1629. Herpes Zoster Risk in Immunocompromised Adults in the United States: A Systematic Review

Abstract Background The two known primary risk factors for herpes zoster (HZ) are age and immunodeficiency yet estimates of HZ risk by immunocompromising medical condition have not been well characterized. We undertook a systematic review of the literature to estimate HZ risk in six categories of immunocompromised patients. Methods We conducted a systematic review of evidence for HZ in patients with hematopoietic cell transplants (HCT), cancer (blood and solid tumor), HIV, and solid-organ transplant (SOT; kidney and other). We identified studies in Pubmed, Embase, Cochrane, Scopus and clinicaltrials.gov using the following outcome search terms: Herpes Zoster, Shingles, VZV, chickenpox, Varicella-zoster virus, or opportunistic infection. We included articles that presented original data from studies in the United States on risk of HZ in adults and were published after 1992 (1996 for HIV). Case reports and conference abstracts were excluded. We assessed risk of bias with Cochrane (clinical trials) or GRADE (observational) methods and categorized studies as high, medium, or low risk. Results We identified and screened 3,765 records; 57 articles were abstracted and 34 deemed low or moderate risk of bias (Figure 1). All articles reported at least one estimate of HZ cumulative incidence, which ranged from 0% to 41%. Thirteen studies estimated HZ incidence, which varied widely within and between immunocompromised populations (Figure 2). The highest estimates were seen in HCT (median = 52 HZ cases/1000 patient-years), followed by blood cancers and SOT, and then solid tumor cancers and HIV (median = 13 HZ cases/1,000 patient-years). Among 17 studies of HCT patients, longer follow-up time and absent or <1 year of post-transplant antiviral prophylaxis were associated with higher HZ cumulative incidence (Figure 3). Conclusion HZ is common among all immunocompromised populations studied—exceeding expected HZ incidence in immunocompetent middle-age adults. Antiviral prophylaxis among HCT patients has an ameliorating effect but long-term HZ risk following discontinuation is unclear. Better evidence for incidence and severity of HZ in immunocompromised populations is needed to inform economic and HZ vaccine policy analyses. Disclosures All authors: No reported disclosures.