Varicella Immunity among Institutionalized Adults in a Long-Term Care Facility, Georgia, September 2008 Beth Ward, R.N., M.P.H. Vaccine Preventable Disease Epidemiologist Georgia Division of Public Health You have just heard the guidelines for management of varicella outbreak investigations in various settings. Now, I will present an outbreak of varicella that occurred in an adult long-term care facility in Georgia in the fall of 2008.
Background September 2008 GA Division of Public Health (GDPH) notified of varicella in a resident of a long-term care facility (Facility X) for developmentally disabled adults Case-patient’s roommate diagnosed with shingles two weeks earlier In early September of last year, the Georgia Division of Public Health was notified of a case of varicella in a resident of a LTCF for developmentally disabled adults. For simplicity and to maintain anonymity, I will refer to the long term care facility as Facility X throughout the rest of the presentation. The case patient reported to us shared a room with a roommate and the roommate was diagnosed with shingles 2 weeks earlier.
Description of the Institutional Facility X State hospital Developmentally disabled population Long-term residents Floor layout 4 suites Residents typically share rooms Facility X is part of a state hospital for institutionalized persons and houses developmentally disabled adults. A majority of the residents have lived in this type of facility for many years. Facility X consists of 4 suites – each with several bedrooms and a common area. Approximately 8-9 residents live in each suite and residents typically share a bedroom with 1-3 roommates.
Facility X Floor Plan Here’s the floorplan for Facility X. Each quadrant is a suite. The pink box shows the common living area of one of the suites. The common living area is surrounded by resident bedrooms and other rooms such as administrative offices. Based on the setup of the facility, strict isolation rooms were not available.
Significance of Varicella in Institutionalized Residents Population with uncertain varicella immunity Limited epidemiologic studies of institutionalized populations Non-immune adults at risk for severe complications Pneumonia (viral or bacterial) Secondary bacterial infections Central nervous system involvement (encephalitis, aseptic meningitis) Transmission facilitated by communal living Varicella in this population is a significant event for a number of different reasons. First, it’s a population with uncertain immunity to varicella because limited information is available on varicella immunity in institutionalized populations. Second, adults who are not immune and develop disease are potentially at risk for severe complications such as pneumonia, secondary bacterial infections, and central nervous system involvement including encephalitis and aseptic meningitis. In addition, transmission is facilitated due to close living quarters and shared living spaces – most of the patients had at least one roommate, but some had as many as three as mentioned in the previous slide.
Objectives of Investigation Prevent additional cases Identify and isolate case(s) Identify and vaccinate non-immune facility residents and Health Care Workers (HCWs) Evaluate varicella immunity among residents and HCWs born in the U.S. before 1980 There were two objectives of the investigation. The first, was to prevent additional cases through identifying and isolating cases and identifying and vaccinating non-immune Facility X residents and HCWs. The second objective was to assess varicella immunity among residents and HCWs born in the U.S. before 1980.
Methods (1) For all residents and HCWs Determine varicella disease and vaccination history Patient chart review Family/guardian telephone interviews Employee health record review Employee interviews The methods took place in 2 phases. First, it was necessary to determine varicella disease and vaccination histories in the residents and HCWs. For the residents, this was done by reviewing pt. charts and through family and guardian telephone interviews. For HCW staff, this was done by reviewing employee health records and conducting employee interviews.
Methods (2) For residents and HCWs with unknown or no disease or vaccination history: Serology performed to determine varicella immunity Specimens tested by the Georgia Public Health Laboratory The second part of the Methods phase took place by performing serologic testing on all HCWs and patients with unknown or no disease or vaccination history. Please note: We did not test everyone, again, only those with an unknown or no disease or vaccination history. After the specimens were collected, serologic testing was performed by Georgia Public Health Laboratory.
