Past papers 3 Flashcards
A 2 month old child brought for routine vaccinations. What is reason to not give full normal vaccination?
a. Coryzal illness and temp 36.5
b. Born prematurely at 34 weeks
c. Older brother just been diagnosed with leukaemia
d. Sister just developed chickenpox
e. Father has epilepsy
Older brother just been diagnosed with leukaemia
- Minor illnesses
without fever or systemic upset are not valid reasons to postpone immunisation. If an
individual is acutely unwell (for example with a fever above 38.5 C), immunisation may be
postponed until they have fully recovered. This is to avoid wrongly attributing any new
symptom or the progression of symptoms to the vaccine. - premature birth is not a contraindication. In fact, they gain more benefit from immunisation
Flu vaccine not indicated for-
COPD
CCF
Inflammatory bowel disease
Asplenia
Inflammatory bowel disease
Following is true about Bordetella:
Polymorphonuclear leucocytosis seen during infection
can be clinically diagnosed initially within days of onset
organism isolated from throat for several days following infection
vaccine gives life long immunity
tetracycline effective in paroxysmal stage
Polymorphonuclear leucocytosis seen during infection
Cattharal phase last 1-2 weeks, before paroxysmal stage. Need to give doxycycline in first 21 days to reduce symptoms
Child with leukaemia on chemotherapy. Due for a polio booster. Method for immunisation:
OPV IPV don’t vaccinate, just protect from food borne viruses vaccinate family members with OPV give immunoglobulin for polio
IPV
OPV - live virus
don’t vaccinate, just protect from food borne viruses - this is impossible
A. Recombinant vaccine produced in a yeast
B. Vaccine which stimulates antibodies against capsular polysaccharides
C. A skin lesion 4-6 weeks following vaccination means successful vaccination
D. Vaccine containdicated in eczema
E. Idiopathic thrombocytopenic purpura is a rare but recognised complication of this vaccine
i. Meningococcus C
ii. BCG
iii. MMR
iv. DPT
v. Influenza
vi. Small pox
vii. Yellow fever
viii. HBV vaccine
A. Recombinant vaccine produced in a yeast
HBV
B. Vaccine which stimulates antibodies against capsular polysaccharides
Meningococcus C
C. A skin lesion 4-6 weeks following vaccination means successful vaccination
BCG
Smallpox?
D. Vaccine containdicated in eczema
smallpox
E. Idiopathic thrombocytopenic purpura is a rare but recognised complication of this vaccine
MMR
Baby born to mother with chickenpox – baby is 1 day old. No details as to when mother developed VZV. What prophylaxis for baby?
VZIG
No time for IgG to cross-placenta, so baby at risk.
If baby had chickenpox, would give aciclovir
A 6 yr old boy is bitten by a dog whilst on holiday in India. His parents bring him home and he presents to A+E 6/7 after the bite. Best management is:
- Rabies vaccination
- Human immune globulin and rabies vaccination
- Immune globulin only
- Ribavirin
Human immune globulin and rabies vaccination
infiltrate immunoglobulin in wound, and any left over give IM
Do not give immunoglobulin if more than 7 days have elapsed after the first dose of vaccine, or more than 1 day after the second dose of vaccine.
Patients presenting for rabies PEP even months after having beenbitten should be treated as if the contact had recently occurred
HBIG HBIG and hep B vaccination High dose hep B vaccination VZIG VZIG plus vaccination VZV vaccination HNIG Do nothing
- Baby of hep B eAg positive mother
- Neonate whose mother develops chickenpox 2 days post delivery
- Non-immune pregnant woman in contact with measles
- CRF patient, not currently on dialysis but who will be commencing dialysis in the near future
- Non-pregnant paediatric nurse, is not varicella immune, who has been looking after her mother with ophthalmic zoster
- Baby of hep B eAg positive mother
HBIG and hep B vaccination - Neonate whose mother develops chickenpox 2 days post delivery
VZIG - Non-immune pregnant woman in contact with measles
HNIG - CRF patient, not currently on dialysis but who will be commencing dialysis in the near future
High dose hep B vaccination - Non-pregnant paediatric nurse, is not varicella immune, who has been looking after her mother with ophthalmic zoster
VZV vaccination
Which of the following vaccines are given at 12-15 months to prevent interference with maternal antibodies?
