Mobiliviruses

Question 1

what are morbilliviruses?

Answer 1

RNA viruses in the family Paramyxoviridae

Question 2

what are some morbilliviruses?

Answer 2

• measles
• rinderpest
• peste des petits ruminants (PPR)
• canine distemper virus (CDV)
• phocine distemper virus

Question 3

what does measles cause?

Answer 3

a rash of the skin

Question 4

what is rinderpest?

Answer 4

cattle plague - eradicated by global vaccination

Question 5

what is PPR?

Answer 5

the ovine rinderpest

Question 6

what is the CDV?

Answer 6

hard pad disease

Question 7

what are the parts of a morbillivirus?

Answer 7

• fusion proteins
• haemagglutinin
• matrix protein
• nucleoprotein
• genome

Question 8

who does measles infect?

Answer 8

is restricted to humans

Question 9

what is the incubation period of measles?

Answer 9

10-12 days

Question 10

what does measles cause?

Answer 10

• red blotches on the skin 7-18 days post-exposure, starting at the hairline then spreading across the body
• appearance of “Koplik’s spots”
• fever, sneezing and coughing

Question 11

what are other consequences of measles?

Answer 11

• ear infections (1/10)
• diarrhoea and pneumonia (1/20)
• febrile convulsions (1/200)
• encephalitis (1/1000)
• fatalities (1/500)

Question 12

how transmissible is measles?

Answer 12

it has the highest transmissible

Question 13

what is the global impact of measles?

Answer 13

one of the leading causes of death among young children even though a safe and cost-effective vaccine is available

Question 14

how many deaths do measles cause?

Answer 14

122,000 in 2012

330 deaths/day; 14 deaths/h

Question 15

how much did measles vaccines reduced deaths?

Answer 15

78%

Question 16

when is the first dose of measles vaccine administered?

Answer 16

children 12 months or older

Question 17

when is the second dose of the measles vaccine administered?

Answer 17

at least 4 weeks after the first dose

intended to catch the 5% of the vaccinates who failed to respond to the first dose

Question 18

why do children have to be 12 months or older in order to receive the firs dose?

Answer 18

because the immune system has to be developed

Question 19

what are the adverse reactions of the measles vaccines?

Answer 19

• fever 5-10%
• rash 5%
• joint symptoms 25%
• thrombocytopenia 1/25,000 doses
• parotitis rare
• encephalopathy 1/1,000,000 doses

Question 20

what does the vaccine have?

Answer 20

ATTENUVAX, MUMPSVAX, MERUVAX

Question 21

what is ATTENUVAX?

Answer 21

attenuated derivative of Edmonton strain (1954) of measles (passaged 40 times in chick embryo cells)
1968

Question 22

what is MUMPSVAX?

Answer 22

attenuated derivative of the Jeryl Lynn strain of mumps passaged in chick embryo cells
1967

Question 23

what is MERUVAX?

Answer 23

Wistar RA 27/3 strain of rubella virus passaged in human cells
1965

Question 24

how do you make a mumps vaccine?

Answer 24

1. take a throat swab form a patient with mumps
2. inoculate into nutrient broth and use to infect embryonate hen’s egg
3. after several passages in eggs, remove embryo and culture cells
4. passage virus in chick embryo cells five times
5. test virus for attenuation and immunogenicity in humans

Question 25

how many hen’s eggs are required to make 300 million doses of influenza vaccine?

Answer 25

900 million

Question 26

what is the acute phase of the canine distemper virus?

Answer 26

• transient fever 3-6 days post-infection with lymphopenia/leukopenia
• second round of fever, nasal and ocular discharges, lethargy and anorexia
• GI and respiratory signs, secondary bacterial infections
  may develop encephalomyelitis

Question 27

what can dog surviving the acute phase develop?

Answer 27

hyperkeratosis of the footpads and nasal plans, enamel hypoplasia in incompletely erupted teeth

Question 28

what may prolonged illness of cDV result in?

Answer 28

neurological signs: circling, head tilting, nystagmus, paresis/paralysis, seizures, involuntary muscle twitching, convulsions characterised by salivation, chewing movements

Question 29

why is CDV dangerous?

Answer 29

it has a high potential for zoonotic spread

Question 30

what happens if CDV is introduced into a population immune to measles?

Answer 30

infection fails to propagate (cross-protection from MeV to CDV)

Question 31

what happens id CDV is introduced into an immunologically naïve population?

Answer 31

infection propagates rapidly

Question 32

what is rubulavirus?

Answer 32

a genus within the family Paramyxoviridae

Question 33

what is the incubation period of Human Parainfluenza virus (HPIV)?

Answer 33

2-7 days

Question 34

what do HPIV-1 and HPIV-2 cause?

Answer 34

75% of croup (laryngotracheobronchitis), upper and lower respiratory tract illnesses, cold like symptoms

Question 35

what does HPIV-3 cause?

Answer 35

bronchiolitis, bronchitis, and pneumonia

Question 36

what does HPIV-4 cause?

Answer 36

mild to severe respiratory tract illness

Question 37

how are children protected against HPIV?

Answer 37

most children 5 years of age and older have antibodies against HPIV-3 and approx. 75% have antibodies against HPIV-1 and HPIV-2

Question 38

what is henopavirus?

Answer 38

a genus within the family Paramyxoviridae

Question 39

what is pneumovirus

Answer 39

a genus within the family Paramyxoviridae

Question 40

what is the most important cause of bronchiolitis in children under 1 year of age?

Answer 40

Respiratory syncytial virus (RSV)

Question 41

by when should children have a RSV vaccination?

Answer 41

by the age of 2

Question 42

what does Metapneumovirus account for?

Answer 42

10% of respiratory tract infections that are not related to previously know aetiologies agents

Question 43

how is metapneumovirus distributed?

Answer 43

worldwide and seasonal

Question 44

who are at risk of severe disease and hospitalisation by metapneumovirus?

Answer 44

children, elderly, immunocompromised people