¾
¾
Godzilla is big and frightening
Godzilla is big and frightening
……
……
.
.
¾
SIZE
SIZE
DOESN
DOESN
’
’
T
T
MATTER
MATTER
....Why community acquired MRSA is
....Why community acquired MRSA is
more frightening than Godzilla
more frightening than Godzilla
…
…
.
.
Richard Bradbury
Staphylococcus
Staphylococcus
aureus
aureus
¾
¾
Most common cause of wound infections
Most common cause of wound infections
¾
¾
Also causes of many other types of disease
Also causes of many other types of disease
z
z Skin and soft tissue (boils, Skin and soft tissue (boils, cellulitiscellulitis, ulcers, etc), ulcers, etc) z
z PneumoniaPneumonia z
z SepticaemiaSepticaemia z
z Urinary tract infectionUrinary tract infection z
z EndocarditisEndocarditis z
Staphylococcus
Staphylococcus
aureus
aureus
colonisation
colonisation
¾
¾
70% Hospitalised
70%
Hospitalised
Population
Population
¾
¾
30-
30
-
50% Community population (transient?)
50% Community population (transient?)
z
z
Colonisation
Colonisation
sites:
sites:
• • Nose Nose -- 30-30-50%50% • • Skin Skin -- 55--10%10% • • Gut Gut -- 20%20% •
• Perineum & genitalia Perineum & genitalia –– 62%62% •
Development of
Development of
antibiotic resistant
antibiotic resistant
Staphylococcus
Staphylococcus
aureus
aureus
¾
¾ 1937 Fleming discovers penicillin1937 Fleming discovers penicillin
¾
¾ 1941 Florey & 1941 Florey & ChaneChane extract active agentextract active agent
¾
¾ 1943 Commercial penicillin1943 Commercial penicillin
¾
¾ 19501950’’s Penicillin resistance in s Penicillin resistance in S. S. aureusaureus
¾
¾ 1961 Development of 1961 Development of penicillinasepenicillinase stable stable penicillinspenicillins
(
(methicillinmethicillin, , cloxacillinscloxacillins))
¾
Methicillin
Methicillin
Resistant
Resistant
Staphylococcus
Staphylococcus
aureus
aureus
¾
¾ MRSA clones quickly spread worldwideMRSA clones quickly spread worldwide
¾
¾ MultiMulti--resistant MRSA (resistant MRSA (mMRSAmMRSA); resistant to all ); resistant to all ββ––lactamslactams
and more than two other classes of antibiotic and more than two other classes of antibiotic
¾
¾ Infections limited to inInfections limited to in--patients or those who have recently patients or those who have recently
been in
been in--patients in hospitalspatients in hospitals
¾
¾ In 1980, MRSA is detected in injecting drug users in Detroit In 1980, MRSA is detected in injecting drug users in Detroit
without significant history of
Community acquired MRSA
Community acquired MRSA
z
z HospitalisationHospitalisation
(incl. out
(incl. out--patient and emergency)patient and emergency)
z
z Long term care facility Long term care facility
(nursing home, prison)
(nursing home, prison)
z
z SurgerySurgery z
z DialysisDialysis
z
z Permanent indwelling Permanent indwelling
catheter or
catheter or percutaneouspercutaneous medical device
medical device
z
z Health care occupationHealth care occupation z
z Previous positive MRSA Previous positive MRSA
culture
culture
¾
¾ S. S. aureusaureus isolated in outisolated in out--patient or emergency setting, or patient or emergency setting, or
<48 hours following hospital admission <48 hours following hospital admission
¾
How did I get that?
How did I get that?
z
z Medically underservedMedically underserved z
z Poor Poor hygeinehygeine z
z Prior antibiotic usePrior antibiotic use z
z Residential crowdingResidential crowding z
z Skin infectionsSkin infections z
z IndigenousIndigenous z
z ImprisonedImprisoned z
z Minority ethnicityMinority ethnicity z
z Military personnelMilitary personnel
¾
¾
Predisposing factors:
Predisposing factors:
z
z PostPost--partum womenpartum women z
z HomelessHomeless z
z IV drug useIV drug use z
z Male to male sexMale to male sex z
Methicillin
Methicillin
Resistant
Resistant
Staphylococcus
Staphylococcus
aureus
aureus
in Australia
in Australia
¾
¾ Late 1970Late 1970’’s s -- MRSA strain emerge in Melbourne and MRSA strain emerge in Melbourne and
Sydney Sydney
¾
¾ Now endemic in Australian and overseas hospitalsNow endemic in Australian and overseas hospitals
¾
¾ WA escapes!WA escapes!
