Infections

Section 1

1) Which of the following is a DNA virus?

a) hepatitis A virusb) hepatitis B virus c) hepatitis C virusd) hepatitis D viruse) hepatitis E virus

2) In hepatitis B infection:

a) 60-65% of acute cases are subclinicalb) 20% of acute cases become “healthy” carriersc) 20% of cases developing cirrhosis will then progress to hepatocellular carcinomad) 10% of acute cases with “subclinical” disease will progress to a carrier statee) 40% of acute infections will cause acute hepatitis

3) In hepatitis C infection:

a) 50% of acute infections will cause acute hepatitisb) 25% of those developing cirrhosis will progress to hepatocellular carcinomac) 25% of cases developing chronic hepatitis will progress to cirrhosisd) 50% of acute infections will produce a chronic hepatitise) 10% of acute infections causing “subclinical” disease will progress to a chronic

hepatitis

4) All of the following tissues are resistant to tuberculosis infection EXCEPT:

a) the heartb) the striated musclec) the thyroidd) the adrenal glande) the pancreas

5) In which area is HIV-2 the predominant cause of AIDS?

a) West Africab) Central Africac) United States of America d) Europee) Philippines

6) In which cell type does HIV infection in the central nervous system predominate?

a) oligodenrocytes b) astrocytes c) microglial cellsd) neurons of the cerebral cortexe) neurons of the basal ganglia

7) The onset of AIDS in an HIV-infected patient is characterised by:

a) 80% of CD4+ T cells in the peripheral pool showing signs of HIV infectionb) extensive viral replication and lysis of macrophagesc) a CD4+ T cell count of < 500 cells/μLd) a CD4:CD8 ratio of 1.0e) a plasma viraemia titre of >1:32

8) Concerning bacterial structure:

a) gram positive and gram negative bacteria share structurally similar adhesin moleculeb) E. coli toxic production depends upon coordinated expression of adhesin proteinsc) a single bacterial species will not exhibit both pili and non pilar adhesin moleculesd) bacterial endotoxins are usually simple lipopolysaccharides e) bacterial exotoxins act almost exclusively to lyse host cells by altering membrane

permeability

9) Staphylococcus aureus:

a) are motile coccib) are gram negative organismsc) does not cause impetigod) is the commonest pathogen in hospital acquired infectionse) virulence factors are predominantly plasmid mediated

10) Streptococci species causing scarlet fever are Lancefield group:

a) Ab) Bc) Cd) De) E

11) In clostridial infections:

a) botulinum neurotoxin is actively secreted by pathogenic clostridial botulinum b) clostridial perfringens infection is rarely caused by biliary surgeryc) “gas gangrene” is marked by a profuse neutrophil infiltrated) tetanus toxin causes inhibition of inhibitory interneurons leading to spasmse) clostridial difficile is unique, as it does not secrete toxins but is directly cytopathic

12) All of the following are paramyxoviruses EXCEPT:

a) the measles virusb) the para influenzae virusc) the rubella virusd) RSVe) the mumps virus

13) Lancefield group B streptococci characteristically cause:

a) urinary tract infectionsb) pharyngitisc) scarlet feverd) rheumatic fevere) impetigo

14) Bacteria:

a) are eukaryocytes b) have nucleic) cannot synthesise their own DNAd) can have two phospholipids bilayers e) in the GIT are predominantly aerobic

15) Clostridium perfringens infection typically causes which of the following?

a) suppurative inflammationb) granulomatous inflammationc) cytopathic inflammationd) necrotising inflammatione) chronic inflammation

16) Streptococci do NOT:

a) stain gram positiveb) cause suppurative wound infectionsc) form grape-like clustersd) cause rheumatic fevere) secrete exotoxin

17) Regarding clostridia:

a) clostridia tetani releases a neurotoxin that blocks synaptic acetylcholine release b) clostridia welchii causes anaerobic cellulitis c) clostridia botulinum releases tetanospasmin d) clostridia perfringens does not release any neurotoxins e) clostridia perfringens grows in inadequately sterilised canned foods

18) Which of the following statements regarding tuberculosis are NOT true?

a) mycoplasma area aerobic non spore-forming bacillib) mycoplasma tuberculosis has not endotoxins nor exotoxins c) ghon complexes are residual from primary infectiond) caseous necrosis is characteristic e) Mantoux testing is an example of a type III immune complex hypersensitivity reaction

19) With respect to viral hepatitis:

a) hepatitis C is transmitted by faecal - oral route b) hepatitis D is commonly found to coexist in hepatitis B positive peoplec) hepatitis A is transmitted by blood–born meansd) hepatitis B E Ag indicates infectivitye) hepatitis B S Ag indicates prior vaccination

