Underutilization of pneumococcal vaccine in nursing home in Washington State: report of a serotype-specific outbreak and a survey

Abstract

Purpose: To describe an outbreak of pneumococcal disease in a Washington state nursing home and to report a survey of pneumococcal vaccine utilization in Washington nursing homes.

Patients and methods: Outbreak. Data were collected from nursing home residents' records. Nasopharyngeal cultures were obtained from residents and staff. Survey. Fifty-four randomly selected Washington nursing homes were surveyed about pneumococcal vaccine utilization and policies.

Results: Outbreak. Three confirmed and 4 possible cases of pneumococcal disease occurred over 9 days among 94 residents; 5 patients (71%) died. Cases were identified among 6 of 42 residents on 1 wing, compared with 1 of 52 on the other 2 wings (relative risk 7.4, 95% confidence interval 1.0, 398.5). Streptococcus pneumoniae serotype 9V was cultured from the blood of 3 confirmed case-patients and the nasopharynx of 2 of 73 residents. Only 7% of residents had received pneumococcal vaccine, including one case-patient who had received 14-valent vaccine without serotype 9V. Survey. Only 22% of residents were reported to have received pneumococcal vaccine; vaccination status was unknown for 66%. Physician discretion determined pneumococcal vaccination in 49 (91%) nursing homes; 9 (17%) had a written policy. Two major barriers to pneumococcal vaccination were cited: low priority among physicians (43%) and difficulty in determining residents' vaccine history (37%).

Conclusions: A pneumococcal disease outbreak among undervaccinated nursing home residents probably resulted from person-to-person transmission. Pneumococcal vaccine appears to be underutilized in Washington state nursing homes.