¾
Methicillin
Methicillin
Resistant
Resistant
Staphylococcus
Staphylococcus
aureus
aureus
in Australia
in Australia
¾
¾ 1989 1989 –– MRSA infections emerge in remote Kimberley MRSA infections emerge in remote Kimberley
region of WA region of WA
¾
¾ Strains is “Strains is “nonnon--multimulti--resistant MRSA (resistant MRSA (nmMRSAnmMRSA))””
(resistant to all
(resistant to all ββ––lactamslactams, but less than two other classes of antibiotic), but less than two other classes of antibiotic)
¾
¾ Patients had no prior history of Patients had no prior history of hospitalisationhospitalisation
¾
WA
WA
-
-
MRSA
MRSA
¾
¾ WA-WA-MRSA strain quickly spreads throughout the stateMRSA strain quickly spreads throughout the state
¾
¾ Foci in the remote Kimberley and Goldfields regionsFoci in the remote Kimberley and Goldfields regions
¾
¾ Between 24% and 42% of people living in remote Between 24% and 42% of people living in remote
communities are
WA
WA
-
-
MRSA
MRSA
¾
¾ 43 isolations per 100,000 of population from January 43 isolations per 100,000 of population from January
1991
1991--June 1995June 1995
¾
¾ Now 144 isolations per 100,000 of population in 2008Now 144 isolations per 100,000 of population in 2008
¾
¾ Distinct from healthDistinct from health--care associated care associated mMRSAmMRSA
¾
Northern Territory
Northern Territory
¾
¾ MRSA not notifiableMRSA not notifiable
¾
¾ 81 81 nmMRSAnmMRSA infectionsinfections per 100, 000 of population per 100, 000 of population
between January 1991
between January 1991--June 1995 at Royal Darwin June 1995 at Royal Darwin Hospital alone
Hospital alone
¾
¾ Distinct from WA-Distinct from WA-MRSA clonesMRSA clones
¾
¾ NT-NT-MRSA may have emerged earlier than WAMRSA may have emerged earlier than WA--MRSAMRSA
¾
NT
NT
-
-
MRSA
MRSA
¾
¾ Approximately 20% of Territory children <15 years have Approximately 20% of Territory children <15 years have
impetigo impetigo
¾
¾ 2000 2000 –– 20% of impetigo cases are 20% of impetigo cases are S. S. aureusaureus
¾
¾ 2008 2008 –– 57% of impetigo cases are 57% of impetigo cases are S. S. aureusaureus
¾
¾ 2006 2006 –– 84% of hospital MRSA isolates are 84% of hospital MRSA isolates are cMRSAcMRSA
¾
¾ Aboriginal people are 13 times more likely to become Aboriginal people are 13 times more likely to become
infected with NT
Queensland
Queensland
SWP
SWP
-
-
MRSA
MRSA
¾
¾ 1997 1997 –– New New nmMRSAnmMRSA clone identified in Brisbane clone identified in Brisbane
community community
¾
¾ Association with Polynesian communityAssociation with Polynesian community
¾
¾ SouthSouth--West Pacific MRSA (SWPWest Pacific MRSA (SWP--MRSA)MRSA)
¾
¾ First identified in Polynesian community in AucklandFirst identified in Polynesian community in Auckland
¾
Queensland
Queensland
QLD
QLD
-
-
MRSA
MRSA
¾
¾ Simultaneously to emergence of SWPSimultaneously to emergence of SWP--MRSA,MRSA,
¾
¾ QueenslandQueensland--MRSA (QLDMRSA (QLD--MRSA)MRSA)
¾
¾ 7% of school children in Aboriginal 7% of school children in Aboriginal communiitiescommuniities
colonised colonised
¾
¾ Not found in patients at Brisbane general practicesNot found in patients at Brisbane general practices
¾
¾ 2006 2006 –– 15% of all community 15% of all community S. S. aureusaureus isolates in isolates in
QLD and the NT are
Australia Wide
Australia Wide
¾
