Military Medical Institute, Nizhny Novgorod, Russia
A special search program for finding out hidden periodicity was used; such program made it possible to put in order the apparently chaotic sequence of numerical data that are summed up to form the resulting curve, the latter reflecting the actual dynamics of the epidemic process. The cyclic character of morbidity in tick-borne encephalitis, hemorrhagic fever with the renal syndrome (HFRS), tularemia and leptospirosis among the population of Russia for the last 45 — 54 years was revealed. In tick-borne encephalitis cycles lasting 17 — 18 years with secondary wave having the period of 3 — 4 years were found out. In HFRS the main cycle lasts for 16 years and has secondary rises every 3 — 4 years. In tularemia the main cycles last for 17 years; secondary rises and drops in morbidity were also found to occur every 3 — 4 years. In leptospirosis regular rises and drops in morbidity were found to occur every 4 — 5 years.
Zh. Mikrobiol. (Moscow), 2002, No. 1, P. 23—27