Invasive Disease and Toxic Shock due to Zoonotic Streptococcus suis: An Emerging Infection in the East?

摘要

Streptococcus suis (S. suis) is widely recognised in the veterinary world as a cause of rapidly progressive and fatal sepsis in infant pigs, associated with meningitis, polyarthritis, and, occasionally, pneumonia. A more fulminant bacteraemic infection is seen in neonatal pigs [1,2]. For reasons that are unknown, adult pigs do not succumb to this infection, although they demonstrate asymptomatic nasopharyngeal carriage (Figure 1), and infant piglets become infected after early contact with colonised adult females. In many respects, S. suis infection is the porcine version of human group B strep disease. Zoonotic disease due to S. suis does occur sporadically in Western countries, but is encountered more commonly in countries such as Thailand, China, and Hong Kong. It affects predominantly individuals with occupational exposure to pigs. In humans, meningitis is the most common presentation (about 80% of all cases), though S. suis disease can be associated with other suppurative complications such as pneumonia and arthritis. Mortalities of 5%–10% of cases are reported [2], and S. suis is the third most common cause of bacterial meningitis in Hong Kong [3].