Clinical and laboratory characteristics of invasive infections due to methicillin-resistant Staphylococcus aureus isolates demonstrating a vancomycin MIC of 2 micrograms per milliliter: lack of effect of heteroresistant vancomycin-intermediate S. aureus phenotype.

We describe clinical and laboratory characteristics of invasive methicillin-resistant Staphylococcus aureus (MRSA) infections with vancomycin MICs of 2 µg/ml and compare heteroresistant-intermediate S. aureus (hVISA) to non-hVISA. Health care-associated community-onset infections were the most common and resulted in frequent complications and relapses. hVISA-infected patients were more likely to have been hospitalized in the year prior to MRSA culture.

Surveillance for severe community-associated methicillin-resistant Staphylococcus aureus infection.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has rapidly emerged in the USA as a cause of severe infections in previously healthy persons without traditional risk factors. We describe the epidemiology of severe CA-MRSA disease in the state of Georgia, USA and analyse the risk of death associated with three different clinical syndromes of CA-MRSA disease - pneumonia, invasive disease, and skin and soft-tissue infections (SSTIs). A total of 1670 cases of severe CA-MRSA disease were reported during 2005-2007. The case-fatality rate was 3.4%; sex and race of fatal and non-fatal cases did not differ significantly. While CA-MRSA pneumonia and invasive disease were less common than SSTIs, they were about 15 times more likely to result in death [risk ratio 16.69, 95% confidence interval (CI) 10.28-27.07 and 13.98, 95% CI 7.74-25.27, respectively]. When controlling for age and the presence of other clinical syndromes the odds of death in patients manifesting specific severe CA-MRSA syndromes was highest in those with pneumonia (odds ratio 11.34). Possible risk factors for severe CA-MRSA SSTI and pneumonia included the draining of lesions without medical assistance and an antecedent influenza-like illness.

Use of stool collection kits delivered to patients can improve confirmation of etiology in foodborne disease outbreaks.

BACKGROUND: In 68% of foodborne disease outbreaks, no etiologic pathogen is identified. In two-thirds of outbreaks with no identified etiology, no stool specimens are submitted for testing. METHODS: From April 2001 to March 2003, we pilot-tested use of prepackaged, self-contained stool specimen collection kits in 3 states, delivered to and from patients by courier or mail, to improve rates of specimen collection in the outbreak setting. Specimens were tested for bacterial and viral pathogens at health department laboratories, and results were correlated with epidemiological investigation data. RESULTS: Specimens were returned by > or =1 person in 52 (96%) of 54 outbreaks in which kits were deployed; in total, 263 (76%) of 347 persons who received kits returned specimens. Resolution of symptoms was the most commonly cited reason for nonsubmission of kits. An etiology was confirmed in 37 (71%) of 52 outbreaks with specimens returned; 28 (76%) were attributable to norovirus, and 9 (24%) were attributed to bacterial pathogens. Stool kits were well received and cost an average of approximately 43 dollars per specimen returned. CONCLUSIONS: In two-thirds of foodborne disease outbreaks in which delivered stool collection kits were successfully deployed, an etiologic organism was identified. Delivery of kits to and from patients to improve rates of stool collection in outbreaks in which specimens might otherwise not be submitted could substantially reduce the number of outbreaks with an unknown etiology.

"Norwalk-like viruses". Public health consequences and outbreak management.

"Norwalk-like viruses" (NLVs) cause outbreaks of gastroenteritis and are spread frequently through contaminated food or water. Molecular diagnostics now enables detecting viruses in clinical and environmental specimens, linking of NLV strains causing outbreaks in multiple geographic locations, and tracing them to their sources in contaminated food or water. This report reviews recent advances in NLV detection and provides guidelines and recommendations for investigating NLV-related outbreaks, including specimen collection and disease prevention and control. This report also updates information provided in CDC's previously published, Viral Agents of Gastroenteritis: Public Health Importance and Outbreak Management (MMWR 1990;39 [No. RR-5]: 1-24). These CDC recommendations are intended for public health professionals who investigate outbreaks of acute gastroenteritis but could be useful in academic and research settings as well.