Infectious Diseases of the Female Genital Tract, 4th edition: by Richard L., Md. Sweet, Ronald S., MD Gibbs By Lippincott Williams & Wilkins Publishers (January 15, 2002) By OkDoKeY Infectious Diseases of the Female Genital Tract CONTENTS Editors Acknowledgment Dedication Preface INTRODUCTION 1 Clinical Microbiology of the Female Genital Tract 2 Use of the Microbiology Laboratory in Infectious Diseases SPECIAL ORGANISMS 3 roup B Streptococci 4 Genital Mycoplasmas 5 Chlamydial Infections 6 Herpes Simplex Virus Infection 7 Sexually Transmitted Diseases 8 Mixed Anaerobic-Aerobic Pelvic Infection and Pelvic Abscess 9 Hepatitis Infection 10 HIV-AIDS GYNECOLOGIC AND OBSTETRIC INFECTIONS 11 Toxic Shock Syndrome 12 Infectious Vulvovaginitis 13 Postabortion Infection, Bacteremia, and Septic Shock 14 Pelvic Inflammatory Disease 15 Urinary Tract Infection 16 Perinatal Infections 17 Premature Rupture of the Membranes 18 Intraamniotic Infection 19 Subclinical Infection as a Cause of Premature Labor 20 Postpartum Infection 21 Wound and Episiotomy Infection 22 Parasitic Disease in Pregnancy ANTIBIOTICS/ANTIVIRALS 23 Antimicrobial Agents 24 Antibiotic Prophylaxis in Obstetrics and Gynecology IMMUNIZATION 25 Immunization EDITORS RICHARD L. SWEET, M.D. The Milton Lawrence McCall Professor and Chair Department of Obstetrics, Gynecology, and Reproductive Sciences University of Pittsburgh School of Medicine Magee-Women's Hospital Pittsburgh, Pennsylvania RONALD S. GIBBS, M.D. Professor and Chair Department of Obstetrics and Gynecology University of Colorado Health Sciences Center Denver, Colorado ACKNOWLEDGMENT We acknowledge the administrative and editorial assistance of Phyllis Catrell, Jane Cook, and Susan Kostilnik in the preparation of this edition. DEDICATION This book is dedicated to our wives, Rhea and Jane, for their continued love, support and understanding. To our children, Jennifer, Suzanne, Andrew, Eric, and Stuart and our grandchildren Hanna, Dylan, Benjamin and Emily and future grandchildren who provide us with the ongoing spark and impetus for our continued commitment to this work. PREFACE During the writing of this fourth edition of Infectious Diseases of the Female Genital Tract, infections seem to have played an ever-expanding role, not only in the practice of obstetrics and gynecology but in the practice of medicine in general. Regularly the news media produced stories about new infections and antibiotic resistance. These, indeed, continue to be challenging and exciting times in the world of infectious diseases. For this fourth edition, we have maintained the goal of providing physicians with up-to-date knowledge that—in a highly readable form—deals with infectious diseases in the female. We have substantially revised and updated every chapter and have added several eye-appealing features. We are especially pleased that accompanying this fourth edition will be an atlas to add to the usefulness of this text. We have been gratified by the place this text has earned in the offices and libraries of many obstetricians and gynecologists, and we thank the readers for their support. 1 CLINICAL MICROBIOLOGY OF THE FEMALE GENITAL TRACT Infectious Diseases of the Female Genital Tract 1 CLINICAL MICROBIOLOGY OF THE FEMALE GENITAL TRACT Virulence Aerobic Organisms Gram-Positive Cocci Gram-Positive Bacilli Gram-Negative Bacilli Gram-Negative Cocci Anaerobic Isolates Gram-Positive Anaerobes Gram-Negative Anaerobes Yeasts and Actinomyces Trichomonads Mycoplasmas Chlamydia Trachomatis Viruses Changes in Vaginal Microflora Age Sexual Activity Contraception Pregnancy and Delivery Surgery Homeostasis Chapter References The microbiology of the female genital tract is indeed complex. In healthy women, the vagina contains 109 bacterial colony-forming units per gram of secretions. Isolates commonly found in the lower genital tract include a variety of aerobic and anaerobic bacteria, yeast, viruses, and parasites (Table 1.1). Influences upon