Wavelet analyses of meningitis time series with annual data from 1939 to 1999 across 9 African countries: (A) Burkina Faso, (B) Chad, (C) Sudan; (D) Nigeria, (E) Niger, (F) Mali, (G) Ghana, (H) Togo, (I) Benin

Copyright information:Taken from "Comparative study of meningitis dynamics across nine African countries: a global perspective"http://www.ij-healthgeographics.com/content/6/1/29International Journal of Health Geographics 2007;6():29-29.Published online 10 Jul 2007PMCID:PMC1939699. For each country (i) left panel represents the time series of cases in the country (ii) middle panel represents the wavelet power spectrum of meningitis cases (detrended); colours code for increasing spectrum intensity, from blue to red; dotted lines show statistically significant area (threshold of 5% confidence interval); the black curve delimits the cone of influence (region not influenced by edge effects) (iii) right panel corresponds to the mean spectrum (in blue) with its significant threshold value of 5% (black line).