A decade review of chickenpox among pediatric immunocompromised patients at the King Chulalongkorn Memorial Hospital, Thailand

Background: Varicella zoster virus (VZV) infection among immunocompromised patients leads to high morbidity and mortality. Objective: Describe the natural history and treatment outcomes of chickenpox among immunocompromised children hospitalized in a tertiary care center in the era of acyclovir treatment. Methods: We conducted a retrospective chart review of immunocompromised children hospitalized with chickenpox at King Chulalongkorn. Memorial Hospital between January 1, 2000 and December 31, 2009. Demographic data, clinical manifestations, treatment, and complications were extracted from the patients' charts. Rate of complications were compared among underlying disease by using chi-square test. Results: There were 61 admissions. Median interquartile range, (IQR) age was 79 (31 to 123) months. There were 31(51%) children with hematologic malignancies, 20 (33%) on immununosuppressive drugs, six (10%) neonates, and four (6%) HIV positive. Index cases were from household members (23%), community (15%), and hospital (6%) whereas 56% had no information. Cases peaked during February to March. Median (IQR) duration of fever and active skin lesions were four (3 to 6) and five (4 to 7) days, respectively. All, except one, received acyclovir (50% intravenous, 48% switched from intravenous to oral, 2% oral). Median (IQR) duration of acyclovir treatment and hospitalization were 10 (7 to 14) and nine (7 to 10) days, respectively. Complications included bacterial skin infections (10%), hepatic transaminitis (8%), pneumonia (5%), and disseminated varicella (1%). Rates of complications were 18% among children with malignancies, 3% on immunosuppressive drugs, and none in neonates or HIV positives (p = 0.047). Two children (3%) died due to disseminated varicella and severe pneumonia. Conclusion: Mortality rate of chickenpox among immunocompromised patients on acyclovir treatment is 3%. Children with hematologic malignancies have the highest rate of complications.