CDC reports strep infection case after allograft implantation

This is the first Streptococcus pyogenes infection reported in association with a musculoskeletal allograft.

Issue: January 2004

The Centers for Disease Control and Prevention recently reported a case of invasive Streptococcus pyogenes in an otherwise healthy 17-year-old Colorado boy after he underwent elective anterior cruciate ligament repair with a hemi-patellar tendon allograft in September.

[image]
Streptococcus pyogenes
bacteria at 900x magnification.

COURTESY OF THE CDC

The patient was hospitalized in intensive care, the allograft implant was removed and he was treated with a course of intravenous antibiotics and computed tomography-guided needle aspirations. Five other patients received tendon allografts from the same donor and as of mid-December none had any adverse outcomes, Arjun Srinivasan, MD, at the CDCï¿½s Division of Healthcare Quality Promotion told Orthopedics Today.

The tissue processor that supplied the graft for the boyï¿½s surgery placed on hold or recalled all the remaining allografts recovered from that donor.

To alert its members about the situation, the American Academy of Orthopaedic Surgeons distributed a patient safety alert explaining the case and encouraging orthopedic surgeons to use only tissues obtained from accredited tissue banks and processors.

ï¿½Although allograft infections are rare, they highlight the need for improved tissue evaluation and processing standards,ï¿½ CDC officials said in the report. In November 2001 a patient died from an infection traced to a contaminated bone-cartilage allograft he received during knee surgery.

Two tissue processors

In the Colorado case, invasive S. pyogenes or group A streptococcus (GAS) was identified by the tissue recovery organization from cultures of the donorï¿½s tissues. The tissue was distributed to two processors. The first found GAS in preprocessing cultures and processed the allografts using an aseptic technique and an antimicrobial solution. Post-processing reports were reportedly negative for GAS and the allografts were distributed.

The second processor held the allografts from that donor.

After their investigation, CDC officials said GAS was detected in preprocessing cultures of all tissues recovered from the donor and in unprocessed tissue they tested, which was obtained from the second processor. GAS was also isolated from the donorï¿½s blood stored by the first processor.

This is the first reported case of invasive GAS associated with a musculoskeletal allograft infection. The CDC is monitoring invasive infections from these types of organisms through an ongoing program, Srinivasan said.

ï¿½We are certainly concerned about this organism and its ability to cause these types of very serious infections in this type of setting, with surgical site infections.ï¿½

Reject tissue

ï¿½Given the apparent ability of the organism to endure tissue processing with antimicrobial treatment, the presence of GAS in donor tissue should prompt rejection of the tissue unless a sterilizing procedure can be used,ï¿½ the CDC recommended.

The infection rate following ACL reconstruction surgery or allograft implantation is generally very low, said Douglas W. Jackson, MD, Orthopedics Today Chief Medical Editor. Therefore, any increasing pain, swelling, redness, fever and chills postoperatively, as occurred in this case, should be a cause for concern whether the patient received an allograft or autograft implant.

ï¿½Allograft users need to be aware of the additional costs of using allografts and the chance for increased infection risk. Their use certainly puts physicians in a much more defensible position if any complication occurs,ï¿½ he said.