In a comprehensive systematic review that assessed risk factors for herpes zoster (HZ) infection, researchers found that immunosuppression through HIV/AIDS or malignancy places individuals at a significant risk of reactivation of latent HZ viral suppression.

Herpes zoster (HZ), commonly known as shingles, is a result of the reactivation of the varicella zoster virus (VZV). VZV, which is commonly referred to as chickenpox, is generally acquired in childhood and lies dormant in the spinal and cranial sensory ganglia after primary infection. When HZ appears, it presents as a painful, erythematous, maculopapular rash inside of which lesions are filled with fluid before crusting over.

According to the study, published in Open Forum Infectious Diseases, there are more than 1 million new cases of HZ reported every year in the United States. Recently, scientists have observed that incidence of HZ seems to be increasing over time, yet without any clear indication as to why this is occurring.

Previously, studies have identified some of the risk factors associated with the reactivation of VZV, demonstrating a potential relation to a decrease in T-cell immunity, which could be caused by aging and immunosuppression. However, researchers have also observed a correlation between VZV and family history or stress, giving rise to the need to further ascertain the risk factors for the disease.

In order to conduct the review, the researchers searched MEDLINE, EMBASE, Cochrane Central, Cochrane Systematic Reviews, Web of Science, and CAB Direct for articles reporting on HZ infection and associated risk between January 1, 1966, and January 31, 2019. Additionally, the findings followed the MOOSE guidelines for the reporting of observational studies and in accordance with the PRISMA guidelines for conducting a meta-analysis.

Out of 4417 total identified studies, 88 were included for analysis in the review. The researchers observed within these selected studies that immunosuppression through HIV/AIDS or malignancy carried a significant risk of HZ compared with controls.

Additionally, the researchers found that family history was also associated with a greater risk, although less significantly than HIV/AIDS or malignancy. Following family history in level of risk were physical trauma and older age.

Furthermore, a slightly smaller risk was observed among patients with psychological stress, females, and other comorbidities, such as diabetes, rheumatoid arthritis, cardiovascular diseases, renal disease, systemic lupus erythematosus, and inflammatory bowel disease compared with controls. The researchers also noted that patients who were Black demonstrated lower rates of HZ development.

With the knowledge that HIV/AIDS, immunosuppression, family history, older age, trauma, female sex, and presence of a comorbid condition may place an individual at a greater risk of HZ, providers can inform patients of their risk level. This, in turn, allows patients to choose whether they wish to pursue a zoster vaccination, which also supports the potential for an improvement in the uptake of zoster vaccination overall.

REFERENCE
Marra F, Parhar K, Huang B, Vadlamudi N. Risk Factors for Herpes Zoster Infection: A Meta-Analysis. Open Forum Infectious Diseases. 2020;7(1):ofaa005. doi: 10.1093/ofid/ofaa005.