Many years ago, it was pointed out that, though the human louse (Pediculus humanus) does not make up a large group and is not an extremely complex insect in itself, the study of its relationship with its host is involved and is influenced very much by individual variations in, and complex behaviours of, humans [Ferris 1935, Buxton 1941].

Moreover, it stands out for its role in human health. The human louse can carry diseases which have had such a devastating impact on human populations that they have possibly shaped the human race - biologically with regard to hairlessness [Rantala 1999] and culturally with regard to civilised hygienic practices [Nuttall 1918]. However, there are no direct reports connecting isolated scalp infestations with louse borne disease carriage in modern, hygienic surroundings. Thus, some people have relegated pediculosis capitis to the trivial illness basket.

Pediculosis capitis has become one of, if not the most, prevalent childhood communicable condition and is causing financial and health-related problems for families worldwide. Well over several million dollars annually are spent on lice control in each of the USA, the UK and Australia. The application of pediculicides on a growing population of lice has, in some areas, exhausted the available range of insecticides to which they were once susceptible.

Treatment is a labour intensive task, with work and family time put on hold. Some people eliminate infestation in the family without dramas; e.g., clipper haircuts for boys make removal of this external parasite a non-event. However for others, sensitive scalps or some hair textures can make manual methods difficult, and it only takes one resistant infection to cause undue hardship.

The obvious rise in head lice in schoolchildren in only a couple of decades has led to many families catching lice, not once but repeatedly over the years while their children progress through childcare centres, preschool and school. Busy families nurturing babies and young children have the least time available for the time-consuming, sometimes distressing, process of physically checking for and removing lice.

Devoted parents put a lot of effort into nursing their children back to good health, whatever the presenting illness. They will resort to a one-off haircut and/or weeks of intensive combing to cure lice once and for all. However, they are utterly frustrated at the prospect of no end to this disruption. Without higher management, their recently cleared children are exposed to further carriers when they return to school, where they must attend but where parents have no control over their contacts.

Understanding the human host and parasite factors that influence diagnosis and treatment is the key to solving the head lice problem. The consistent thrust of control policies since the 1980s has been to motivate and educate, with the worthwhile aim of empowering families to detect and cure lice, but with little or no professional monitoring. The problem with this is that underdiagnosis is common because detection in the hair is more complex than previously thought.

We do not deny that many people, armed with knowledge of head lice and their practical treatment, can do much to safely control their own lice. However, the rising prevalence of head lice infestation in schoolchildren and recent scientific findings by Bailey and Prociv, in particular regarding louse appearance and hair factors, support the contention that education of parents alone, without enforced screenings of populations at risk, will fail to halt the spiralling transmission.

The primary reservoir for head lice has been confirmed. The coming together of children in large numbers, in most societies in preschools and schools, facilitates the spread of lice. Their natural contact with multiple classmates is unavoidable. However, head lice is completely curable in the individual. For some, it will take a caring health professional to recognize a relapsing condition and demonstrate ways to tackle the missed lice.

Were it not for uncured carriers, the general community for whom the majority have never had lice would otherwise never be exposed to this communicable parasitosis. More effective louse management is needed to halt what is a preventable communicable disease problem. Investment in time-honoured strategies aimed at louse eradication may save far more costs for the community in the long-run.