Infectious Diseases- Chickenpox

Chickenpox

*4 million cases US/yr before vaccine* (early 90's) 90% under 10 yrs old *Winter/spring* 1995 vaccine- 120, 624 cases 1999- 40,016 cases Member of herpes viruses (over 100!)

shingles

1888/1892 chickenpox connection to _____ was determined

Vaccine Adverse Event Reporting System (VAERS)

1995-1998 6,574 reports of health problems after vaccination 1 in 33,000 doses (4%) adverse effects- shock, encephalitis, thrombocytopenia 14/6,574 end in death Avg 2,350/yr (20,004 cases reported VAERS 1995- 2003, 12%) 1998- 2013 *1 death reported from vaccine* Little English girl with pre-existing leukemia *Approximately 5% of children who receive the vaccine develop a fever or rash* Adverse reaction reports 1998 to 2005, found no deaths attributed to the vaccine (~ 55.7 million doses delivered)

1658

1st documented use of "chickenpox" in? Relative mildness of the disease

2nd, 98%

2006 added ____ varicella vaccine requirement ( _____ effective)

Chickenpox: Death

40-200 patients die per year worldwide Half immunocompromised Current US, <50/yr (no data on this!) 2002-2008: 6 deaths among children aged 1-9 Pre-vaccine era, annual death rates averaged at 100 Infants & immunocompromised persons increased risk, before vaccine majority of hospitalizations and deaths *healthy* persons aged <20 years

Shingles Vaccine

51% effective, lasts 5 years Recommended for age 60 and over

Death of an Unvaccinated Healthy 15 year old (Ohio 2009)

Admitted hospital 3-day rash, 1-day fever (101.1 F), facial edema, hypotension, shortness of breath Diagnosis of septic shock Very low platelet and WBC count, blood culture negative IV *acyclovir* (day 4 of illness), broad-spectrum antibiotics and antifungals Awake, alert, breathing on her own Respiratory function continued to deteriorate requiring invasive mechanical ventilation Pneumonia complicated by acute respiratory distress syndrome, multi-organ dysfunction Health-care acquired bacterial infection (respiratory tract-* Enterobacter cloacae,*) UTI- *Pseudomonas aeruginosa*), and sepsis (blood cultures on hospital days 19 and 20 were positive for *Stenotrophomonas maltophilia*) Dies 3 weeks after admission

Weakened

Cases of vaccine-related chickenpox have been reported in patients with a ______ immune system

Prodromal symptoms

Chickenpox ____ ____ include nausea, loss of appetite, aching muscles, headache, fatigue *Rash, oral sores, malaise, low-grade fever that signal presence of the disease* Children, not usually preceded by prodromal symptoms, 1st sign rash

Before

Chickenpox contagious 1-2 days _____ rash appears until all blisters have scabbed over (6-10 days after rash appears) Watery nasal discharge contains live virus

Acyclovir

Chickenpox has increased risk of complications with the antiviral medication? Children <12 years old are not meant to receive antiviral medication unless they have another medical condition which puts them at risk of developing complications *Antiviral medicines do not kill the virus but stop it from multiplying* Chronic skin disorder, lung disorder, HIV/AIDS Must be given IV, larger dose VZV relatively resistant (compared to herpes simplex)

Communicable, 90%

Chickenpox highly _____, infection rate _____ in close contacts (airborne spreads through coughs and sneezes); contact with blisters 99 people, put them in a room with 1 infected person, let them talk for a couple hours- 85 of the 99 people will get chickenpox

Adults

Chickenpox in _____ have longer fever, more severe, more intense rash, breathing problems, pneumonia, secondary infections, longer recovery 20% of them develop severe complications (usually due to immunocompromised or the health problems)

Children

Chickenpox in _______ results in lower fever, less severe, recover ~10 days 99% healthy have mild disease without complications

Different, Uniform

Chickenpox occurs in _____ stages, while smallpox is ____

Number of people born

Chickenpox occurs in all parts of the world, before vaccination, number cases similar to?

Face, scalp, torso, upper arms, and legs

Chickenpox rash begins as small red dots on the? Progresses over 10-12 hours to small bumps, blisters and pustules, formation of scabs Blister stage- intense itching

After

Chickenpox symptoms begin 10-20 days ____ exposure

Chickenpox Signs and Symptoms

Contagiousness persists lesions scab, 4-5 days, by which time nasal shedding of live virus ceases Resolves within a couple of weeks Rash -> Scabs (1-3 weeks)

Chickenpox parties

Deliberately exposed to promote immunity *Before vaccine*, almost everyone got it- can be more serious in teens & adults, get in childhood better *Today*- anti-vaxxers (send infected lollipops/ blankets through mail- federal offense) Vaccine just as effective, less consequences

Complications of Chickenpox

Develop severe pneumonia (1 in 1000 children) Brain infections- *Encephalitis*- headaches, vomiting, altered thought patterns, seizures *Cerebellar ataxia*- inflammation cerebellum - vertigo, vomiting, altered speech, tremors Flesh-eating bacterial infections in scabs, can be fatal Bacterial infection *Reye's syndrome*- effects the liver, can cause multiple organ failure, linked to giving children aspirin while having a viral disease so no aspirin! (children) *Encephalopathy* (swelling brain), liver damage, no jaundice *Meningitis:* swelling of meninges around spinal cord *Pneumonitis*- inflammation of alveoli caused by virus (adults)

Jesse Lee Newman

Dies at age 9 1995, vaccine just introduced No previous complications Not immunocompromised Pneumonia

Winter and spring

During what seasons is chickenpox most contagious?

