Zika virus, which has long been recognized as a mosquito-borne infection, may also be transmitted via kissing and oral sex, a new study confirms.

Aedes mosquitoes are the primary culprits being linked to Zika virus, but several reports also indicate the possibility for the sexual transmission of the virus. Because of this, French scientists have embarked on a study that found Zika virus in semen.

Zika Cases In Paris

In Paris, the presence of Aedes aegypti and Aedes albopictus mosquitoes are not very apparent. Even in the entire country, the Aedes species undergoes a diapause, a period of suspended development.

The first patient that the team presented was a 24-year-old woman who started feeling muscle and joint pains and experiencing fever and rashes on Feb. 20. These symptoms lasted for seven days.

The patient had not traveled to any Zika-affected countries, and her last out-of-France trip was in Japan, which was from Dec. 21, 2015 to Jan. 1.

The woman reported she had sexual contact from Feb. 11 to Feb. 20 with a man who stayed in Brazil from Dec. 11, 2015 to Feb. 9. The sexual encounter entailed seven instances of vaginal intercourse without ejaculation and without condoms, and oral sex with ejaculation.

The 46-year-old partner developed clinical symptoms of fever, rash, chills and muscle pain beginning on Feb. 7. The symptoms dissipated on Feb. 10, when he arrived in Paris. Upon physical examination on Feb. 23, the patient had normal medical results.

Laboratory Tests

Both patients underwent laboratory examinations. The woman submitted saliva and urine samples on Feb. 23, which yielded positive results for Zika virus. The vaginal swab, however, returned negative.

Sixteen days after the onset of the illness, the man had a urine test, which was positive for Zika virus. His blood and saliva samples returned negative results, but his semen samples were positive.

Establishing The Link

The findings of the study support the hypothesis that Zika virus was transmitted via sexual means from the male to the female patient.

"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," the authors wrote.

The recent outbreaks should pave the way for more studies that delve into the nature of Zika.

"We need to better define recommendations to prevent transmission of the virus," they added. These include indicating specific times when condom use or abstinence must be practiced by men returning from Zika-affected countries, and increasing awareness of oral viral transmission.

Photo: Jon Mitchell | Flickr