Biomaterial Database

Epidemiological studies on the background of the endemic occurrence of tsutsugamushi disease in Toyama Prefecture. I. Epidemiology of infection with Rickettsia tsutsugamuchi among field rodents in endemic and nonendemic areas. 1985

M Ishikura, and M Watanabe, and O Morita, and H Uetake

In order to clarify the epidemiological background of the endemic occurrence of tsutsugamushi disease in Toyama Prefecture, Japan, since 1978, comparative surveys have been carried out between endemic and nonendemic areas. Rickettsia tsutsugamushi (Rt) was isolated at a rate of about 36% (158/439) from field rodents in the endemic area while it was not isolated from any of 280 in nonendemic areas. In all of six stations in the endemic area, a significantly high proportion of rodents were found to be Rt carriers. However, no Rt was isolated from rodents captured from July to September. The organism was isolated from rodents captured in the other months, especially in a high proportion in November when infestation of rodents with Leptotrombidium pallidum was at its peak. When the rodents were examined by indirect immunofluorescence staining, the rate of anti-Rt antibody-positive animals was about 55% (157/287) and about 17% (62/368) in endemic and nonendemic areas, respectively. Larvae of mites collected from the rodents were found to belong to four genera and 11 species. Among them L. pallidum was the only mite that had been known to be a vector of Rt. L. pallidum was found most frequently and in abundance from rodents in the endemic area, whereas it was present in very small numbers in rodents in nonendemic areas. The infestation of rodents with L. pallidum showed a seasonal variation, i.e. two peaks per year, in spring and autumn, and the number of mites detected was markedly greater in November than in spring. Rt was isolated from L. pallidum on rodents captured in the endemic area.

UI	MeSH Term	Description	Entries
D007564	Japan	A country in eastern Asia, island chain between the North Pacific Ocean and the Sea of Japan, east of the Korean Peninsula. The capital is Tokyo.	Bonin Islands
D008925	Mites	Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.	Acarus,Mite
D004199	Disease Vectors	Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.	Infectious Disease Vectors,Disease Vector,Disease Vector, Infectious,Disease Vectors, Infectious,Infectious Disease Vector,Vector, Disease,Vector, Infectious Disease,Vectors, Disease,Vectors, Infectious Disease
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000907	Antibodies, Bacterial	Immunoglobulins produced in a response to BACTERIAL ANTIGENS.	Bacterial Antibodies
D001096	Arachnid Vectors	Members of the class Arachnida, especially SPIDERS; SCORPIONS; MITES; and TICKS; which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.	Arachnid Vector,Vector, Arachnid,Vectors, Arachnid
D012285	Orientia tsutsugamushi	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.	Rickettsia tsutsugamushi
D012377	Rodentia	A mammalian order which consists of 29 families and many genera.	Beavers,Capybaras,Castor Beaver,Dipodidae,Hydrochaeris,Jerboas,Rodents,Beaver,Capybara,Hydrochaeri,Jerboa,Rodent,Rodentias
D012612	Scrub Typhus	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.	Tsutsugamushi Disease,Typhus, Scrub,Orientia tsutsugamushi Infection,Tsutsugamushi Fever,Disease, Tsutsugamushi,Diseases, Tsutsugamushi,Fever, Tsutsugamushi,Fevers, Tsutsugamushi,Infection, Orientia tsutsugamushi,Infections, Orientia tsutsugamushi,Orientia tsutsugamushi Infections,Tsutsugamushi Diseases,Tsutsugamushi Fevers