Varicella post-exposure management for pediatric oncology patients

The objective was to evaluate health care providers' (HCP) adherence to and efficacy of varicella post-exposure prophylaxis (PEP) recommendations. It was an observational, prospective, multicenter study set in Ile-de-France, France.

All children under 18 with a cancer diagnosis, currently or within 3months of receiving cancer treatment, regardless of varicella zoster virus (VZV) serostatus or previous personal history of varicella, were eligible. Study participants with significant exposure were reviewed prospectively for PEP indications. Main outcome measures were the percentage of exposure situations for which HCP were guideline-compliant, the proportion of available VZV serostatuses and the incidence of breakthrough varicella after different PEP approaches.

A total of 51 patients from 15 centers were enrolled after 52 exposure episodes. Median age at exposure was 5 years (range, 1-15). Exposure within the household led to 38% of episodes. Prophylactic treatment consisted in specific anti-VZV immunoglobulins (V-ZIG) (n=19) or in oral aciclovir (n=15). No prophylactic treatment was given for 18 patients (in compliance, n=16). In compliance with guidelines, 17 patients received V-ZIG, 11 did not develop varicella (65%, [95% CI, 39-90%]); 15 received aciclovir, 13 did not develop varicella (87%, [95% CI, 67-100%]). Breakthrough varicella occurred in 11 patients, with simple clinical course in all cases; in 8/47 (17%) episodes when PEP was guideline-compliant versus 3/5 (60%) when not.

Recommendations have been respected and are efficient. PEP needs to be standardized and a study carried out to define the optimal approach. Anti-VZV immunization of seronegative family members should be encouraged.