VaricellaZosterVirusReaktivierung

Varicella-zoster virus (VZV) is a human herpesvirus (HHV-3) that causes two distinct diseases: varicella (chickenpox), the primary infection, and herpes zoster (shingles), the result of viral reactivation. Transmission occurs mainly by respiratory droplets or direct contact with vesicular fluid.

Varicella typically affects children and begins with a pruritic rash that appears in crops, fever, and malaise. The incubation period is usually 10 to 21 days. In adults and some immunocompromised people, disease can be more severe and lead to pneumonia or encephalitis.

After recovery, VZV remains latent in sensory ganglia, such as the dorsal root or cranial nerve ganglia. Reactivation later in life causes herpes zoster, a painful, unilateral vesicular rash in a dermatomal distribution; postherpetic neuralgia is a common complication.

Diagnosis is usually clinical; laboratory tests such as PCR on vesicle fluid or DFA can confirm the diagnosis in atypical cases or in immunocompromised patients.

Treatment includes antiviral agents such as acyclovir, valacyclovir, or famciclovir. Early initiation within 72 hours of rash onset improves outcomes. Supportive care includes analgesia, hydration, and management of complications; hospitalization may be required for severe disease.

Prevention relies on vaccination. Varicella vaccines (two-dose series) protect against primary varicella and reduce transmission. For herpes zoster, newer vaccines such as Shingrix (recombinant zoster vaccine) are recommended for adults 50 years and older; Zostavax is less commonly used.