Infection à Streptococcus suis

Streptococcus suis is a pathogenic, Gram-positive bacterium primarily residing in pigs that causes sudden death and meningitis in swine and can induce septic shock and meningitis in humans ^[1]. It is recognized as a major swine pathogen worldwide and an emerging zoonotic agent, particularly in Asia ^[3].

In a systematic review of 913 patients with Streptococcus suis meningitis across 24 studies (1980–2015), the mean age was 49 years and 82% were male ^[1]. Clinical presentation commonly included fever (97% of 528 patients), headache (95% of 451), and neck stiffness (93% of 496) ^[1]. Skin injury in the presence of pig or pork contact occurred in 20% of 384 patients ^[1]. Hearing loss was a frequent sequel, affecting 53% of 489 patients, while case fatality was low at 2.9% ^[1]. In humans, S. suis is capable of causing septic shock and meningitis, and is the most important cause of adult bacterial meningitis in Southeast Asia ^[2].

S. suis meningitis is the most common cause of meningitis in pork-consuming and pig-rearing countries of South-East Asia ^[4]. A systematic review identified 913 adult patients across 24 studies from 1980 to 2015, with 61% reporting exposure to pigs or pork ^[4].

Human infection is clearly associated with contact with pigs or pork, with 61% of meningitis patients reporting such exposure and 20% having a skin injury in the presence of pig or pork contact ^[4]. The pathogen is zoonotic, with transmission routes described between species, particularly from pigs to humans ^[2].

No effective licensed vaccines are currently available for S. suis despite extensive research ^[1]. Subunit vaccine candidates such as SaoA, Enolase, and multi-antigen formulations have shown robust immune responses and high protection in animal models, but translational validation in pigs is still needed ^[5]. Identification of conserved antigens and optimization of delivery platforms are prioritized future directions for achieving broad, durable immunity ^[5].

1. 1 Meurens F et al. Innate immune response to Streptococcus suis infection: advances and future challenges. Vet Res. 2026 Oct 11. PMID: 42860541. doi: 10.1186/s13567-026-01838-3. PubMed: https://pubmed.ncbi.nlm.nih.gov/42860541/
2. 2 Liu F et al. Streptococcus suis: Epidemiology and resistance evolution of an emerging zoonotic bacteria. One Health. 2025 Dec. PMID: 40599646. doi: 10.1016/j.onehlt.2025.101098. PubMed: https://pubmed.ncbi.nlm.nih.gov/40599646/
3. 3 Haas B et al. Understanding the virulence of Streptococcus suis: A veterinary, medical, and economic challenge. Med Mal Infect. 2018 May. PMID: 29122409. doi: 10.1016/j.medmal.2017.10.001. PubMed: https://pubmed.ncbi.nlm.nih.gov/29122409/
4. 4 van Samkar A et al. Streptococcus suis Meningitis: A Systematic Review and Meta-analysis. PLoS Negl Trop Dis. 2015. PMID: 26505485. doi: 10.1371/journal.pntd.0004191. PubMed: https://pubmed.ncbi.nlm.nih.gov/26505485/
5. 5 Fang L et al. Decadal advances and future prospects in subunit vaccine development against Streptococcus suis infection. Front Immunol. 2025. PMID: 41050700. doi: 10.3389/fimmu.2025.1680732. PubMed: https://pubmed.ncbi.nlm.nih.gov/41050700/