Book excerpt: New insights into one of the world's most common infectious diseases Chlamydiae are obligate intracellular bacteria that cause one of the most common sexually transmitted infectious diseases in the world. The infection disproportionately impacts women and the highest prevalence of infection is found in adolescents. Most chlamydial infections are asymptomatic. Untreated infections are sources of further spread of infection and can lead to serious consequences including pelvic inflammatory disease, infertility and chronic pelvic pain. Chlamydial infections also increase a person's susceptibility to HIV and other STDs. Featuring contributions by internationally recognized experts in epidemiology, infectious disease research and chlamydial biology, this book provides up-to-date reviews from a clinical and public health perspective on chlamydia epidemiology and control programs, genomics and pathogenicity, diagnosis, treatment, host immune responses, and the latest on the search for an effective vaccine. Also included are chapters on the impact of chlamydial infection on specific populations such as the lesbian, gay, bisexual and transgender community, and an update on the outbreak in Europe of the invasive chlamydial infection, lymphogranuloma venereum or LGV. This comprehensive publication is intended for clinicians, public health workers and scientists with interest in sexually transmitted diseases, medical microbiology, infectious diseases and clinical research.