Post on 07-May-2015
Embed Size (px)
- 1.Chickenpox (Varicella)
- Ana Corona, PHN
- July 2002
2. What is Chickenpox (Varicella)?
- Chickenpox is an acute viral infectious disease
- Varicella-zoster virus (VZV)
- VZV is a DNA virus
- A member of Herpes virus group.
- Primary infection results in Varicella.
- Recurrent infection results in herpes zoster (shingles).
3. Pathogenesis of Varicella
- Infection of skin and appearance of
- vesicular rash
- Secondary Viremia
- Primary Viremia
- Viral replication in liver, spleen,
- and other organs
- Infection of conjunctivae and/or
- mucosa of the upper respiratory tract
- Viral replication in regional lymph
Day 14 Days 10 12 Day 4 6 Day 0 3 4. Clinical Features
- Mild prodrome (fever, malaise) for 1-2 days
- Successive crops (2-4 days) of pruritic vesicles
- Generally appear first on head; most concentrated on trunk
- Can spread over the entire body causing between 250 to 500itchy blisters
- Generally mild in healthy children
5. What is The Chickenpox Illness Like?
- Chickenpox most commonly causes an illness that lasts about 5-10 days.
- Children usually miss 5 or 6 days of school or childcare due to chickenpox.
- 1 child in 10 has a complication from chickenpox serious enough to visit a health care provider
- Including infected skin lesions and other infections.
- Dehydration from vomiting or diarrhea
- Exacerbation of asthma
- More serious complications such as pneumonia
6. The Lesions
- Each lesion progresses through a series of characteristic stages over about a week.
- Papules and vesicles develop into pustules, which then crust over prior to healing.
- A prominent feature of chickenpox is the development of several crops of spots.
- The peak of the illness, 3-4 days after first appearance of the rash, there are lesions at all stages of development, from new vesicles through to crusts.
7. Transmission: How do you get Chickenpox?
- Acquired by inhaling virus-containing particles, trapped in tiny droplets released into the air from the nose or throat of an infected person.
- The virus (VZV) enters the body by infecting cells in the respiratory tract.
- It spreads to many other parts of the body, including the skin, where it causes the characteristic rash.
- A person with chickenpox is contagious 1-2 days before the rash appears and until all blisters have formed scabs.
- It takes from 10-21 days after contact with an infected person for someone to develop chickenpox
8. Incubation period and prodromal illness
- The wide range commonly quoted for the incubation period:7-23 days.
- Time of contact and true source of infection may be difficult to pinpoint.
- General constitutional symptoms sometimes precede the rash. This is called a prodrome.
- Young children generally have either no or a very mild prodrome.
- Older children and adults: the prodrome may be more pronounced.
- Symptoms include fever (which may precede the rash by up to 6 days), headache, backache and sore throat
9. The Stages of Chickenpox Incubation PeriodUsually (14-17 days) Prodrome (1 3 days) Vesicles PustulesScabsRecovery typically 7 days afterrash appears (ranges 5 - 35 days) 10. Herpes Zoster (Shingles)
- Reactivation of Varicella Zoster Virus
- Associated with:
- Intrauterine exposure
- Varicella at 12 months with chronic cutaneous or pulmonary disorders or on salicylate therapy
- Children receiving short intermittent or aerosolized steroids
- IV in Immunocompromised children and adults with viral-mediated complications
- Not recommended for post-exposure prophylaxis
20. What home treatments are available for chickenpox?
- Fingernails trimmed short
- Calamine lotion and Aveeno (oatmeal) baths may help relieve some of the itching
- Aspirin or aspirin-containing products to relieve your child's fever are not recommended.
- The use of aspirin has been associated with development of Reye syndrome (a severe disease affecting all organs - most seriously affecting the liver and brain, that may cause death).
- The use of non aspirin medications such as acetaminophen is recommended.
- Certain groups of persons are more likely to have more serious illness with complications.
- These include adults, infants, adolescents and people with weak immune systems from either illnesses or from medications such a long-term steroids.
22. What Complications Result From Varicella?
- The most common complications are:
- Bacterial infections of the skin and soft tissues in children
- Toxic Shock Syndrome
- Necrotizing Fascitis
- Bacterial pneumonia
- Septic arthritis.
23. Complications: Continued
- Varicella is a well described risk factor for invasive group A streptococcus infections.
- Other complications:
- Cerebellar ataxia
- Hemorrhagic complications leading to bleeding disorders including disseminated intravascular coagulation (DIC).
24. Morbidity and mortality
- Since 1999, states have been encouraged to report chickenpox deaths to CDC.
- In 1999 and 2000, CDC received reports that showed that deaths from chickenpox continue to occur in healthy, unvaccinated children and adults.
- Most of the healthy adults who died from chickenpox contracted the disease from their unvaccinated children.
25. How serious a disease is varicella?
- Prior to the availability of varicella vaccine there were approximately 4 million cases of varicella a year in the U.S.
- Many health care providers are not aware that 11,000 hospitalizations and 100 deaths occurred every year in the United States before varicella vaccine became available.
- The majority of deaths and complications occurred in previously healthy individuals.
26. When is it necessary to go to the doctor for treatment?
- If a fever lasts longer than 4 days or rises above 102 F.
- Lesions which become very red, warm, tender, or is leaking pus may mean there is a bacterial infection.
- Difficulty walking
- Stiff neck
- Severe Vomiting
- Difficulty breathing
- Severe cough.
27. Can chickenpox be prevented ?
- Yes, chickenpox can
- now be prevented by vaccination
28. Varicella Vaccine 1 dose (7 years Duration of Immunity 95% (range 65%-100%) Efficacy Live Virus (Oka-Merck strain) Composition 29. Varicella Vaccine Recommendations
- Routine vaccination at 12 to 18 months of age
- Recommended for all susceptible children by the 13 thbirthday
- Persons> 13 years of age without history of Varicella
- Two doses separated by 4 8 weeks
30. Varicella Vaccine: Post-exposure Prophylaxis
- Varicella vaccine is recommended for use in susceptible person after exposure to Varicella
- 70% - 100% effective if given within 72 hours of exposure
- Not effective if >5 days but will produce immunity if not infected
31. Varicella Vaccine: Adverse Reactions
- Injection site complaints:20%
- Rash: 3% - 4%
- May be maculopapular rather than vesicular
- Average 5 lesions
- Systemic reactions uncommon
32. Zoster Following Vaccination
- Most cases in children
- Risk from wild virus 4 to 5 times higher than from vaccine virus
- Mild illness without complications
33. Varicella Vaccine: Contraindications and Precautions
- Severe allergy to vaccine component or prior dose of vaccine
- Moderate or severe acute illness
- Recent blood product
- Immunocompromised persons should not be vaccinated
- Vaccinate persons with humoral immunodeficiency
34. Varicella Zoster Immune Globulin (VZIG)
- May modify or prevent disease if given