Streptococcus suis

Streptococcus suis is a bacterial zoonosis and a major swine pathogen, with pigs described as its principal reservoir ^[1][4]. The organism is reported to be widespread across numerous countries and to occur in diverse serotypes and complex population structures ^[3]. The provided sources also note that it has been studied as an emerging zoonotic agent and as a pathogen of veterinary, medical, and economic importance ^[1][3].

In pigs and humans, S. suis has been reported to cause septicemia, pneumonia, endocarditis, arthritis, and meningitis ^[1]. The available sources specifically highlight meningitis as a clinically important manifestation and note that irreversible sequelae may occur ^[1]. A case summary in the provided material describes fever, myalgias, headache, imbalance, persistent vomiting, asthenia, and new hearing loss, with meningitis diagnosed and residual deafness and vestibular dysfunction after recovery ^[4]. The sources further state that meningitis may have a generally favorable course but commonly leaves sensorineural hearing loss as a sequela ^[4].

S. suis is described as a major swine pathogen worldwide and as an emerging zoonotic agent, mainly in Asia ^[1]. Other source material states that it is widespread across numerous countries and has increasing reports of infection over the last decade ^[3][4]. The pathogen is reported to pose serious threats to both human and animal health and to cause considerable economic losses in the swine industry ^[1][2]. The provided literature also emphasizes ambiguous epidemiological patterns and the growing public-health concern of multidrug resistance among clinical isolates ^[2][3].

The available sources indicate that S. suis is transmitted from the swine industry to environments and human communities, supporting a zoonotic exposure pattern linked to pig-associated settings ^[2]. One source identifies pigs as the principal reservoir ^[4]. Specific exposure mechanisms beyond this swine-associated transmission context are not fully detailed in the provided material, so source-backed detail on routes such as contact types or aerosol persistence is not yet available ^[2][3].

The provided sources identify pigs as the principal reservoir and place the swine industry at the center of exposure, making pig-associated workers and people with swine or pork contact the most clearly implied risk group ^[4][2]. Human cases are documented in the literature, including a reported adult male case with meningitis and sequelae ^[4]. Beyond swine-linked exposure, the snippets do not define additional high-risk groups with enough specificity to support further inference ^[1][2][3].

The provided sources suggest that prevention focuses on careful practices in contact with pigs and pork products, and one source explicitly states that prevention in humans involves care in contact with swine and their meat ^[4]. Another source notes that identification of virulence factors has opened promising avenues for vaccine development, but it does not provide a usable preventive schedule or recommendation ^[1]. Because the snippets do not specify standardized exposure-control protocols, source-backed detail on formal preventive measures is not yet available ^[1][4].

In surveillance, S. suis should be interpreted as a zoonotic infection signal spanning animal and human interfaces, with attention to pig-associated exposure ecology and the possibility of severe invasive disease ^[1][2][3]. The sources also indicate that antimicrobial resistance is an increasing challenge and that epidemiological patterns are described as ambiguous, so case counts alone may understate the complexity of local transmission and strain structure ^[2][3]. Source-backed detail on routine case definitions, laboratory thresholds, or reporting intervals is not yet available ^[2][3].

1. 1 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/
2. 2 Lv R et al. Current prevalence and therapeutic strategies for porcine Streptococcus suis in China. Appl Environ Microbiol. 2025 Mar 19. PMID: 39998255. doi: 10.1128/aem.02160-24. PubMed: https://pubmed.ncbi.nlm.nih.gov/39998255/
3. 3 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/
4. 4 Streptococcus suis. Revista Portuguesa de Doenças Infecciosas (RPDI). 2016. doi: 10.65332/rpdi.v12.26. DOI: https://doi.org/10.65332/rpdi.v12.26
5. 5 Streptococcus suis. Veterinary Public Health & Epidemiology. 2023. doi: 10.1007/978-981-19-7800-5_33. DOI: https://doi.org/10.1007/978-981-19-7800-5_33
6. 6 Streptococcus suis. Definitions. 2020. doi: 10.32388/najcp8. DOI: https://doi.org/10.32388/najcp8

ICD-10

A40.0

ICD-11

1C1Y

Total cases

271

Total deaths

1

Peak month

2026-05

Coverage

2 reporting countries · 2026-01-01 → 2026-05-01