20) HIV infection:

a) is caused by rhino virusb) results in increased CD4 and T cell memoryc) results in inversion of the CF4-CD8 ratiod) increases immature precursors of CD4 and T cellse) causes a CD4-CD8 ratio close to 2

21) A typical feature of AIDS:

a) decreased delayed type hypersensitivity reactionb) lymphocytosisc) hypogammaglobulinaemia d) increased CD4 and T cellse) increased chemotaxis and phagocytosis

22) Mumps virus is a:

a) adenovirus b) herpes virusc) paramyxovirus d) pox viruse) picornavirus

23) All of the following organisms cause a clinical effect via the production of an exotoxin EXCEPT:

a) clostridium tetani b) staphylococcus aureusc) E. colid) pseudomonas aeruginosa e) vibrio cholera

24) A 34 year old HIV positive man presents with headache and fever. A cerebral CT scan shows a 3cm diameter mass lesion in the left cerebral hemisphere. Which pathogen is MOST likely to be responsible for this lesion?

a) mycobacterium tuberculosis b) atypical mycobacteria c) toxoplasmad) cryptococcus e) staph aureus

25) In viral hepatitis:

a) the majority of cases of acute hepatitis B infection result in a carrier state, without clinical evidence of disease

b) anti HBs appear in the first week of infectionc) anti HCV IgG does not confer immunity to hepatitis Cd) the major cause of death from hepatitis B is hepatocellular carcinomae) hepatitis A virus has an outer surface envelope of protein, lipid and carbohydrate

26) Mycobacterium tuberculosis owes its pathogenicity in part to:

a) exotoxinsb) histolytic enzymes c) cell wall sulfatides d) endotoxins e) the nutritional status of the host

27) The following enteritis may frequently be carried by domestic dogs:

a) shigellab) salmonellac) cholerad) campylobactere) yersinia enteritis

28) The following is transmitted by droplet inhalation:

a) rocky mountain spotty feverb) scrub typhusc) epidemic typhusd) Q fevere) rickettsial pox

29) With regard to infectious mononucleosis, which is INCORRECT?

a) IgG antibodies against EBV persist for lifeb) IgA Abs prevent infection of B cells, but increase infectivity for epithelial cellsc) cytotoxic CD8+ T cells and NK cells are needed in controlling B cell proliferation d) latent EBV remains in some B cells and some epithelial cellse) raised circulating monocyte levels assist in its diagnosis

30) Which of the following is NOT true with respect to N. gonorrhoea?

a) it is a gram negative diplococcusb) capsular polysaccharides inhibit the antibody responsec) it induces the production of tumour necrosis factor α in infected cellsd) pathogenic Neisseria bind avidly to IgEe) it may cause pharyngitis

31) Which of the following is NOT due to infection with clostridium species bacteria?

a) pseudo membranous colitisb) botulismc) Lyme diseased) tetanuse) gangrene

32) Which of the following is the most common cause of childhood diarrhoea in Australia?

a) yersinia enterocoliticab) rotavirusc) Giardia lambliad) E. colie) campylobacter jejuni

33) Which is transmitted mainly by inhalation of dust from pigeon droppings?

a) chlamydia trachomatisb) mycobacterium avium-intracellularec) Legionella pneumophila d) Cryptococcus neoformanse) Aspergillus species

34) Which of the following diseases is NOT caused largely by toxin production?

a) whooping coughb) tetanusc) cholerad) giardiasise) scalded skin syndrome

35) What is the major cause of the common cold?

a) adenovirusb) influenza virusc) coxsackie virusd) rhino viruse) none of these

36) With regard to malaria, which is INCORRECT?

a) sporozoites invade hepatocytesb) hepatocyte rupturing releases thousands of merozoitesc) chloroquine inhibits heme polymerased) merozoites bind RBCs and infect them where they maturee) mature merozoites infect mosquitoes to continue the cycle

37) Regarding tetanus toxin, which is CORRECT?

a) it reaches the CNS via the blood streamb) it acts at the neuromuscular junctionc) it blocks secretion of inhibitory neurotransmittersd) it acts by inhibiting protein synthesise) it causes demyelination of nerves

38) With regard to leprosy, which is INCORRECT?

a) presence of CD4+ T cell-mediated response results in tuberculoid typeb) lepromatous type occurs in anergic patients with CD8+ suppressor cells dominatingc) antibody production is impaired in lepromatous leprosyd) type IV HS reactions result in the granulomatous lesions of tuberculoid leprosye) patients with lepromatous leprosy have nodular lesions and are more infectious

39) Which of the following is NOT gram positive species of bacteria?

a) bacillusb) clostridiumc) listeriad) neisseriae) lactobacilli

40) Which is the major cause of croup?

a) adenovirusb) influenza virusc) coxsackie virusd) rhino viruse) none of these

41) Which of the following is an obligate anaerobe?

a) pseudomonasb) bacillusc) bacteroidesd) E. colie) neisseria

The following statements (a) to (e) relate to Question 42 to Question 46:

A E.coliB proteus mirabilisC pseudomonas aeruginosaD all of the aboveE none of the above

42) Which micro-organism is a source of endotoxin?

