Early Exposure to Other Children May Ward Off Asthma: Not all the germs children pick up at school are necessarily bad for them, a study has found.
Young children who go to day-care centers or who have older siblings at home are less likely to develop asthma later in life—probably because they were exposed as infants to the microbes that cause the condition, according to a study published last month in The New England Journal of Medicine.
Asthma, which is often acquired in childhood and is characterized by temporary blockage of the lungs, is the No. 1 chronic health condition among children and the leading cause of school absences. The rate of childhood asthma has risen in the past few decades.
For the study, researchers from the University of Arizona's respiratory-sciences department examined 1,035 children from birth to age 13 in day-care centers in Tucson. The researchers gathered data on infants' exposure to day care, how many siblings they had, and how many colds and asthma attacks they had that were diagnosed by their doctors.
The researchers found that the children who had entered day care before they were 6 months old were 40 percent less likely to come down with asthma than babies who were not in day care or exposed to older siblings. Babies who entered day care when they were between 6 and 12 months old also had a lower risk of asthma later in childhood compared with youngsters not enrolled in day care.
By age 2, babies in child-care settings did have more bouts of wheezing and coughing than children in home care with no siblings, the researchers found, but they were less likely to have frequent attacks by age 6.
Having one or two older siblings also appeared to protect young children. Children with two siblings had a 30 percent lower risk of developing asthma than only children; children with three or more siblings had 40 percent less risk.
The study lends support to a growing scientific theory that early exposure to certain bacteria and viruses helps children build up immunities to some illnesses later in life.
Drug Use: The decline in drug use among 12- to 17-year-olds that began in 1997 continued into last year, while the abuse of illicit drugs among the overall population remained flat, a national survey released last week shows.
According to the annual National Household Survey on Drug Abuse, an estimated 9 percent of youths reported current illegal drug use last year, meaning they had used such a drug at least once during the 30 days before they were interviewed for the survey. The U.S. Department of Health and Human Services report says the results show a significant, consistent downward trend over the past three years—from 11.4 percent in 1997, to 9.9 percent in 1998, and 9 percent in 1999.
Marijuana use for youths 12 to 17 decreased from 9.4 percent in 1997 to 7.7 percent last year. Cocaine, inhalant, hallucinogen, and heroin use remained stable, the report says.
Cigarette smoking dropped among the same age group, to 15.9 percent last year, down from 18.2 percent in 1998 and 19.9 percent in 1997, while alcohol consumption for youths and the general public has remained flat for the past several years, the report notes.
This year marks the first time the survey provides state-by-state estimates of drug, alcohol, and cigarette use by age group. Findings are available at www.samhsa.gov/household99.htm.
Smoking Declines: Another government study suggests that pricier cigarettes and smoking-prevention programs aimed at teenagers may have contributed to a slight decline in adolescent-smoking rates in the past few years. The new statistics represent the first overall decline in those rates since researchers at the federal Centers for Disease Control and Prevention began collecting such data in 1991.
Smoking rates among U.S. high school students dropped slightly in the past few years after climbing steadily during the early to mid-1990s, researchers from the CDC reported in the Aug. 25 edition of the federal Morbidity and Mortality Weekly Report. In 1999, 34.8 percent of high school students surveyed said they had smoked a cigarette in the past 30 days, down from 36.4 percent in 1997.
For the ongoing study, the CDC surveyed more than 15,000 9th through 12th graders in the 50 states and the District of Columbia.
Among high school freshmen, the decline was most pronounced. The smoking rate among seniors, however, climbed each year during that period.
Ritalin Alternative: The federal Food and Drug Administration has approved a drug named Concerta as the first medication for treating attention deficit hyperactivity disorder that can be taken in a single dose. Methylphenidate, or Ritalin, the most commonly used drug for treating ADHD, generally requires multiple doses throughout the day.
School nurses dispense more Ritalin to students than any other drug apart from pain relievers. Concerta, which is methylphenidate in a different form, lasts for 12 hours and can be taken before a child leaves for school. The extended-release-formula tablet does not require students to leave class to get their pills from the nurse's office.
Between 4 percent and 12 percent of school-age children—or about 2.5 million youngsters—have been diagnosed with ADHD, a condition characterized by hyperactivity and short attention span.
-Jessica Portner & Adrienne D. Coles
Vol. 20, Issue 1, Page 24Published in Print: September 6, 2000, as Health Update