This case book of infectious diseases brings to you the excitement of that unusual element of patient history,the crucial physical sign,the key investigation report or that microscopic image which links all the clinical features of the case & brings home the diagnosis.It emphasizes the myriad factors that decide which treatment is most appropriate for the patient.It highlights the close dialogue between clinicians and microbiologists as they partner to do the best for the patient . It conveys the sense of fulfillment when the sickest person turns the corner and returns for follow-up ,alive and well .It underscores the fact that infectious diseases ar eamng those ailments that can actually be prevented or cured