Case report: One human Streptococcus suis occurred in Shandong Province, China

Streptococcus suis (S suis) is a major pathogen of bacterial infectious diseases, which can be transmitted to human beings through close contact with sick pigs or carriers, and can cause toxic shock, meningitis, septicemia, pneumonia, and other complications, with an extremely high mortality and disability rate. S suis is also an emerging zoonotic agent, mainly occurring in China, Thailand, and the Netherlands. This seriously threatens the health and family economy of patients. CASE PRESENTATION: A 75-year-old man presented with a 1-day history of fever, vomiting, coughing, chills, and unconsciousness. He was admitted with the diagnosis sepsis and intracranial infection. At admission, hematologic studies showed a leukocyte count of 23.45 × 10(9)/L with 91% neutrophils. Chest computed tomography revealed double pneumonia. Blood cultures grew small colonies, which were identified as S suis. Antibiotic susceptibility testing revealed that the pathogen was susceptible to levofloxacin. And then, treatment with levofloxacin was implemented. Epidemiological investigations showed that the patient had eaten pork from a sick pig. When a patient with bacterial infection has a history of eating pork from sick pigs, human S suis infection should be taken seriously. CONCLUSION: Although human S suis infection generally presents as a sporadic disease, its high burden highlights the importance of epidemiological surveillance and health education regarding human S suis infection.