional period are at increased risk of delivering a baby with certain congenital heart defects, most notably right-sided obstructive lesions in all infants and atrioventricular septal defects (AVSD) in infants with Down syndrome.
However, maternal use of antipyretic agents in the setting of fever or influenza may attenuate these associations, the researchers reported in the January 24 online issue of The Journal of Pediatrics.
Dr. Adolfo Correa, Medical Officer in the National Center on Birth Defects and Developmental Disabilities, part of the Centers for Disease Control and Prevention, in Atlanta, Georgia, led the study.
"Although our findings are consistent with a few previous studies, the literature on the associations we found is still somewhat limited for drawing conclusive clinical implications," Dr. Correa noted in an e-mail to Reuters Health.
"Further efforts are needed to corroborate our findings and to elucidate the reasons for the observed associations. From a precautionary perspective, women planning to become pregnant should avoid exposure to influenza or other febrile illnesses and seek preconception care," the researcher added.
Maternal febrile illness and hyperthermia have been linked to a variety of birth defects, especially those involving the central nervous system, Dr. Correa and colleagues note in their report. Associations between maternal fever and hyperthermia with congenital heart defects are "less clear-cut," they say.
Moreover, while associations between congenital heart defects and some viral illnesses, particularly rubella, have been well documented, studies on the role of influenza in risk of congenital heart defects have yielded mixed results.
Dr. Correa and colleagues investigated associations between maternal fever and influenza and congenital heart defects using data from the Baltimore-Washington Infant Study, an epidemiologic study of congenital heart defects conducted between 1981 and 1989 in Maryland, Washington DC, and northern Virginia.
Cases were 2,361 infants with congenital heart defects and controls were 3,435 infants without congenital heart defects.
Participating mothers were asked whether they had a fever of 101°F or higher, had influenza, or used an antipyretic agent (acetaminophen, salicylate, or nonsteroidal anti-inflammatory agent) during the period extending from 3 months prior to pregnancy through the end of the third month of pregnancy.
For congenital heart defects overall, no significant associations were found with fever, influenza, or fever/influenza.
However, for specific defects, significant associations were found for right-sided obstructive defects and maternal fever (OR 2.04), influenza (OR 1.75) and fever/influenza (OR 1.69).
These findings were most notable for tricuspid atresia in the setting of fever (OR 7.54), influenza (OR 6.04), and fever/influenza (OR 5.46) and for pulmonary atresia with intact ventricular septum in the setting of influenza (OR 2.71) and fever/influenza (OR 2.80), the researchers reported.
And in infants with Down syndrome, the authors found significant associations between atrioventricular septal defects and periconceptional fever (OR 1.92), influenza (OR 1.66) and fever/influenza (OR 1.66). No significant associations were evident between other cardiac phenotypes and fever, influenza or both.
Maternal antipyretic use tended to decrease these associations, as mentioned.
Dr. Correa and colleagues say the link between fever and influenza and AVSD only in infants with Down syndrome may be "spurious" or it may represent an "important gene-environment interaction that warrants further investigation."
J Pediatr. Published online January 24, 2011. Abstract
Clinical Context
Congenital heart defects continue to be a leading cause of morbidity and mortality in children, and maternal exposures during pregnancy may contribute to the risk for such defects. Maternal fever has been linked to birth defects, especially those of the central nervous system, and studies have noted an almost 2-fold increase in the risk for aggregate congenital heart defects with maternal fever and influenza.
This is a case-control study of infants in a population-based cohort to examine the association between maternal fever or influenza during the 3 months before and after conception and the risk for congenital heart defects.
News Author: Megan Brooks
CME Author: Désirée Lie, MD, MSEd
NEW YORK (Reuters Health) February 4, 2011 — New research confirms that women who develop influenza or a fever of 101°F or higher during the periconceptional period are at increased risk of delivering a baby with certain congenital heart defects, most notably right-sided obstructive lesions in all infants and atrioventricular septal defects (AVSD) in infants with Down syndrome.
However, maternal use of antipyretic agents in the setting of fever or influenza may attenuate these associations, the researchers reported in the January 24 online issue of The Journal of Pediatrics.
