Japanese Spotted Fever: Report of 31 Cases and Review of the Literature

Tick- and flea-borne rickettsial emerging zoonoses

“…As expected, all cases occurred between April and mid-August, including 16 (56%) in July. For 1997, and 1999, the calculated incidence for HME was 2, 4.7, and 3 per 100 000 population, respectively (incidence calculations were based on the total population of all counties where the patients lived). According to the authors, HME was even probably underestimated in this prospective study throughout the rural southeastern and south central states.…”

“…Between 1984 and 2004, nine more species or subspecies of tick-borne spotted fever rickettsiae were identified as emerging pathogens throughout the world, including, R. japonica in Japan [6,46,65,71,72,[82][83][84]146]; "R. conorii caspia" in Astrakhan [35,38,39,143], Africa [47] and Kosovo [48]; R. africae in sub-Saharan Africa and the West Indies [62,63]; R. honei in the Flinders Island, offshore of Australia [9,57,140,141], the Island of Tasmania, Australia [153], Thailand [73], and possibly in the USA [13]; R. slovaca in Europe [29,74,101,122]; "R. sibirica mongolotimonae" in China [157], Europe [44,118] and Africa [106,113]; R. heilongjiangensis in China [42,49]; R. aeschlimannii in Africa [11,112,121] and Europe [43]; and finally R. parkeri in the USA [104]. R. helvetica is also suspected to be a human pathogen in Europe [45] and Asia [46,61,107], but this needs c...…”

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

“…In our epizootiologic field surveys [22], we were able to capture wild rodents harboring B. microti-like parasites in various places in Japan, including Hokkaido, Chiba, Shiga, Hyogo, Shimane and Tokushima Prefectures. Interestingly, clinical cases of tick-borne diseases have been reported from most of these places; Japanese Spotted Fever from Chiba, Hyogo, Shimane and Tokushima Prefectures [12], and Lyme borreliosis from Hokkaido [15]. In our IFAT, serum samples exhibiting antibody titers of 1:100 or higher were considered to be positive, because those sera exhibited specific fluorescent reaction patterns that are consistent with the shapes of parasite bodies within the erythrocytes.…”

“…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.…”