File; Maria Camila Davila, a pregnant woman infected with the Zika virus, is attended at the Erasmo Meoz University Hospital in Cucuta, Colombia. AFP

Switzerland has recorded 16 cases of infection by the mosquito-borne Zika virus since March this year, local newspaper Tribune de Geneve reported on Monday.

Tests had revealed the presence of the virus transmitted by the Aedes aegypti mosquito in each of the known cases, the report said, citing the Swiss Federal Office of Public Health (FOPH)’s pandemic preparation unit head Patrick Mathys.

All of them had previously travelled to areas affected by the virus which has reached pandemic proportions in regions including but not limited to South America, Central America and the Caribbean.

Tribune de Geneve  said two  of the infected had travelled to Brazil and Colombia, one each  to Bolivia, Guadeloupe and Ecuador.

The number of infections could be much higher however as data reveals that only around one in four infected individuals develop symptoms which include fever, rash, joint pain and conjunctivitis.

Though rarely fatal, Zika presents a risk for pregnant women and their unborn babies as the causal relationship between microcephaly and other severe foetal brain defects has been confirmed.

First isolated in 1947 from a monkey in Uganda, the Zika virus was limited for decades to a narrow equatorial belt stretching across Africa and Asia, rarely affecting humans.

In 2007, the virus breached its geographical range as the first documented outbreak was recorded in the Pacific Islands.

The situation since has drastically changed. In 2015, the mosquito-borne virus was detected in the Americas with Brazil reporting its first case in May last year.

The World Health Organisation’s (WHO) latest situation report indicates that 57 countries and territories report continuing mosquito-borne transmission.