The doctors are warning the Zika virus could be transmitted by oral sex or even kissing after a French woman caught the disease from her partner.

The 24-year-old woman tested positive for the disease after her boyfriend returned home from a trip to Rio de Janeiro in Brazil.

While being in Brazil, the man had fallen ill suffering from fever, headache and a rash. After his recovery he returned to France on February 10.

The couple had sex seven times over the next 10 days, but they later revealed that he only ejaculated during oral sex, leading to fears the virus can also be spread this way, as the Sun reports.

The woman became sick and the pair went to the doctors, who tested them both for the Zika virus and found high levels of the bug in man’s semen and saliva and woman’s urine and saliva.

A swab of her vagina came back negative, therefore doctors warned the virus can be transmitted from person to person by oral sex or even kissing.

Doctors from Institute of Health and Medical Research in Paris have written a letter to the New England Journal of Medicine describing the case.

The document says: “We cannot rule out the possibility that transmission occurred not through semen but through other biologic fluids, such as pre-ejaculate secretions or saliva exchanged through deep kissing.”

Moreover, the World Health Organisation’s most recent report said six countries in the world – Argentina, Chile, France, Italy, New Zealand and the US – had recorded instances of the virus being transmitted directly from person to person.

The Zika disease is mainly carried by mosquitos in the tropical climates it thrives in and can cause microcephaly in babies when pregnant mums are infected.