The researchers found that the monkeys that received saliva swabs avoided the infection entirely; however, the 3 monkeys that were swabbed with high-dose virus were all infected with Zika. The amount of virus in the saliva was far less viral than the amount that mosquito bites transmit. The monkeys infected directly by the virus, as opposed to saliva containing the virus, were exposed to 80,000 times more Zika particles, suggesting that saliva may have an effect on the virus particles by preventing the virus from making contact with cells that it could infect.
"The viral loads in the saliva in general are low, but there are also anti-microbial components in saliva making that low level of virus even less infectious than it might be in another medium," said Christina Newman, co-first author of the study from University of Wisconsin Madison Zika Experimental Science Team, in a press release
From the evidence, the scientists determined that kissing and other casual contact do not pose a serious threat in Zika transmission. It is possible for Zika to be transmitted through saliva, but it is highly unlikely because infected individuals are unable to produce the high number of particles necessary to infect another person.
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