This is according to 20 top scientists, including Nobel Laureate Francoise Barre-Sinoussi, who released a consensus statement at the International Aids Conference to address the use of science in criminal prosecutions.
Some 68 countries have laws that criminalise HIV non-disclosure, exposure or transmission, while 33 have applied similar laws in specific cases.
But the scientists reviewed the best available scientific evidence relating to HIV transmission and concluded:
* It is not possible for an HIV-positive person to transmit the virus in their saliva while kissing, biting or spitting.
* The risk of HIV transmission from a single act of unprotected sex is very low, and there is no possibility of transmission during either vaginal or anal sex if the HIV-positive partner has an undetectable viral load.
* It is not possible to establish proof beyond reasonable doubt that one person has infected another, even with advanced phylogenetic scientific tools.
Kerry Thomas, serving a 30-year sentence in Idaho in the US for having sex without disclosing his HIV status to a partner, joined the press conference where the statement was released.
“I regret that I did not properly disclose my HIV status, but I worked with my doctor and did everything to protect my partner. I used a condom and had an undetectable viral load,” said Thomas, who has already served 10 years of his sentence.
He did not infect his partner with HIV but received two 15-year sentences, one for each act of unprotected sex.
These are to run consecutively, with a minimum time served of 20 years.
Thousands of people living with HIV have been prosecuted, most of whom did not actually pass on the virus. Most prosecutions have taken place in the USA, Belarus, Ukraine, Russia and Zimbabwe.
“HIV criminalisation laws are ineffective, unwarranted and discriminatory,” according to the International Aids Society.