Varicella morbidity in Czechoslovakia

Area of Science:

• Epidemiology
• Virology
• Public Health

Background:

• Varicella (chickenpox) and herpes zoster (shingles) are significant public health concerns.
• Accurate morbidity data are crucial for understanding disease burden and implementing control strategies.

Purpose of the Study:

• To compare notified varicella incidence with serologically confirmed varicella incidence in Czechoslovak children.
• To assess the actual prevalence of varicella-zoster virus (VZV) infection in a pediatric population.

Main Methods:

• Analysis of notified varicella and herpes zoster morbidity data from 1970-1978 in Czechoslovakia.
• Serological testing (indirect hemagglutination reaction) for VZV-specific antibodies in children aged up to 12 in the North-Moravia region.
• Comparison of notified case rates with seropositive rates across different age groups.

Main Results:

• Significant discrepancies were observed between notified and serologically confirmed varicella cases.
• Notified varicella peaked in 3-4 year olds, while seropositivity was highest in 2 year olds.
• Cumulative notified varicella reached 35% by age 6 and 45% by age 12, but VZV antibodies were found in 60% of 6 year olds and 90% of 12 year olds.
• No applicable serological methods exist for herpes zoster morbidity studies.

Conclusions:

• Notified varicella incidence underestimates the true VZV infection rate in children.
• Serological studies are essential for a more accurate assessment of VZV epidemiology.
• Public health surveillance for varicella requires refinement to capture the full disease burden.