The Social Behavior and the Evolution of Sexually Transmitted Diseases

TL;DR

This paper presents a model linking social behavior, specifically promiscuity levels, to the evolution and threshold dynamics of sexually transmitted diseases, emphasizing the role of social attitudes in disease spread.

Contribution

It introduces a quantitative model incorporating social behavior as a key factor in STD evolution, relating promiscuity to epidemic thresholds and epidemiological parameters.

Findings

Identifies a critical promiscuity threshold for epidemic onset

Relates promiscuity to the basic reproductive number

Analyzes disease spread in homosexual populations

Abstract

We introduce a model for the evolution of sexually transmitted diseases, in which the social behavior is incorporated as a determinant factor for the further propagation of the infection. The system may be regarded as a society of agents where in principle anyone can sexually interact with any other one in the population. Different social behaviors are reflected in a distribution of sexual attitudes ranging from the more conservative to the more promiscuous. This is measured by what we call the promiscuity parameter. In terms of this parameter, we find a critical behavior for the evolution of the disease. There is a threshold below what the epidemic does not occur. We relate this critical value of the promiscuity to what epidemiologist call the basic reproductive number, connecting it with the other parameters of the model, namely the infectivity and the infective period in a quantitative way. We consider the possibility of subjects be grouped in couples. In this contribution only the homosexual case is analyzed.