43) Which micro-organism grows best in aerobic conditions?

44) Which micro-organism does not cause infections enterocolitis?

45) Which micro-organism is a cause of UTI?

46) Which micro-organism is not associated with suppurative infections of the abdominal cavity?

47) With regard to the parasitic metazoan (helminths), which is INCORRECT?

a) trematodes are flukesb) cestodes are tapewormsc) nematodes are roundwormsd) echinococcus is a trematode that causes hydatid cystse) taenia solium is ingested in rare pork

48) With regard to staphylococcus aureus, which is INCORRECT?

a) it is catalase positiveb) it differs from micrococcus in that it is fermentativec) it differs from other staph. in that it is coagulase positived) in humans, it resides mainly on skine) it is subgrouped by phage typing

49) With regard to streptococci, which is INCORRECT?

a) viridans streptococci are α-haemolyticb) streptococci faecalis is α-haemolytic c) streptococci pneumoniae is α-haemolyticd) streptococci pyogenes is GpA β-haemolytic streptococcie) rheumatic fever is caused by streptococci pyogenes infections

50) Campylobacter species induce enteric disease by all the following mechanisms EXCEPT:

a) toxin induced disease similar to that of cholerab) invasion and proliferation within the intestinal epitheliumc) a shigella-like dysentery d) translocation to the intestinal lamina propria and mesenteric lymph nodese) induction of granuloma formation

51) Which of the following is NOT a pyogenic coccus?

a) pseudomonas aeruginosab) staphylococcus epidermidisc) streptococcus pyogenesd) streptococcus pneumoniaee) neisseria meningitides

52) Which, if any, of the following are facultative intracellular parasites of macrophages?

a) L. pneumophilia and M. tuberculosisb) M. tuberculosis and C. trachomatisc) Epstein Barr virus and cytomegalovirusd) M. pneumonia and C. trachomatise) none of the above combinations

53) Which of the following is NOT a member of the Herpes family of viruses?

a) herpes simplexb) varicella-zosterc) cytomegalovirusd) Epstein-Barr viruse) none – all of the above belong to the herpes family

54) Streptococcus pneumoniae uses all the following mechanisms to escape the immune system EXCEPT:

a) carbohydrate capsule which inhibits phagocytosis or the organismb) use of pili (fimbriae)c) secretion of proteases that degrade antibodies d) surface lipoteichoic acid which binds to host extracellular matrixe) M-protein on the surface which prevents the organism from being phagocytosed

55) Which of the following is NOT a member of the Paramyxo family of viruses?

a) parainfluenzab) respiratory syncytial virusc) rubella virusd) measles viruse) mumps virus

56) Coxsackie viruses cause all EXCEPT for:

a) hand, foot and mouth diseaseb) herpanginac) pleurodyniad) erythema infectiosume) myocarditis

57) Which of these is associated with the Guillain-Barre syndrome:

a) adenovirusb) influenza virusc) coxsackie virusd) rhino viruse) none of these

Infections – Answers

1 B2 A3 D4 D5 A6 C7 E8 B9 E10 A11 D12 C13 A14 D15 D16 C17 B18 E19 D20 C21 A22 C23 D24 C25 C26 C27 D28 D29 E30 D31 C32 B33 D34 D35 D36 E37 C38 C39 D40 E41 C42 D43 C

44 B45 D46 D47 D48 D49 B50 E51 A52 A53 E54 B55 C56 D57 C

Section 2

Infection and Environment

1) Which is TRUE for radiation injury?

a) hyperbaric oxygen protects against radiation injuryb) median lethal dose of total body irradiation is 25-40 Gyc) ionising radiation exposure increases proto-oncogenes expression, decreases

production of tumour necrosis factor, and decreases production of manganese superoxide dismutase

d) ionising radiation increases the rate of chronic lymphocytic leukaemiae) most cancers induced by ionising radiation have occurred at doses greater than 0.5 Gy

2) For obesity, which is NOT TRUE?

a) approximately 25% of Americans are obeseb) a body mass index of 25kg/m2 is normalc) leptin acts as an anti-obesity factord) obesity is associated with hyperinsulinaemiae) normotensive obese people are at increased risk of stroke

