Our aim has been to provide guidelines, protocols and clinical algorithms, while avoiding pedantic clinical instruction in order to help you make therapeutic choices of drugs offering the best likelihood of pathogen eradication and clinical cure.

While sharing experiences, we discovered that one of the drawbacks of our present system of medical instruction is the lack of knowledge and skill in disciplines like clinical microbiology, when physicians practice infectious diseases care management. Also, as the patient is the end user, physicians have to adequately evaluate trials of clinical efficacy while remaining focused on cost effectiveness. The above factors have been compounded by the lack of a structured infectious disease training program during internship and residency.

Lack of these factors has resulted in use of antibiotics by clinicians based on anecdotal and peer experience. Studies have shown that physicians often do not follow clinical practice guidelines. The reasons are often multi-factorial: Unfamiliarity with products listed, disagreement with protocols used, or lack of scientific support against clinical outcome. External barriers may influence a doctor's ability to comply with practical guidelines. The more common among these are lack of time, failure of a reminder system, or an environment which is not conducive to change, resulting in an all encompassing inertia which has to be overcome. This makes it all the more imperative that scientific guidelines be established, validated, and focused on cost effectiveness.

The myriad of etiological agents (bacterial, parasitic, fungal and viral) persists, none really having been vanquished, while newer pathogens like HIV, opportunistic organisms and multiple drug resistant organisms continue to emerge. This has led to confusion in the ranks with an arbitrary, unregulated use of antimicrobials in medical practice.

Organisms acquire new resistances as antimicrobials increase in numbers. Dynamic situations lead to nosocomial infections and prolonged stay in the hospital. In each instance it is only a variation of the degree of pathophysiological effects on the system, while drugs remain the same.6

Resistance to antibiotics in the community depends not only on the region but also on the type of practice. In most cases, treatment is initiated before culture and sensitivity results are available, guided by the symptoms of the patient and the experience of the clinician.

In our work, we have provided a systematic review of published work; interspersed with widely prevalent recommendations based on availability and feasibility of treatment.

By writing this, our first book, we hope not only to advance the underlying knowledge and practice of infectious diseases, but also to foster appropriate day-to-day treatment, prevention, prophylaxis and the eventual eradication of infectious diseases.

A work like this is a collective enterprise, and we must thank the patience, generosity and input offered by our support staff.

We rejoice with you in sharing our love of the specialty of infectious diseases.

Dr Navin Paul MD who did the final reviews for us, Dr Anil Kumar, Dr Ravi Kiran, Dr Senthil, Dr Mayank, Dr A George Vasanthan who painstakingly made the final round of editing along with our publishers. Lastly to our wives, Dr Sunita Jain and Dr Gita Mathai for bearing with us during this ongoing venture.

Often I wish I had an experienced colleague by my side, someone like my senior registrar or my residency director.

This manual is unique. Likely pathogens and suggested regimens are based on microbiological data, antimicrobial availability, and common practices. The limitations on availability of antibiotics and laboratory data are accounted for in the decision making. We have emphasized tuberculosis, HIV and malaria.

Use this manual to confirm your decisions, or to look up other treatment options that your colleague or senior registrar or consultant may have chosen. Use the book as a second opinion.