- BCG
- MMR
- DPT
MMR
DPT given at 8/12/16 weeks old
BCG given teenager - now no longer given
If a person is repeatedly HepBsAg pos, HepBeAg pos, IgM core antibody negative and IgG core antibody negative, they are what?
Acute infection
Carrier
Vaccinated
Acute infection
or my have chronic infection, but be immunocompromised
What is vector for yellow fever?
Anopheles
Aedes aegypti
Sandfly
Aedes aegypti
What is the vector for epidemic Typhus?
- Xenopsylla cheopis
- Aedes Aegypti
- Pediculus humanus
pediculus humanus - body louse
What is the vector for bubonic plague?
- Xenopsylla cheopis
- Aedes Aegypti
- Pediculus humanus
Xenopsylla cheopis is rat flea - transmit bubonic plague
- Ixodes tick
- Aedes mosquito
- Anopheles mosquito
- Reduvid bug
- Mastomys rat
- Human louse
- Tse tse fly
- Culex mosquito
- Sandfly
- A Brazilian with Megaoesophagus
- A patient with malaria
- A 40 yr old Ugandan woman at Lake Victoria with progressive illness, now in coma
- A person hiking in USA with centrifugal rash on leg.
- A Brazilian with Megaoesophagus
Reduviid bug - A patient with malaria
Anopheles mosquito - A 40 yr old Ugandan woman at Lake Victoria with progressive illness, now in coma
Tsetse fly - African trypanosomiasis - A person hiking in USA with centrifugal rash on leg.
Ixodes tick
Mastomys rat - transmits Lassa
Which statements are true -
Dengue virus infection result from bites by Aedes mosquitoes
Cases of dengue haemorrhagic fever usually result from reinfection by a different serotype of dengue virus
Pigs act as the reservoir for dengue virus
Yellow fever is prevalent throughout Asia
Yellow fever may be prevented by vaccination
Dengue virus infection result from bites by Aedes mosquitoes T
Cases of dengue haemorrhagic fever usually result from reinfection by a different serotype of dengue virus T
Pigs act as the reservoir for dengue virus F
Yellow fever is prevalent throughout Asia F although Aedes mosquito is there
Yellow fever may be prevented by vaccination T
- Which one of these has an animal reservoir?
Dengue
EBV
S. epidermidis
Yellow Fever
Dengue - monkeys act as reservoir in sylvatic life cycle
The following is true of rabies virus -
The majority of cases worldwide result from bat bites
Infection may be prevented by active and passive immunisation
Rabies vaccine is a live attenuated vaccine
The animal reservoir differ from country to country
May be diagnosed by serology
The majority of cases worldwide result from bat bites F
Infection may be prevented by active and passive immunisation T
Rabies vaccine is a live attenuated vaccine F
The animal reservoir differ from country to country T
May be diagnosed by serology F
Which viruses are not routinely grown in culture
A ADV B Echo C Parvo D HSV E Flu A
Parvovirus B19
Viral culture is a laboratory technique in which samples of a virus are placed to different cell lines which the virus being tested for is able to infect. If the cells show changes, known as cytopathic effects, then the culture is positive
Viruses grown in culture -
adenovirus, cytomegalovirus, enteroviruses, herpes simplex virus, influenza virus, parainfluenza virus, rhinovirus, respiratory syncytial virus, varicella zoster virus, measles and mumps.
Molecular testing has replaced viral culture. But culture still required in certain circumstances e.g unknown pathogen
Detergent has been swapped for sodium hypochlorite, which virus is the most likely to have survived?
Influenza
Hep A
HIV
HAV
Influenza/ HIV are enveloped viruses
A. Binds to 30s ribosome and inhibits peptide chain elongation
B. Activated by thymidine kinase and inhibits viral DNA polymerase
C. Binds to 50s ribosome and inhibits peptide chain elongation
D. Binds to 30s and causes misreading of mRNA codons
E. Inhibits viral reverse transcriptase
i. Tetracycline
ii. Gentamicin x
iii. Ciprofloxacin x
iv. Amantadine
v. Linezolid
vi. Acyclovir x
vii. Erythromycin x
viii. Zidovudine x
A. Binds to 30s ribosome and inhibits peptide chain elongation
Tetracyclines
B. Activated by thymidine kinase and inhibits viral DNA polymerase
Aciclovir
C. Binds to 50s ribosome and inhibits peptide chain elongation
Linezolid
D. Binds to 30s and causes misreading of mRNA codons
Gentamicin - aminoglycosides
E. Inhibits viral reverse transcriptase
Zidovudine
Why are prion diseases not classified as viruses?
