Definition Whipple disease is a rare chronic systemic infection that is caused by Tropheryma whipplei and is characterized by a wide range of symptoms including fever, diarrhea, malabsorption, weight loss, arthralgias, arthritis, central nervous system involvement, lymphadenopathy, and serositis. T.…
Definition Actinomycosis is an uncommon, subacute to chronic bacterial infection that induces both suppurative and granulomatous inflammation. Localized swelling with suppuration, abscess formation, tissue fibrosis, and draining sinuses characterize this disease. The infection spreads contiguously and often forms draining sinuses…
Definition Zoonoses, derived from the Greek words zōio (animal) and nósos (disease), are infectious diseases transmitted from animals, both wild and domestic, to humans or from humans to animals. Among emerging or reemerging infectious diseases, 60 to 75% are zoonoses.…
Definition Rickettsial diseases are emerging infectious diseases. Because of better diagnostic tools, increased awareness, and changes in tick exposure, new rickettsial diseases continue to be described in recent years. Three families of diseases are grouped under rickettsioses: ehrlichioses and anaplasmoses…
Definition Leprosy (Hansen disease), which is caused by Mycobacterium leprae, is a chronic infection found worldwide but with about 75% of cases reported in India, Brazil, and Indonesia. The primary clinical manifestation is hypopigmented, hypoesthetic or anesthetic, nonpruritic skin lesions.…
Definition Nontuberculous mycobacteria generally include the growing number of mycobacteria other than Mycobacterium tuberculosis and its close relatives ( Chapter 299 ) and M. leprae ( Chapter 301 ). Other names that have been used include atypical mycobacteria , mycobacteria…
Definition Tuberculosis (TB) is a granulomatous disease caused by the slow-growing, acid-fast bacillus Mycobacterium tuberculosis . Prior to the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2; Chapter 337 ), TB was the leading infectious disease cause of death worldwide.…
Definition Leptospirosis is a zoonotic bacterial infection caused by pathogenic spirochetes belonging to the genus Leptospira . It has a global distribution and is most prevalent in tropical areas with poor urban infrastructure and heavy rainfall. Leptospirosis is transmitted to…
Definition Relapsing fever is a spirochetal infection with bacteria of the genus Borrelia . The two modes of transmission are epidemic louse-borne and endemic tick-borne relapsing fever. Disease is characterized by recurrent bouts of fever and spirochetemia separated by short…
Definition Lyme disease (also known as Lyme borreliosis) is a zoonotic infection that is transmitted by certain Ixodes tick species and caused by a group of related spirochetes referred to formally as Borrelia burgdorferi sensu lato, or more simply as…