Denmark and Switzerland yesterday joined a growing number of European countries to report Zika infections among travellers returning from Latin America, where the mosquito-borne virus has been blamed for a surge in birth defects.

"A Danish tourist who travelled to Central and South America was diagnosed on his return with the Zika virus," a hospital in eastern Denmark said in a statement late Tuesday. The Danish patient was a young man who was expected to make a full recovery.

Two people returning to Switzerland from Haiti and Colombia were also diagnosed with the virus, the Swiss Federal Office of Public Health said. Neither was pregnant and neither required hospital care.

US President Barack Obama on Tuesday called for the rapid development of tests, vaccines and treatments to fight the mosquito-transmitted Zika virus, which has been linked to birth defects and could spread to the United States in warmer months.

"The president emphasized the need to accelerate research efforts to make available better diagnostic tests, to develop vaccines and therapeutics, and to ensure that all Americans have information about the Zika virus and steps they can take to better protect themselves from infection," the White House said in a statement.

Colombia issued an alert Tuesday over the Zika virus, which has already infected 13,800 people in the country, as it warned that the number is likely to uptick as the disease spreads.

The virus has been linked to brain damage in thousands of babies in Brazil. There is no vaccine or treatment for Zika, a close cousin of dengue and chikungunya, which causes mild fever and rash.

Zika virus is spread to people primarily through the bite of an infected Aedes species mosquito.

The virus can pass from a pregnant women to her fetus, and global health authorities are concerned by an apparent link between Zika virus and nearly 4,000 cases of babies born with unusually small heads -- a condition known as microcephaly -- in Brazil.

An estimated 80 percent of people infected have no symptoms, making it difficult for pregnant women to know whether they have been infected.

Health watchdogs in a string of European countries meanwhile said they had recorded Zika cases dating back to as early as March 2015.

The Netherlands confirmed 10 cases and Britain five, all among people returning from South America.

In Italy, the Spallanzani National Institute of Infectious Disease said four cases were recorded in March 2015, while in Portugal, the health ministry said four Portuguese had been infected.

All eight had been travelling in Brazil.