Study: treated clothing stops ticks in their tracks



A new study shows that clothing treated with permethrin, an insecticide, was able to alter and impair the ability of human ticks to bite, including Ixodes scapulari s (the tick or deer tick) of black legs), the main vector of Lyme disease in the eastern United States.

Although permethrin-treated clothing is commercially available in the United States, there has been some debate about how effective it is to repel ticks. This study, conducted by researchers at the Centers for Disease Control and Prevention (CDC) and published yesterday in Journal of Medical Entomology challenged three types of ticks with contact with clothes treated with permethrin during 1 minute, and measured, mark the activity for the next hour.

The tick studies were the deer tick, the solitary star tick ( Amblyomma americanum), and the American dog tick ( Dermacentor variabilis) . [19659004] Movement of limited ticks of treated tissue

The authors used 10 articles of clothing treated with permethrin from the Insect Shield company to conduct the study and untreated cotton T-shirts as controls. The authors covered playing cards with the tissue and held them at 45 degree angles during the test and exposure of the experiment.

While 100% of the ticks remained on the untreated cloth charts in 1 minute, only 58% of the ticks treated cloth remained in contact with the fabric after 1 minute.

After 5 minutes, the difference was even more striking in the nymph ticks raised in the laboratory: young and small ticks that have already pbaded the larval stage. All nymphs of deer ticks on the untreated cloth remained on the charts after 5 minutes, compared to 5% of the nymphs on the treated material. The tick nymphs collected in the field, however, showed a different pattern. In clothes without treatment, only 23% remained on the cards after 5 minutes, compared to 8% on the fabric treated with permethrin.

In addition, exposure of 1 minute to clothing with permethrin caused a normal loss of movement for the three species of ticks in nymph and adult forms for at least 1 hour. Permethrin had the strongest effect on tick nymphs, since none showed normal movement after 1 hour of exposure, only 14% of Americanum nymphs showed normal movements after 1 hour, and 38% of the adult deer ticks were able to move normally after contact with the treated clothing.

Lars Eisen, PhD, research entomologist at CDC's National Center for Emerging and Zoonotic Infectious Diseases and lead author of the study, told CIDRAP News that the findings were not surprising, but were encouraging.

"Treatment with permethrin causes [the ticks] irritation, making it more likely to fall out of clothing before reaching bare skin than in regular untreated clothing," Eisen said.

New tools such as ticks are needed to disseminate EE. UU

A study conducted earlier this month by the CDC said that diseases transmitted by mosquitoes and ticks have doubled in recent years, given that warm weather and suburban development in forest areas mean greater human contact with the ticks. About 300,000 Americans contract Lyme disease each year, the highest profile of tick-borne diseases.

Heartland virus, babesiosis, and Rocky Mountain spotted fever are other diseases that can cause serious health consequences.

clothing and equipment such as boots, pants, socks and tents with products containing 0.5% permethrin.

See also:

May 24 J Med Entomol Study

May 1 CIDRAP News story "The CDC reports that diseases transmitted by vectors since 2004 "


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