Module 8: Influenza/Prenatal Pathogens

Question 1

What are the two antivirals approved for treatment of influenza A/B?

Answer 1

Zanamivir (Relenza), Oseltamivir (Tamiflu)

Question 2

Therapy for primary influenza pneumonia is directed at maintaining what?

Answer 2

Oxygenation undertaken, aggressive reparatory/hemodynamic support

Question 3

Infection of influenza for mother during pregnancy has a higher risk for __________ ____________ ______. Is there utero transfer?

Answer 3

Secondary bacterial pneumonia. No.

Question 4

Influenza is a ______-stranded _______ virus with an ________ __________ __________. What are the 3 types?

Answer 4

Single, RNA, outer lipoprotein envelope. Types A, B, C.

Question 5

Where are antigenic differences found on the internal structural proteins of influenza viruses?

Answer 5

1. nucleocapsid
2. matrix proteins

Question 6

Influenza A viruses are further subdivided by which 2 surface antigens?

Answer 6

1. hemagglutinin
2. neuraminidase

Question 7

What are some differences between influenza A, B, and C?

Answer 7

A: Infect people, animals, birds. Can cause epidemics & pandemics.
B: Infect humans, morbidity/mortality, less severe epidemics.
C: Mild illness, no epidemics.

Question 8

Where does hemagglutinin bind to? How does an antibody inhibit it?

Answer 8

Binds to sialic acid to initiate infection.
Neutralizes the infectivity of virus, useful in vaccines.

Question 9

What are the three functions of neuraminidase?

Answer 9

1. binds sialic acid to release progeny virus from infected cell
2. degrades protective layer of mucus in resp tract
3. enhances ability of virus to infect resp tract

Question 10

Describe the 2 types of antigenic changes?

Answer 10

1. antigenic shifts: major changes on the re-assortment of segments of genome RNA
2. antigenic drifts: minor changes due to mutations

Question 11

Describe herd immunity.

Answer 11

Provided by vaccinated population, thought to prevent spread, protect non-vaccinated individuals.

Question 12

What are the five herpes dsDNA enveloped viruses?

Answer 12

1. HSV 1
2. HSV 2
3. VSV (varicella-zoster)
4. EBV (epstein-barr)
5. CMV (cytomegalovirus)

Question 13

What are two distinguishing features of dsDNA viruses?

Answer 13

1. envelop of lipid bilayer taken from host nuclear membrane
2. ability to cause latent infections

Question 14

What are symptoms of HSV1, how is it transmitted, and importance for pregnancy/postnatal?

Answer 14

Symptoms: cold sores
Transmission: indirect contact, kissing
Pregnancy: Reactivation during pregnancy, rare fetal transmission, but higher risk for postnatal infection

Question 15

What are symptoms of HSV2, how is it transmitted, importance for pregnancy/postnatal?

Answer 15

Symptoms: Blisters on outer genital tissues
Transmission: Sex
Pregnancy: Rare fetal transmission, but high risk postnatal, treat infant with acyclovir

Question 16

What is VSV and how is it transmitted?

Answer 16

Herpes that causes chickenpox, can later cause shingles. Transmitted by saliva or direct contact with vesicles.

Question 17

Can fetal infection occur in VSV? When is it most dangerous? Which vaccination would be used for infant AFTER birth?

Answer 17

Yes, most dangerous <20 weeks. Varicella-zoster immune globulin (VZIG) is used to treat newborn, NO vaccination during pregnancy.

Question 18

Why does shingles occur? How can it be prevented (2 methods)?

Answer 18

VSV is reactivated and emerges from nerve cells, usually due to reduced immunity in host.
1. Varivax for children
2. Zostavax for adults
NO vaccination during pregnancy

Question 19

What are examples of reasons for HSV reactivation?

Answer 19

1. febrile illnesses ex. common cold
2. direct sunlight
3. stress/trauma
4. menstruation
5. immunocompromised

Question 20

How is EBV transmitted? What does it cause? Pregnancy implications?

