Any unprotected penetrative sex (anal, vaginal or oral: anal = highest risk; vaginal = high risk; oral = lowest risk).
Nakuphi na ukungenwa ngokwabelana ngesondo (empundu, kwilungu langasese lebhinqa okanye ngomlomo: ukungenwa empundu = umngcipheko mkhulu kakhulu; kwilungu langasese lebhinqa = umngcipheko mkhulu; ngomlomo = umngcipheko uphantsi kakhulu).