Two police officers are receiving medical attention after they were scratched and bitten by a man infected with HIV.
The officers were on a street in Brighton when they stopped to help an ambulance crew deal with a man who appeared to be under the influence of drugs.
The man then attacked the two police officers. He punched and scratched the male officer, who received minor cuts and bruises.
The female officer was bitten and scratched on the arm, and also scratched on the face. She also had her arm twisted during the incident, but was not seriously harmed.
The assailant was HIV positive, so both officers are now taking medication to prevent them contracting the virus.
Chief Superintendent Nev Kemp, of Sussex Police, said: "The medication will make both of the officers extremely nauseous for about a week but is necessary to try to reduce the chance of them catching an infection.
"We are giving them as much support as we can while they recover from the incident. What they are now going through highlights the enormous risks that officers experience each and every day to help keep people safe, putting themselves in danger to protect the public.
"The two [police constanbles] were injured doing their duty by trying to help a man who needed assistance. I have wished them a speedy recovery and am looking forward to having them back doing the job they do so well."
A 47-year-old man was arrested on suspicion of assaulting a police officer and possession of a controlled drug. He is out on bail, awaiting a court appearance on 18 January.