3) For viral respiratory infections, which is TRUE?

a) coronaviruses are the most common cause of the common coldb) rhinoviruses grow best at 33-35Cc) influenza virus C infects humans, horses, pigs and birds and is the leading cause of

pandemicsd) viral induced tonsillitis is uncommon in childrene) rotavirus is a frequent cause of lower respiratory tract infections in infants

4) For mycobacterium, which is TRUE?

a) M. avium, M intracellulare, and M. bovis have no virulence in normal hostsb) type II hypersensitivity to tubercle bacillus leads to resistance to the organismc) T cell mediated immunity is demonstrable by a positive purified protein derivative test

reaction d) granulomas of secondary tuberculosis that occur in the lung apex are known as Ghon

complexese) miliary tuberculosis refers to haematogenous dissemination of tuberculous lesions

throughout the body especially to the heart, striate muscles, thyroid, and pancreas

5) For syphilis, which is TRUE?

a) the secondary stage is characterised by lesions of the aorta, heart, and central nervous system

b) the hallmark of syphilis is an obliterative endarteritis and plasma-cell mononuclear infiltrate

c) a primary syphilis lesion is a painful, raise, red lesion known as a chancred) the classic triad of congenital syphilis is a keratitis, saddle nose deformity and

deafnesse) congenital syphilis is more severe the younger the foetus is

6) Which is a TRUE post bacterial sequelae?

a) shigella may lead to Reiters syndrome in HLA-DR4 patientsb) campylobacter may lead to Guillain-Barre in HLA-B27 patients c) yersinia in a chronic carrier state may lead to cholelithiasisd) salmonella infection may result in erythema nodosum e) gonorrhoea may lead to an immune-complex glomerulonephritis

7) For bacterial respiratory infections, which is NOT TRUE?

a) haemophilus influenzae type B is the most common type to cause severe diseaseb) mycobacterium tuberculosis is the single most important infectious cause of death

worldwide c) bordetella pertusis colonises the brush border of bronchial epithelium and invades

macrophages d) DPT vaccine prevents corynebacterium diphtheriae infectione) most patients with cystic fibrosis die due to pseudomonas aeruginosa infection

8) For vector born infections, which is TRUE?

a) hosts previously unexposed to Dengue are susceptible to haemorrhagic dengue fever b) rickettsiae are obligate intracellular protozoan parasites that cause epidemic typhus c) yersinia pestis is a gram-negative facultative intracellular bacterium that is transmitted

to humans by rats d) duffy antigen positive red blood cells are resistant to plasmodium vivax e) 5% of hosts infected with schistosomes develop severe portal hypertension

9) For vitamin deficiencies, which is TRUE?

a) niacin deficiency results in pellagra-dementia, dermatitis, and diarrhoeab) vitamin D deficiency in adults results in ricketsc) folic acid deficiency results in bleeding diathesis d) vitamin B2 deficiency results in Korsakoff syndromee) pantothenic acid deficiency results in megaloblastic anaemia and neural tube defects

10) For oral contraceptives, which is TRUE?

a) oral contraceptive therapy increases the risk of endometrial carcinoma tenfold after ten years use

b) nulliparous women younger than 25 on the pill have an increased risk of breast cancerc) the longer the use, the greater the risk of ovarian carcinoma d) young women smokers, who use the pill, are 10 times less likely to suffer a myocardial

infarct than non-pill users e) there is a slight increased risk of hepatic carcinoma especially in older women who

have used the pill for a prolonged period

Section 2Answers

1 E2 E3 B4 C5 B6 B7 D8 E9 A10 B

Section 3

Infectious Disease

1) Which association is INCORRECT?

a) HHV-8 and Kaposi sarcomab) helicobacter pylon and chronic gastritisc) Escherichia coli and haemolytic-uremic syndrome d) Bartonella henselae and lyme diseasee) cryptosporidium parvum and chronic diarrhoea

2) What are the smallest free-living organisms known?

a) chlamydiaeb) rickettsiaec) mycoplasmad) viruses e) spirochetes

3) Which is the most common cause for the common cold?

a) influenza virusb) parainfluenza virusc) respiratory syncytial virusd) adenoviruse) rhinovirus

4) Cytomegalovirus:

a) is an α-group herpes virusb) infects white blood cells of the immunocompromisedc) can be transmitted in organ transplantsd) is usually accompanied by candidiasis in AIDSe) 90% of CMV-infected neonates suffer full-blown congenital CMV infection, resembling

erythroblastosis foetalis

5) Regarding tuberculosis:

a) the Ghon complex is part of the secondary infectionb) primary granulomas mostly occur at lung apicesc) mycobacteria are aerobic spore-forming mobile bacillid) M. avium and M. intracellulare cause disseminated infection in AIDS patientse) mycobacteria grow faster than other bacteria

