(Reuters) - U.S. health regulators on Thursday approved a first-of-its-kind DNA test by Swiss drugmaker Roche Holding AG to help physicians track progress in treating organ transplant patients for a common virus.

Roche's COBAS AmpliPrep/COBAS TaqMan CMV Test is designed for use on solid organ transplant patients undergoing cytomegalovirus (CMV) antiviral therapy.

CMV is a common virus that can cause pneumonia and colitis in patients with weak immune systems, such as organ transplant patients.

There were 28,538 solid organ transplants in the United States in 2011, according to the U.S. Health Resources and Services Administration.

Clinicians can measure the effectiveness of their treatment by using Roche's device and perform tests to track changes in the viral load of patients on anti-CMV therapy, the U.S. Food and Drug Administration said in a statement.

The approval was based on clinical data that showed the test's accuracy in measuring viral load and its ability to accurately measure variations in the amount of CMV virus.

The test, manufactured by Roche Molecular Systems, may not be used to diagnose CMV infection, the regulator added.

(Reporting by Zeba Siddiqui in Bangalore; Editing by Sreejiraj Eluvangal)