2.3

Question 1

lancefeild group a

Answer 1

streptococcus pyogenes

Question 2

2 beta haemolytic streptococci

Answer 2

strep progenies and agalactiae

Question 3

streptococcus pyogenes

Answer 3

• May be found as a commensal of the oropharynx

causes suppurative and non-suppurative disease

Question 4

progenies suppurative disease

Answer 4

tonsillitis, peritonsilar abscess, retropharyngeal abscess, otitis media, mastoiditis, skin and other soft tissue infections

Question 5

progenies suppurative skin and soft tissue infections

Answer 5

impetigo, cellulitis, erysipelas, necrotising fasciitis, puerperal fever and puerperal sepsis

Question 6

tonsillitis

Answer 6

® Causes most bacterial cases of pharyngitis 
					® Causes 
						◊ Acute sore throat 
						◊ Fever
						◊ Malaise
						◊ Headache 
						◊ Cervical lymphadenopathy

Question 7

pritonsillar sbcess

Answer 7

® Streptococcal tonsillitis may sometimes be followed by a peritonsillar abscess, also called quinsy

Question 8

retropharyngeal abscess

Answer 8

® A collection of pus in the tissue between the cervical spine vertebral bodies and the back of the pharynx

Question 9

otitis media

Answer 9

® Suppurative infection of the middle ear

Question 10

• Mastoiditis

Answer 10

® The mastoid sinus, which lies behind the middle ear, may become infected if there is concurrent otitis media
® May progress to an infection of the surrounding bone

Question 11

impetigo

Answer 11

◊ Pyoderma
◊ This infection of the superficial layers of the skin is typically caused by streptococcus pyogenes or staphylococcus aereus
◊ Yellow crusted plaques of inflamed red skin
◊ Highly contagious
◊ School sores in children
◊ Typically occurs on the face, around the mouth and the nose

Question 12

® Cellulitis

Answer 12

◊ Infection of the skin consisting of
} Redness
} Swelling
} Pain
} Warmth
◊ Typically enters the skin through a wound or other break in the epithelium
◊ The infection may spread rapidly to involve large areas of skin eg. A whole limb
◊ Patients may be systemically unwell with fever and the infection can enter the blood stream
◊ Most cases are caused by S pyogenes or S aureus

Question 13

® Erysipelas

Answer 13

◊ When the dges of the inflamed skin are sharply demarcated, the diagnosis is more suggestive of erysipelas
◊ This is a more superficial infection that cellulitis although the two conditions may be hard to ditinguish
◊ Superficial lymphatic cahnne;s become obstructed in erysipelas, causing skin swelling with retracted pores, the peau d’orange or ‘orange peel’ appearance

Question 14

® Necrottising fasciitis

Answer 14

◊ This is a serious infection which may develop from cellulitis, when the causative bacteria infect the deeper layers of the skin and spread along fascial planes
◊ Toxins produced by the bacteria, together witth the effects of the inflammatory response, lead to damage to arteries and arterioles, liquefaction of fat, and necrosis of tissue

Question 15

® Puerperal fever and puerperal sepsis

Answer 15

◊ Fever in the mother in the first 10 days after gicing birth - puerperal fever
◊ If the infection becomes systemic and life threatending - pueperal sepsis
◊ Led to infection control practises in hospitals

Question 16

pyogenes non suppurative strains

Answer 16

rheumatogenic, nephritogenic, pyrogenic exotoxin secreting

Question 17

rheumatogenic strain causes

Answer 17

rheumatic fever

Question 18

nethritogenic strains cause

Answer 18

post streptococcal glomerulonephritis

Question 19

pyrogenic exotoxin secreting strains

Answer 19

scarlet fever

Question 20

3 non suppurative diseases

Answer 20

rheumatic fever, post streptococcal glomerulonephritis, screlett fever

Question 21

◊ Rheumatic fever

Answer 21

} Follows infection of the pharynx with rheumattogenic strains
} It is believed that this disease is autoimmune and due to human antibodies arising from the streptococcal infection attacking host tissue

Question 22

features of rheumatic fever

Answer 22

– Carditis - inflammation of heart muscle, pericardium, endocardium, permanent heart value damage may result
– Polyarthritis - inflammation of large joint
– Subcutaneous nodules
– Sydenham’s chorea - writhing movement of the arms and face
– Erythema marginatum - characteristic skin rash

Question 23

Carditis

Answer 23

inflammation of heart muscle, pericardium, endocardium, permanent heart value damage may result

Question 24

Sydenham’s chorea

Answer 24

writhing movement of the arms and face

Question 25

Erythema marginatum

Answer 25

characteristic skin rash

Question 26

Polyarthritis

Answer 26

inflammation of large joint

Question 27

◊ Post streptococcal glomerulonephritis

Answer 27

} Occurs often infection of the pharynx or skin with nephritogenic strains
} Immune mediated disease in which immune complexes containing streptococcal antigens are deposited in glomeruli, resulting in reduced function
} The condition is most common in tropical, developing countries with the world incidence being highest in australian aboriginal children

Question 28

Post streptococcal glomerulonephritis clinical features

Answer 28

– Dark urine (haemolysed red cells)
– Proteinuria
– Reduced urine output
– Oedema (defective excretion of salt and water
– Hypertension
– Impaired left ventricular cardiac function

Question 29

◊ Post streptococcal glomerulonephritis most common in

Answer 29

} The condition is most common in tropical, developing countries with the world incidence being highest in australian aboriginal children

Question 30

rhuematic fever caused by

Answer 30

® Rheumatogenic strains

Question 31

◊ Post streptococcal glomerulonephritis caused by

Answer 31

nephritogenic strains

Question 32

Scarlett fever caused by

Answer 32

® Pyrogenic exotoxin secreting strains

Question 33

◊ Scarlet fever

Answer 33

} Occur with Pharyngeal infections, and less commonly skin and soft tissue infections

Question 34

Scarlett fever clinical features

Answer 34

} Signs and symptoms of pharyngitis, and also
– Red face with circumoral palor
– Erythematous patches of skin on neck, spreading to trunk and limbs
– Rash develops ‘sandpapery’ feel
– ‘white strawberry’ tongue following by ‘red strawberry’ tongue
– Desquamation of skin as rash resolves

Question 35

progression to non suppurative disease

Answer 35

Non-suppurative disease may follow a suppurative infection when the particular strain involved possesses certain virulence factors

Question 36

streptococcus agalactiae

Answer 36

• This organism may be found as a commensal of the human bowel and vagina
  - Coloniser of the gastrointestinal tract and vagina of up to 30% of women

Question 37

streptococcus agalactiae typically causes

Answer 37

post partum maternal sepsis, neonatal infections, § Less commonly it can cause a variety of infections not associated with pregnancy

Question 38

§ Postpartum maternal sepsis

Answer 38

- Colonised mothers may develop invasive disease associated with pregnancy 
					® UTI
					® Chorioamnionitis 
					® Endometritis 
					® Sepsis

Question 39

§ Neonatal infections

Answer 39

• Infants may become colonised in utero or during delivery

- Disease is more likely in premature infants or following premature rupture of membranes

Question 40

neonatal infection disease appearances

Answer 40

® Disease appearing during the first 7 days post partum is typically pneumonia with bacteraemia
® Disease appearing from 7 days to 3 months post partum is typically meningitis with bacteraemia

Question 41

neonatal infection reduction

Answer 41

• Early onset neonatal disease has been significantly reduced by screening pregnant women for carriage of S agalactiae (rectovaginal swabs) at 35-37 weeks and giving carriers a dose of penicillin during labour