Appearance of lesions at *all stages*

Hallmark of chickenpox?

Intra-muscular varicella zoster immune globulin (VZIG)

High titers of antibodies to fight VZV Disease prevention

The torso and spreads less to the limbs; doesn't usually affect palms and soles No umbilication, more red

In contrast to smallpox, chickenpox rash occurs mostly on? It doesn't usually affect?

smallpox

Late 18th century, chickenpox was separated from?

Varicella Vaccine Side Effects

Low-grade fever most common Rash occurs in 4 of 100 children around the area of the shot Rash can also occur on parts of the body other than the area of the shot, <30 blisters, not contagious *Contains gelatin, people who are severely allergic to gelatin cannot get the vaccine*

Why Vaccinate?

Many people cannot get the vaccine, also more susceptible to severe complications of the disease: Infants HIV/AIDS Cancer patients (and survivors) Organ transplant Immunosuppressed (drugs for treatment) You (your kid) could spread it to a community member (family member) who could be more at risk and die

Chickenpox Treatment

No cure Easing the symptoms: Rest, fluids Calamine lotion- itching Short fingernails prevent scratching, gloves (socks!) Acetaminophen (Tylenol) help with fevers (not aspirin) Baking soda bath

Chickenpox diagnosis

PCR Rash Antibody test

Increasing

Shingles cases are _____ Not enough data, no mandate to collect it Are we tracking it better? Are there more cases?

90%

Since immunization, US chickenpox incidence decreased ____ 2013 chickenpox resulted in 7,000 deaths globally 1990 there were 8,900 deaths Death occurs in about 1 per 60,000 cases

Frankie Wagner

Staten Island kindergartner barred from attending school because she hasn't been vaccinated against chickenpox Pediatrician refused to vaccinate her- 14 week old baby sister possibly inherited immunodeficiency disease from mom Live virus vaccine could be transmitted and kill baby sister Request medical exemption from Department of Education Denied on no proof, tests to determine if baby inherited immunodeficiency cannot be performed until she's one year old

Humans Too expensive

The only known reservoir for chickenpox? Why not eradicate?

Does Not

The vaccine ______ ____ cause shingles. Believed vaccinating would reduce the general populations exposure and lower immunity overall, leading to a higher incidence of shingles.

Cell-culture adaptation

The varicella vaccine is a live vaccine attenuated by? (grow in other cells to make less effective virus) Natural varicella virus 1st taken from a young child in Japan (Oka), strain of vaccine virus called "Oka" strain Grew virus in human embryonic fibroblast cells and guinea pig fibroblast cells (used to use aborted fetuses) Growing virus in fibroblast cells it became less and less able to grow in epithelial cells (line back of the throat or skin)

Live

The varicella vaccine uses ___ virus Protects ~70 to 90% Outbreaks occurring, decided *2 vaccines, 1 works for most population* 100 deaths US annually before vaccine Routine immunization schedule in the US; only states that do not require for entry to public elementary school Ohio, Wyoming

Shingles

VZV reactivation results in _____ (herpes zoster) In neuron pathway, not all over body, more painful; same virus but new location Don't know what triggers it; ~30% get it

Dorsal root ganglion (sensory nerves)

VZV spreads mucosal/epidermal surfaces to Remains dormant in ____ ___ ____ cells Red, inflammation burst out of the cells (why itchy), After erupted on skin, moves to spinal cord via the dorsal root and hangs out (low metabolic activity, evades immune system) If stressed could replicate and become inflamed causing shingles

Reproduction

Varicella vaccine caused the genes for ____ to change (less efficient) Typically varicella virus reproduces itself thousands of times during natural infection; varicella vaccine virus reproduces <20 times

Life long immunity

Varicella vaccine provides? Stable virus, low mutation rate CDC study 2002: vaccine effectiveness 85% against moderate or 100% against severe infection

Varicella Zoster Virus Herpes Virus Family (HHV-3) Varicella= little pox

What virus causes chickenpox?

Lytic Viral Replication

____ ____ ____ causes chickenpox lesions Red itchy spots turn into fluid-filled blisters in a few hours New spots form over 4-7 days Typical 250-500 blisters; sibling as high as 5,000 blisters (more exposure, more viral infection)

Herd Immunity

protect entire population by vaccinating high proportion of community