Study of Complications of Varicella-Zoster Virus Infection in Hospitalized Children at a Reference Hospital for Infectious Disease Treatment.

OBJECTIVES: Varicella is a disease with potentially severe complications. We aimed to investigate characteristics of hospitalized children with varicella in Brazil in the prevaccine period and to identify predictors for requiring intensive care treatment. METHODS: A prospective cohort study was conducted from May 2011 to April 2014. Patients up to 13 years of age with varicella diagnosis were included. Information was collected through interview and review of medical records. Logistic regression analysis was performed. RESULTS: A total of 669 patients were admitted. The median age of subjects was 2.7 years (range 0-14 years) with a predominance of boys (56.6%). The main causes of hospitalization were bacterial complications (77.7%), viral complications (11.4%), and at-risk patients (10.9%). Main bacterial complications were skin infection and pneumonia. Main viral complications were herpes zoster, cerebellitis, and encephalitis. Most at-risk patients used corticosteroids or had a diagnosis of leukemia. At-risk patients were hospitalized earlier (P < .01) and remained hospitalized for longer periods (P = .03). A total of 44 patients (6.6%) were admitted to the ICU, and 5 (0.8%) died of septic shock. Thrombocytopenia was associated with more severe illness in patients with bacterial infections (P = .001). The long-time interval between onset of infection and admission was associated with the need for intensive care in all groups (P = .007). CONCLUSIONS: Secondary bacterial infection is the main cause of hospitalization, and thrombocytopenia in these patients leads to worse outcomes. Difficulties of access to the health system and delay in medical care are determining factors of greater severity in this population.