The ALF had 160 beds in 2 adjacent buildings with 2–3 residents/room. Among 139 residents present in March 2010, median age was 59 years (range: 28–93 years); 57 (41%) were female; 82 (59%) were black; and median duration of residence at the facility was 1,645 days (range: 1–8,364 days). Neuropsychiatric diagnoses were documented for 129 (93%) residents and included schizophrenia (95), other psychiatric diagnoses (45), mental retardation (21), seizure disorder (20), substance abuse (13), dementia (11), stroke (7), and traumatic brain injury (5). A majority of residents were dependent on Medicaid and Supplemental Security Income to pay expenses.
Among 36 ALF employees, 3 were trained to perform AMBG and administer insulin injections, including a licensed practical nurse, a certified nursing assistant, and a registered medication aide. However, AMBG was also performed routinely by direct care staff, who are unlicensed and comprise the majority of ALF employees. Staff usually rotated between buildings, but some worked routinely in a single building. Phlebotomy, wound care, and podiatry services were performed by contracted providers who visited the facility periodically and not by ALF staff. Antipsychotic medication injections were administered by psychiatrists.
Infection Control Assessment and Record Review
The ALF had no written infection control policy. We observed lapses in infection control practices. When observed performing AMBG or injecting insulin, staff sometimes failed to wash hands or change gloves between residents. Staff struggled to don gloves, suggesting glove use was not routine practice, especially for staff with long fingernails.
Staff in each building performed AMBG for residents, and blood samples were routinely obtained by using a single ACCU-CHEK® Softclix (F. Hoffman-La Roche, Ltd., Basel, Switzerland) reusable lancet-holding fingerstick device. A new lancet was inserted for each fingerstick, but the fingerstick device, which is intended for personal use, was used for multiple residents. Blood glucose readings were obtained with a single meter device in each building. The meter was not cleaned or disinfected between uses. No resident performed self-monitoring of their own blood glucose.
Staff and resident interviews and record review produced limited information about resident HBV-related risk behaviors. Sexual contact was uncommon in the facility and unknown to have occurred among residents uninfected before the investigation. Injection-drug use and sharing of personal care items could not be reliably assessed.
HBV serologic status was determined for 126 residents (91%) (). Of these, 5 (4%) had chronic infection (2 were known to be infected before the investigation). Thirty-three (26%) were immune (24 had evidence of past infection; 9 vaccinated). Fourteen residents (11%) had acute infection and 74 (59%) remained susceptible to infection. Two (14%) residents with acute infection were hospitalized with hepatitis symptoms, and 12 (86%) were asymptomatic and diagnosed on the basis of serologic screening. Serologic status was unknown for 10 ALF residents who refused serologic testing and for 3 ALF residents whose results were ambiguous.
Flowchart Depicting Results of Serological Testing for Hepatitis B Virus Among Assisted Living Facility* Residents and Identifying Members of Cohort for Risk Factor Analysis.
Retrospective Cohort Study
Among 88 residents included in the retrospective cohort study, the attack rate was 16% (). Residents who experienced acute infection were similar to the total cohort in terms of age, sex, and race (). Mean length of stay at the ALF was shorter for acutely infected residents than for the total cohort. Among 14 acutely infected residents, 11 (79%) lived in building 2; 12 (86%) had diabetes; 12 (86%) had received AMBG; 7 (50%) had received injected medications; 9 (64%) had received podiatry services; and 1 (7%) had received hemodialysis.
Characteristics of the Cohort of 88 Assisted Living Facility Residents, Virginia – March 2010.
The risk for experiencing acute HBV infection was higher among residents who received AMBG ([RR], 35; 95% [CI], 8.7–137) or injected medications ([RR], 3.0; 95% [CI], 1.2–7.6) compared with residents who were not exposed to these procedures (). Stratifying injected medications by receipt of AMBG revealed that all 7 acutely infected residents who received injected medications also had received AMBG (). Acute HBV infection developed among 12 (92%) of 13 residents who received AMBG, compared with 2 (3%) of 75 residents who did not (RR
35; 95% CI, 8.7, 137).
Assessment of Assisted Living Facility Resident Risk Factors for Hepatitis B Virus Infection, Virginia – March 2010.
HBV DNA Sequence Analysis
HBV DNA was available for genotyping and sequencing for 11 (79%) of 14 residents with acute infection and 4 (80%) of 5 residents with chronic infection. Among these 15 residents, 14 had HBV belonging to subgenotype A2; 1 resident with chronic HBV infection who did not receive blood glucose monitoring had HBV that belonged to A1 subgenotype. Sequences from residents infected with HBV subgenotype A2 formed 2 genetic clusters, each with 99.8–100% sequence identity (). Each cluster was comprised only of specimens from infected persons residing in the same building.
Dendrogram Illustrating the Genetic Relatedness of the Hepatitis B Virus* DNA Sequences from Assisted Living Facility† Residents with Acute or Chronic Infections.
The building 1 cluster included specimens from 1 resident with chronic infection and 2 residents with acute infection; all 3 received AMBG. The chronically infected resident (whose HBV DNA concentration was 2×109 IU/mL) had resided at the facility for 9 years. The building 2 cluster included specimens from 2 residents with chronic infection and 9 residents with acute infection. Among these 11, a total of 10 residents had received AMBG, including a chronically infected resident (whose HBV DNA concentration was 1.2×108 IU/mL) who had resided at the facility for 1 year.
Outbreak Control Measures
VDH provided infection control recommendations both to the ALF and to the Department of Social Services, the agency responsible for licensing and inspecting ALFs in Virginia. VDH worked with ALF staff and licensing inspectors to ensure adoption of single-use, auto-disabling lancets and separate glucose meters for each resident needing AMBG. VDH offered susceptible residents the hepatitis B vaccine: 61 of 74 (82%) residents agreed to be vaccinated and completed the 3-dose vaccination series. Only one resident who had diabetes was susceptible to HBV infection, and this resident was discharged from the ALF before receiving the third dose of the 3-dose vaccination series. VDH coordinated with Virginia Commonwealth University to ensure all HBV-infected residents received clinical follow-up and evaluation of therapy for chronic infection.