The Big Question

What should a PCO do about a school, daycare or home where the people have head lice or scabies (itch) mites? The answer is simple and this article could end with one sentence, "Nothing…it’s a medical problem; refer them to a doctor." However, it might be helpful to explain why PCOs should avoid lice and scabies control efforts.

WHAT TO DO. Most PCOs have at one time been asked (pressured?) to spray/fog a school or daycare for lice or scabies mites. This insistence by parents and/or school administrators for spraying to control lice and scabies is usually because they don’t understand the biology of human lice and itch mites.

They think lice and scabies mites are a bug problem and therefore a bug exterminator is what’s needed. They are a bug problem but human lice (including head, body and pubic lice) and scabies mites are true human parasites occurring only on humans. They do not live in carpet, in bedding, on the dog or cat, etc. When lice or mites fall off a human into the bed or carpet, they die within several hours. In addition, when on the floor or in bedding (after falling off), they have a very difficult time getting back on another human. They can’t jump, swim or run fast.

One thing that confuses this issue is that there are animal forms of scabies (dog, horse, etc.) that humans can get temporarily from these animals. However, the animal forms of scabies cannot take up permanent residence on a human.

Human lice (all three forms) and scabies are only found on humans and are transmitted from person-to-person by close physical contact. Modes of transmission include sleeping in the same bed, hugging, sharing hats or combs and even sex. But, just lying on the floor or sleeping in a bed where an infested person had previously been is not the usual way transmission occurs. British professor Kenneth Mellanby and colleagues performed experiments in the 1940s to determine how scabies mites are transmitted. They would get an infested person to sleep overnight in a bed and then put a non-infested person in the same bed the next night. In more than 300 experiments, scabies was transmitted only four times in this manner, proving that it can happen but is certainly unlikely.

PROPER TREATMENT. Infestation with human lice and scabies mites is a medical issue and not a pest control issue. Treatment involves medicated creams or lotions (some have to be prescribed by a doctor) applied on the body. At the same time of the treatment, doctors recommend removing all bedding and bedclothes and laundering them on the hottest setting. No spraying is needed or advisable. No public health authority (professor or health department doctor) recommends spraying a building for lice or scabies.

If you end up doing a pesticidal treatment in a facility for lice or scabies, you are vulnerable to lawsuits claiming that you "poisoned" someone. And, when you try to justify your spraying, nobody in the public health sector will be on your side. You’re out on a limb!