6) Which organ is relatively resistant to tuberculosis infection?

a) thyroidb) bone marrowc) adrenalsd) epididymise) meninges

7) Which bacterial infection is Guillain-Barre syndrome associated with?

a) salmonella b) shigellac) gonorrhoead) yersiniae) campylobacter

8) Which is NOT a feature of neisseria gonorrhoea?

a) diplococcusb) flagellatedc) encapsulatedd) gram negativee) pyogenic

9) Which is NOT a feature of streptococcus?

a) gram positive coccib) aerobicc) most are β-haemolyticd) minimal destruction of host tissues e) grow in pairs or chains

10) Streptococcus pyogenes is typed as:

a) α -haemolyticb) β-haemolytic Lancefield group Ac) β haemolytic Lancefied group Bd) β-haemolytic Lancefield group Ce) β-haemolytic Lancefield group D

11) Which bacterial infection produces lymphocytosis?

a) clostridium perfringensb) neisseria gonorrhoeaec) bordetella pertussis d) haemophilus influenzae e) Epstein-Barr virus

12) Which microbe does not produce exotoxins?

a) bordetella pertussisb) clostridium difficlec) staphylococcus aureusd) bacteroides fragilise) corynebacterium diphtheriae

13) Which is the most common cause of hospital acquired infection?

a) pseudomonas aeruginosa b) Escherichia colic) staphylococcus aureusd) campylobacter jejunie) neisseria gonorrhoeae

14) Legionella pneumophilia infects:

a) macrophagesb) neutrophilsc) T-lymphocytesd) B-lymphocytese) eosinophils

15) Regarding candidiasis:

a) candida species are not part of the normal flora of the bodyb) severe invasive candidiasis commonly involves the kidneyc) candida exists in yeast form, not hyphal formd) candida does not invade the blood streame) candida grows best in warm dry environments

16) Cryptococcus neoformans causes:

a) oesophagitisb) pneumoniac) thrushd) amnionitise) meningoencephalitis

17) Aspergillus:

a) causes distiller’s lungb) causes serious pneumonia in healthy peoplec) produces allergic alveolitis by inducing type II and type IV hypersensitivity reactionsd) may cause chronic obstructive lung diseasee) does not secrete exotoxins

18) Regarding mycoplasmas:

a) obligate intracellular parasites b) lack ATP synthesisc) have a cell walld) ureaplasmas cause nongonococcal urethritise) mycoplasma pneumoniae spreads by faecal-oral transmission

19) Which diarrhoeal illness is associated with steatorrhoea:

a) giardia lambliab) entamoeba histolyticac) salmonella enteritidisd) rotaviruse) campylobacter jejuni

20) Giardia lamblia:

a) causes dysentery b) cysts are killed by chlorinec) ferments glucosed) are not flagellatede) IgA provides life-long immunity

21) Regarding protozoal infections:

a) toxoplasma can only reproduce in the intestinal epithelium of the catb) cryptospordia cause chronic debilitating diarrhoea in normal childrenc) trichomonas exists in cyst and trophozoite formsd) plasmodium malaride is the major parasitic cause of death worldwidee) schistosoma mansoui is the protozoal schistosoma with highest mortality rates

22) Which is not a typical feature of plasmodium falciparum infection?

a) cerebral symptomsb) renal failurec) pulmonary oedemad) mild anaemiae) death

23) Regarding plasmodium protozoan parasites:

a) sporozoites infect mosquitoesb) gametocytes infect red blood cellsc) merozoites are released from ruptured hepatocytesd) sporozoites are released from ruptured red blood cellse) merozoites infect hepatocytes

24) Schistosomiasis:

a) is caused by a spirocheteb) is transmitted by freshwater wormsc) infect humans by the faecal-oral routed) schistosomes mature in the portal venous systeme) has an association with lymphocytosis

25) Which infection is the most common cause of Waterhouse Friderichsen syndrome?

a) streptococcus pyogenesb) mycoplasma pneumoniaec) neisseria meningitidesd) mycobacterium tuberculosise) cytomegalovirus

26) Which is not due to coxsackie virus infection?

a) mylocarditisb) herpanginac) hand, foot and mouth diseased) pleuritis e) enterocolitis

27) Staphylococcus aureus:

a) is coagulase negativeb) causes scarlet feverc) more commonly causes lymphangitis than streptococcusd) is the second most common cause of skin abscessese) is catalase positive

28) Which is a gram negative anaerobe?