ACIP Criteria Defining Presumptive Varicella Immunity Varicella/zoster disease verified by health care provider Laboratory evidence of immunity Documented varicella vaccination (age-appropriate) Birth in the U.S. before 1980 Here is a summary of the Advisory Committee on Immunization Practices’ Guidelines to determine immunity to varicella. These include diagnosis or verification of history of varicella or zoster by a health care provider, laboratory evidence of immunity or confirmation of disease, and documentation of age-appropriate vaccination with varicella vaccine. The guideline I’d like to highlight in the presentation today is the last mentioned which is birth in the U.S. before 1980.
Outbreak Containment Measures Isolate index case Furlough susceptible staff 1 HCW Consider post-exposure prophylaxis (PEP) for residents and HCWs Vaccinate susceptible residents and staff 5 residents As the investigation proceeded, several outbreak containment measures were put into place. The first measure was immediate isolation of the index case after the initial report from the facility. Due to the facility setup, strict isolation was not possible. Second, after serologic testing results were reported to us from the lab, we furloughed one non-immune HCW from work for the duration of the disease incubation period. Next, we considered post-exposure prophylaxis for the residents and HCW and I’ll elaborate on that point a little later in the talk. Last, we vaccinated 5 susceptible residents and the HCW with the first dose of vaccine. They then received the second dose as per ACIP guidelines 4 weeks later.
Varicella PEP Recommendations Varicella vaccine Immediate protection if given within 3-5 days of exposure Protection against subsequent exposures if given > 5 days after exposure Varicella Zoster Immune Globulin (VariZIG) Investigational product Recommended for individuals at high risk for severe disease and complications Here are the guidelines for varicella post-exposure prophylaxis. When varicella occurs in a high risk setting, such as a healthcare facility, persons without evidence of immunity should be offered varicella vaccine within 3-5 days of exposure to provide the greatest protection against developing disease. Post-exposure vaccination should be given as soon as possible after exposure, but vaccination is still indicated after 5 days because it induces protection against subsequent exposures. For persons without evidence of immunity who have contraindications to vaccination and are at high risk of severe disease such as immunocompromised persons and pregnant women, administration of an investigational product, Varicella Zoster Immune Globulin should be considered. If given, it must be administered within 96 hours of exposure.
Results Now I’ll present our results.
Facility X Demographics 34 Residents Median age 47 years (18-60 years), 71% male 59 HCWs Median age 45 years (19-69 years) 27% male In our investigation, we found that Facility X housed 34 residents. The median age of the residents was 47 years and a majority or 71% of the –residents were male. 59 HCWs work in the building and provide 24 hour a day care and supervision of the residents. The median age of the HCWs was 45 years, similar to the residents, but only 27% of the staff were males.
Positive Varicella History Reported Varicella Disease History among Residents and HCWs by Age Group, Facility X, Georgia Positive Varicella History Age Group Residents (n=34) HCWs (n=59) Born before 1980 3/33 (9%) 26/52 (50%) Born on or after 1980 0/1 (0%) 5/7 (71%) This table displays reported varicella disease history among residents and HCWs born before and after 1980. The majority of residents and HCWs in Facility X were born before 1980, and would be considered presumptively immune by ACIP Criteria. Of this group born before 1980, only 9% of the residents and 50% of the HCWs had a documented or reported history of varicella disease. The HCWs born on or after 1980 with a positive varicella history had either documentation of disease and/or documentation of vaccination.
Varicella Immunity in Residents and HCWs born before1980, per serology, Facility X, Georgia Positive (+) serology 25/30 (83%) 25/26 (96%) Negative (-) serology 5/30 (17%) 1/26 (4%) This table displays the serology results only on residents and HCWs born before 1980 who were tested because they had no evidence of varicella immunity. Of this group, we found that most persons were immune: 83% of residents and 96% of HCWs.
Varicella Immunity in Residents and HCWs born before1980, per serology and hx, Facility X, Georgia Positive (+) history 3/33 (9%) 26/52 (50%) Positive (+) serology 25/33 (76%) 25/52 (48%) Total 28/33 (85%) 51/52 (98%) This slide now shows varicella immunity among residents and HCWs born before 1980 based on documented or reported history of disease and positive serology results from those tested. So, in summary, considering both positive history of disease or vaccination and positive serology in both populations, only 85% of residents were immune in contrast to 98% of HCWs. Given the ACIP criteria of birth in the U.S. prior to 1980 as criteria for immunity, we find the level of immunity in the resident population to be lower than expected.
