Infectious Disease: Evolving Challenges to Human Health

Drug-Resistant Bacteria Are Emerging

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Antibiotic-resistant, disease-causing bacteria are increasingly common. For example, methicillin-resistant Staphylococcus aureus (“Staph”) (MRSA) infections are a growing problem. Staph bacteria live on the skin and in the nose of healthy people; Staph infections occur when the bacteria penetrate the surface of the skin through cuts or scrapes and grow within deeper tissues or enter the bloodstream. MRSA first appeared in hospitals and prisons, but have now spread to the community. Because these Staph bacteria can cause serious infections in otherwise healthy young people, and because they are resistant to nearly all available antibiotics, the emergence and spread of MRSA is worrisome.

1943   Penicillin became available and killed Staph
1947   First resistant strains reported
1960s  Methicillin replaced penicillin for treating Staph infections
1961   Methicillin-resistant Staph reported in Cairo
1980s  Methicillin resistance rising, vancomycin used as a last resort
1992   15% of Staph are methicillin-resistant
1996  35% are methicillin-resistant
2000   50% are methicillin-resistant
2001   Vancomycin resistance reported (fortunately, not in Staph that are methicillin-resistant)

Staphylococcus aureus

A photo of Staphylococcus aureus taken with an electron microscope. Antibiotic resistance is an increasingly common problem worldwide. (Photo courtesy of CDC/ Janice Carr/ Jeff Hageman, M.H.S.)

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