Infection control important for high-risk patients

NEW YORK (Reuters Health) - The best way to protect high-risk cancer patients from life-threatening infection is to combine preventive antibiotics and antifungal treatment with isolation and other methods, such as the use of gloves and face masks, according to a new review of 40 studies.

Chemotherapy destroys cancer patients' blood cells, including white blood cells that are responsible for immune protection, leaving the patients vulnerable to infection. Recipients of bone marrow transplants are also at very high risk. Before they can receive the transplant, patients must first have all of their own immune cells destroyed.

Infections are the leading cause of preventable death among cancer patients, Dr. Mical Paul of Rabin Medical Center in Petah-Tikva, Israel, and his colleagues note in their report in Lancet Infectious Diseases. However, there is no consensus on the best way to protect these patients, they add, which is particularly important today given the increase in drug resistance among disease-causing organisms.

To investigate, Paul and his team reviewed published studies comparing various infection control measures among high-risk patients undergoing chemotherapy or bone marrow transplants. Among the 40 studies they reviewed, which were published between 1971 and 2008, there were 26 that used isolation to protect patients -- for example, controlling air flow to and from the patient's bed and putting barriers between the patient and the outside environment.

While isolation methods alone did not seem to significantly reduce mortality and infections among the cancer patients, isolation methods combined with prophylactic antibiotics reduced the 30-day mortality from any cause by 40 percent, the researchers found.

In the studies with the longest follow-up, the combined methods reduced 3-year mortality risk by 14 percent. Isolation plus antibiotics also reduced bacterial infections of the blood, infections with Gram-negative and Gram-positive bacteria and Candida (yeast) infections. The intervention did not have a significant effect on the risk of mold infections.

Eleven studies that compared inpatient with outpatient treatment after bone marrow transplant found that outpatients were 18 percent less likely to die. The researchers note however that the patients treated on an outpatient basis may have been healthier than those treated in the hospital.

The older studies included in the review, done before the development of stronger antibiotic and antifungal drugs, may not be relevant to current practice, the researchers say. But infections are still a key factor in how patients fare after treatment, they add, and the same types of organisms still infect patients.

"The current absolute gain in survival is probably higher than that observed in older studies, in which a larger proportion of patients died from their underlying disease," the researchers write.

They suggest that clinical trials that randomly assign patients to a treatment group be performed to see if outpatient treatment of stem cell transplant patients is indeed as safe and effective as impatient care.

SOURCE: Lancet Infectious Diseases, February 2009.