In this study, researchers at one children’s hospital look back over the years at the incidence of musculoskeletal infections caused by methicillin-resistant Staphylococcus aureus (MRSA, pronounced mersa).
The purpose of the study was to see if they needed to update their treatment guidelines or do anything different at their hospital. This is an important step to take because of the increased number of patients these days needing treatment for MRSA. Not only are there more cases of MRSA-resistant musculoskeletal infections, they are more severe and affect more than one area of the body.
MRSA is a bacterium responsible for difficult-to-treat staph infections in humans. It’s resistant to a large group of antibiotics including penicillin and cephalosporin drugs. That makes it a dangerous infection that can spread.
The most common musculoskeletal problems caused by MRSA in children are highlighted in this article. These include infections of the spine, pelvis, or arms/legs caused by osteomyelitis (bone infection), septic arthritis (joint infection), cellulitis (skin infection), and pyomyositis (muscle infection or abscess). MRSA-related abscess anywhere else in the body were also reported.
The updated study was done by reviewing the medical records of children admitted to the hospital for a musculoskeletal infection. The time period selected was for the years 2002 through 2004. Anyone with a skin, muscle, joint, or bone infection was included. Data was collected on each child to help better understand how things might be different now from when this study was last done in 1982 (20 years ago).
The authors report over 3,000 children were included in the study. One-third of those children had cellulitis treated with an oral (taken by mouth) antibiotic. Another one-third had skin abscesses that required drainage and oral antibiotics. A small number of children needed intravenous antibiotics and hospitalization for abscesses or deep musculoskeletal infections.
They took a closer look at the 554 children with deep musculoskeletal infections. Almost half of the children in this group had osteomyelitis, another group had septic arthritis, a third group had deep abscesses, and the rest had pyomyositis. Antibiotics and surgical drainage were often the course of treatment.
Comparing this to data collected 20 years ago, there were almost three times as many cases of osteomyelitis during the 2002-2004 time period. Staphylococcus aureus was the cause in about half of the cases. Half the children with S. aureus had the kind that was resistant to the antibiotic methicillin (a type of penicillin). Some children had a combination of different infections involving bone, joint, and soft tissues.
There was no change in the number or type of cases of septic arthritis. Twenty children had pyomyositis. Half were resistant to methicillin. Most of the children with deep abscess only had one area of the musculoskeletal system involved. This was usually the groin, thigh, buttock, or foot. In a small number of cases, there were abscesses found in more than one place. Once again, methicillin resistant S. aureus was the major cause of these abscesses.
In this study, the types of musculoskeletal infection were grouped as described (bone, muscle, skin, other soft tissue) for future reference. Looking at the data in groups showed a linear trend. In other words, the severity was based on the location of the infection. This means that the cases involving bone were the most severe. Tissue involvement was the least severe when skin and soft tissue abscesses were present.
In order to make the distinction among these different musculoskeletal infections, careful diagnosis is required. Symptoms are often the same from one condition to the other. The physician must rely on advanced diagnostic imaging to make the final diagnosis and plan the correct treatment. The increased risk of a blood or lung clot with musculoskeletal infections also means the physician must monitor children with musculoskeletal infections carefully.
Twenty years from now, when the next update is done, it will be possible to use these categories to compare changes that have occurred or trends that are developing. The current diagnostic classification replaces the one used in 1982. At that time, everyone was divided into just two groups: osteomyelitis and septic arthritis (bone or joint infection).
The authors suggest that since there are differences in what occurs in one area of the country from another, it’s important that each institution conduct similar research for themselves. Comparing current trends with historical data for the same hospital helps each facility keep up with what’s going on in their own area. This type of research allows physicians to refine current treatment guidelines in their own facilities.