The pathogenicity of the Streptococcus genus

Abstract

Streptococcus infections are still one of the important problems facing contemporary medicine. As the World Health Organization (WHO) warns, Streptococcus pneumoniae is responsible for the highest number of pneumonia cases all over the world. Despite an increasing number of pneumococcal vaccinations, incidences of disease connected to this pathogen's infection stay at the same level, which is related to a constantly increasing number of infections caused by nonvaccinal serotypes. Unfortunately, the pathogenicity of bacteria of the Streptococcus genus is also connected to species considered to be physiological flora in humans or animals and, additionally, new species exhibiting pathogenic potential have been discovered. This paper presents an opinion concerning the epidemiology of streptococci infections based on case studies and other publications devoted to this problem. It also sheds new light based on recent reports on the prevention of protective vaccinations application in the case of streptococci infections.

Fig. 1

Percentage Streptococcus contribution in particular infections. The diagram was prepared based on the studies of Fontán et al. [34], Bharathi et al. [35], Skoczyńska et al. [36], Juvén et al. [37], and Szczepańska et al. [38]

Fig. 2

Number of cases of invasive pneumococcal disease caused by Streptococcus pneumoniae over the years in Europe, using Denmark as an example. The diagram was prepared based on the studies of Harboe et al. [76] and Ingels et al. [77]