The Macroepidemiology of Parasitic and Infectious Diseases: A Comparative Study Using Artificial Neuronal Nets and Logistic Regressions

Abstract

Of the about 270 species of helminths, protozoa and arthropods which may permanently or occasionally infect human populations, less than 45 species, or about 16 percent, are strictly dependent on humans for their survival (Ashford 1991; Petney and Andrews 1998).For the few West European countries providing reasonably reliable demographic data before the nineteenth century, epidemics, famines and wars are favoured as the three critical controlling mechanisms in human demographic crisis (Jones 1990. For instance, bubonic plague, one of the most dreadful epidemic killers dominated the pattern of mortality variation from 1340 to its disappearance after 1670 in Europe, when smallpox epidemics may well have assumed a similar determining effect. Undoubtedly, mankind has experienced such disease effects along its evolution, leaving each time relatively resistant populations (Anderson and May 1991; Ewald 1994). Adopting a wider perspective, the “health” of man is determined essentially by his behaviour, his food and the nature of the world around him, and as such he is directly or indirectly influenced by different forms of parasitic and infectious diseases (Combes 1995). It may appear obvious that human conditions represent foci for a wide range of diseases (Anderson and May 1991). Unfortunately, the intimate interactions between different forms of diseases and human life-history traits have been virtually neglected (Immerman 1986). Life-history theory predicts that faced with virulent parasites, hosts should adjust their reproductive output and/or reducing age maturity (Stearns 1992; Michalakis and Hochberg 1994; McNamara and Houston 1996; Sorci et al. 1996; Reeson et al. 1998; Kris and Lively 1998; Brooke et al. 1998).