Dr. Adolfo Correa, Medical Officer in the National Center on Birth Defects and Developmental Disabilities, part of the Centers for Disease Control and Prevention, in Atlanta, Georgia, led the study.
"Although our findings are consistent with a few previous studies, the literature on the associations we found is still somewhat limited for drawing conclusive clinical implications," Dr. Correa noted in an e-mail to Reuters Health.
"Further efforts are needed to corroborate our findings and to elucidate the reasons for the observed associations. From a precautionary perspective, women planning to become pregnant should avoid exposure to influenza or other febrile illnesses and seek preconception care," the researcher added.
Maternal febrile illness and hyperthermia have been linked to a variety of birth defects, especially those involving the central nervous system, Dr. Correa and colleagues note in their report. Associations between maternal fever and hyperthermia with congenital heart defects are "less clear-cut," they say.
Moreover, while associations between congenital heart defects and some viral illnesses, particularly rubella, have been well documented, studies on the role of influenza in risk of congenital heart defects have yielded mixed results.
Dr. Correa and colleagues investigated associations between maternal fever and influenza and congenital heart defects using data from the Baltimore-Washington Infant Study, an epidemiologic study of congenital heart defects conducted between 1981 and 1989 in Maryland, Washington DC, and northern Virginia.
Cases were 2,361 infants with congenital heart defects and controls were 3,435 infants without congenital heart defects.
Participating mothers were asked whether they had a fever of 101°F or higher, had influenza, or used an antipyretic agent (acetaminophen, salicylate, or nonsteroidal anti-inflammatory agent) during the period extending from 3 months prior to pregnancy through the end of the third month of pregnancy.
For congenital heart defects overall, no significant associations were found with fever, influenza, or fever/influenza.
However, for specific defects, significant associations were found for right-sided obstructive defects and maternal fever (OR 2.04), influenza (OR 1.75) and fever/influenza (OR 1.69).
These findings were most notable for tricuspid atresia in the setting of fever (OR 7.54), influenza (OR 6.04), and fever/influenza (OR 5.46) and for pulmonary atresia with intact ventricular septum in the setting of influenza (OR 2.71) and fever/influenza (OR 2.80), the researchers reported.
And in infants with Down syndrome, the authors found significant associations between atrioventricular septal defects and periconceptional fever (OR 1.92), influenza (OR 1.66) and fever/influenza (OR 1.66). No significant associations were evident between other cardiac phenotypes and fever, influenza or both.
Maternal antipyretic use tended to decrease these associations, as mentioned.
Dr. Correa and colleagues say the link between fever and influenza and AVSD only in infants with Down syndrome may be "spurious" or it may represent an "important gene-environment interaction that warrants further investigation."
J Pediatr. Published online January 24, 2011. Abstract
Clinical Context
Congenital heart defects continue to be a leading cause of morbidity and mortality in children, and maternal exposures during pregnancy may contribute to the risk for such defects. Maternal fever has been linked to birth defects, especially those of the central nervous system, and studies have noted an almost 2-fold increase in the risk for aggregate congenital heart defects with maternal fever and influenza.
This is a case-control study of infants in a population-based cohort to examine the association between maternal fever or influenza during the 3 months before and after conception and the risk for congenital heart defects.
FDA Approves First 3-Dimensional Mammography System
From Medscape Medical News > Alerts, Approvals and Safety Changes > FDA Approvals
Steven Fox
February 14, 2011 — The US Food and Drug Administration (FDA) has approved the first mammography system employing 3-dimensional (3-D) imaging, and preclinical studies show that the new technology is 7% more accurate than traditional 2-D mammography in spotting breast tumors.
The new technology is to be marketed as the Selenia Dimensions System and is being manufactured by Hologic, Inc. The system is an upgrade to Hologic's currently available 2-D system.
The system has already been approved in Latin America, Europe, and in Asia.
In approving the device for use in the United States, the FDA assessed results from 2 studies in which radiologists reviewed 2-D and 3-D images from more than 300 mammography studies.
In both studies, radiologists viewing both 2-D and 3-D images were 7% more likely to accurately distinguish between cancerous and noncancerous lesions compared with viewing 2-D images alone.
