Rescue of Severely Immunocompromised HIV‐Positive Persons. Part 4
Case investigation. From 4 December 2008 through 7 January 2009, 11 of the 70 residents of facility A had varicella rash onset, for an overall attack rate (AR) of 15.7%. Varicella diagnoses were laboratory confirmed for 3 case patients (2 who were positive for varicella IgM and 1 with VZV DNA detected in a skin lesion). Case patients ranged in age from 32 to 49 years (median, 39 years). All case patients resided in buildings 1 and 3 (8 cases in building 1 and 3 cases in building 3; AR in buildings 1 and 3 were 33% and 13%, respectively) and attended 1 of 2 off‐site day programs using 1 of 2 transportation vehicles. In addition to day programs, residents interacted with each other at occasional facility‐wide social events. Five case patients had 50 lesions, and 1 had >500 lesions. The median duration of rash was 9 days, and fever was present in 90% of case patients. Complications did not develop in any case patients, but 1 patient died 10 days after rash onset of causes unrelated to varicella. Two case patients had a documented history of varicella disease.
Varicella was identified among 2 facility A staff (a nurse and a caregiver, aged 28 and 33 years, respectively). Both developed a rash with >250 lesions on 22 December 2008. Neither staff member reported a history of varicella vaccination or disease; one was born outside the United States. One additional case was identified in a severely disabled nonfacility participant of one of the day programs attended by 7 of the 11 infected residents. This case patient had no history of varicella vaccination or disease and developed a rash with 250–500 lesions on 18 December 2008.
During the medical records review conducted in January, we identified a possible case of herpes zoster in the 41‐year old roommate of the first varicella case patient. The roommate developed a localized vesicular rash on his right arm on 17 November 2008 (18 days before the start of the varicella outbreak) that lasted 8 days. He had a documented history of varicella disease in 1985 and a positive VZV IgG test result from a blood sample obtained on 10 December 2008. His lesions were thought to be fungal in origin at the time of rash. Because his lesions were not diagnosed as herpes zoster at the time of presentation, his rash was not kept covered.
Analysis. There were no statistically significant differences among case patients and non‐case residents by age, sex, or race and/or ethnicity. The mean age when they were first admitted to a residential facility was younger for case patients than non‐case residents (9.5 vs 15.0 years; ). A larger proportion of case patients than non‐case residents required full or some physical assistance, and proportionally more of them attended day program A. Non‐case residents were more likely to attend other day programs. Only 1 case patient was on an immunosuppressive medical regimen (methotrexate and tumor necrosis factor α inhibitor) for treatment of rheumatoid arthritis; there were no statistically significant differences between cases and non–case residents in the prevalence of medical conditions associated with immunosuppression.