Compléter Infectious diseasesVersion en ligne Unhealthy habits: Infectious diseases par Jose Ricardo Desfilis 1 stronger pathogens rest spread defences contagious mouth cells colds diet air Some diseases , such as , are . This means they from person to person through the . The germs or usually enter the body through the nose or the . The body has natural , such as white blood , to protect itself against germs . If you get plenty of , drink enough water , exercise and have a healthy , your defences will be .