From the Guidelines
Chickenpox is primarily transmitted through direct contact, airborne droplets, or infected respiratory tract secretions, with 80% to 90% of susceptible people exposed in a household setting developing clinical infection. The virus, called varicella-zoster virus (VZV), enters a susceptible host through the upper respiratory tract or the conjunctivae 1. An infected host is contagious from 1 to 2 days before the onset of the rash until all skin lesions are crusted.
Key Transmission Facts
- Direct contact with the fluid from chickenpox blisters is a primary mode of transmission
- Airborne droplets from an infected person coughing or sneezing can also spread the virus
- Infected respiratory tract secretions can transmit the virus
- The virus can spread from person to person beginning 1-2 days before the rash appears until all blisters have formed scabs
High-Risk Groups
- Pregnant women
- Newborns
- People with weakened immune systems These groups are at higher risk for severe disease if infected with varicella-zoster virus (VZV) 1. The virus has an incubation period of 10-21 days before symptoms appear, and indirect transmission can also occur through contact with contaminated objects that have the virus on them, though this is less common.
From the Research
Transmission of Chicken Pox
- Chicken pox, also known as varicella, is a highly contagious infectious disease caused by the Varicella zoster virus 2.
- The virus can be transmitted from person to person through direct contact or airborne transmission 3.
- The primary infection with Varicella zoster virus causes varicella (chickenpox), and the virus then establishes latency in sensory ganglia, which can reactivate later in life to cause herpes zoster (shingles) 3, 4.
Prevention and Treatment
- Vaccination is an effective way to prevent varicella, and live, attenuated varicella virus vaccine is recommended for healthy persons ≥ 12 months of age 5.
- Antiviral agents such as acyclovir, valacyclovir, and famciclovir are used to treat varicella and herpes zoster, but their efficacy in controlling post-herpetic neuralgia is limited 3, 4.
- Newer antiviral agents such as amenamevir, a helicase-primase inhibitor, have shown promise in treating herpes zoster and may be effective against acyclovir-resistant mutants 4.
Complications and Risk Factors
- Varicella vaccine meningitis is a rare complication of herpes zoster in twice-immunized immunocompetent adolescents, and risk factors include waning immunity to varicella-zoster virus 6.
- Recurrent asthma and treatment with prednisone tablets and beclomethasone inhaler may also be risk factors for varicella vaccine meningitis 6.