What is a viroid?
Prion - a self-propagating misfolded conformer of a protein that is responsible for a number of diseases that affect the brain and other neural tissue
Prions consist solely of protein, with no enclosed nucleic acid - no genes of RNA/ DNA. Thus, they are definitely not viruses despite sharing the superficial properties of size and infectiousness.
Viroid - plant pathogens that consist of just a short section of RNA, but without the protein coat typical of viruses
4yrs old child from Kenya presents with 3 months history of chicken pox unresponsive to acyclovir.
Next step:
check HIV status
EM from skin lesions
Specifics IF for VZV
resistance testing for acyclovir
resistance testing for acyclovir
The genetic support of acyclovir resistance is often a single mutation in the viral thymidine kinase (TK) gene, which is required to phosphorylate acyclovir to acyclovir monophosphate
Even if HIV positive, would expect response to aciclovir
A. Enveloped, icosahedral DNA virus, grows in many cell lines
B. Non enveloped positive sense RNA virus, grows easily
C. Slow growing DNA virus in fibroblast cell lines, narrow host range
D. Small DNA virus, grows in Cells in S phase
E. Enveloped icosahedral RNA virus, not much CPE
i. Rubella
ii. CMV
iii. Influenza
iv. Polio
v. HHV-6
vi. HSV
vii. VZV
viii. Parvovirus
A. Enveloped, icosahedral DNA virus, grows in many cell lines
HSV
B. Non enveloped positive sense RNA virus, grows easily
Polio - icosahedral, but non-enveloped
C. Slow growing DNA virus in fibroblast cell lines, narrow host range
VZV
D. Small DNA virus, grows in Cells in S phase
Parvovirus B19
E. Enveloped icosahedral RNA virus, not much CPE
Rubella
Basic virology a- Adeno virus b- Vaccinia virus c- Influenza virus d- Parvo virus e- Papova virus (Papillomaviridae and Polyomaviridae) f- Paramyxo virus g- Reo virus
- ve sense SS RNA virus with 8 segments
- circular double stranded DNA virus
- linear double stranded DNA virus
- double stranded RNA virus
-ve sense ssRNA virus with 8 segments
Influenza
-circular double stranded DNA virus Papova viruses (Papillomaviridae and Polyomaviridae)
-linear double stranded DNA virus
adenovirus
vaccinia
-double stranded RNA virus
Reovirus
Parvovirus has linear single stranded DNA
Paramyxovirus is -ssRNA virus
Which virus grows best in human fibroblasts?
VZV
HBV
HCV
rhinovirus
VZV
Virus grows in MRC 5 cells, at 33°C.
Acid labile
What is the virus?
Rhinovirus
lower temperature - URTI
Why is vaccinia unique amongst DNA viruses?
Replicates in cytoplasm, whereas every other virus replicates in nucleus
What is a virus quasi-species?
A quasispecies is a well-defined distribution of mutants that is generated by a mutation-selection process
population structure of viruses with a large numbers of variant genomes (related by mutations). Quasispecies result from high mutation rates as mutants arise continually and change in relative frequency as viral replication and selection proceeds.
44 Some infectious organisms may have ‘quasi species’ as an evasion strategy, one organism to employ this method of host immune evasion is
A HDV
B HAV
C HCV
D CMV
HCV - genotypes
other examples - HBV HIV - HIV 1 and HIV 2 influenza flaviviruses (HCV)
More commonly seen in RNA viruses, as they have higher replication rates, and higher mutation rates
An 18 year old woman with viral meningitis has CSF sent for cell culture.
After 5 days, a dramatic CPE is seen in MRC5, monkey kidney and
Fibroblast lines. What is the most likely cause?
