Transcript CS11 Group 11 Case Study Parvovirus powerpoint

Parvovirus
Matthew Ward
Maria De Arcos
November 20, 2012
Parvovirus B19 (fifth disease)
The first epidemic of this virus was in 1886. People
named it the fifth disease, because it was the fifth
disease known to caused a rash in children.
1. Measles
2. Scarlet fever
3. German measles
4. Duke's disease
5. Fifth disease (parvovirus B19)
Parvovirus B19 was accidentally discovered in well 19 of
plate B in England in 1974 while performing a screening
test for Hepatitis B on a healthy blood donor. It was
finally accepted in 1975. It infects mainly children who
are at elementary level, but it can also infect adults. It
has the highest incidence between winter and spring
B19 Parvovirus
Family: Parvoviridae
Genus: Erythrovirus
small ssDNA
non-enveloped
two capsids
autonomous( doesn't require co-infection to
cause infection)
only infects human
human is the natural host
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It replicates in the nucleus of replicating erythroid cells
(pronormoblast) in the bone marrow causing a cytopathic effect. It
binds to the receptor Gb4Cer and co-receptor Ku80 of the
pronormoblast.
-"Infected cells contain enlarged cell nuclei
with chromatin displaced to the marginal
area."
-Incubation time: 4-14 days
-Can be asymptomatic or
symptomatic
Symptoms
First symptoms:
• Fever
• Runny nose
• Headache
• Tiredness
Secondary symptoms:
• Rash: the rash starts on the face
giving the appearance of
“slapped cheeks” and later it may
spread to the arms, legs, chest,
back or buttocks .
• Joint pain and swelling: known as
polyarthropathy syndrome and is
usually prominent in adult women
• Temporary anemia
-The interruption of the red cell maturation leads to reticulocytopenia in healthy individuals
that last for about a week
-The virus can cause Transient aplastic crisis in those individuals who are
immunocompromised.
-After the first sign of symptoms the immune
system will develop IgM against the virus
that could last between 8-10 weeks
-IgG will also be developed lasting a lifetime.
Case Study
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Mrs. Doe brought her daughter to the
pediatrician with the complaint of a rash.
The daughter’s face appeared as if it had
been slapped, but she had no fever or
other notable symptoms. On questioning,
Mrs. Doe reported that her daughter had
had a mild cold within the previous 2
weeks and that she, herself, was currently
having more joint pain than usual and was
very tired.
1. What features of this history
indicate a parvovirus B19 etiology?
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Parvovirus B19 only infects humans
There were several symptoms that
indicated a parvovirus B19 infection
-Rash on cheeks
-Had a mild “cold” recently
-The mother was experiencing joint pain and
fatigue
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Parvovirus causes erythema (reddening
of the skin) on the cheeks, forehead,
mouth, upper lip and nose
The disease begins with cold-like
symptoms prior to the rash
Adults may develop seronegative arthritis
resulting in joint pain
Parvovirus infection can cause temporary
anemia resulting in fatigue
2. Was the child infectious at
presentation? If not, when was she
contagious?
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The child was not infectious at presentation
Individuals are not contagious when the
characteristic rash symptom becomes present
However, the infection is contagious before this,
such as during the “cold symptoms” stage
The contagious period is variable, and is usually
between four and twenty-eight days
3. What caused the symptoms?
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Viremia occurs during the first week of
infection causing symptoms of malaise and
fever
The rash is thought to be immunologically
mediated. It corresponds to the appearance
of immunoglobulin M (IgM) in the serum.
Recurrence of the rash may be provoked by
sunlight, stress, or exercise.
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Parvovirus causes stiffness, and inflammation/swelling
of joints. This causes arthropy in adults.
Parvovirus can cause temporary anemia, resulting in
weariness
http://www.stanford.edu/group/virus/par
vo/2005/B19.html
http://www.humpath.com/IMG/jpg/parvo_inclusion_
12_1.jpg
4. Were the symptoms of the
mother and daughter related?
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Yes, the symptoms of the mother and daughter
were very likely related
Adults do not develop the characteristic rash
that young children do
Instead, many adults develop joint pain and
may develop prolonged fatigue
Child and mother contact is a common method
of spread of the disease
5. What underlying condition would
put the daughter at increased risk
for serious disease after B19
infection? The mother?
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There are several underlying conditions
that would put individuals at an increased
risk for serious disease after B19 infection
o -Weak/compromised immune system
o -Blood disorder such as sickle cell anemia
o -Pregnancy
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Individuals with weak immune systems are at risk for
extended and severe symptoms of infection
In individuals with chronic red blood cell disorders, such
as sickle cell disease, infection may result in severe
anemia, in which there is a deficiency of red blood cells
or hemoglobin in the blood, resulting in pallor and
fatigue
Parvovirus B19 can cause a miscarriage in pregnant
women by causing anemia in the unborn child
6. Why is quarantine a poor means
of limiting the spread of B19
parvovirus?
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Quarantine is a poor means of limiting the
spread of the disease because the
characteristic symptoms do not appear
while the disease is contagious
During the contagious period, an
individual may have cold-like symptoms,
or may be asymptomatic
References
1. Corcoran A., Doyle S. (2004). Advances in the biology, diagnosis and
host-pathogen interactions of parvovirus B19. J Med Microbiol. 53(6) pp.
459-475.
2. Broliden K., Tolfvenstam T., Norbeck O. (2006). Clinical aspects of
parvovirus B19 infection. J Intern Med. 260(4). pp. 285-304.
3. Servey J.T., Reamy B.V., Hodge J. (2007). Clinical presentations of
parvovirus B19 infection. Am Fam Physician.75(3). pp.373-376.
4. Matano S, Kinoshita H, Tanigawa K, Terahata S, Sugimoto T. (2003).
Acute parvovirus B19 infection mimicking chronic fatigue syndrome.
Intern Med. 42(9). pp. 903-905.
5. Sabella C, Goldfarb J. (1999). Parvovirus B19 infections. Am Fam
Physician. 60(5). pp.1455-1460.
6. Mayo Clinic
http://www.mayoclinic.com/health/parvovirus-infection
1. National Center for Biotechnology Information
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001972/