Varicella

Varicella, or chickenpox, is a common childhood illness caused by the varicella-zoster virus (VZV). Although often seen as a mild disease, varicella can cause serious complications in some individuals, particularly in adults, pregnant women, and those with weakened immune systems. The disease is characterised by an itchy, blister-like rash, fever, and fatigue. While the introduction of vaccines has significantly reduced cases worldwide, chickenpox continues to circulate, especially in areas with low immunisation coverage.

Understanding varicella, including how it spreads, who is at risk, and the importance of vaccination, is crucial for effective prevention and management. This comprehensive guide provides a detailed overview of the condition, with a focus on its impact in India and around the world.

Varicella is an infectious disease caused by the varicella-zoster virus, a member of the herpesvirus family. It primarily affects children but can occur at any age. Once a person contracts the virus, they typically develop lifelong immunity. However, the virus remains dormant in the body and can reactivate later in life as shingles (herpes zoster).

Chickenpox spreads easily through respiratory droplets when an infected person coughs or sneezes, and also through direct contact with the fluid from the blisters. The incubation period is usually 10 to 21 days, and infected individuals are contagious from one to two days before the rash appears until all blisters have crusted over.

Global Prevalence

Before the introduction of routine varicella vaccination, chickenpox was nearly universal in childhood. According to the World Health Organization (WHO), in countries without vaccination programmes, over 90% of people become infected before adulthood. In the United States and Europe, widespread immunisation has led to a 90% reduction in cases, hospitalisations, and deaths.

Prevalence in India

In India, varicella remains endemic and occurs throughout the year, with increased incidence in late winter and early spring. Although exact numbers vary, studies indicate that most Indian children contract chickenpox by the age of 10. Outbreaks are common in schools and densely populated areas. India does not yet include the varicella vaccine in its Universal Immunisation Programme, which contributes to continued transmission.

While varicella is generally considered a single disease, it can be classified based on severity and progression:

1. Uncomplicated Varicella:
   
   • Mild to moderate symptoms.
   • Self-limiting in healthy children.
      
2. Complicated Varicella:
   
   • Associated with secondary bacterial infections, pneumonia, or encephalitis
   • More common in immunocompromised individuals and adults.
      
3. Breakthrough Varicella:
   
   • Occurs in vaccinated individuals.
   • Milder illness with fewer lesions and less fever.

Varicella is caused by the varicella-zoster virus (VZV), which belongs to the herpesvirus group. It enters the body through the mucous membranes of the respiratory tract or conjunctiva. After entering the bloodstream, the virus multiplies and spreads to the skin, causing the characteristic rash.

Key modes of transmission include:

• Coughing or sneezing (airborne spread).
• Direct contact with an infected person’s blisters.
• Touching contaminated surfaces followed by touching the face.

The virus is highly contagious, with a secondary attack rate of over 85% among household contacts.

The symptoms of varicella usually appear within 10 to 21 days of exposure. They tend to follow a predictable pattern:

• Fever: Often the first sign, ranging from mild to high-grade.
• Fatigue and loss of appetite: Common in the early stage.
• Itchy rash: Begins as red spots that evolve into fluid-filled blisters.
• Lesions: Typically appear on the face, chest, and back, then spread.
• Crusting: Blisters burst and form scabs within 5 to 7 days.

In severe cases, especially in adults, complications such as pneumonia, encephalitis, and bacterial infections may develop.

Varicella is usually diagnosed based on clinical signs and symptoms. However, in atypical or severe cases, laboratory tests may be required:

• Clinical diagnosis: Based on the characteristic rash and symptom pattern.
• Polymerase Chain Reaction (PCR): Detects VZV DNA from skin lesions or blood.
• Direct Fluorescent Antibody (DFA) test: Identifies viral antigens.
• Serological tests: Measure VZV-specific IgM and IgG antibodie

Accurate dianosis is particularly important in pregnant women, immunocompromised individuals, and those with unusual presentations.

Treatment depends on the age and health status of the patient:

For Healthy Children:

• Symptomatic relief:
  
  • Paracetamol for fever.
  • Calamine lotion or antihistamines for itching.
• Hydration and rest are essential.

For Adolescents, Adults, or High-Risk Patients:

• Antiviral therapy:
  
  • Acyclovir or valacyclovir, especially if started within 24 hours of rash onset. (Zoviarex suspension). 
• Hospitalisation:
  
  • In cases of complications or immunosuppression.

Avoid using aspirin, as it is linked to Reye’s syndrome in children with viral infections. You can also opt for Asa 50 mg Tablet.

While conventional treatment is the mainstay, some people opt for complementary therapies to relieve symptoms:

• Oatmeal baths: Can soothe itching.
• Neem leaves: Used in Indian households for their antibacterial properties.
• Aloe vera gel: Applied topically to reduce inflammation.

It is important to note that these remedies should not replace medical treatment, especially in high-risk cases.

Certain groups are more likely to develop varicella or suffer complications:

• Unvaccinated individuals.
• Adults (especially over 20 years).
• Infants and newborns.
• Pregnant women.
• People with weakened immune systems (e.g., cancer, HIV, organ transplant patients).
• Individuals on long-term steroid therapy.

Although most cases of varicella are mild, complications can occur:

• Bacterial skin infections: Due to scratching.
• Pneumonia: More common in adults and smokers.
• Encephalitis: Inflammation of the brain.
• Reye’s syndrome: Linked to aspirin use in children.
• Hepatitis and nephritis: Rare but serious.
• Congenital varicella syndrome: Affects babies born to infected mothers.

Prompt medical attention and proper care can minimise the risk of these complications.

Living with varicella can be uncomfortable, but certain practices can make it more manageable:

• Rest and stay hydrated.
• Avoid scratching to prevent scarring and secondary infections.
• Use cool compresses or calamine lotion for itching.
• Wear loose, comfortable clothing.
• Maintain a clean and calm environment.
• Keep fingernails trimmed short.

1. "Chickenpox is always mild."
   
   • It can be serious in adults or high-risk individuals.
2. "You can only get it once."
   • Rarely, a second infection can occur; shingles is more common later.
3. "Vaccinated people can’t get chickenpox."
   
   • Breakthrough infections are possible but milder.
4. "It’s just a childhood illness."
   
   • Adults can have more severe symptoms and complications.
5. "Natural infection is better than vaccination."
   
   • Vaccination prevents serious complications and is much safer.

Seek medical help if:

• High fever lasts more than four days.
• Breathing becomes difficult.
• The rash spreads to eyes or becomes very painful.
• Neurological symptoms such as confusion or unsteadiness appear.
• You are pregnant or immunocompromised and exposed to varicella.

Early intervention can reduce the risk of complications.

• Should I get vaccinated if I’ve never had chickenpox?
• What treatment options are best for my age and health?
• How long will symptoms last?
• When is it safe to return to work or school?
• How can I prevent spreading the virus to others?
• Is antiviral medication necessary in my case?

If someone you know has varicella:

• Help them rest and stay hydrated.
• Prepare soothing meals and teas.
• Keep them cool and comfortable.
• Encourage them not to scratch lesions.
• Support them emotionally, especially if they are missing school or work.
   

Varicella remains a common and highly contagious disease, but it is largely preventable through vaccination and manageable with timely care. Though often mild in children, it can lead to serious health issues in adults and vulnerable populations. Raising awareness, encouraging immunisation, and practising good hygiene are essential in reducing the spread and impact of chickenpox in India and globally.