Analysis of the causes of spawning of large-scale, severe malarial epidemics and their rapid total extinction in western Provence, historically a highly endemic region of France (1745–1850)

摘要: The two main puzzles of this study are the onset and then sudden stopping severe epidemics in western Provence (a highly malaria-endemic region Mediterranean France) without any deliberate counter-measures absence significant population flux. Malaria during period from 1745 to 1850 were analysed against temperature rainfall records several other potentially relevant factors. Statistical analyses indicated that relatively high temperatures early spring September/October, previous winter (principally December) even November September year could have played a decisive role emergence these epidemics. Moreover, most likely not driven by parameters (e.g., social, cultural, agricultural geographical). Until 1776, very malarial affected large areas, whereas after date, they rarer generally milder for local people due canal digging activities. In latter period, decreased December, more extreme variable observed. It is known anomalies fluctuations may be detrimental vector parasite development. This showed particular characteristics malaria historical Provence. Contrary situation Plasmodium falciparum was involved (during years with epidemics, mean months July August, among factors, did play role) had no protective mutation. species vivax, which responsible diseases, but contrary northern Europe, it transmission occurred only where outdoor sporogony possible, P. vivax always feasible, colder summers. Possible key elements understanding course include changes virulence strains, refractoriness anophelines and/or degree or efficiency acquired immunity. open new lines investigation into comprehension conditions disappearance/emergence endemic areas.