Weather conditions prior to major outbreaks of meningococcal meningitis in the United Kingdom.

Meningitis has been a notifiable disease in the United Kingdom for some 70 years. Only in recent years, stimulated by the work of the Meningitis Trust, has there been a more general awareness of the geographical distribution of cases, with certain locations being more prone than others to episodic outbreaks of the disease. In this paper we consider weather conditions prior to major outbreaks of meningitis in Hereford and Worcester, and Cleveland and the northwest Midlands. Possible causal links to air quality and large temporal changes of relative humidity are found from analysis of case data. However, whilst the diagnostic studies reported are encouraging, an independent test of the relative humidity gradient criterion using independent data for Gloucester was not successful. It is clear that meteorological and air quality data actually of the area from which the disease is reported must be analysed more fully to sustain or overrule the hypothesis proposed. In addition, the need for further clinical research into the likelihood of disease triggers generated by atmospheric smoke, dust and moisture is identified.