UK: Prior use of antibiotics raises the risk of subsequent herpes zoster infection, is the conclusion drawn from a recent study published in PLOS One.
The researchers observed a strong association between the first antibiotic prescribed ten years ago and herpes zoster infection risk in younger patients aged 18 to 50. Given the wide range of individual responses to viral infection, the study findings are essential; any indirect effect of antibiotics on the immune response may be specifically significant.

The effect of antibiotics on the human microbiome is established correctly now, but there needs to be more clarity on their indirect impact on the related immune response. The plausible association of Herpes zoster involving reactivation of previous varicella-zoster virus infection with prior antibiotic use may suggest a potential link with the immune response.
Considering the above, David Armstrong, Affiliation School of Life Course and Population Sciences, King's College London, London, United Kingdom, and colleagues aimed to determine the effect of antibiotics on the reactivation of the varicella-zoster virus. The authors, therefore, conducted a case-control study comparing the antibiotic prescriptions of patients with a diagnosis of Herpes zoster (HZ) and those without it.
The study was carried out using a clinical database, the UK's Clinical Practice Research Datalink. The authors identified 163,754 patients with varicella-zoster virus infection and 331,559 age/sex-matched controls and their antibiotic exposure over the previous ten years or more. Regarding timing and volume, the association between antibiotic exposure and subsequent infection was identified.
The study led to the following findings:
The prior antibiotic prescription was associated with a higher risk of herpes zoster infection (adjusted OR [aOR] 1.50).
The use of the first antibiotic prescribed over ten years ago was strongly associated with an increased risk of subsequent herpes zoster infection (aOR 1.92).
This association was more pronounced in younger patients aged 18-50 (aOR 2.77).
By discovering an association between prior antibiotics and Herpes zoster, the study has revealed that antibiotics may be involved in the reactivation of the varicella-zoster virus. Moreover, that effect may be relatively long-term. The indirect impact of antibiotics on viruses, medicated possibly through their mark on the immune system and microbiome, merits further research.
The study's limitations include its case-control design and the risk of residual confounding.
Reference:
Armstrong D, Dregan A, Ashworth M, White P (2022) Prior antibiotics and risk of subsequent Herpes zoster: A population-based case control study. PLoS ONE 17(10): e0276807. https://doi.org/10.1371/journal.pone.0276807