Causes of Chickenpox
Causes of chickenpox stem from infection with the varicella-zoster virus (VZV), a member of the herpesvirus family. The virus is extremely contagious and primarily affects children, although anyone who hasn’t had chickenpox or received the vaccine is at risk. Understanding the causes of chickenpox is crucial for prevention and control.
1. Varicella-Zoster Virus (VZV)
VZV is the single cause of chickenpox. Once a person is exposed, the virus enters through the respiratory tract or conjunctiva (eye lining), then spreads through the bloodstream to the skin, where it causes the characteristic rash.
2. Transmission | Causes of Chickenpox
Chickenpox is spread through:
- Airborne droplets when an infected person coughs, sneezes, or talks
- Direct contact with the fluid from blisters
- Contaminated objects like clothing or bedding touched by someone infectious
The virus is most contagious from 1–2 days before the rash appears until all blisters have crusted over — typically 5–7 days after rash onset.
3. At-Risk Groups
While chickenpox is most common in children under the age of 10, certain groups are more susceptible to severe disease:
- Adults, particularly those not previously infected
- Pregnant women, due to risk to the unborn baby
- Newborns if the mother is infected near the time of birth
- Immunocompromised individuals, such as those undergoing cancer treatment or with HIV
4. Reactivation: Shingles
Even after recovery, VZV stays dormant in the nervous system. It can reactivate years later as shingles (herpes zoster), especially in older adults or people with weakened immunity. Shingles is not chickenpox but can cause chickenpox in unexposed individuals.
5. Vaccine Failure | Causes of Chickenpox
Rarely, vaccinated individuals can develop a mild form of chickenpox known as “breakthrough chickenpox.” These cases tend to have fewer spots, little to no fever, and a quicker recovery.
By understanding the causes of chickenpox, people can take proper steps to protect vulnerable individuals, reduce transmission, and ensure vaccination coverage is maintained.
[Next: Symptoms of Chickenpox →]
