Post exposure prophylaxisTreatment should be staed within 72 hours of exposure, preferably as early as possible At first the wound is washed with soap and water. Secondly before initiating drug therapy blood samples are taken to measure the baseline viral markers Then three drug therapy is given for 28 days. The drugs include 2 NI PLUS a protease inhibitor (or alternative drug). Commonly used therapy include Tenofovir + Lamivudine + Atazanavir/r After 6 weeks again viral markers are measured to check for the infection. Post-exposure prophylaxis of HIV infection For adults and adolescents Preferred 2 NI: Tenofovir (300 mg) + Emtricitabine (200 mg) daily Preferred PI: Lopinavir/r (400 + 100 mg) or Atazanavir/r (300 + 100 mg) daily Alternative 3rd drug: Darunavir/r (600 + 100 mg BD) or Raltegravir/r (400 mg BD) or Eirenz (600 mg daily) For children <= 10 years Preferred 2 NI: Zidovudine + Lamivudine Alternative 3rd drug: Atazanavir/r or Darunavir/r or Eirenz or Raltegravir Preferred PI: Lopinavir Alternative 3rd drug: Atazanavir/r or Darunavir/r or Eirenz or Raltegravir Duration of regimen: 4 weeks