Central nervous system involvement in adult patients with invasive infection caused by Streptococcus agalactiae

Abstract Introduction Streptococcus agalactiae is frequently an asymptomatic coloniser and a cause of neonatal and puerperal sepsis. Infections in non-pregnant adults are uncommon. The frequency of neurological complications caused by invasive infection with this microorganism in adults remains unknown. Here, we study the frequency and characteristics of central nervous system (CNS) involvement in adults with invasive S. agalactiae infection. Patients and methods Review of all adults with invasive S. agalactiae infection between 2003 and 2011 in a tertiary hospital. Results S. agalactiae was isolated from blood, cerebrospinal fluid or synovial fluid in 75 patients. Among them, seven (9.3%) displayed neurological involvement: five men and two non-pregnant women, aged between 20 and 62 years. Diagnoses were spinal epidural abscess due to spondylodiscitis with spinal cord compression; acute bacterial meningitis; ischaemic stroke as presentation of bacterial endocarditis (two patients each); and meningoventriculitis after neurosurgery and ventricular shunting. One patient with endocarditis caused by S. agalactiae and S. aureus died in the acute phase, and another died 3 months later from metastatic cancer. The other patients recovered without sequelae. All patients had systemic predisposing factors for infection and five (71.4%) had experienced disruption of the mucocutaneous barrier as a possible origin of the infection. Conclusions CNS involvement is not uncommon in adult patients with invasive infection caused by S. agalactiae. Isolating S. agalactiae , especially in cases of meningitis, should lead doctors to search for predisposing systemic disease and causes of mucocutaneous barrier disruption.