The etiologic agent of murine typhus (see TYPHUS, ENDEMIC FLEA-BORNE).

An infectious disease clinically similar to epidemic louse-borne typhus (TYPHUS, EPIDEMIC LOUSE-BORNE), but caused by RICKETTSIA TYPHI, which is transmitted from rat to man by the rat flea, XENOPSYLLA CHEOPIS.

A genus of gram-negative, aerobic, rod-shaped bacteria often surrounded by a protein microcapsular layer and slime layer. The natural cycle of its organisms generally involves a vertebrate and an invertebrate host. Species of the genus are the etiological agents of human diseases, such as typhus.

A species of gram-negative, aerobic bacteria that is the etiologic agent of epidemic typhus fever acquired through contact with lice (TYPHUS, EPIDEMIC LOUSE-BORNE) as well as Brill's disease.

Infections by the genus RICKETTSIA.

A species of gram-negative bacteria transmitted by the flea Ctenocephalides felis, and known to infect CATS, oppossums, and humans.

A serotype of SALMONELLA ENTERICA which is the etiologic agent of TYPHOID FEVER.

A species of gram-negative, aerobic bacteria that is the etiologic agent of ROCKY MOUNTAIN SPOTTED FEVER. Its cells are slightly smaller and more uniform in size than those of RICKETTSIA PROWAZEKII.

An order of parasitic, blood-sucking, wingless INSECTS with the common name of fleas.

The classic form of typhus, caused by RICKETTSIA PROWAZEKII, which is transmitted from man to man by the louse Pediculus humanus corporis. This disease is characterized by the sudden onset of intense headache, malaise, and generalized myalgia followed by the formation of a macular skin eruption and vascular and neurologic disturbances.

A species of gram-negative, aerobic bacteria that is the etiologic agent of BOUTONNEUSE FEVER. It resembles RICKETTSIA RICKETTSII but is antigenically distinct and less virulent for animals and man. (From Bergey's Manual of Systematic Bacteriology, vol 1)

A gram-negative, rod-shaped to coccoid bacterium. It is the etiologic agent of SCRUB TYPHUS in humans and is transmitted by mites from rodent reservoirs.

A family of small, gram-negative organisms, often parasitic in humans and other animals, causing diseases that may be transmitted by invertebrate vectors.

Immunoglobulins produced in a response to BACTERIAL ANTIGENS.

An acute febrile illness caused by RICKETTSIA RICKETTSII. It is transmitted to humans by bites of infected ticks and occurs only in North and South America. Characteristics include a sudden onset with headache and chills and fever lasting about two to three weeks. A cutaneous rash commonly appears on the extremities and trunk about the fourth day of illness.

An acute infectious disease caused by ORIENTIA TSUTSUGAMUSHI. It is limited to eastern and southeastern Asia, India, northern Australia, and the adjacent islands. Characteristics include the formation of a primary cutaneous lesion at the site of the bite of an infected mite, fever lasting about two weeks, and a maculopapular rash.

A genus of gram-negative bacteria characteristically appearing in chains of several segmenting organisms. It occurs in man and arthropod vectors and is found only in the Andes region of South America. This genus is the etiologic agent of human bartonellosis. The genus Rochalimaea, once considered a separate genus, has recently been combined with the genus Bartonella as a result of high levels of relatedness in 16S rRNA sequence data and DNA hybridization data.

An acute systemic febrile infection caused by SALMONELLA TYPHI, a serotype of SALMONELLA ENTERICA.

A febrile disease of the Mediterranean area, the Crimea, Africa, and India, caused by infection with RICKETTSIA CONORII.

Substances elaborated by bacteria that have antigenic activity.

EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.

Blood-sucking acarid parasites of the order Ixodida comprising two families: the softbacked ticks (ARGASIDAE) and hardbacked ticks (IXODIDAE). Ticks are larger than their relatives, the MITES. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many TICK-BORNE DISEASES, including the transmission of ROCKY MOUNTAIN SPOTTED FEVER; TULAREMIA; BABESIOSIS; AFRICAN SWINE FEVER; and RELAPSING FEVER. (From Barnes, Invertebrate Zoology, 5th ed, pp543-44)