In-vivo systems and methods for the detection of early signs of post-surgery infection are described. The in-vivo systems include a drain system with a tube configured to drain fluids from a surgery site, at least one sensor unit for sensing the presence of at least one infection biomarker, a processor for processing a signal generated by the at least one sensor unit, a transmitter for transmitting the signal, and a notification system for receiving the signal, analyzing the signal by comparing it to a threshold, determining presence of infection, and generating an indication on the presence of infection.
