Head Lice: a report for Consultants in Communicable Disease Control (CCDCs)

Head lice: Glossary and Terminology

Glossary

Terminology

Glossary

Head louse An insect parasite, Pediculus capitis, which can only survive on the human scalp and with has a needle-like mouthpart with which it pierces the scalp to feed on blood.

Incidence

The proportion of people who develop new infection in a given group over a period of time, usually one year (compare "prevalence").

Prevalence (point prevalence)

The proportion of people with active infection in a given group at a given time (compare "incidence").

Nit The empty egg shell of the head louse left stuck to a hair shaft after the insect has hatched.

"Nit nurse"

Also known as "Nitty Norah", this was formerly a nurse who was expected to inspect the heads of all children in schools regularly.

Detection comb

A special plastic comb which should have rigid teeth no further than 0.3mm apart, each tooth preferably having at least one flat surface.

Terminology

The following are recommended for use in policies and leaflets:

Head louse / head lice. The form headlouse / headlice is non-standard.

Head louse problem/prevention/treatment/lotion etc. The widespread use of the plural as modifier ("head lice problem...etc.") is not standard usage in other similar constructions in English. For example, "The rat problem.." and "rat poison..", not "the rats problem" or "rats poison. It is not clear why this usage has crept in, but it may be due to the common mistake of considering a plural strong noun like "lice" as singular, as in "one pence" rather than "one penny".

Infection. "Infestation", though correct, has unpleasant overtones and tends to reinforce social stigma.

Lotion. For simplicity the term lotion used in this document includes all types of licensed products, except shampoos (which are ineffective).

(This document was originally appendix 8 of Head Lice: a report for Consultants in Communicable Disease Control (CCDCs).)