Answer 20

Called the “kissing disease,” leads to mononucleosis. Fever, lethargy, sore throat, enlarged spleen, T cell response against B cells, B cell response against RBCs. EBV not associated with fetal infections.

Question 21

What does CMV affect, what is it transmitted by? Pregnancy implications?

Answer 21

Infection of salivary glands and lung cells, transmitted by saliva & sex.
In utero transmission is possible - CNS disorders, deafness, rash, treatment with acyclovir.

Question 22

What is hepatitis? Difference between chronic/acute?

Answer 22

Inflammation of liver, caused by hep virus, toxins, or drugs.
Chronic: detected by elevated liver enzymes in blood
Acute: jaundice, hepatic enlargement

Question 23

What are distinguishing features of hep B? Transmission?

Answer 23

dsDNA enveloped, nucleocapsid core contains dsDNA, DNA polymerase, can cause chronic infection.
Transmission mainly by blood, sexual contact.

Question 24

What is the likelihood of acute vs. chronic hepatitis from HBV? Mortaility?

Answer 24

Acute: 25% of HBV cases.
Chronic: 5-10% of HBV cases.
Mortality: Liver failure in acute, cancer, cirrhosis in chronic cases

Question 25

What happens if a mother is discovered to be a carrier of hep B?

Answer 25

HBsAg vaccine, protect infant through antibodies. Hep B immunoglobin can be given if active infection, passes protection too.

Question 26

Describe parvovirus, infection, pregnancy implications.

Answer 26

Small ssDNA viris, "slapped cheek" syndrome, 50% of population has had parvo. Transmission: usually resp, can occur in utero Pregnancy: mild illness, can rarely cause miscarriage

Question 27

What is special about the structure of Hep A? Which is special about its pathology?

Answer 27

ssRNA, non-enveloped with a nucleocapsid. Causes 50% of acute viral hepatitis but NO chronic disease, NO carrier state, very mild.

Question 28

How is Hep A transmitted, symptoms?

Answer 28

Fecal-oral route. Fever, dark urine, jaundice.

Question 29

What are pregnancy implications for HAV?

Answer 29

Almost never transmitted in utero, no birth defects. IgG antibodies protect infant, vaccine available for during pregnancy.

Question 30

___% of chronic state HCV leads to _____/_______. HCV represents __% of all chronic hepatitis cases.

Answer 30

80, cancer/liver cirrhosis, 50

Question 31

HCV (can/can't) be transferred from mother to fetus. There is a much higher chance of transmission if which disease is present? Which anti-viral cannot be used in pregnancy?

Answer 31

Can. HIV. Ribavirin, is a known teratogen (malformation-causer).

Question 32

How is Hepatitis E transferred? Is there a chronic/carrier state? What are pregnancy implications? What is DIC?

Answer 32

Fecal-oral route. No. More severe acute disease in pregnant women, 20 mortality rate. DIC = disseminated intravascular coagulation. Excessive clotting, kidney dysfunction caused by HEV causes mortality.

Question 33

Is rubella enveloped? How can it be transferred, and prevented?

Answer 33

ssRNA, enveloped. Transferred via respiratory or through placenta. Prevented by MMR vaccine or natural infection (lifelong immunity).

Question 34

Which malformations can occur due to rubella (3)?

Answer 34

Microcephaly, cataracts, heart defects.

Question 35

What is HTLV-1 as a virus? How is it transmitted, and where is it prevalent? What implications does it have for newborns?

Answer 35

ssRNA, retrovirus, enveloped. Transmitted via sex, blood, milk. Endemic to Africa, South America, Caribbean. Transfers through breast milk (20%), high risk for leukemia later.

Question 36

What does HIV target? What implications does it have for newborns?

Answer 36

Kills CD4 t-cells, dendritic cells, CNS damage. 25% of infants with HIV+ mothers will have HIV.

Question 37

Which 2 hepatitis viruses cause chronic infection and liver cancer?

Answer 37

HEP B and C