Streptococcus Suis: A New Emerging or an Old Neglected Zoonotic Pathogen?

Abstract

Infections caused by Streptococcus suis are considered a global and an economical problem in the swine industry. Moreover, S. suis is an agent of zoonosis that afflicts people in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infections in humans (mainly meningitis) have been reported during the last 40 years, a large outbreak due to this pathogen emerged in the summer of 2005 in China. The severity of the infection in humans during the outbreak, such as a shorter incubation time, more rapid disease progression and higher rate of mortality, attracted a lot of attention from the scientific community and the general press. In fact, the number of publications on S. suis (including the number of reported human cases) has significantly increased during recent years. In this article we critically review the present knowledge on S. suis infection in humans, we discuss the hypotheses that may explain the 2005 outbreak and the repercussion of such an episode on the scientific community.

Keywords:

• emerging disease
• highly virulent strains
• meningitis
• occupational disease
• septic shock
• Streptococcus suis
• toxic shock-like syndrome
• zoonosis

Acknowledgements

The authors would like to recognize the scientific contribution of Streptococcus suis research by their collaborators, the graduate students and post-doctoral fellows who worked on projects involving characterization of virulence factors and studies on the pathogenesis of S. suis infections over the past 20 years, as well as the invaluable help of members of the China CDC research team working on the isolation and characterization of the strains involved in the 2005 Chinese outbreak.

Financial & competing interests disclosure

Funding for Streptococcus suis research was provided by the National Science and Engineering Research Council of Canada (CRSNG) to M Gottschalk (grant 154280 and Discovery Accelerator Supplement) and to M Segura (grant 342150–07), collaborating project Quebec-Chine PSR-SIIRI-102 from the Ministère de Développment économique, innovation et exportation du Québec to M Gottschalk and M Segura, and 973 Program (2005CB522904) from the Ministry of Science and Technology, China, to J Xu. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Additional information

Funding

Funding for Streptococcus suis research was provided by the National Science and Engineering Research Council of Canada (CRSNG) to M Gottschalk (grant 154280 and Discovery Accelerator Supplement) and to M Segura (grant 342150–07), collaborating project Quebec-Chine PSR-SIIRI-102 from the Ministère de Développment économique, innovation et exportation du Québec to M Gottschalk and M Segura, and 973 Program (2005CB522904) from the Ministry of Science and Technology, China, to J Xu. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.