PEDIATRICS Vol. 108 No. 5 November 2001, p. e79
Received Mar 13, 2001; accepted Jun 20, 2001.
,
,
From the * Pediatric Infectious Diseases, Zentrum für
Präventive Pädiatrie, Johannes Gutenberg University Mainz,
Mainz; and Objective. Varicella is a common
infectious disease, usually benign and self-limited, and complications
are believed to be rare. The purpose of this study was to describe the
epidemiology of severe varicella complications in immunologically
healthy children in Germany.
Methods. Information on any admission of children with a
severe complication associated with chickenpox was solicited throughout
1997 from all 485 pediatric hospitals in Germany using an established surveillance system. The case definition included nonimmunocompromised individuals who were up to 16 years of age and hospitalized with neurologic complications, bacterial superinfections, or hematologic complications.
Results. The response rate to the surveillance
questionnaire during the observation period was high: 93.4%. Of the
153 reported cases, 119 met the case definition. There was a seasonal
distribution of reported complications with a peak in March. The
majority of complications occurred in preschool-age children with a
maximum age of 4 years. No gender predominance was found with a
distribution of 56 female and 63 male patients. Multiple entries for
complications were allowed. The most frequent complications were
neurologic, which were reported in 73 children (61.3%); cerebellitis
was the leading diagnosis (n = 48), followed by
encephalitis (n = 22), meningitis
(n = 2), and central facial palsy
(n = 1). A total of 46 (38.6%) infectious
complications were identified. Superinfections of the skin were present
in 31 (26.0%), pyogenic arthritis was present in 5 (4.2%),
osteomyelitis was present in 4 (3.3%), necrotizing fasciitis was
present in 3 (2.5%), orbital cellulitis was present in 2 (1.6%), and
pneumonia was present in 1 (0.8%). Streptococcus pyogenes was the leading cause of bacterial infections (18 cases [15.1%]), with invasive disease in 6 patients (8.4%) and
linked to 4 of 8 cases with defect healing. Infectious complications were reported in the majority in younger children up to 4 years of age,
whereas neurologic complications occurred more frequently in an older
age range. Five children experienced thrombocytopenia or severe anemia.
There was no bleeding disorder, no fatality, and no case of Reye
syndrome reported during the 1-year observation period. In total, 8 (6.7%) of 119 patients reported having long-term sequelae, 6 attributable to infectious complications and 2 to persistent deficits
after neurologic complications.
Conclusion. This is the first prospective nationwide study
of severe complications of varicella in immunologically healthy
children. Related to 14 025 867 children up to the age of 16, a crude
incidence of severe chickenpox complications of 8.5/100 000 could be
calculated. The actual hospitalization rate attributable to complicated
chickenpox is probably much higher, because this calculation refers to
a population theoretically at risk and not the truly susceptible individuals. The results of this study demonstrate considerable morbidity with a comparatively high rate of encephalitis,
osteomyelitis, and pyogenic arthritis. Although infectious
complications were present in only 38.6% of the reported cases, they
contributed disproportionately to the cases with chronic sequelae.
Looking at these cases in more detail, S pyogenes
involvement was identified as the major risk factor for invasive
disease with an unfavorable long-term outcome.
varicella-zoster virus, chickenpox/epidemiology, chickenpox/complications, encephalitis, cellulitis, osteomyelitis, necrotizing fasciitis, group A
Institute for Social Pediatrics and Adolescent Medicine,
University of Munich, Munich, Germany.
-hemolytic streptococci, Europe.