Roane Viruses Flashcards
measles has a deficiency in what
Vitamin A
Infections involving the skin: three routes
1 Direct Inoculation (Papillomavirus, Poxviruses except smallpox, virus and primary HSV).
2 Local Spread from an Internal Focus (Recurrent HSV and VZV). S
3 ystemic Infection (Primary VZV, Rubella virus, Measles virus, and B19 parvovirus).
Measles epidemiology:
what group?
What time of year?
Measles is most prevalent in children 5 to 10 years of age and is seen primarily during the winter and spring.
incubation period for measles
The incubation period is 10 to 11 days. Theprodromal phase (3-4 days)
symptoms of measles
high fever, cough coryza, conjunctivitis, malaise,mucosa inflammation.
An erythematous macular and papular rash then develops behind the ears and over the forehead, spreading to the face, neck, trunk and extremities within 3 days. The lesions tend to reach confluence over the face and upper back, at which time the fever, cough and conjunctivitis are most severe. Koplik’s spots disappear 2 to 3 days after the appearance of the rash. Uncommon complications include encephalitis and purpura. SSPE is a rare but usually fatal complication.
How do skin lesions result
Skin lesions may result from the direct effect of viral multiplication (cell damage or cell death) or may result from the host response to the virus. Skin lesions of rubella and measles are thought to be at least partly due to the cell-mediated immune response to the virus. There is evidence for its direct attack of measles virus-infected endothelial cells by specific T-lymphocytes. Alternatively, the rash of Fifth Disease which is caused by B19 parvovirus is the result of immune-complex formation. These antigen-antibody complexes accumulate in the skin.
- Picture of a teen with measles: started behind the ears spread to the throat and then went all over, this picture is showing you the systemic spread
Rubella incubation
The incubation for this disease is 14 and 21 days following exposure to the virus
rubella symptoms
The prodromal symptoms can consist of low gradefever, headache, conjunctivitis, cough, sore throat and marked lymphadenopathy, arthritis can be seen in adults. From 1 to 4 days after initiation of the prodrome, an erythematous macular to papular rash appears, first on the face and then on the neck, trunk and extremities. The rash usually clears after 2 to 3 days.
When is rubella most common
spring months
rubella complications common in
intrauterine infections produces congenital malformation in 50% of neonates.
The earlier during pregnancy the infection occurs, the more severe the teratogenic findings. A wide variety of systems can be affected, especially the heart, eyes, auditory system, bones and CNS.
rubella
Rubella
parvovirus
most important parvovirus
B19
- Fifth disease: B19 infects the progenitor cells and an immune response occurs where you have a high antibody to viral ration è immune complex formation and these will accumulate in the skin (rash) or joints (arthritic like condition),
- Transient aplastic crisis – is a disease where B19 infects a lot of progenitor cells and a tremendous amount of viruses are made in a short time before the immune system can attack or kick in è viral excess è transient aplastic crisis where RBC aren’t produced and can die if don’t get transfusion
- No antibody is produced in the infected host and the virus persists for an extended period of time called pure red blood cell aplasia, if you give commercial IgG to try and shut down the virus giving partial recovery, likes the red blood cell because it has the P antigen
B19
B19
- Fetal: hydrops fetalis- [A severe form of the genetic disorder thalassaemia in which all four alpha chain polypeptides making up the haemoglobin molecule (the protein which transports oxygen in the body) are missing due to a defect in the gene which codes for them. As a result, affected individuals die at or before birth.] infect the fetus , erythroid progenitor cells found in the liver and they are infected, some evidence that myocardial and bone marrow may be infected, baby doesn’t develop normally, they have edema all over the body,
- congenital pure red blood cell aplasia- fetus is infected during development and the bone marrow and liver infected, if give a transfusion may fix it, RBCs fail to be made, result of autoimmunity or immune toleranceèviral persistent
Hand food and mouth disease
Hand, foot and mouth disease (HFMD): This disease is frequently caused by Coxsakieviruses, especially Coxsackie A virus. The virus is contracted by the fecal-oral route, and colonizes the small intestine where it does not cause disease. Periodically, the virus may spread beyond the small intestine and infect tissues all over the body. Herpangina is a classical example of this type of outcome.
B19 is very concerning for what disease
sickle cell
B19 is a (structure)
single strand DNA virus
HFMD epi
HFMD usually affects persons in their pre-teens or early teens
HFMD incubation period
After an incubation period of 3 to 6 days,
symptoms of HFMD
a problem characterized by low grade fever, malaise and abdominal or respiratory symptoms precedes the mucocutaneouslesions. Oral lesions are most common on the hard palate, tongue and buccal mucosaand begin a macule then progress to vesicles and then to ulcers. Cutaneous vesicles appear concomitantly with the oral lesions.
