RNA virus

Question 1

This virus is an enveloped ssRNA and non-segmented genome, filamentous virions (thread-like structure), that causes Ebola hemorrhagic fever.

Answer 1

Ebola virus

Question 2

There is no cure for this virus, it is acute, no carriers, is transmitted by direct spread, fever, headache, joint and muscle aches, sore throat, and weakness followed by diarrhea, vomiting, and stomach pain,

Answer 2

Ebola virus

Question 3

This virus is naked ssRNA and is associated with the common cold. Sensitive to acidic environments and has a unique molecular surface makes the development of a vaccine unlikely. Can be acquired from contaminated hands and fomites.

Answer 3

Human Rhinovirus

Question 4

Positive-sense naked ssRNA
Symptoms: fever, runny nose, sneezing, cough, skin rash, mouth blisters, body, and muscle aches.
Infection occurs via the faecal-oral route.

Answer 4

Enteroviruses

Question 5

What diseases do Enteroviruses cause?

Answer 5

Coxsackie A16 and EV71-HFMD (lesions and fever)

Question 6

It is a positive-sense ssRNA and can survive stomach acids when ingested.

Answer 6

Poliovirus and Poliomyelitis

Question 7

Acute enteroviral infection of the spinal cord and can cause neuromuscular paralysis.

Answer 7

Poliomyelitis

Question 8

Positive-sense ssRNA, faecal-oral transmission, flu-like symptoms, no specific treatment once the symptoms begin.

Answer 8

Hepatitis A

Question 9

How does Hepatitis A spread?

Answer 9

Not washing hands, sex with infected partners, eating/drinking contaminated food, and recreational drug use

Question 10

Belongs to the family of Flaviviridae, an enveloped positive-sense ssRNA, and is transmitted by blood.

Answer 10

Hepatitis C

Question 11

Liver cirrhosis, liver transplant, and damage are accelerated by alcoholism and drug use.

Answer 11

Hepatitis C

Question 12

Naked dsRNA and Genus Reoviridae. Pin-wheel-shaped, 11 double-stranded RNA molecules, packaged in capsid proteins and can bind receptors on enterocytes (intestine cells).

Answer 12

Rotavirus

Question 13

Causes gastroenteritis in children

Answer 13

Rotavirus

Question 14

Oral-faecal transmission, pass from child to child, incubation time is 2 days and symptoms usually start with vomiting followed by 4-8 days of severe watery diarrhea.

Answer 14

Rotavirus

Question 15

Positive-sense non-segmented ssRNA. Cruise ship virus. Viral gastroenteritis and stomach flu (Winter Vomiting Disease). Transmitted by the faecal-oral route. Acute onset, nausea, vomiting, cramps, diarrhea, chills.

Answer 15

Caliciviruses

Question 16

Loose envelope positive-sense ssRNA, caused by a Rubivirus.

Answer 16

Rubella virus

Question 17

What are the diseases under Rubella?

Answer 17

German measles, Postnatal rubella, and Congenital rubella.

Question 18

Intense red rashes and transmitted through contact with respiratory secretions

Answer 18

German measles

Question 19

Positive-sense ssRNA with crown-like spikes on their surface, cold or flu-like symptoms.

Answer 19

Coronavirus

Question 20

Severe Acute Respiratory Syndrome, Transmitted through droplet or direct contact, fever, body aches, and malaise. Diagnosis-PCR, seroconversion (ELISA or IFA).

Answer 20

SARS

Question 21

Enveloped ssRNA, encode reverse transcriptase enzyme which makes a DNA copy of their RNA genome.

Answer 21

Retroviruses

Question 22

Cause of Acquired Immunodeficiency Syndrome (AIDS), infects the immune system including T lymphocytes (CD4+ T cells). Incapacitation of T lymphocytes allows opportunistic pathogens to infect the body. Infects and paralyzes B lymphocytes. Does not survive long outside of the body.

Answer 22

HIV

Question 23

How is HIV transmitted?

Answer 23

Sexual intercourse, infected mother to her child before or during birth and from breastfeeding, sharing needles, and blood transfusion or organ transplant from an infected person.

Question 24

The disease cause extreme leukopenia (reduction of WBC in the blood, CD4+ cells in particular), formation of giant T cells and other syncytia (allows the virus to spread directly from cell to cell), infected macrophages release the virus in CNS (toxic effect, inflammation), and destruction on CD4 lymphocytes (allows for opportunistic infections and malignancies).

Answer 24

Effects of HIV infection

Question 25

What does it mean when T4 cells fall below 200 cells/mm3?

Answer 25

This means that AIDS symptoms appear

Question 26

Diagnosis of HIV infection

Answer 26

ELISA, detection of antibodies specific to the virus in serum or other fluids.

Question 27

What are the criteria for AIDS?

Answer 27

Positive for HIV, CD4 count lower than 200 cells/mm3 of blood and lower than 14% of all lymphocytes.

Question 28

What is the treatment for HIV?

Answer 28

AZT. It interferes with the reverse transcriptase activity of the virus. HAART is when the virus is resistant to some antivirals and reduces the risk of HIV transmission and can extend the life of patients by about 8 years.

Question 29

What are the important laboratory investigations for HIV?

Answer 29

Coinfections (check for syphilis, Hep A, B, and C serology)
Chest X-Ray (To look for TB)
Full blood count
ECG
Fasting lipid profile
Blood sugar
Liver function test
Renal function test
Serum lactate
Cervical pap smear for women

Question 30

Paramyxoviruses is an enveloped ssRNA and is transmitted by respiratory droplets. What are the families under this virus?

Answer 30

Parainfluenza, mumps, morbillivirus (measles), and pneumovirus (RSV)..

Question 31

Red measles and rubeola, very contagious, transmitted by respiratory aerosols, human is the only reservoir. Sore throat, dry cough, headache, conjunctivitis, lymphadenitis, fever, koplik spots, oral lesions, and rash. Most serious complication is SSPE (meningitis layer). Leads to coma and death. Attenuated viral vaccine is MMR.

Answer 31

Measles

Question 32

Respiratory transmission, seen mostly in children, minor cold, bronchitis, bronchopneumonia, and croup (coughing, barking sounds).

Answer 32

Parainfluenza

Question 33

Infects the upper respiratory tract, and produces giant multinucleate cells, rhinitis, wheezing, otitis, and croup.

Answer 33

RSV

Question 34

Rhabdovirus family, Bullet-shaped virions, enveloped RNA, slow progressive zoonotic disease

Answer 34

Rabies

Question 35

The virus enters through bite, grows at trauma site for a week. Enters nerve endings and advances toward the ganglia, spinal cord and brain which could cause neurological problems.

Answer 35

Rabies

Question 36

What are the two forms of rabies?

Answer 36

Dumb form (non-responsive, paralyzed, stuporous) and Furious form (hydrophobia, fear of water, seizures, twitching)

Question 37

What are the two types of spikes in Influenza?

Answer 37

Haemagglutinin (H) helps the virus attach and penetrate host cells.
Neuraminidase (N) helps release the virus from the host cell after replication and assembly.

Question 38

Acute, highly contagious respiratory illness.
Causes rapid shedding of cells, stripping respiratory epithelium, and severe inflammation.
Fever, headache, myalgia, pharyngeal pain, shortness of breath, coughing.

Answer 38

Influenza A

Question 39

What are the diseases in immunocompromised people for Influenza?

Answer 39

Guillain-Barre syndrome (occurs when the body damages its own peripheral nerve cells)
Reye syndrome (often occurs in children who take aspirin to treat pain and fever) , enlargement of brain and liver.