"I feel fear, anger, sadness and anxiety," one of the alleged victims testified before the district court in Groningen on the third day of the week-long trial.
"I have lost a lot of weight," lamented the student, who is infected with HIV.
The three accused, all HIV-positive, are charged with drugging gay men at sex orgies, raping them, and injecting them with blood contaminated with HIV. They are aged 39, 49 and 50.
The three, including a nurse, are accused of intentionally spreading the deadly virus at sex parties they promoted on the Internet.
They face charges of aggravated assault, rape, and illegal possession of drugs and face up to 21 years in jail.
Another witness, identified only as Erwin, questioned the motives behind intentionally infecting another with the immunodeficiency virus. He said he has been taking anti-retroviral medication for six months.
"One must have incredible hatred," he said in a statement read out to the court by the presiding judge.
"This question occupies my days and nights. For the rest of my life I will carry this crime with me, and its consequences."
The trio were arrested in May last year after 14 alleged victims, 12 of whom are HIV-positive or sick with AIDS, lay charges. It is not known whether they had contracted the virus before the orgies.
The prosecution alleges the victims were sedated with a combination of ecstasy and the date rape drug GHB (gamma-Hydroxybutyric acid), before being raped or injected with a cocktail of their assailants' blood.
The combination of drugs leaves a victim helpless and often with no memory of what happened.
At the time of their arrest, police said two of the men had confessed to the crime and claimed to have been motivated by a pursuit of excitement.
The prosecution will conclude its case on Wednesday.
If the three defendants are convicted, the victims plan to launch legal action for compensation, their lawyer has told AFP.