Head Lice Resistant To Commonly Used Insecticide
Head lice in the United States have become resistant to the
insecticide most commonly used to combat them, researchers at Harvard
University's school of public health say in a recently released
Richard Pollack and Andrew Spielman collected head lice from infested patients in Massachusetts and Idaho. The researchers then exposed the lice to progressively higher doses of permethrin--the active ingredient in the most commonly used anti-louse insecticide. Most of the lice collected were not killed by the insecticide, even when higher concentrations were used.
In comparison, the researchers also collected lice from patients on Borneo, an island where permethrin is rarely used to kill lice. The Bornean lice were quickly killed by permethrin.
The findings, which appear in the September issue of the Archives of Pediatric and Adolescent Medicine, have implications for the treatment of lice in the United States. Typically, if over-the-counter medication fails, patients seek prescription alternatives, many of which simply contain a higher level of permethrin.
"If you have head lice, and an over-the-counter medication containing permethrin doesn't solve your problem, then neither will a prescription for a higher dose," Mr. Pollack said in a written statement.
Alternatives to permethrin include other, more expensive insecticides containing lindane and malathion, both available only through prescription.
Concussions: Two or more concussions received while playing sports can weaken cognitive skills, according to a recently published study.
In addition, the researchers found that an athlete who sustains multiple concussions and has a learning disability suffers even worse long-term problems.
The findings were published in the Sept. 8 issue of The Journal of the American Medical Association. In a separate study in that issue, researchers say they found an estimated 63,000 cases of mild traumatic brain injury among high school varsity athletes, with football players accounting for more than 60 percent of the cases.
Mild traumatic brain injury, or concussion, is defined as traumatically induced alteration in mental status. It does not necessarily result in a loss of consciousness.
Michael W. Collins of the Henry Ford Health System, a medical center in Detroit, and his colleagues found poorer academic performance among those with learning disabilities and multiple concussions than in other groups. The researchers evaluated 393 football players from four universities between May 1997 and February of this year. They collected data on the players' academic and neurological histories.
The prevalence of a learning disability--which was defined as difficulties in the acquisition and use of listening, writing, reading, reasoning, or mathematical ability--was 13.5 percent overall. Of those with no history of concussion, 10 percent had a diagnosed learning disability; of those who had experienced at least one concussion, 14.7 percent had a learning disability. Of those who had experienced multiple concussions, 19 percent had a learning disability.
"Despite high prevalence and potentially serious outcomes, research on the subject is lacking," the authors write.
In the second study, researcher John W. Powell examined the frequency patterns for concussions among boys and girls in football, soccer, basketball, softball, baseball, field hockey, volleyball, and wrestling. The study at 235 high schools between the 1995-96 and 1996-97 school years found that there were incidences of concussion in each of the sports.
Violence Study: Real-life exposure to violence, lack of parental monitoring, and television viewing all have a significant impact on a child's behavior, a new report says.
Researchers at Case Western Reserve University used an anonymous self- reporting questionnaire administered to 2,245 students in grades 3-8. The subjects ranged in age from 7 to 15, and 51 percent were boys. The breakdown by race was 57 percent white, 33 percent black, 5 percent Hispanic, and 4 percent "other." Percentages were rounded.
The students were asked a series of questions: whether they had experienced or witnessed an act of violence in the past year; whether they had had exposure as a victim or witness to violence at any time; to what degree parents were aware of the youngsters' daily activities and friends; how much television they watched per day; and how often they had engaged in a violent act during the past year.
The researchers found that the amount of exposure to violence and parental monitoring had the most influence on children's behaviors, with television viewing coming in a distant but significant third, said Mark I. Singer, the lead author and a professor of social work at Case Western in Cleveland.
"Our findings underscore the importance of parental monitoring of children because low parental monitoring was a primary contributor to children's reports of engaging in violent behavior," the authors write.
"Parents can do something to help their children behaviorally," Mr. Singer said last week.
The researchers' findings appear in this month's issue of Pediatrics.
- -Adrienne D. Coles [email protected]
Vol. 19, Issue 7, Page 13Published in Print: October 13, 1999, as Health Update