Spotted Fever Group Rickettsiosis in Chiba Prefecture

Abstract

In Chiba Prefecture, the first patient of infection with spotted fever group Rickettsia was found in 1987, thereafter nine patients were detected serologically by the end of 1990. Patients were found in the villages of Amatsukominato, Katsuura and Ootaki, which were located in southern part of Chiba Prefecture. The illness occurred from June to October. On the other hand, patients with Rickettsia tsutsugamushi were seen from October to September. Difference of prevalent seasons of these two types of rickettsiosis is important to make a clinical diagnosis and serological identification of this spotted fever group rickettsiosis. Antibody of the patients showed the highest titer to YH strain of Rickettsia and showed high cross-reactivity to other spotted fever group rickettsiae. For the diagnosis of the patient serologically, it was confirmed that any strain of spotted fever group Rickettsia were useful.

Case Report: Concurrent Sympatric Scrub Typhus and Japanese Spotted Fever in Japan

“…The patient likely contracted the diseases in an area where mites (Leptotrombidium scutellare and Leptotrombidium pallidum) and ticks (Haemaphysalis flava, Haemaphysalis longicornis, and Ixodes ovatus) co-exist, and where ST and JSF have been previously reported. [9][10][11][12] Furthermore, September and October are the only months when both infections occurred in Chiba Prefecture. Previous reports on concurrent infection with rickettsial diseases have included, in China and Laos, O. tsutsugamushi with R. typhi.…”

Retrospective Seroepidemiological Survey for Human Babesiosis in an Area in Japan Where a Tick-Borne Disease is Endemic.

“…Meanwhile, the human sera examined in the present study were obtained from a rural area of southern Boso Peninsula in Chiba Prefecture, which was far away from Awaji Island (approximately 500 km apart). Even though there is no geographically meaningful connection between these two places, both are known to be the regions where the Japanese Spotted Fever [12], another tick-borne disease caused by Rickettsia japonica, is endemic [6,7]. In both southern Boso Peninsula and Awaji Island, ticks are abundant during spring and summer in mountainous bushy areas, but whether or not the co-existence of babesiosis and rickettsiosis is linked to the presence of any tick species common in both the places is not clear, as the vector ticks transmitting these two diseases have not been identified yet.…”

“…The serum samples were collected in 1985 for serosurvey of Japanese Spotted Fever [12], a ticktransmitted rickettsiosis that is endemic in that area [6], and have been stored since then at -20°C.…”

Rickettsia japonica, the Etiologic Agent of Oriental Spotted Fever

“…1). Clinical and epidemiologic data were accumulated (27,33,35,36,40,43,53,73). Isolation of the causative agent from patients in Anan-city (38) and on Awaji Island (39) was also reported.…”