The number of studies to prove or disprove a problem with head lice vary. Only one study has been conducted in Oceania, particularly Australia. At the start of the 21st century the prevalence of head lice was reported to be 13%, with more girls suffering from an infection than boys in Australia.
In other parts of the world, like combining the Americas into one study, the prevalence ranges from 3.6% to 61.4%, whereas African data ranges from 0% to 60%. Asia also has a large range from 0.7% to 59%. This would suggest that on a worldwide scale head lice is still a huge problem in the 21st century. All data was obtained from the article Worldwide Prevalence of Head Lice on the NCBI.nlm.nih.gov website. The studies were conducted prior to the release of the article in 2008.
According to writer Adam Ward, head lice have become resistant to over-the-counter pesticide shampoos and conditioners. In the 1980s, the pesticide shampoo and conditioner treatments were highly effective. However, in the 21st century many of the lice shampoos are not working. Studies are showing a ‘super lice’ strain that is very difficult to kill. This super strain may account for the rising and huge problem head lice poses.