ZURICH • The United States Food and Drug Administration (FDA) yesterday issued emergency authorisation for a Zika diagnostics test from Swiss drugmaker Roche, skirting normal approval channels as the regulator moves to fight the disease's spread.

The Zika virus, detected in Brazil and elsewhere last year before spreading to the Americas, is associated with microcephaly, a birth defect characterised by an unusually small head and potential developmental problems.

Through last week, the United States reported 2,517 Zika cases, 29 of which were likely acquired locally in Florida through mosquito bites and the rest brought in by travellers, the US Centres for Disease Control and Prevention (CDC) said.

Some 9,000 additional cases have been reported in US territories, including Puerto Rico.

With FDA approval, Roche's test now can be used to screen patients exhibiting Zika symptoms that meet CDC criteria, including fever, rash, joint pain and red eyes. Samples will be sent for analysis to specially certified US laboratories with the appropriate equipment, a Roche spokesman said.

The FDA issues such emergency-use authorisation during public health emergencies to quickly deploy unapproved medical products for as long as they are needed.

Meanwhile, a team of researchers from Florida State University, Johns Hopkins University and the National Institutes of Health said yesterday that a common drug used to kill tapeworm prevented the Zika virus from replicating in lab experiments.

The medicine, Nicolsamide, was previously shown to be safe for pregnant women, which may boost its rapid deployment to treat Zika infection, they reported in the journal Nature Medicine.

"The findings should significantly advance current Zika virus research and have an immediate effect on the development of anti-Zika therapeutics," the team concluded.

The researchers, however, cautioned that the encouraging results have yet to be reproduced outside the laboratory.

"Additional animal studies, and then human clinical trials, are necessary," said Johns Hopkins University virologist Hongjun Song, who co-authored the study.

REUTERS, AGENCE FRANCE-PRESSE