Man is a host to variety of pathogenic bacteria, protozoa and viruses. They can cause
various infectious and non-infectious diseases. In order to control the disease and its
transmission, it is essential to isolate and identify the causal agent from blood, sputum, urine,
stool or pus. Various cultural and molecular methods can be employed for identification of
pathogen. Sterilization techniques, use of disinfectants and vaccination can help control
transmission of disease.