Officials with the Leon County Health Department are actively investigating the unusually high number of staph infections. A Health Department representative told the Tallahassee Democrat that investigators are looking into the possibility that the Pain Institute may have received a contaminated batch of medicine, but the source of the staph bacteria has yet to be determined. There is no evidence that the clinic is to blame for the outbreak.

Patients began calling the Pain Institute of North Florida on March 14 with what seemed like viral symptoms. Cultures revealed that they had contracted staph infections, probably on or around March 12. The infections were not the drug resistant variety of staph known as methicillin-resistant Staphylococcus aureus, or MRSA, and can be treated with antibiotics.

The owner of the Pain Institute, Dr. George Arcos, informed County health officials of the apparent staph outbreak, and asked them to investigate. Patients of the Pain Institute of North Florida who visited the clinic between March 10 and March 21, 2008 have been notified, and Dr. Arcos has suspended pain procedures at the clinic while the investigation is being conducted. Patients who underwent treatment during that period who have not received a phone call should contact the Leon County Health Department at 850-606-8161.

The seven month study identified 53 cases of community-acquired pneumonia, or CAP, caused by the Staphylococcus aureus bacterium. This number is higher than expected based on anecdotal evidence and case studies. Lead researcher Alexander Kallen noted that case studies “tend to highlight the severest of cases and may present a biased picture.”

While CAP caused by staph may be more common than thought, the incidence of fatality may actually be lower than case studies suggested. Previously believed to be between 30% and 50%, the CDC study indicates a case-fatality rate of approximately 13%.

Methicillin-resistant Staphylococcus aureus, or MRSA, was responsible for just under half of the staph-related cases of CAP. The researchers discovered that nearly 40% of the pediatric patients with CAP caused by MRSA were given antibiotics that did not cover the resistant strain of staph. Medical professionals may not recognize MRSA as a significant cause of pneumonia during flu season, Alexander Kallen said.

Researchers indicated that further study is necessary to expand upon these preliminary results and build a more complete picture of this disease. The full findings of the study were presented on March 19 at the 2008 International Conference on Emerging Infectious Diseases.

The research supported by the National Institutes of Health revealed that squalene synthase inhibitors act as a sort of Kryptonite to Staphylococcus aureus bacteria by removing their natural defense: staphyloxanthin, a carotenoid pigment that gives staph a golden hue. S. aureus bacteria that lack that pigment have inhibited ability to fight off the human immune response, resulting in decreased virulence.

In studies, the squalene sythase inhibitor BPH-652 interfered with the enzyme responsible for producing the staphyloxanthin pigment. The resulting colorless staph bacteria were significantly weakened. Lab mice injected with S. aureus bacteria that also received BPH-652 exhibited a 98% reduction in bacterial counts.

Researchers are testing hundreds of additional compounds to determine if any are more effective in stripping staph bacteria of their color and virulence. The research is still in a very early stage – too early for human trials – but pigment reduction appears to be a promising area for further investigation.

The complete study results were reported in the article “A Cholesterol Biosynthesis Inhibitor Blocks Staphylococcus aureus Virulence” published in Science Express, the online edition of Science magazine.

The contaminated cheeses were made from raw milk, and were sold in several retail health food stores in Indiana, as well as directly from the Grassy Meadows dairy. The recalled cheeses were sold in blocks or wedges, and include the following:

• Colby (lots 210317 and 19177)

• Jalapeno natural cheese (lots 2617, 21017 and 11017)

• “Homemade” cheese (lots 19267 and 19227)

• Monterey Jack (lots 18207 and 2937)

• Garlic pepper cheese (lot 19147)

No illnesses related to the contaminated cheese have been reported.

Products should be returned to the place of purchase.

The new test, manufactured by BD diagnostics, identified 100 percent of MRSA-positive specimens in clinical trials. In addition, the speedy new test is a significant improvement over other MRSA tests which take more than two days to yield results.

“The BD GeneOhm test is good news for the public health community. Rather than waiting more than two days for test results, health care personnel will be able to identify the source of a staph infection in only two hours, allowing for more effective diagnosis and treatment,” announced Daniel G. Schultz, M.D., director of the FDA Center for Devices and Radiological Health.

Fast, accurate lab results mean doctors can begin treating infections with the appropriate antibiotic almost immediately. Selection of the proper antibiotic is critical in the treatment of MRSA, and can decrease recovery time and the serious complications sometimes associated with methicillin-resistant infections.

BD Diagnostics is currently developing additional rapid tests to aid in the detection of the healthcare-associated infections vancomycin-resistant enterococci and Clostridium difficile.

The authors of the new study examined hospital discharge data from 1999 to 2005 and estimated that MRSA-related hospitalizations more than doubled, growing from 127,036 to 278,203. The estimated number of hospitalizations involving S. aureus–related infections also increased remarkably from 294,570 to 477,927.

So why is the rate of hospitalizations due to MRSA on the rise? “Contrary to the generally accepted view, community-associated MRSA strains may be spreading into the healthcare system rather than the other way around, ” the study authors suggested.

The study did not find a significant variation among geographic regions, with the rate of staph infections rising as follows:

• Northeast: 5% per year
• Midwest: 7% per year
• South: 7% per year
• West: 8% per year.

The rate of infections caused by the MRSA variety of staph rose 9% per year in the Northeast, 11% per year in the Midwest, and 12% per year in the South. Although the incidence of MRSA-related infections is lowest in the West, the rate of increase in the West was 18% per year during the study period.

Based on study findings, the researchers recommend prioritizing Staphylococcus aureus and more specifically, MRSA, in national disease control efforts. The study results indicate the need for expanded reporting requirements at the national level and increased research funding, as well as further inquiry into the relationship between community-acquired infections and hospital-acquired infections.