"Physicians can now access this unique and innovative 3-D technology that could significantly enhance existing diagnosis and treatment approaches," said Jeffrey Shuren, MD, JD, who directs the FDA's Center for Devices and Radiological Health in a press release.
Previous studies have shown that 2-D imaging techniques do not always provide clear images of breast masses, as overlapping skin and other anatomical features can obscure tumors and sometimes create the appearance of a tumor when there is none.
A caveat is that the combination of 2-D and 3-D images approximately doubled the radiation dose to which women were exposed, but the new technology increases efficacy, which presumably will help cut down on the need for follow-up exams. At this time, about 10% of women who undergo 2-D mammography are called back for follow-up X-rays, only to find out later that masses spotted with the 2-D systems are noncancerous.
Mammography Quality Standards require that healthcare professionals undergo 8 hours of instruction before using the new 3-D technology. The FDA also stipulates that the manufacturer provide each user with a manual that defines tests required to maintain quality control.
Steven Fox
February 14, 2011 — The US Food and Drug Administration (FDA) has approved the first mammography system employing 3-dimensional (3-D) imaging, and preclinical studies show that the new technology is 7% more accurate than traditional 2-D mammography in spotting breast tumors.
The new technology is to be marketed as the Selenia Dimensions System and is being manufactured by Hologic, Inc. The system is an upgrade to Hologic's currently available 2-D system.
The system has already been approved in Latin America, Europe, and in Asia.
In approving the device for use in the United States, the FDA assessed results from 2 studies in which radiologists reviewed 2-D and 3-D images from more than 300 mammography studies.
In both studies, radiologists viewing both 2-D and 3-D images were 7% more likely to accurately distinguish between cancerous and noncancerous lesions compared with viewing 2-D images alone.
"Physicians can now access this unique and innovative 3-D technology that could significantly enhance existing diagnosis and treatment approaches," said Jeffrey Shuren, MD, JD, who directs the FDA's Center for Devices and Radiological Health in a press release.
Previous studies have shown that 2-D imaging techniques do not always provide clear images of breast masses, as overlapping skin and other anatomical features can obscure tumors and sometimes create the appearance of a tumor when there is none.
A caveat is that the combination of 2-D and 3-D images approximately doubled the radiation dose to which women were exposed, but the new technology increases efficacy, which presumably will help cut down on the need for follow-up exams. At this time, about 10% of women who undergo 2-D mammography are called back for follow-up X-rays, only to find out later that masses spotted with the 2-D systems are noncancerous.
Mammography Quality Standards require that healthcare professionals undergo 8 hours of instruction before using the new 3-D technology. The FDA also stipulates that the manufacturer provide each user with a manual that defines tests required to maintain quality control.
Tuesday, February 8, 2011
Early Introduction of Solid Foods Linked to Risk for Early Childhood Obesity
From Medscape Medical News
Laurie Barclay, MD
February 7, 2011 — Early introduction of solid foods is linked to a risk for early childhood obesity, according to the results of a prospective prebirth cohort study reported online February 7 in Pediatrics.
"Parental feeding practices during early infancy, such as the timing of solid food introduction, may be 1 key modifiable determinant of childhood obesity," write Susanna Y. Huh, MD, MPH, from the Division of Gastroenterology and Nutrition, Children's Hospital Boston in Boston, Massachusetts, and colleagues.
"Data suggest that the introduction of solid foods earlier than 4 months of age is associated with increased body fat or weight in childhood or with greater weight gain during infancy, which itself predicts later adiposity. Other studies have found no association between the timing of solid food introduction and body fat or an association between delayed introduction of solid foods after 6 months and greater adiposity."
The goal of the study was to evaluate the association between timing of introduction of solid foods during infancy and obesity at age 3 years, defined as a body mass index for age and sex at the 95th percentile or above, using a cohort of 847 children enrolled in Project Viva. Timing of introduction of solid foods was categorized as younger than 4 months, ages 4 to 5 months, and 6 months or older. Logistic regression models were applied separately for infants who were breast-fed for at least 4 months ("breast-fed"; n = 568; 67%) and for infants who were never breast-fed or in whom breast-feeding was stopped before age 4 months ("formula-fed"; n = 279; 32%). These models were adjusted for child and maternal factors, including change in weight-for-age z score from 0 to 4 months as a marker of early infant growth.
