Long-term outcomes of patients with Streptococcus suis infection in Viet Nam: A case-control study

Summary Objectives Streptococcus suis is a zoonotic cause of severe meningitis and sepsis in humans. We aimed to assess the long-term outcomes in patients who survived S. suis infection, in particular the progress and impact of vestibulocochlear sequelae. Methods This case-control study evaluated outcomes of S. suis infection at discharge and 3 and 9 months post-discharge for 47 prospectively enrolled cases and at 11–34 months for 31 retrospectively enrolled cases. Outcomes in patients were compared to 270 controls matched for age, sex and residency. Results The prevalence ratio (PR) of moderate-to-complete hearing loss was 5.0(95%CI 3.6–7.1) in cases at discharge, 3.7(2.5–5.4) at 3 months, 3.2(2.2–4.7) at 9 months, and 3.1(2.1–4.4) in retrospective cases compared to controls. Hearing improvement occurred mostly within the first 3 months with a change in hearing level of 11.1%(95%CI 7.0–15.1%) compared to discharge. The PR of vestibular dysfunction was 2.4(95%CI 1.7–3.3) at discharge, 2.2(1.4–3.1) at 3 months, 1.8(1.1–2.5) at 9 months, and 1.8(1.1–2.6) for retrospective cases compared to controls. Cases also indicated more problems with mobility, self-care and usual activities. Conclusions Both hearing and vestibular impairment were common and persist in cases. Appropriate patient management strategies are needed to reduce the incidence and impact of these sequelae.