a) bacteroides fragilisb) Escherichia colic) pseudomonas aeruginosa d) clostridium difficlee) bacillus anthracis

29) What causes the rash in measles infection?

a) direct cellular injuryb) secondary infectionc) immunoglobulin secretion (B cell immunity)d) T cell mediated immunitye) inhibition of protein synthesis

30) Which is NOT a post-streptococcal syndrome?

a) glomerulonephritisb) scarlet feverc) rheumatic feverd) erythema nodosume) arthritis

31) Which doesn’t infect macrophages?

a) bordetella pertussisb) mycobacterium tuberculosis c) mycobacterium lepraed) legionella pneumophiliae) HIVf) none of the above

Section 3

Infectious Disease – Answers

1 D2 C3 E4 C5 D6 A7 E8 B9 B10 B11 C12 D13 C14 A15 B16 E17 D18 D19 A20 C21 A22 D23 C24 D25 C26 E27 E28 A29 D30 B31 F

Section 4

Environmental

1) Which is a cilia toxin in tobacco?

a) nitrogen dioxideb) carbon monoxidec) phenold) nicotinee) nickel

2) Which are the most potent chemical carcinogens?

a) volatile organic compoundsb) leadc) solventsd) rubber productse) aromatic halogenated compounds

3) Which is NOT a feature of lead toxicity?

a) renal toxicity b) anaemiac) lung fibrosisd) insomnia, fatiguee) peripheral neuropathy

4) Regarding lead poisoning:

a) lead is absorbed through the skinb) lead absorption is greatest in adultsc) there is a macrocytic normochromic anaemiad) lead readily crosses the placentae) lead deposited in bones has a half-life of 3 years

5) Organochlorines, such as DDT, persist in:

a) bonesb) fat tissuec) peripheral nervesd) bone marrowe) kidney

6) In hyperthermia:

a) core body temperature is not maintained in heat exhaustionb) heat cramps arise due to water depletionc) in heat stroke, there is profound peripheral vasoconstrictiond) atrial fibrillation is the most common arrhythmia e) muscle necrosis may occur

7) Regarding lead, which is TRUE?

a) adults absorb lead more easily than infants and childrenb) the half-life of lead in bone is three yearsc) most of absorbed lead ends up in soft tissuesd) lead is rapidly cleared from the blood streame) in lead poisoning, you may see radio dense deposits in metaphysis of bones in

children

8) Regarding radiation, which is TRUE?

a) UV radiation is a type of ionising electromagnetic radiationb) cells in B2 and mitotic phases of cell cycle are most sensitive to ionising radiationc) UVB has a wavelength range of 400-600nmd) particulate ionising radiation of alpha particle kind consists of electronse) alpha particles have high tissue penetration

9) Regarding influenza virus, which is FALSE?

a) is a single stranded RNA virusb) clearance of primary influenza infection is by cytotoxic T cells and macrophagesc) influenza pandemics are caused by antigenic driftd) antibodies to haemagglutinins and neurominidases antigens on lipid bilayer of

influenza envelope confers immunity to re-infectione) influenza types B and C commonly cause respiratory infections in children and do not

show antigenic shift or drift

10) Mycoplasma tuberculum – which is TRUE?

a) is an anaerobic non motile acid-fast bacillib) the Ghon complex consists of an apical parenchymal lesion and enlarged nodes drain

the primary focusc) Pott’s disease is Tb of the kidneyd) T lymphocyte mediated response controls 95% of infections in AIDS cases e) reactivation of latent lesions to secondary Tb occurs 5-10% of cases

11) Regarding gastrointestinal infections:

a) campylobacter infection may result in Guillain-Barre syndrome and Reiters syndrome in HLA-B27 positive individuals

b) “Typhoid Mary” probably had a chronic colonisation of her spleen, thus making her a carrier???????

c) vibrio cholerae invade the epithelium and causes these cells to express enterotoxinsd) entomoeba histolytic infection results in one or more hepatic abscesses in up to 40% of

patients in amoebiasise) giardia lamblia are the most common cause worldwide of dysentery

12) The cytochrome P-450:

a) gene CYPIAI is induced by polycyclic chromatic hydrocarbons in cigarette smoke and is protective against lung cancer

b) isoelzymes are only expressed in the liver of normal personsc) metabolises 2-napthylenine, an azo-synthetic dye component associated with

increased rates of hepatocellular cancerd) system is involved in the metabolisation of alcohol to acetaldehyde e) all of the above are false

13) Regarding physical environmental injuries:

a) immersion blast injuries would not be expected to damage solid tissuesb) high altitude pulmonary oedema (HAPE) is caused by reduced barometric pressurec) air-embolism is not a risk of free (non-SCUBA) depth divingd) “the bends” is a painful symptom of aseptic necrosis of bone caused by ??????e) window glass transmits UVA therefore allowing tanning

