Endogenous endophthalmitis caused by group B streptococcus; case reports and review of 35 reported cases

A clinical summary of the 6 cases observed at our clinics is shown in Table 1. The average age was 73.5 years. Every patient had unilateral endophthalmitis (3 left eyes and 3 right eyes). Four patients had DM. Three patients reported visual disturbance as the initial symptom, while the other three initially reported systemic symptoms, such as fatigue, anorexia and algor. The specialties of the initially consulted doctors were as follows: ophthalmologist (3 cases), physician (2 cases), and surgeon (1 case). The diagnosis of EBE caused by GBS was based on positive findings from blood culture testing in 5 of 6 cases. Culture testing of ocular samples was also performed in 3 of these 5 cases, with positive findings in 2 cases. One of 6 cases (case 4) had negative findings in blood culture testing, but had positive findings in ocular sample culture testing, leading us to diagnose EBE caused by GBS. The focus of the infection in the cases was as follows: urinary tract infection (UTI) (3 cases); cellulitis (2 cases); arthritis (1 case); peritonitis (1 case); catheter-associated infection (1 case); and endocarditis (1 case). UTI and cellulitis co-occurred in 2 cases, and arthritis additionally co-occurred in one of these 2 cases. Susceptibility testing used blood samples in all cases except for case 4, for which ocular samples were used (both aqueous and vitreous samples in this case returned the same result). Susceptibility testing revealed that all the strains of GBS in these patients were sensitive to β-lactam antibiotics (penicillins, cephems and carbapenems) and vancomycin. Each strain had varying susceptibility to other antibiotics, such as macrolides (erythromycin and clarithromycin), tetracyclines (minocycline), fluoroquinolone (levofloxacin) and aminoglycoside (arbekacin), although some data were unavailable, as shown in Table 2. Among them, 4 strains were resistant to levofloxacin (no data for 1 isolate). Vitrectomy was performed in 4 cases, including the intravitreal injection of antibiotics. In case 2, vitrectomy could not be performed due to a poor systemic condition. In case 3, the patient’s condition improved with only systemic antibacterial therapy. Visual acuity recovered in 4 cases. In the other cases (cases 4 and 6), visual acuity did not recover even after vitrectomy.

We reviewed 41 cases of EBE caused by GBS, including the 6 cases observed at our clinics. Twenty-two cases were from East Asia (16 cases from Japan, 5 cases from Singapore and 1 case from South Korea). The other 19 cases were from Western countries (11 cases from the United States, 5 cases from the United Kingdom, 2 cases from Canada and 1 case from Spain). The 41 cases included 21 men, 18 women and 2 cases with unstated sex. The average age was 65.5 years (SD: 12.7; range: 42–95 years). In 29 patients (71%), EBE was unilateral: 16 cases (55%) in the right eye, 11 (38%) cases in the left eye, and unstated in 2 (7%) cases. Twelve patients (29%) had bilateral EBE. Visual acuity (initial and final) in the 43 eyes of 34 patients for whom these data were available is shown in Fig. 1. Of these 43 eyes, 24 eyes of 19 patients were from East Asia and 19 eyes of 14 patients were from Western countries. Twenty-six eyes (60%) finally lost all vision or died (i.e., no light perception [NLP], phthisis bulbi, evisceration, enucleation or death). Seven eyes (16%) achieved final visual acuities greater than 0.6 in decimal values. There was no significant difference in the visual acuity outcome between the cases from East Asia and Western countries. The group of subjects with a final outcome of loss of vision or death (including NLP, phthisis bulbi, evisceration, enucleation and death) had a significantly greater incidence of initial visual acuity of less than counting fingers (CF) (Table 3). Among the 15 cases that underwent vitrectomy, 10 cases had an initial visual acuity of less than CF. However, 7 of these 10 cases lost vision even after vitrectomy. This rate of vision loss was not significantly different than in the cases with initial visual acuity of less than CF that did not undergo vitrectomy (17/22 cases; 77%). Moreover, a patient age ≥ 80 years at presentation was not associated with a final loss of vision (Table 3). Of 41 patients, 13 (32%) had DM as an underlying medical condition. The second most common condition was human immunodeficiency virus infection (3 cases, 7%). Extraocular infection foci are shown in Table 4. The most common focuses were as follows: endocarditis (15, 37%); arthritis (13, 32%); cellulitis (8, 20%); UTI (6, 15%); pneumonia (4, 10%); and meningitis (3, 7%). These showed no significant differences in the cases from East Asia and Western countries. Of 41 patients, 17 (41%) had infection foci in more than 3 organs (multiple infections in a single type of organ, such as joints or soft tissue, were counted as single foci).