these microbes include phase of the menstrual cycle, sexual activity, contraceptive use, childbirth, surgery, and antibiotic therapy. The upper genital tract usually is sterile, but bacteria from the lower genital tract may ascend into the uterine cavity, fallopian tubes, or pelvic peritoneum because of menstruation, instrumentation, foreign bodies, surgery, or other predisposing factors. TABLE 1.1. OVERALL CLASSIFICATION OF MICROORGANISMS FOUND IN THE FEMALE GENITAL TRACT This chapter presents a working knowledge of genital tract microbes for the clinician. More detailed descriptions of selected microbes are provided in other chapters. VIRULENCE Distinguishing “virulent” or “pathogenic” isolates from “nonvirulent” or “nonpathogenic” ones often is difficult because the behavior of a given isolate is so dependent upon the numbers of isolates present, host factors, and local conditions (presence of necrosis and foreign body). For example, although group B streptococcus is a leading cause of maternal and neonatal septicemia, most women with genital colonization by group B streptococci (GBS) suffer no consequences. On the other hand, Staphylococcus epidermidis is generally considered a low-virulence organism and is commonly considered part of the normal skin and vaginal flora, but it also may cause disease when conditions allow. For example, S. epidermidis has been recognized as a cause of infective endocarditis of neurologic shunts. Despite such widely ranging behavior patterns, it still is practical to distinguish “high”- from “low”-virulence genital isolates. For practicality, the bacteria are divided into aerobes and anaerobes. Each of these groups is subdivided further into Gram-positive and Gram-negative organisms. AEROBIC ORGANISMS Gram-Positive Cocci The organisms in this group include the aerobic streptococci and staphylococci (Table 1.2). TABLE 1.2. ANTIBIOTIC THERAPY FOR AEROBIC AND FACULTATIVE BACTERIA FOUND IN FEMALE GENITAL INFECTIONS Streptococci Many varieties of streptococci have been found in the pelvis, and they have been classified by two independent schemes. In one scheme, the streptococci are distinguished by their hemolytic properties on blood agar plates. Aerobic streptococci showing partial (or green) hemolysis are termed alpha (a) streptococci, those showing complete (or clear) hemolysis are termed beta (b) streptococci, and those showing no hemolysis are termed gamma (g) streptococci. In the other scheme, the Lancefield system, many streptococci can be classified according to surface antigens, designated by the letters A through O. In humans, streptococci of groups A, B, and D are common pathogens. Group A and B streptococci nearly always produce b hemolysis. Group D streptococci usually are nonhemolytic (g streptococci), but on occasion they may be either a or b hemolytic as well. Group A Streptococci (Streptococcus pyogenes) Streptococcus pyogenes causes pharyngeal, cutaneous, puerperal, and postoperative infections and necrotizing fasciitis. Sequelae of group A streptococcal infections may include rheumatic fever and acute glomerulonephritis. It is not generally considered to be a member of the normal vaginal flora, as it is isolated in less than 1% of asymptomatic women. Pelvic infection caused by group A streptococci may produce a characteristic clinical picture, with a high, early initial fever, chills, prostration, and diffuse tenderness. Historically, the group A b-hemolytic streptococcus was the organism responsible for fatal puerperal sepsis. On Gram stains, one sees Gram-positive cocci in chains. The microorganism remains exquisitely sensitive to penicillin, and erythromycin or a cephalosporin usually can be substituted for treatment of the penicillin-allergic patient. Clindamycin is an alternative agent, as is vancomycin. Group A streptococcal pelvic infections occur in both sporadic and epidemic forms. Epidemics usually are exogenous in origin, commonly resulting from nasopharyngeal