Streptococcus suis Meningitis: A Systematic Review and Meta-analysis.
BACKGROUND
Streptococcus suis is the most common cause of meningitis in pork consuming and pig rearing countries in South-East Asia. We performed a systematic review of studies on S. suis meningitis to define the clinical characteristics, predisposing factors and outcome.


METHODS
Studies published between January 1, 1980 and August 1, 2015 were identified from main literature databases and reference lists. Studies were included if they were written in West-European languages and described at least 5 adult patients with S. suis meningitis in whom at least one clinical characteristic was described.


RESULTS
We identified 913 patients with S. suis meningitis included in 24 studies between 1980 and 2015. The mean age was 49 years and 581 of 711 patients were male (82%). Exposure to pigs or pork was present in 395 of 648 patients (61%) while other predisposing factors were less common. 514 of 528 patients presented with fever (97%), 429 of 451 with headache (95%), 462 of 496 with neck stiffness (93%) and 78 of 384 patients (20%) had a skin injury in the presence of pig/pork contact. The case fatality rate was 2.9% and hearing loss was a common sequel occurring in 259 of 489 patients (53%). Treatment included dexamethasone in 157 of 300 (52%) of patients and was associated with reduced hearing loss in S. suis meningitis patients included in a randomized controlled trial.


CONCLUSIONS
S. suis meningitis has a clear association with pig and pork contact. Mortality is low, but hearing loss occurs frequently. Dexamethasone was shown to reduce hearing loss.
Academic Medical Center, Center of Infection and Immunity Amsterdam (CINIMA), Department of Neurology, Amsterdam, the Netherlands.
Anusha
A
van Samkar
Academic Medical Center, Center of Infection and Immunity Amsterdam (CINIMA), Department of Neurology, Amsterdam, the Netherlands.
Matthijs C
MC
Brouwer
Academic Medical Center, Department of Global Health-Amsterdam Institute for Global Health and Development, Amsterdam, the Netherlands.
Constance
C
Schultsz
Academic Medical Center, Center of Infection and Immunity Amsterdam (CINIMA), Department of Medical Microbiology, Amsterdam, the Netherlands; Netherlands Reference Laboratory for Bacterial Meningitis, Academic Medical Center, Amsterdam, the Netherlands.
Arie
A
van der Ende
Academic Medical Center, Center of Infection and Immunity Amsterdam (CINIMA), Department of Neurology, Amsterdam, the Netherlands.
Diederik
D
van de Beek
D017677:Age Distribution; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001210:Asia, Southeastern / Q000453:epidemiology; D003907:Dexamethasone / Q000627:therapeutic use; D004781:Environmental Exposure; D006801:Humans; D016920:Meningitis, Bacterial / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D009026:Mortality; D016273:Occupational Exposure; D012307:Risk Factors; D017678:Sex Distribution; D013290:Streptococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D017011:Streptococcus suis / Q000302:isolation & purification*; D013552:Swine
D000893:Anti-Inflammatory Agents; D003907:Dexamethasone