Preface

In 2003, when the first edition of this book was published, national magazines and newspapers were declaring the end of the antibiotic era. Their warning continues to apply in 2019. The incidence of infections due to multidrug-resistant (MDR) bacteria continues to rise and now MDR infections represent a major cause of preventable harm in our hospitals. Clostridium difficile colitis has spread to many of our most vulnerable patients as a consequence of continued use of broad-spectrum antibiotics that allow this pathogen to overgrow and release cytotoxins into the gastrointestinal tract. HIV remains a challenge throughout the world particularly in the African continent.

Viruses and bacteria continue to emerge as threats to humans including MARS, Ebola virus, and Zika virus. As a consequence of global warming the tick season has progressively lengthened increasing the incidence of Lyme disease, Ehrlichia, and other tick-borne illnesses. And global warming promises to increase the spread of other insect-borne infections including malaria, Chikungunya virus, and Dengue fever.

As never before clinicians require a solid understanding of infectious diseases and a logical and cost-effective approach to their diagnosis and treatment. In the United States the cost of health care has become prohibitively high consuming over 18% of our gross domestic product (GDP), and many of the anti-infectives required to treat MDR infections are extremely expensive. Furthermore, these infections are associated with prolonged hospitalizations and a higher risk of permanent harm or death. The era of the indiscriminate use of broad-spectrum antibiotics is over. Antibiotic stewardship programs are now restricting the use of many of these agents with the hopes of slowing the progressive selection of MDR bacteria and viruses. A fundamental understanding of infectious diseases will allow the clinician to proactively order high yield diagnostic tests and prescribe the proper anti-infective agents bypassing the need to interact with the antibiotic stewardship program.

But how can the busy clinician and health professions student achieve this goal? Infectious Diseases: A Clinical Short Course is designed to be read in 30 days. Below the title of each chapter is a recommended time for completion. Key points are highlighted using text boxes to encourage review and to enhance studying for specialty board and maintenance of certification exams (MOCs). Tables summarize critical clinical presentations, antibiotic dosing and cost, anti-infective toxicities, and figures demonstrate visually the spectrum of activity of each antibiotic. Real cases are included in each chapter to illustrate the clinical presentation of each disease and each case report is followed by an illness script (summary statement) to enhance pattern recognition and improve diagnostic expertise. Chapter 2, “Sepsis,” has been completely rewritten to reflect the 2016 consensus report. Chapter 3, “The Febrile Patient,” now includes a unique approach to effective diagnosis and management that applies manufacturing value stream mapping, illness scripts, tiered differential diagnosis, and Bayes’ theorem to more efficiently and effectively arrive at the correct diagnosis for each infectious disease. This chapter describes how “less is often more” and highlights the dangers of ordering excessive numbers of low-yield tests.

Chapter 4, “Pulmonary Infections,” highlights the use of respiratory multiplex PCR and the discovery that the majority of pneumonias are viral in origin; the leading viral causes being the common cold viruses, rhinovirus, and coronavirus. The latest diagnostic and therapeutic approaches to tuberculosis are reviewed. Diagnosis and management recommendations follow closely the Infectious Diseases of America (IDSA) guidelines. Chapters 5 and 6 update the approaches to ENT, eye infections, and central nervous system infections. The more liberal use of corticosteroids to blunt the excessive inflammatory response associated with meningitis is now emphasized.

The recent IDSA guidelines for the treatment of endocarditis are included in Chapter 7 as are the very recent IDSA guidelines for the management of C. difficile colitis in Chapter 8. Chapter 9 includes the latest CDC guidelines for sexually transmitted diseases, and Chapter 10 includes a more logical classification of soft tissue infections that in turn encourages a more effective and timely approach to differentiating infections that require surgical debridement. Chapter 11 covers the latest IDSA guidelines for the management of prosthetic joint infections as well as a comprehensive approach to the diagnosis and management of osteomyelitis.

Chapter 12 provides updates for the diagnosis and treatment of parasitic diseases and includes life cycle diagrams that allow a clearer understanding of the epidemiology and clinical presentations of these infections. Chapter 13 reviews the latest recommendations for zoonotic emerging bacterial infections including Lyme disease, babesiosis, and rickettsial diseases. Chapter 14 reviews serious viral infections other than HIV and now includes material on the emerging viral pathogens—Ebola virus, MERS, and Zika virus—and also reviews the latest anti-viral agents for influenza, herpes simplex, and CMV. Chapter 15 includes the latest IDSA guidelines on the outpatient management of neutropenia and fever. This chapter also reviews the increased risk for opportunistic infections associated with biological cytokine and lymphocyte inhibitors that are now being widely prescribed for many inflammatory disorders. Finally, Chapter 16 provides a succinct and timely update of the latest medications, diagnostic, and treatment recommendations for HIV infection.

On completing this whirlwind tour of infectious diseases, the busy clinician and health profession student will possess the knowledge and understanding to more judiciously prescribe anti-infectives and to more efficiently and effectively diagnose and manage infectious diseases. With this knowledge you can improve the health and wellbeing of your patients and save lives.