MRSA History Timeline: The First Half-Century, 1959–2009

1959
Methicillin, the first beta-lactamase-resistant penicillin, was licensed in England

1960
First MRSA isolates identified in a British study

1960-1967
Infrequent hospital outbreaks of MRSA in Western Europe and Australia

1968
First hospital outbreak of MRSA in the United States at the Boston City Hospital, Massachusetts

1968–mid 1990s
MRSA gradually recognized as an endemic pathogen in hospitals, especially in large urban university hospitals
Percent of Staphylococcus aureus infections in hospitalized patients that were caused by MRSA increased slowly but steadily

1982
Large outbreak of MRSA infections among intravenous drug users in Detroit, Michigan

Late 1980s–1990s
Outbreaks of MRSA noted in Australia among Aboriginal populations with no exposure to hospitals

1998–2008: The CA-MRSA Epidemic Decade
While rates of HA-MRSA infection remained stable, rates of CA-MRSA increased

Mid-1990s
Scattered reports of CA-MRSA infections in children in the United States

1998
*Comparing 2 periods—1993-1995 and 1995-1997—among children with no risk factors for health care exposure, there was a 25-fold increase in the rate of hospitalizations due to MRSA (See the 2/25/98 issue of JAMA and the accompanying press release)

1999
*First reports of healthy, young children dying of severe MRSA infections

2001
Shift from USA400 to USA300 as predominant strain of CA-MRSA in the United States

2003
*SCCmec IV recognized
Major groups of MRSA defined by the U.S. Centers for Disease Control and Prevention (USA100, USA200, USA300, ...USA1000)

2003-2004
In large studies, correlations made between different MRSA genotypes and specific clinical syndromes

2005
CA-MRSA risk factors identified to date include: athletes, military recruits, incarcerated people, emergency room patients, urban children, HIV patients, men who have sex with men, indigenous populations

2009: MRSA infections cause people to go to hospitals; hospital stays less commonly cause MRSA infections
1) CA-MRSA has confusing criteria because CA-MRSA strains commonly cause infections in health care settings.
2) CA-MRSA infections now common in most U.S. cities.
3) CA-MRSA infection and asymptomatic colonization remain less common outside the U.S.

*University of Chicago-led findings