Two major Texas health centres have developed what they are calling the country's first hospital-based, rapid test for the Zika virus that can produce results in a matter of hours, the hospitals said on Tuesday.

Researchers at Texas Children's Hospital and Houston Methodist Hospital developed the test that detects the genetic material of the Zika virus, which can speed diagnosis and treatment, they said in a statement.

"With travel-associated cases of the Zika virus becoming more prevalent in the US, coupled with the looming increase in mosquito exposure during spring and summer months, we must be prepared for a surge of Zika testing demand," said James Versalovic, pathologist-in-chief at Texas Children's and leader of test development team.

The test is designed to cut down on testing time, which can take days or even weeks. Typically the testing would be done by state health agencies equipped to do so or federal authorities such as the US Centers for Disease Control of Prevention.

The test is available only at the two hospitals for now but the researchers are looking to take the tests to more hospitals.

The Zika virus has been reported as having been transmitted by mosquito in Puerto Rico and the the US Virgin Islands, but in the continental US the only cases reported so far are associated with travel abroad.

Brazil is worst hit in the current Zika outbreak, which has spread to more than 30 countries and territories, most of them in the Americas. The World Health Organisation declared a global emergency over Zika this month, citing concerns that it may be linked to a birth defect called microcephaly, a condition marked by unusually small heads that can result in developmental problems.

Much remains unknown about Zika, including whether the virus actually causes microcephaly.

Texas Children's Hospital is a not-for-profit health care organisation affiliated with Baylor College of Medicine, while Houston Methodist comprises an academic medical centre in the Texas Medical Center and six community hospitals serving the Greater Houston area, according to the hospitals' websites.