Obesity was present in 75 children (9%) at age 3 years.
The timing of solid food introduction was not associated with odds of obesity in breast-fed infants, (odds ratio, 1.1; 95% confidence interval [CI], 0.3 - 4.4). However, introducing formula-fed infants to solid foods before age 4 months was associated with a 6-fold increase in odds of obesity at age 3 years, which was not explained by rapid early growth (odds ratio after adjustment, 6.3; 95% CI, 2.3 - 6.9).
"Among infants who were never breastfed or those who stopped breastfeeding before the age of 4 months, the introduction of solids before the age of 4 months was associated with a sixfold increase in the odds of obesity at the age of 3 years," the study authors write.
Limitations of this study include possible residual confounding; some loss of the cohort to follow-up; limited generalizability to more socioeconomically disadvantaged populations; and small numbers in some cells, leading to possible chance results.
"Among infants breastfed for 4 months or longer, the timing of the introduction of solid foods was not associated with the odds of obesity," the study authors conclude. "Increased adherence to guidelines regarding the timing of solid food introduction may reduce the risk of obesity in childhood."
The National Institutes of Health supported this study. The study authors have disclosed no relevant financial relationships.
Pediatrics. Published online February 7, 2011. Abstract
Laurie Barclay, MD
February 7, 2011 — Early introduction of solid foods is linked to a risk for early childhood obesity, according to the results of a prospective prebirth cohort study reported online February 7 in Pediatrics.
"Parental feeding practices during early infancy, such as the timing of solid food introduction, may be 1 key modifiable determinant of childhood obesity," write Susanna Y. Huh, MD, MPH, from the Division of Gastroenterology and Nutrition, Children's Hospital Boston in Boston, Massachusetts, and colleagues.
"Data suggest that the introduction of solid foods earlier than 4 months of age is associated with increased body fat or weight in childhood or with greater weight gain during infancy, which itself predicts later adiposity. Other studies have found no association between the timing of solid food introduction and body fat or an association between delayed introduction of solid foods after 6 months and greater adiposity."
The goal of the study was to evaluate the association between timing of introduction of solid foods during infancy and obesity at age 3 years, defined as a body mass index for age and sex at the 95th percentile or above, using a cohort of 847 children enrolled in Project Viva. Timing of introduction of solid foods was categorized as younger than 4 months, ages 4 to 5 months, and 6 months or older. Logistic regression models were applied separately for infants who were breast-fed for at least 4 months ("breast-fed"; n = 568; 67%) and for infants who were never breast-fed or in whom breast-feeding was stopped before age 4 months ("formula-fed"; n = 279; 32%). These models were adjusted for child and maternal factors, including change in weight-for-age z score from 0 to 4 months as a marker of early infant growth.
Obesity was present in 75 children (9%) at age 3 years.
The timing of solid food introduction was not associated with odds of obesity in breast-fed infants, (odds ratio, 1.1; 95% confidence interval [CI], 0.3 - 4.4). However, introducing formula-fed infants to solid foods before age 4 months was associated with a 6-fold increase in odds of obesity at age 3 years, which was not explained by rapid early growth (odds ratio after adjustment, 6.3; 95% CI, 2.3 - 6.9).
"Among infants who were never breastfed or those who stopped breastfeeding before the age of 4 months, the introduction of solids before the age of 4 months was associated with a sixfold increase in the odds of obesity at the age of 3 years," the study authors write.
Limitations of this study include possible residual confounding; some loss of the cohort to follow-up; limited generalizability to more socioeconomically disadvantaged populations; and small numbers in some cells, leading to possible chance results.
"Among infants breastfed for 4 months or longer, the timing of the introduction of solid foods was not associated with the odds of obesity," the study authors conclude. "Increased adherence to guidelines regarding the timing of solid food introduction may reduce the risk of obesity in childhood."
The National Institutes of Health supported this study. The study authors have disclosed no relevant financial relationships.
Pediatrics. Published online February 7, 2011. Abstract
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