Enterovirus 71
Echovirus 11
Mumps virus
HSV
Echovirus
A four year old child with diarrhoea for several days has stool taken for
EM. Numerous 75nm icosahedral particles are seen.
Rotavirus Enteric adenovirus Norovirus Astrovirus Calicivirus
rotavirus
- Last antibody to be detected following EBV infection
A EBV IgA B Heterophil C IgM capsid D IgG nuclear protein E IgG capsid
D IgG nuclear protein - EBNA
Farmer with wound.
Microscopy shows GNR,
growing aerobically
What is potential organism?
Burkholderia Brucella Francisella Bordetella Legionella Pseudomonas
- A young surfer develops a wound on forearm. Microscopy shows a GNR.
a. V. vulnificus
b. M. marinum
c. Spirillum
d. Erysipelothrix
e. V. parahaemolyticus
vibrio vulnifucus
V. parahaemolyticus - causes GI illness
- Lab importance of deoxycholate
a. Faecal coliform count
b. salmonella culture
c. select salmonella/shigella
d. E coli selection
For enteric pathogens
Particularrly with salmonella species
- Management of leprosy
a. dapsone + Rifampicin
b. rif/ isoniazid and pyrazinamide
c. dapsone and isoniazid
d. quinolone and isoniazid
Dapsone and rifampicin
+/- clofazimine
for 6-12 months depending if paucibacillary or multibacillary leprosy
- Infection that requires an intermediate snail host.
a. schistosomiasis
b. Echnococcus
c. T solium
d. W bancroftii
schistosomiasis
- A person returns from Africa with plasmodium falciparum. The parasitaemia count is 2.5 %. What should be his treatment regimen be?
Parasite count >5% is severe
Non-severe
- artemether/ lumefantrine 4 tablets at 0, 8, 24, 36, 48 and 60 h
- Atovaquone-proguanil
- quinine + doxycycline
- There is only one UVC theatre and the surgeons are squabbling. Which procedure should take place in the theatre based on evidence?
a. VP shunt
b. Hip replacement
c. CABG
d. Central line in a neutropenic patient
e. Meningioma removal
?
- What distinguishes vCJD from CJD?
a. Invariable death
b. Diagnosis at older age
c. Long clinical course
d. prions in tonsil
Classic (sporadic) CJD diagnosed median age 68
Variant CJD diagnosed median age 28
CJD falls into four categories: sporadic (classic) -85% of case total variant familial iatrogenic
Why are prions not classified as viruses?
No nucleic acid
- a man develops a painful penile ulcer on return from a trip to Thailand. There is GNR on microscopy.
What is the organism
Haemophilus ducreyi - chancroid
- In a CAT 3 lab. Only one is mandatory
a. Shiny wooden bench
b. HEPA filter
c. Disposable loops
d. Containment shower
e. Sealed for fumigation
sealed for fumigation?
- In a CAT 3 room, a spillage must be cleaned with
a. 10000ppm of chlorine
b. Water and detergent
c. Heat at 60 C
10000ppm of chlorine
- This sample should be worked up in the Cat 3
a. HIV + blood
b. PUO from Thailand
c. Influenza
d. Sputum from man with cough and night sweats.
TB?
Although PUO from Thailand could be melioidosis
17.A Young child attends clinic for a Influenza vaccine. What would prevent the child from having the vaccine?
a. epilepsy
b. cystic fibrosis
c. congenital heart disease
d. egg allergy
egg allergy
- the haematology department are setting up a travel vaccine protocol for a man one year after his BMT. What vaccine should he not have.
a. Hep A
b. Typhoid(whole cell)
c. Yellow fever
d. Diphtheria
e. Meningococcal
yellow fever - live vaccine
- A patient with Chronic granulomatous disease has recurrent staph infection. What is the mechanism
a. chemotaxis inhibition
b. oxidase
c. lack of c3d receptor
d. Failure of phagollysosome fusion
Failure of phagollysosome fusion - do not produce hydrogen peroxide
20.Which infection is associated with least human- human transmission?
a. Q fever
b. Leprosy
c. Salmonellosis
d. Pertussis
Q fever
- C Psittaci diagnosis should be obtained by
a. PCR
b. Sputum culture
c. Sputum PCR
d. Blood culture
e. Clotted serology
f. EDTA PCR
Sputum PCR?