14) Smoking:

a) stroke is five times more common in cigarette smokers than in non-smokersb) smoking induced emphysema begins to reverse within 1-2 years of cessation of

smokingc) maternal smoking has deleterious effects on foetal intellectual developmentd) reduction in risk of MI after cessation of smoking approaches baseline in 5-20 yearse) 50% of bronchogenic carcinoma is attributable to cigarette smoking

15) All are common adverse drug reactions EXCEPT:

a) tinnitus and dizziness with salisylateb) acute tubular necrosis with salisylatec) dystonic reactions with phenothiazinesd) haemolytic anaemia with methyldopae) diffuse hepatocellular damage with hepothane

16) Poisons and drugs of abuse – all true EXCEPT:

a) wrist drop and foot drop may develop with peripheral neuropathy in lead poisoningb) marijuana may be used in treating asthmac) marijuana may reduce fertility in malesd) Weincke’s syndrome in chronic alcoholism is associated with thiamine deficiencye) use of cocaine may precipitate rupture of the descending aorta

17) Radiation injury:

a) gamma rays are high velocity and more likely to produce a radiation effect than alpha rays

b) the radio sensitivity of cells is proportional to their level of spendlisation c) well-oxygenated tissues are less prone to radiation damaged) one hundred rads of whole-body radiation can cause significant systemic reactions e) radiation with CNS effects, has approximately 50% of survival

18) Tumours:

a) haematomas are tumours of blood vessels b) leucomyosarcomas arise from or resemble striated muscle cellsc) teratomas do not represent more than two germ cell layersd) anaplasia is common in benign tumourse) metastasis via haematogenous spread is typical of sarcomas

Section 4

Environmental – Answers

1 B2 E3 C4 D5 B6 E7 D8 B9 C10 E11 A12 D13 A14 D15 B16 E17 D18 E

Section 5

Infectious Disease

1) With regards to tuberculosis, which is false?

a) drug mutations is caused by mutations in the RM polymerase and catalase (for rifampicin and isoniazid respectively)

b) mycobacterium tuberculosis infects about one fifth of the world’s population and kills around 3 million people per year

c) M. tuberculosis pathogenicity is related to its ability to escape killing by macrophages and induce delayed type hypersensitivity

d) after initial infection, it takes 2-3 weeks until development of cell mediated hypersensitivity

e) M. bevis is transmitted by milk from diseased cows

2) What is the second leading cause of diarrhoea among infants?

a) shigella dysenteriaeb) o-type enterotoxic E.colic) rotavirusd) enteric adenovirusese) norwalk-like viruses

3) Syphilis – which is false?

a) in congenital syphilis, placental invasion by treponemes does not occur until 5 th month gestation

b) the histological hallmarks are obliterative endarteritis and ??plasma cell rich mononuclear infiltration

c) the aorta is involved in 80% of tertiary syphilis casesd) lack of antigens (proteins) within the outer membrane of the sprochaete allow it to be

less affected by host cellular and humoral immune responsese) Hutchinson teeth are commonly found in tertiary syphilis

4) EBV may cause all but which of the following symptoms and signs?

a) sore throat, fever, lymphadenitisb) splenomegalyc) hepatitis and a peripheral neuropathyd) orchitise) afebrile rash resembling rubella

5) With respect to drugs of abuse:

a) pheneyclidine characteristically induces nystagmus b) pisilocybin was once used as an anaestheticc) cocaine is classed as a narcotic and blocks uptake of noradrenaline and dopamine at

the synapsed) chronic marijuana smoking, like tobacco smoking, can increase the risk of lung cancers

and cause lung damagee) intravenous addicts have a higher risk of endocarditis, the common organism isolated

being staph epidermidis

6) All but one of the following cytokines have been implicated in cancer cachexia or sepsis cachexia:

a) TnF α b) IL-1c) IL-2d) IL-6e) IFn δ

7) All but one of the following pathogens show significant antigenic variation:

a) rickettsia prowazekiib) rhinovirusesc) neisseria gonorrhoead) barrelia burgdorfeie) giardia lamblia

8) Guillain-Barre syndrome is a complication of:

a) yersinia enterocolitia b) campylobacterc) shigellad) viral gastroenteritise) cholera

9) Many cholera epidemics begin along the:

a) Thames Riverb) Ganges Riverc) Mississippi Riverd) Avon Rivere) Nile River

10) Silver stains identify:

a) pneumocystisb) cryptococcic) malariad) GNBe) TB

11) Staphylococcal protein A:

a) is a pore forming protein that depolarizes cell neuronsb) is also secreted by streptococcic) binds Fe portion of Igd) causes inhibition of SFN activated macrophagese) is a detergent-like peptide

