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 APIC survey served as an informal six-month follow-up to the organization’s MRSA Prevalence Study released in June. The MRSA Prevalence Study indicated that MRSA was “significantly more widespread” than previously thought, with rates measuring eight times higher than earlier estimates.

The follow-up poll sought to gauge the impact of the MRSA Prevalence Study results on infection control measures in hospital settings. 41 percent of respondents said that their facility had not implemented any new prevention measures since June. Explanations indicated that “many infection prevention programs are still inadequately funded and that facilities lack resources, staff, and buy-in from senior management to prevent the transmission of MRSA, ” according to Kathy L. Warye, Chief Executive Officer of APIC.

APIC provides their membership with guidelines for implementing a MRSA transmission prevention program. Recommended components include risk assessment, surveillance, hand hygiene, contact precautions, proper housekeeping, and testing of new admissions and high risk groups. Controlling MRSA also requires the explicit support of hospital administrators, and a transformation of the facility’s culture, APIC guidelines suggest.

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.

The rate of MRSA infection in Baltimore was recorded as nearly 117 per 100,000 in 2005. That rate is well over three times higher than the average infection rate of 31.8 per 100,000 recorded in the study. The other areas studied were:

• The State of Connecticut
• The Atlanta, Georgia, metropolitan area
• Davidson County, Tennessee
• The Denver, Colorado, metropolitan area
• Monroe County, New York
• The Portland, Oregon metropolitan area
• Ramsey County, Minnesota
• The San Francisco, California metropolitan area

It is unclear why the rate of MRSA infections is so high in Baltimore, according to the principal investigator for the Maryland Active Bacterial Core Surveillance, the group that collected the Baltimore data. Laura Herrera of the Baltimore City Health Department mentioned that chronic diseases have been found to be more common in urban areas.

The study also found that more Baltimore residents acquired the infection in the community (almost 63 cases per 100,000) than in hospitals (almost 20 cases per 100,000.)

Schools in the Chicago area and throughout the state of Illinois have reported cases of drug-resistant staph infections this month. Four American children died from the superbug methicilllin-resistant Staphylococcus aureus (MRSA) in October 2007, prompting heightened awareness of the the virulent infection. While state health officials have assured the public that an epidemic is not present in the state, parents and school officials have grown increasingly concerned about the potentially lethal bacteria.

Illinois schools that have students with confirmed or suspected cases of MRSA this month include:

• Aurora: Holy Angels Catholic School
• Aurora: West Aurora High School
• Bellwood: Wilson Elementary School
• Bluford: Webber Township High School
• Buffalo Grove: Cooper Middle School
• Carol Stream: Glenbard North High School
• Chicago: Chavez Elementary School
• Chicago: Walter Payton Prep High School
• Evergreen Park: Northwest Elementary School
• Evergreen Park: Southwest Elementary School
• Gurnee: Woodland Middle School
• Joliet: St. Paul the Apostle School
• Lake in the Hills: Martin Elementary School
• Lincolnshire: Adlai E. Stevenson High School
• Monmouth: Monmouth College
• Naperville: Neuqua Valley High School Frontier Campus
• North Aurora: Fearn Elementary School
• Reddick: Reddick Grade School
• Rolling Meadows: John G. Conyers Learning Academy
• Schiller Park: John F. Kennedy School
• Streamwood: Canton Middle School
• Wilmington: Wilmington High School
• Woodstock:Woodstock High School

Periodic updates to this list will be added at the bottom of this article.
Some of the schools informed parents of more than one case of MRSA, and many of the school buildings were closed temporarily to undergo thorough disinfection. Although Illinois schools are not required to notify parents if a local student is diagnosed with MRSA, most of the above schools communicated with families about the new superbug cases in a timely manner. Many schools directed families to the Illinois Department of Health’s Basic Hygiene Guidelines for the Prevention of Staphylococcal Infections in Schools.

The state of Illinois is a national leader on MRSA-related legislation. In April 2007, Illinois became the first state in the nation to require hospitals to screen incoming patients for MRSA. However, medical professionals are not required to report individual cases of MRSA to the state, so there are no accurate and comprehensive statistics on the prevalence of antibiotic-resistant staph in Illinois.

The Illinois Department of Public Health may implement the mandatory reporting of MRSA clusters of three or more cases by 2008.

Update, 10/27/07:

• Serena: Serena High School (2 MRSA infections)
• La Salle: La Salle-Peru Township High School (2 MRSA infections)

Update, 10/28/07:

• Tinley Park: Andrew High School

Update, 11/1/07:

• Elgin: Hillcrest Elementary School
• Geneva: Geneva High School
• Joliet: Forest Park Individual Ed School
• Lake Villa: Olive Martin School
• LaMoille: undisclosed elementary school
• Maple Park: Kaneland High School
• Naperville: Naperville North High School
• West Dundee: Dundee Highlands Elementary

Update, 11/4/07:

• Coal City: Coal City Middle School
• Coal City: Coal City High School
• Merrillville: Pierce Middle School
• Riverside: Riverside-Brookfield High School

Update, 11/6/07:

• Darien: Hinsdale South High School
• Plainfield: Plainfield North High School

Update, 11/9/07:

• Chicago: Mark Skinner Elementary School
• Lake Villa: JJ Pleviak Elementary School
• Sheridan: Sheridan Elementary School

Update, 11/13/07:

• Chicago Heights: Marian Catholic High School
• North Chicago: South Elementary School
• West Chicago: West Chicago High School

Update, 11/15/07:

• Palatine: District 211 Academy- North

Update: 11/19/07:

• Grayslake: Grayslake Community High School

Update, 11/30/07:

• Hoffman Estates: Conant High School
• Quincy: Adams County Juvenile Detention Center

Media coverage of MRSA did not keep pace with public interest – only 3% of national news stories between October 14 and 19, 2007 addressed staph infections. MRSA was the ninth most heavily covered news item of the week.

The Pew survey also revealed that 44% of the general public are at least somewhat worried about exposure to MRSA. During the spring of 2003, just 35% of survey respondents were worried about exposure to SARS.