The most common infectious diseases are - cholera,dengue,hepatitis A,B,C ,HIV aids,influenza,Japanese encephalitis,malaria,measels,meningitis,pneumonia,rotavirus,tuberculosis and typhoid.These mentioned diseases spread through infected cough,sputum,blood transfusion,infected needles or syringes,water,air or are sexually transmitted as in case of HIV and some form of hepatitis.