12) Chlamydiae differ from bacteria in that they:

a) lack a cell wallb) are faultive intracellular pathogens ?????c) lack ATP synthesisd) cause STDse) are the tiniest free living organisms known

13) The infective organism of Kala-azar is:

a) Wuchereria bancroftib) Trypanosoma cruzic) Leishmania donovanid) Babesia microtie) Completae bastardo questioni

14) The reservoir hosts of Lyme disease:

a) field miceb) humansc) cowsd) mosquitoese) pet hamsters

15) Which of the following pathogens shows significant antigenic variation?

a) staphylococcus aureusb) neisseria gonorrhoeaec) H. influenzaed) adenoviruse) E.coli

16) Yersinia pestis causes which disease?

a) lyme diseaseb) relapsing feverc) rocky mountain spotted feverd) dengue fevere) bubonic plague

17) Regarding plasmodium falciparum infection:

a) it causes mild anaemiab) does not cause cerebral malariac) merozoites are transmitted by mosquito bitesd) parasites change appearance from ring to schizont form inside RBCse) as hepatocytes rupture, they release approximately 300 merozoites into the circulation

18) In what city was the 1976 convention of the American Legion held, (the first named outbreak of Legionnaires disease)?

a) Pontiacb) New Yorkc) Baltimored) Philadelphiae) Green Bay

19) Which of the following organisms produces a toxin to cause diarrhoea?

a) shigella flexneerib) campylobacter jejunic) yersinia enteritisd) salmonella typhie) Escherichia coli

20) The third leading cause of hospital acquired infections is:

a) Staph aureusb) E. colic) P. aeruginosad) St. pneumoniaee) H. influenzae

21) Members of the picornavirus family include all EXCEPT:

a) hepatitis A virusb) measles virusc) coxsackie virus Bd) polio viruse) rhinovirus

22) The following are true about Haemophilus influenza EXCEPT:

a) H. influenzae causes meningitis, URTIs, pneumonia and endocarditisb) H. influenzae causes various suppurative infectionsc) it is the most common cause of meningitis in > 5 year oldsd) it is an encapsulated coccobacillary gram negative organismse) over 90% are encapsulated type is strains

23) Chlamydial organisms:

a) respond to penicillinb) synthesize their own nucleic acids but not their own ATPc) possess DNA not RNAd) are extracellular organismse) all cause urethritis and cervicitis

24) The following about CMV are all true EXCEPT:

a) there are several serotypesb) the infection is almost always latent or asymptomatic in adults unless the patient is

immunocompromised or debilitatedc) it can be transmitted through breast milkd) there are two peaks of contraction of CMV – in utero and after age 15e) it can cause entercolitis secondary to ulcerative lesions in the intestine

25) Mumps:

a) is a togavirusb) is bilateral (parotitis) in 50% of casesc) orchitis occurs in 30% of casesd) the vaccine is prepared from a cell-free toxine) can cause myocarditis, encephalitis and meningitis

26) Which are obligate intracellular organisms?

a) plasmidsb) bacteriophagesc) mycoplasmad) RNA viruses

27) Mycoplasma differs from bacteria in that it:

a) lacks metabolic capacityb) lacks a cell wallc) is susceptible to antibioticsd) have nuclei

28) Causes of bloody diarrhoea include all but:

a) staphylococci enterotoxinsb) salmonellac) shigellad) campylobacter

29) Which is most likely to cause systemic infection?

a) cholerab) salmonella typhic) campylobacterd) shigella

30) Which bacteria causes diarrhoea via production of an exotoxin?

a) staphylococcib) shigellac) toxigenic E. colid) campylobacter

31) Haemophilus influenzae:

a) vaccine is directed against cell wall proteinsb) type C is most commonly associated with severe invasive diseasec) unencapsulated form is responsible for about 50% of pharynx colonisationd) can release a toxin to disrupt ciliary beating

32) Tertiary syphilis is evidenced in all of the following organs except:

a) external genitaliab) liverc) bonesd) aorta

33) The underlying histological abnormality in treponema pallidum infection is

a) granulomatous inflammationb) toxin mediatedc) obliterative endarteritisd) cytolysis of superficial epithelium

Section 5

Infectious Diseases – Answers

1 B2 D3 E4 D5 A6 C7 A8 B9 B10 A11 C12 No answer13 No answer14 No answer15 No answer16 No answer17 No answer18 No answer19 No answer20 No answer21 No answer22 No answer23 No answer24 No answer25 No answer26 D27 B28 A29 B30 C31 D32 A33 C