There can be many causes for this post-operative wound infection. If the necessary infection prevention practices were not followed by the doctors and the nurses involved in the surgery and the subsequent plan of care, then it is possible that they had introduced the infection into the body. Also, the operation theater or room in which the surgery was performed should have had a negative pressure ventilation, with the room being disinfected as per the CDC protocol periodically. The instruments should have been sterilized using Sterrad. Alcohol-based hand rubs are a must in the ward in which your sister was treated post-operatively. Breach in any of these can lead to a post-operative wound infection. Given that the infection has been diagnosed, you might want to focus on getting the infection treated, as it should be the surgeon s and hospital s headache to address any lapses in the infection control practices. Start an antibiotic based on the culture & sensitivity results. If it s too late, start IV Cefoperazone and Sulbactam and continue for 5 days. She should be alright after this course.