Prostate Biopsy and the Risk of Infection

Medically Reviewed

Each year, more than 1 million prostate biopsies, in which a needle is pushed a dozen times through the rectum and into the prostate to collect tissue samples, are performed in the United States.

But the 15-minute test carries an infection risk. Bacteria from the bowel can be transported by the needle into the prostate, so men are given antibiotics before the biopsy.

Using vital information from the tissue samples, the doctor can determine if prostate cancer is present and then make recommendations about possible next steps for men considering treatment.

When things go wrong

Unfortunately, within 30 days after the biopsy the next steps for some men include hospitalization and emergency treatment for fever, chills, and a raging bacterial infection directly related to the biopsy procedure.

In many cases, the bacteria are resistant to the antibiotics given before the biopsy. While most men recover after being treated in the hospital with a variety of antibiotics to battle the drug-resistant bacteria, some men die as a direct result of infectious complications, including sepsis, a systemic response to the infection. How safe is a prostate biopsy?

With antimicrobial-resistant organisms on the rise in the U.S. and abroad, Johns Hopkins researchers, cognizant of the challenge of controlling these infections, set out to determine just how safe—or unsafe—a prostate biopsy actually is. Making use of a random sample of 5 percent of male Medicare participants (65 and older) between 1991 and 2007, doctors identified 17,000 men who underwent prostate biopsy. They then checked to see how many of them were hospitalized in the subsequent 30 days.

The results, reported in the Journal of Urology, were surprising and upsetting: Almost 7 percent of the biopsied men were hospitalized within a month, compared with 3 percent in the control group who did not undergo a biopsy. The presumption of the Hopkins experts was that an infection after biopsy was directly related to antibiotic resistance.

The threat of infection

Anton van Leeuwenhoek, a Dutch cloth merchant, was the first person to see bacteria. In the 1660s, he began grinding special lenses so that he could examine his fabrics, and he soon achieved magnifications up to 500 times life size.

For reasons that history has not recorded, van Leeuwenhoek turned his lenses on a sample of pond water and was surprised to find it teeming with life—algae and bacteria. It would be two centuries before scientists figured out that these simple bacteria could be a contributing factor in causing diseases that passed from one person to another, sickening and killing in the process.

In the early 20th century, before the advent of antibiotics, the threat of bacterial infection was always significant and the consequences, including death, was common. For example, pneumonia, which can be caused by bacterial infection, was the leading cause of death in the United States until 1936, and often the only treatment for an infected wound on an arm or leg was amputation.

However, after Sir Alexander Fleming’s 1928 discovery of penicillin, doctors finally had something to effectively battle these hardy, primitive, single-cell life forms. Over the years, newer antibiotics were developed to try to keep pace with genetic evolution.

Antibiotic resistance grows

Various forms of bacteria have managed to stay ahead of heroic efforts to wipe them out. Over the years, as bacteria became more resistant, pharmaceutical companies backed off on new drug development because of a lack of adequate monetary incentives. Antibiotic resistance—the inability of any drug to wipe out a particular bacterial infection—has now become a global scourge.

For more than 75 years we have been battling bacteria with drugs, but the survival of bacteria has been aided in great measure by overuse of antibiotics (some doctors hand them out like “candy” to patients for nonbacterial coughs and sore throats caused by viruses), which leads to eventual resistance.

Also encouraging resistance are the heavy use of antibiotics in livestock (it’s estimated that 70 percent of antibiotics in the U.S. are used in agriculture) and the overuse of broad-spectrum antibiotics in hospitals.

When people do not take their antibiotics as prescribed, including men who don’t take them after their prostate biopsy, or don’t take the full course as directed, drug resistant bacteria have the opportunity to multiply and thrive.