Viral infection of regional lymph nodes is followed by viremia resulting in intradermal vesicles. These lesions frequently can cause serious discomfort and may require hospitalization.
why named HMFD
Hand, foot and mouth disease is so named because of the location of the viral blisters that form. The blisters are mostly on the palms and soles, and inside the mouth. The illness is caused by a virus (usually Coxsackie virus A16). It is not related to the disease of a similar name that affects cattle.
Monkey pox
The disease known as Monkeypox is really a combination of possible sites of infections. The term “Monkeypox” is derived from the clinical finding that is manifested in a series of lesions. Actually, Monkeypox virus may cause systemic lesions that are very serious.
examples of monkey pox? what is is similar to
Monkeypox is caused by a virus known as the Monkeypox virus. This agent is a member of the very large Poxvirus family. This agent shares antigenic and biochemical characteristics of the Smallpox Virus.
Examples of the lesions that can be caused by this virus are shown in the next series of slides.
Treatment considerations for monkey pox
vaccines for orthopoxvirus (monkey pox)
Jynneos
acam2000
Treatment for orthopoxvirus (including monkey pox)
techovirimat
vaccinia immune globulin intravenous (VIGIV)
cidofovir
ebola
Ebola is the name of viral disease that is characterized by severe damage to the mucosal tissues and skin. The mortality rate can reach 90%. The name Ebola comes from the location of a 1976 outbreak in Zaire. The epicenter of the outbreak was in a small missionary hospital in Yambuku, close to the Ebola river.
family and structure of ebola
The Ebola virus is one of two members of the Filovirus family. These agents are negative- sense single-stranded RNA viruses. Infectious particles have a constant diameter of 80 nm but are pleomorphic and vary in length from 800 to 14,000 nm.
One of the most important features of Ebola virus is that it is virtually a pantropic virus; which means that it infects a wide-range of tissues and organs. This property is the basis of reports that describe patients hemorrhaging from all orifices.
An arm showing Ebola lesions. The dark purple bruise like lesions give way to blood filled blisters of highly infectious fluid.
Ebola prognosis
Where a victim has breaks in the skin, blood seeps out, as the disease takes hold. The virus has a death rate of up to 90 per cent, and is highly-contagious, spreading through contact with an infected person’s blood, secretions, organs and other bodily fluids
Ebola prognosis
Where a victim has breaks in the skin, blood seeps out, as the disease takes hold. The virus has a death rate of up to 90 per cent, and is highly-contagious, spreading through contact with an infected person’s blood, secretions, organs and other bodily fluids
Herpes family and structure
herpesviridae
enveloped
tegument located between the envelope and an icosahedral capsid
double stranded
linear DNA molecule
List 4 of the human herpesviruses that routinely cause skin virus
Although there are eight (8) Human Herpesviruses, only 4 of the agents routinely cause skin lesions in persons in the U.S. These viruses are:
- Herpes simplex virus 1/2 (HHV 1 – 2)
- Varicella Zoster virus (HHV– 3)
- Human herpes virus – 6 (HHV– 6)
- Human herpes virus 8 (HHV– 8)
Describe the major skin disease that are caused by HSV-1
1 causes a disease called Herpes labialis (Figure 1). This disease is actually the result of reactivation of a latent infection.- trigeminal nerve , seen in corner of the mouth
can cause other manifestations, for example, herpes gladiatorum which occurs in wrestlers as a result of direct skin to skin contact.
Eczema herpeticum is a manifestation of HSV – 1 infection in patients with skin disorders such as atopic dermatitis, pemphigus, or Darier’s disease. This herpes infection is shown in Figure 5.
Disease caused by HSV 2
– 2 causes primary and recurrent genital herpes. An example of primary genitalisis presented in Figure 2.
sacral ganglia
Varicella Zoster virus (HHV– 3) causes what disease
causes a primary infection in children and adults known as chickenpox. This infection can be very painful in adults.
Zoster (shingles)
the result of successful reactivation of latent infection in dermatomes of immunocompromised patients (AIDS, chemotherapy, etc.). This is a very painful condition.
dorsal root ganglion
disease caused by HHV-6
causes the most common childhood exanthem known as roseola infantum (exanthema subitum/sixth disease).
Human herpesvirus – 8 (HHV-8) causes what disease
Kaposi sarcoma in AIDS patients. An examples of scrotal lesions caused by HHV-8 is shown in
Note: Herpes virus B (monkey herpesvirus) causes highly fatal encephalitis that results from a bite by the infected monkey.
