Nosocomial Varicella Infections in a Pediatric Unit by the Exposure to Herpes Zoster and Effectiveness of Postexposure Acyclovir Prophylaxis for Varicella

• Published in: The Japanese Journal of Pediatric Hematology Vol. 18; no. 5; pp. 548 - 553
• Main Authors: NAKAZAWA, Shinpei, INUKAI, Takeshi, SUGITA, Kanji, HIROSE, Kinuko, NEMOTO, Atsushim, TAKAHASHI, Kazuya, AKAHANE, Koshi, GOI, Kumiko
• Format: Journal Article
• Language: Japanese
• Published: THE JAPANESE SOCIETY OF PEDIATRIC HEMATOLOGY/ONCOLOGY 2004; 特定非営利活動法人 日本小児血液・がん学会
• Subjects: acyclovir; immunocompromised children; nosocomial infection; prophylaxis; varicella zoster virus
• ISSN: 0913-8706; 1884-4723
• DOI: 10.11412/jjph1987.18.548

Following the exposure to 2 patients with zoster, nosocomial varicella infections were spread in 4 immunocompromised patients in a pediatric unit including 2 who were varicella zoster virus (VZV) -seropositive or vaccinated. The first and second outbreaks were from a patient with myelodysplastic syndrome who developed VZV-meningitis post-allogeneic bone marrow transplantation and a patient with Wilms' tumor under chemotherapy who were not isolated for 3 days after development of zoster, respectively. To prevent subsequent nosocomial spread of varicella, acyclovir (ACV) was orally administered for 7 days starting from 7 days after the exposure in 6 nonimmunocompromised patients without history of varicella, but one of 6 children contracted the disease. In contrast, oral administration of ACV for 21 days starting immediately after the exposure was performed in 21 immunocompromised patients including 7 children without history of varicella and 9 non-immunocompromised patients without history of varicella, and resulted in no development of the disease without any adverse reactions, suggesting that long-term ACV prophylaxis could be safe and effective. For prevention of nosocomial varicella infection from zoster patients, not only isolation precaution but also postexposure prophylaxis by ACV should be performed for immunocompromised patients even with history of varicella infection or vaccination.