| Urgent |
| Clostridium difficileA1,A2 |
Deaths related to C. difficile increased 400% between 2000 and 2007, in part because of a stronger strain Most infections are connected to receiving medical care Hand sanitizer does not kill C. difficile, and hand washing may not be sufficient |
| Carbapenem-resistant EnterobacteriaceaeA3 |
Difficult to treat and, in some cases, untreatable Kills up to one-half of patients who get bloodstream infections Easily spreads antibiotic resistance to other bacteria |
| Drug-resistant Neisseria gonorrhoeaeA4 |
Cases in the United States are more prevalent in the West and among men who have sex with men All patients treated for gonorrhea should routinely be offered condoms, referred for risk-reduction counseling, and retested for gonorrhea three months later |
| Serious |
| Multidrug-resistant AcinetobacterA5 |
Increasingly common in U.S. health care facilities; hard to treat Noted in U.S. service members wounded in Iraq and Afghanistan |
| Drug-resistant CampylobacterA6 |
Most cases are sporadic and not part of outbreaks Ciprofloxacin (Cipro) resistance to Campylobacter increased from 12% in 1997 to 24% in 2011 |
| Fluconazole- (Diflucan-) resistant Candida (fungus)A7-A9 |
Antifungal resistance in mucosal candidiasis varies by species |
| Extended spectrum ß-lactamase producing EnterobacteriaceaeA10,A11 |
Infections have become more common in recent years Once confined largely to hospitals, these bacteria, especially Escherichia coli, are increasingly common in community-acquired infections, particularly urinary tract infections |
| Vancomycin-resistant EnterococcusA12-A14 |
Enterococci are the fifth most common cause of health care–associated infections Most likely to be found in urine and in wounds; may pose a risk for spreading in the outpatient setting |
| Multidrug-resistant Pseudomonas aeruginosaA15,A16 |
About 8% of all health care–associated infections are caused by P. aeruginosa; about 13% of severe P. aeruginosa health care–associated infections are multidrug resistant P. aeruginosa may be isolated from outpatients with otitis, skin rash, and urinary tract infections |
| Drug-resistant non-typhoidal SalmonellaA17,A18 |
Estimated 1.2 million cases occur each year in the United States; most go unreported About 100,000 of cases (8%) are caused by drug-resistant Salmonella Outbreaks occur each year; some involve multiple states and/or national distribution |
| Drug-resistant Salmonella serotype TyphiA19 |
Estimated 5,700 cases annually in the United States Most (up to 75%) are acquired during international travel Increasing resistance to antibiotics, especially fluoroquinolones |
| Drug-resistant ShigellaA20 |
High-risk groups include children in day care centers (younger than five years) and their caregivers, men who have sex with men, international travelers, and persons in custodial institutions Increasing resistance to ciprofloxacin and azithromycin (Zithromax) is of particular concern |
| MRSAA21-A23 |
Although overall cases of invasive MRSA are declining, the proportion of community-associated infections has increased MRSA should be considered in the differential diagnosis of skin and soft tissue infections |
| Drug-resistant Streptococcus pneumoniaeA24 |
The increasing threat of antibiotic resistance makes vaccination according to the Advisory Committee for Immunization Practices’ recommendations for children and adults more important |
| Drug-resistant TBA25,A26 |
The number of TB cases is declining in the United States 63% of TB cases in the United States occur among foreign-born persons The proportion of primary multidrug-resistant TB cases occurring among foreign-born persons has been increasing |
| Concerning |
| Vancomycin-resistant Staphylococcus aureusA27 |
Rare; 13 cases have been identified in the United States since 2002 The severity of the consequences of S. aureus resistance to vancomycin require continued vigilance for this pathogen |
| Erythromycin-resistant Group A StreptococcusA28 |
Penicillin remains the drug of choice, but the resistance to other drugs needed for patients allergic to penicillin is worrisome Of samples tested by the CDC, 10% were erythromycin-resistant and 3.4% were clindamycin-resistant |
| Clindamycin-resistant Group B StreptococcusA29 |
Neonates, pregnant women, and persons older than 65 years with underlying conditions are at highest risk Penicillin remains the drug of choice, but the resistance to other drugs needed for patients allergic to penicillin is worrisome |