Staph with the Seasons?

Staph infections affect on seniors and children during different seasons

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Mention of a "staph" infection can strike fear and the heebie-jeebies into the hearts of many, but a new study may tell us when we should really be on high alert.

The study shows that different strains of the bacteria are more likely to strike different age groups at different times of the year – children in the summer, and seniors in the winter.

Methicillin-resistant Staphylococcus aureus (or MRSA) is an antibiotic resistant strain of Staph that has the potential to be deadly in some patients.

"When wounds show signs of infection, visit a doctor."

To examine MRSA, researchers led by Eili Klein, Ph.D., of the Johns Hopkins Center for Advanced Modeling in the Social, Behavioral and Health Sciences, looked at data gathered from a variety of laboratories and hospitals across the nation between 2005 and 2008, including data from the Nationwide Inpatient Sample (NIS), which collects data from around 1,000 different hospitals.

According to the researchers, the number of MRSA hospitalizations more than doubled between 1999 and 2005. This rate stabilized between 2005 and 2008, neither significantly growing or declining.

While earlier MRSA infections were largely acquired in hospital settings, the rising numbers seen during the early 2000s were due largely to MRSA that patients were exposed to outside of health care, in the community.

The researchers found that children are more likely than older adults to become infected with this community strain (often from injuries or issues with the skin or with the soft tissues, like muscles, fat and blood tissues).

For example, in 2008, 74 percent of hospitalizations for MRSA in patients under the age of 20 were from an infection that occurred in the community, and the same was true for 55 percent of patients between the ages of 20 and 64 years old. 

By contrast, community acquired MRSA was the case in only 37 percent of patients aged 65 and older. This group was more likely to obtain MRSA in a hospital, perhaps because people tend to spend more time or even live in health care settings (including nursing homes) as they age.

The researchers also analyzed rates of infections at different points in the year and found that the community-based MRSA, the type young people are more likely to develop, peaks in the summer – specifically in August. 

On the other hand, the health care-based strand, more commonly affecting seniors, peaks during the winter – specifically in February.

While Dr. Klein and team report that “the reasons behind the observed seasonality remain unclear,” they do see a value in understanding and continuing to research what seasons certain MRSA infections are at their peaks.

“Further validation of seasonal patterns of infection and resistance is warranted because understanding seasonal patterns can improve patient care by informing more prudent drug prescription practices, diagnoses, infection control programs, and seasonally appropriate treatment guidelines,” the researchers conclude.

The study was published online by the American Journal of Epidemiology on February 28, 2013.  No conflicts of interest were reported.

Reviewed by: 
Review Date: 
March 5, 2013
Last Updated:
August 15, 2013