Shingles, also known as herpes zoster, is a painful rash which usually appears in a stripe across the body. It is caused by the same virus that causes chickenpox. After chickenpox, the virus remains in the body. When our immune system is weakened through illness or age, the virus can reactivate to cause shingles.
It generally resolves by itself; after about one month the symptoms will usually have disappeared. However, some patients go on to develop complications. If you were to take 100 patients over 60 years of age with zoster, around 10 would develop long-term pain, called postherpetic neuralgia, and around 4 would develop complications involving the eye such as eye infections. It is estimated that another 4 in the 100 patients will develop one of a range of other complications, some of which are severe. We have a very poor understanding of the proportion and characteristics of zoster patients developing these rarer complications. However, they can have serious impacts on patients, and be costly to the healthcare system. We can now vaccinate against zoster: therefore, a better understanding of the epidemiology of these rare but severe zoster complications (and how well vaccination protects against them) is important right now to inform vaccine policy.
The objective of this research is to carry out a longitudinal study using UK healthcare data to estimate the number of people experiencing acute complications following a first ever episode of zoster and to estimate how effective the current shingles vaccine is at protecting against these complications.
Herpes zoster can have serious complications, beside postherpetic neuralgia, many of which are severe, life-threatening and costly to the healthcare system. However, data on their incidence and their risk factors is limited. The objective of this research is therefore to estimate the incidence of acute complications following zoster and to estimate the effectiveness of the Zostavax vaccine against these complications.
We will first carry out a cohort study among individuals with zoster, matched on age, sex and practice, to ten patients without zoster. We will fit Cox models, with current age as the underlying time-scale, to obtain hazard ratios for our outcomes in patients with and without zoster, adjusting for covariates, within the first year of zoster. We will go on to stratify our results on age group, severe immunosuppression and common comorbidities. We will also assess the incidence of and risk of the outcomes according to whether patients were given antiviral treatment within seven days of diagnosis.
We will then use a self-controlled cases series (SCCS) to quantify the relative risks of four zoster attributable acute complications (encephalitis, pneumonia, cellulitis or keratitis). Use of a SCCS design ensures we remove between-person confounding. Conditional Poisson regression will be used to estimate the incidence rate of each outcome during risk periods following zoster and compared with the incidence in baseline periods, adjusted for age.
We will estimate the effectiveness of Zostavax against complications of zoster among the subset of zoster patients who were eligible for zoster vaccination after its introduction on 01/09/2013. Cox regression will be used to assess the overall association between vaccination and outcome and model rates of outcomes by exposure status, adjusting for covariates.
Primary
Zoster-related dermatological complications
Zoster-related neurological complications
Zoster-related visceral/systemic complications
Zoster-related ophthalmic complications
Secondary
Individual conditions which collectively comprise the primary outcomes
Zoster-related mortality
Zoster-related hospitalisation
Harriet Forbes - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Harriet Forbes - Corresponding Applicant - London School of Hygiene & Tropical Medicine ( LSHTM )
Caroline Morton - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Charlotte Warren-Gash - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Helen McDonald - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Jemma Walker - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Krishnan Bhaskaran - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Liam Smeeth - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Sara Thomas - Collaborator - Not from an Organisation
Sinead Langan - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Victor Hu - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation