Relapsing fever is characterized by recurring fevers and flu-like symptoms such as headaches, myalgia, arthralgia, and rigors. Etiology Relapsing fever is an arthropod (lice or ticks)-transmitted infection caused by spirochetes of the genus Borrelia . Louse-borne (epidemic) relapsing fever is…
Leptospirosis is a common and widespread zoonosis caused by aerobic, motile spirochetes of the genus Leptospira. Etiology Leptospira spp. are thin, helix-shaped members of the phylum Spirochaetes. There are 22 species identified within the genus Leptospira , and these are…
Nonvenereal treponemal infections—yaws, bejel (endemic syphilis), and pinta—are caused by different subspecies of Treponema pallidum and occur in tropical and subtropical areas. The causative agents of nonvenereal treponematoses— T. pallidum pertenue, T. pallidum subspecies endemicum, and Treponema carateum —cannot be…
Syphilis is a chronic systemic sexually or vertically (mother to child) transmitted infection that can be easily treated if detected early but manifests with protean clinical symptoms and significant morbidity if left unchecked. Etiology Syphilis is caused by Treponema pallidum,…
Chancroid is a sexually transmitted disease characterized by painful genital ulceration and inguinal lymphadenopathy. Etiology and Epidemiology Chancroid is caused by Haemophilus ducreyi, a fastidious gram-negative bacillus. It is prevalent in many developing countries but occurs sporadically in the developed…
Corticosteroids play a key role in the management of many neoplastic, autoimmune, allergic, and autoinflammatory disorders. Corticosteroids are used for their lympholytic and antiinflammatory effects during infection, for example, to prevent airway obstruction during croup or Epstein-Barr virus−associated tonsillitis, or…
Biologic response modifying drugs (BRMs) are substances that interact with the host immune system and modify it. BRMs include cytokines, chemokines, and antibodies that occur naturally in the body to protect against infections. Synthetic BRMs generally target or mimic natural…