Timeline of Varicella Investigation, Facility X, Georgia, 2008 8-22-08 9-4-08 9-5-08 9-8-08 9-12-08 9-18-08 9-10-08 HCW furloughed, non-immune vaccinated Furloughed HCW diagnosed w/ varicella GDPH notified, investigation begun, index case isolated Varicella case diagnosed Serologic testing completed The timeline summarizes the events that occurred in the investigation. On August 22nd, a shingles case was diagnosed. On September 4th, the roommate of the shingles case was diagnosed with varicella. On September 5th, a Friday afternoon, GA public health was notified of the varicella case, the investigation began, and the index case was isolated. On September 8th serologic testing began and was then completed on September 10th. On September 12th, one HCW was determined to be non-immune, was furloughed from work and along with 5 non-immune residents was given the first dose of vaccine. Looking at this timeline, you can see we were not able to vaccinate within the 5 day period to prevent disease from this exposure. And subsequently, as you can see, on September 18th the furloughed HCW was diagnosed with varicella. Serologic testing begun Shingles case diagnosed
Summary Two cases of varicella resulted from exposure to a resident with shingles in Facility X 1 resident 1 HCW 15% of the residents in Facility X born before 1980 were susceptible to varicella infection So in summary, two cases of varicella resulted from exposure to a resident with shingles. And, 15% of the residents born before 1980 were susceptible to varicella infection.
Investigation Barriers No good history Reporting reliability among residents questionable due to medical diagnosis Resident medical records archived off-site No documentation in employee health records Physical setup of facility Strict isolation not feasible We had a number of challenges in the investigation. First, it was difficult to determine histories to varicella because reporting reliability among residents was questionable due to their medical diagnoses. In addition, the residents medical records were archived off-site, and no information on varicella immunity was documented in employee health records. The second challenge was the physical set up of the facility which did not allow for strict isolation of the case patient.
Discussion High prevalence of non-immune residents may result from sequestered population Institutionalized adults (in LTCF setting) may not have same opportunities for exposure to varicella as others Our point of discussion is that high prevalence of non-immune residents may result from a sequestered population: Institutionalized adults may not have the same opportunities for exposure to varicella as the general population.
Conclusion Two cases of varicella linked to an institutional setting resulted from incomplete immunity among residents and staff In conclusion, two cases of varicella linked to an institutional setting resulted from incomplete immunity among residents and staff
Recommendations Adhere to ACIP guidelines to document varicella immunity among staff in institutional settings Consider reappraisal of ACIP criteria for varicella immunity (birth before 1980) in residents of similar facilities And our recommendations are as follows: Adhere to ACIP guidelines to document varicella immunity among staff in institutional settings. Second, consider reappraisal of ACIP criteria for varicella immunity (birth before 1980) in residents of similar facilities.
Recommendations Isolate infectious residents and consider furlough of HCWs with no documentation of varicella immunity Consider post-exposure prophylaxis (PEP) for residents and HCWs Administer two doses of varicella vaccine (4-6 weeks apart) to persons with no evidence of immunity Third, isolate infectious residents and consider furlough of HCWs with no documentation of varicella immunity. Next, consider post-exposure prophylaxis (PEP) for residents and HCWs. And last, administer two doses of varicella vaccine (4-6 weeks apart) to persons with no evidence of immunity.
Acknowledgements GDPH -Cherie Drenzek -Julie Gabel -Katie Arnold -Elizabeth Sullivan -Melissa Tobin D’Angelo GA Public Health Lab -Mahin Park -Kim Kilgour GA Regional Hospital -Delories Powell -Rama Gangaiah -Delores Smalling GA District Health Official -Heidi Davidson