PCR Test Detects Malaria in Urine or Saliva

A new test has been developed for detecting the malaria parasite, Plasmodium falciparum, in human urine and saliva.

The test uses the polymerase chain reaction (PCR), a technique for duplicating and then examining unique bits of DNA from a sample, thereby allowing DNA to be multiplied in the laboratory. The same PCR technique is used for examining malaria in blood, but it has never been applied to urine and saliva samples.

The method could potentially reduce the need for blood sampling in epidemiologic studies where large-scale malaria screening is required. Drawing blood increases the risk of spreading human immunodeficiency virus (HIV) and other diseases, particularly in those developing countries where both HIV and malaria are prevalent. Blood drawing must also be performed by trained personnel, whereas urine and salvia sampling do not. The study was published online in the November 8, 2006, edition of Malaria Journal.

"Testing urine or saliva could be an easier and safer way to collect the information needed for studying malaria in communities. For instance, it could be used in studies to determine if a population is growing resistant to malaria drugs, which is a very serious problem,” said David J. Sullivan, M.D., senior author of the study and a professor in the Johns Hopkins Bloomberg School's Malaria Research Institute (Baltimore, MD, USA).

The study was conducted by the Bloomberg School's scientists in collaboration with colleagues at the Malaria Research Institute's research hospital in Macha, Zambia. Urine and saliva samples were obtained from 47 volunteers with malaria and four without and were then examined with the PCR method. DNA from the Plasmodium falciparum, the parasite that causes malaria, was replicated at higher levels from the saliva compared to the urine samples.



Related Links:
Johns Hopkins Bloomberg School's Malaria Research Institute