Urine Tests Can Detect Zika Virus Apart from Blood, Doctors Say

Urine tests are now being recommended by the Centers for Disease Control and Prevention (CDC) in checking patients who have symptoms of Zika infections.

Previously, CDC has only advised conducting blood tests. But Zika virus is found to disappear from blood in about five days, which means blood tests from suspected victims may appear negative.

There's a new data showing that traces of Zika virus are retained longer in urine than in the blood, about a week longer, therefore checking the patient's urine may give more accurate diagnosis.

The study was done by the Florida Department of Health, where 66 people suspected of being infected by Zika virus underwent blood and urine tests on the same day.

Traces of the virus were detected in the urine of 52 out of 55 patients who were subjected to urine tests within five days of their first wave of symptoms. The blood tests, however, only picked up existence of the virus in only 31 patients out of the same 55.

On the basis of these findings, the CDC advises doctors to make use of urine tests within the first two weeks of Zika-like symptoms. If symptoms appear less than a weak earlier, doctors should use both urine and blood tests.

This additional testing procedure will now "definitively diagnose" some infections.

"This gives us more specific finding of the presence of genetic material of the virus," CDC epidemiologist Marc Fischer said.

The presence of Zika virus can be hard to tell. Only 20% of Zika patients experience the most common symptoms, which include fever, joint aches, rash and conjunctivitis.

There are also other tests that detect the presence of antibodies that are produced in response to the virus. However, antibodies are also produced in those who have been infected with dengue and other viruses linked to Zika. Tests that will tell these antibodies apart can be more complicated and can take longer.