Predictive value of a self-reported history of varicella infection in determining immunity in adults

Abstract

ResearchRecherche V aricella infection (chickenpox) is highly contagious 1 and is spread by respiratory droplets or direct contact. Varicella can occur in nonimmune adults, in whom severity of the infection increases with age, 2 often causing serious morbidity and loss of work time. In Canada, 70% of 53 reported deaths caused by varicella between 1987 and 1996 occurred in adolescents and adults.3 When acquired during pregnancy, varicella can cause significant maternal, perinatal and infant morbidity.3 After varicella infection, more than 95% of people develop antibodies, 4 which are detected by serologic testing and indicate lifelong immunity.The recent introduction of a vaccine for varicella means that nonimmune adults may benefit from vaccination. 5 This has led to studies to determine whether a self-reported history of varicella infection is an accurate indication of the presence of antibodies. Studies to date have yielded disparate conclusions and recommendations, [6][7][8][9][10][11] and no study has yet investigated this question for adults in a primary care population. Our objective was to determine, in an adult primary care population, the accuracy of a self-reported history of varicella infection in determining immunity.St. Michael's Hospital Family Practice Unit serves a population with a wide range of socioeconomic groups and countries of origin. The mean patient age is 44 years, and 60% of patients are female. On randomly selected clinic dates between October and December 2000 we enrolled patients aged 18 to 65 years who were having blood taken for reasons other than serologic testing for varicella antibodies. Using a structured interview, patients were asked about their history of varicella infection (Box 1), and their blood samples were analyzed for antibody titres using the VZVscan latex agglutination test (Becton Dickinson, Cockeysville, Md.). We excluded patients with psychiatric or medical conditions impairing memory, a history of varicella vaccination or active varicella infection. All patients gave informed consent, and the study was approved by the St. Michael's Hospital Research Ethics Board.A sample size of 200 patients provides power to detect a 95% confidence interval (CI) of ± 3% if the baseline positive predictive value of a history of varicella is 95%.Of 204 participants enrolled, 184 had a serologic test for varicella antibodies. For unknown reasons, the serologic test was not performed in the remaining 20 cases.Of the 184 participants whose blood sample was tested for varicella antibodies, 101 (55%) were women, 117 (64%) were born in North America, and 107 (58%) had postsecondary education. The mean age was 43 (standard devia- Predictive value of a self-reported history of varicella infection in determining immunity in adultsCandice N. Holmes, Karl T. Iglar, Brenda J. McDowell, Richard H. Glazier Abstract THE RECENT INTRODUCTION OF A VACCINE FOR VARICELLA has raised questions about whether, for adults, a patient's history of varicella infection is useful in determining if vaccinatio...

Seroepidemiology of varicella‐zoster virus and reliability of varicella history in Turkish children, adolescents and adults

“…On the other hand, the NPV of a negative history of varicella was 34.5% in adolescents and 8.3% in adults. These findings indicate that a negative history of varicella is not a reliable predictor of lack of immunity in adolescents and young adults, a finding consistent with other studies 35–40 …”

“…These findings indicate that a nega-tive history of varicella is not a reliable predictor of lack of immunity in adolescents and young adults, a finding consistent with other studies. [35][36][37][38][39][40] A presumptive varicella immunisation strategy for all adolescents with a negative history has been administrated in several European countries. 7,9,41 WHO also recommends that varicella vaccine may be offered to individual adolescents and adults without a history of varicella.…”

Growth hormone secretion and immunological function of a male patient with a homozygous STAT5b mutation

“…Initially, we thought that the hemorrhagic varicella infection at the age of 16 years (6) could be a sign of immunodeficiency. However, the patient did not have a history of chickenpox in the past (a reliable surrogate of a lack of seroimmunity (42,43)) and he developed the varicella secondary to his brother, who suffered a less severe case. Varicella secondary attack rate among susceptible household contacts is high and at higher age, e.g.…”

Varicella-zoster virus immunity in dermatological patients on systemic immunosuppressant treatment

“…Several studies have been undertaken to establish whether a self‐reported history of primary VZV infection is a reliable indicator of seropositivity 11,12 . Specific population groups that have been studied include health care workers, pregnant women and military personnel 11 .…”

“…7,8 Several studies have been undertaken to establish whether a self-reported history of primary VZV infection is a reliable indicator of seropositivity. 11,12 Specific population groups that have been studied include health care workers, pregnant women and military personnel. 11 We are unaware of any studies investigating the prevalence of VZV immunity and the predictive value of a self-reported history of VZV in a group of patients receiving systemic immunosuppressive therapies.…”