Tainted solution linked to nosocomial outbreak

CDC advises tissue-graft problems may arise

An unusual cluster of nosocomial meningitis cases caused by Ochrobactrum antropi infections was apparently caused by a contaminated saline solution used to prepare human pericardial tissue grafts, the Centers for Disease Control and Prevention in Atlanta (CDC) reports.1

The solution used to process the pericardial grafts before implantation was a balanced salt solution containing 25% proportions of albumin, dimethyl sulfoxide, gentamicin, and penicillin. The grafts from two pericardial-tissue donors had been prepared using the same lots of solutions. The tissue grafts probably were contaminated during processing by the solution, but the original source of the organism could not be determined.

The contamination led to three cases of O. anthropi meningitis among pediatric patients at a hospital in Utah. The three patients had undergone neurosurgical procedures in which pericardial grafts processed at another hospital were used to close defects of the dura mater. Although the first two patients received pericardial tissue from one donor, the third patient received tissue from a different donor.

A motile, gram-negative bacillus found in the environment, O. anthropi has rarely been reported as a human pathogen. However, as transplantation of tissues of both human and animal origin increase, infection control problems — including those involving unusual pathogens — may become increasingly common, the CDC warns.

After harvesting tissue grafts, contamination can occur during the extensive processing procedures or during preservation procedures before implantation.

Furthermore, recipients of certain tissue grafts (e.g., solid organs such as kidneys and hearts) require immunosuppression to reduce the risk for graft rejection. Immunosuppression can result in susceptibility to organisms that may have contaminated the graft tissue. Multiple viral, bacterial, fungal, and parasitic agents have been linked to infections associated with tissue grafts.

Issues in the tissue-banking industry — such as tissue preparation with solutions marketed for in vitro use only — need to be addressed.

In addition, becoming increasingly critical are routine infection control practices, such as assessing sterility of transplant tissue before and after processing and storage and conducting post-transplant infection surveillance.’As tissue transplants become more widespread, more stringent infection control guidelines will be needed,” the CDC concludes.

Reference

1. Centers for Disease Control and Prevention. Ochrobactrum antropi meningitis associated with cadaveric pericardial tissue processed with a contaminated solution — Utah, 1994. MMWR 1996; 671-673.