¾ cMRSAcMRSA has now been reported from all states and has now been reported from all states and
territories territories
¾
¾ Associated difficulty in empirical treatment of Associated difficulty in empirical treatment of
community acquired infections community acquired infections
¾
Australia Wide
Australia Wide
2005
2005
Australia Wide
Australia Wide
2006
2006
“
Panton Valentine
Panton Valentine
Leukocidin
Leukocidin
¾
¾ One of many One of many S. S. aureusaureus toxinstoxins
¾
¾ Associated with: Associated with:
z
z Boils and Abscess formationBoils and Abscess formation z
z Tissue necrosisTissue necrosis z
Panton Valentine
Panton Valentine
Leukocidin
Leukocidin
¾
¾ In United States, virtually all In United States, virtually all cMRSAcMRSA (USA300 strain) (USA300 strain)
strains elaborate a PVL toxin strains elaborate a PVL toxin
¾
¾ In Australia, only QLDIn Australia, only QLD--MRSA and SWPMRSA and SWP--MRSA produce MRSA produce
the PVL toxin the PVL toxin
¾
¾ PVL is significantly associated with: PVL is significantly associated with:
z
z Skin and soft tissue infectionSkin and soft tissue infection z
z More severe infection More severe infection z
z Younger age of infection Younger age of infection
(median 32 years
Even more frightening
The Dog did it
The Dog did it
…
…
¾
¾ A number of different SCCA number of different SCCmecmec gene gene casettescasettes code for code for
methicillin
methicillin ((ββ--lactamlactam) resistance ) resistance
¾
¾ The majority of cMRSAThe majority of cMRSA strains carry SCCstrains carry SCCmecmec type IVtype IV
¾
¾ SCCSCCmecmec type IV may have originated in type IV may have originated in Staphylococcus Staphylococcus sciuri
Mobility of
Mobility of
SCC
SCC
mec
mec
Type IV
Type IV
¾
¾ The gene has been shown to transfer between The gene has been shown to transfer between S.aureusS.aureus
and other Staphylococcal species and other Staphylococcal species
¾
¾ Potential for the emergence & transmission of new Potential for the emergence & transmission of new
cMRSA
All Things Come to Those Who
All Things Come to Those Who
Wait
Wait
…
…
¾
¾ Currently, Tasmania has the lowest rates of MRSA Currently, Tasmania has the lowest rates of MRSA
colonisation
colonisation and infection in the countryand infection in the country
¾
¾ cMRSAcMRSA is an unsualis an unsual occurrence in Tasmaniaoccurrence in Tasmania
¾
¾ However, history shows that things will not remain so However, history shows that things will not remain so
simple forever
Back to Godzilla
Back to Godzilla
…
…
.
.
¾
¾ Godzilla is big and scary, but in the original 1954 film, Godzilla is big and scary, but in the original 1954 film,
virtually no
virtually no--one was shown being killed by Godzilla on one was shown being killed by Godzilla on film
film
¾
¾ In 2005, MRSA resulted in 94,360 invasive infections In 2005, MRSA resulted in 94,360 invasive infections
Godzilla
Godzilla
vs
vs
MRSA
MRSA
0 18,650 0 5000 10000 15000 20000 C o n fir m e d K ills Godzilla MRSA
Ҳ2 analysis: Significance of difference between
Conclusion
Conclusion
¾
¾
MRSA is significantly (p<0.001) more deadly
MRSA is significantly (p<0.001) more deadly
than Godzilla
than Godzilla
¾
¾
Godzilla is approximately 70
Godzilla is approximately 70
metres
metres
tall
tall
¾
¾
MRSA is approximately 1.5
MRSA is approximately 1.5
µ
µ
m tall
m tall
¾
¾
