The risk of developing herpes zoster appears to be strongly associated with a family history of the disorder, researchers said in a study published in the Archives of Dermatology.
If further studies confirm this link, people whose family histories put them at risk can be targeted for vaccination, according to Lindsey D. Hicks, a medical student at the University of Texas at Houston, and her associates.
Noting that a recent literature review suggested that a family history of herpes zoster might be predictive but that the issue has not been adequately studied, the investigators conducted a case-control analysis involving 504 patients treated between 1992 and 2005 and 523 well-matched control subjects who never had herpes zoster.
Nearly equal proportions of cases and controls (76%) recalled having had primary infection with varicella-zoster virus.
Case patients were about four times more likely than control subjects were to report having a first-degree relative with a history of herpes zoster, and they were only slightly less likely to report having a more distant blood relative with a history of the disorder.
Moreover, the risk of developing herpes zoster rose in a dose-dependent fashion as the number of affected relatives increased.
"An odds ratio of 4.5 was calculated for [patients] reporting single [affected] relatives, and an odds ratio of 13.7 was calculated for those reporting multiple [affected] relatives," Ms. Hicks and her associates wrote (Arch. Dermatol. 2008;144:603-8).
"Our study indicates the possibility of inherited susceptibility to herpes zoster and indicates that further studies into this area may be necessary in order to recognize and vaccinate susceptible individuals," the researchers said.
Vaccinating these at-risk individuals "may decrease both their chance of future herpes zoster infection and health care expenditures toward herpes zoster morbidity," they added.
At press time, the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) had recommended that all individuals aged 60 years and older should receive the herpes zoster vaccine to prevent the development of shingles.
The new herpes zoster vaccine recommendation, which was published in an early-release electronic edition of Morbidity and Mortality Weekly Report, replaced a provisional recommendation that ACIP had made after licensure of the vaccine in 2006 by the Food and Drug Administration.
Although most adults are seropositive for primary varicella zoster infection, the lifetime risk of developing herpes zoster—reactivation of latent varicella-zoster virus residing in dorsal root ganglia after primary infection—is 10%-30%, the investigators noted.
Risk rises dramatically with age, so that the risk for people aged 85 years and older approaches 50%, said Ms. Hicks and her associates, who reported that they had no financial conflicts regarding this study.
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