1979) A preliminary report on the trombiculid mites from rodents in Kweichow province. Acta Entomologica Sinica, 22, 93 -97. Wang Dun-qing et al. (1965) Studies of two types of Trombicula deliense Walch (Trombiculidae, Acarina). Acta Entomologica Sinica, 14, 383-389. Wang Dun-qing (1981) Tentative regrouping of subgenus Leptotrombidium Nagayo et al., 1916 (Trombiculidae, Acarina). Acta Entomologica Sinica, 24, 459-464. Wang Dun-qing et al. (1981) Five new trombiculid mites of the genus Leptotrombidium (Acarina: Trombiculidae). Acta Zootaxonomica Sinica, 6 (l), 44-52. Wang Dun-qing & Liao, Hau-rong (1984) Type A of Leptotrombidium deliense is a new species, Leptotrombidium rubellum sp.nov. Wuyi Science Journal, 4, 231-234. Wang Dun-qing et al. (1985) Two new species of chigger mites in western Hunan, China (Acari: Trombiculidae). Acta Zootaxonomica Sinica, 10, 152-155. Wang Dun-qing (1985) Studies on the monstrosities of trombiculid larvae. Acta Entomologica Sinica, 28, 437-443. Wang Dun-qing (1988) Biosystematic problems in relation to the vectors of scrub typhus in China.
INTRODUCTIONA fundamental concept in the ecology of ectoparasite-borne disease is that of the reservoir, or the wellspring of the infection in nature during interepidemic periods. In the case of chigger-borne rickettsiosis (scrub typhus), it has often been argued that chiggers (larval trombiculid mites) are not only the vectors but also the true reservoirs of the infection and that the small mammals (theraphions) that serve as hosts of the chiggers are of no importance as a source of rickettsiae for the chiggers.' This point of view has been based largely upon several factors, namely, the known transovarian transmission of the causative agent, Rickettsia tsutsugamushi. from mother to progeny in certain species of chiggers,' the demonstration of the efficiency of the mechanism of transovarian transmission by Rapmund and his colleagues,+-" the difficulty or impossibility to show that chiggers can acquire R . tsutsugamushi while feeding on infected hosts in the laboratory,'. c -l l the fact that chiggers are unique among vectors in that in their lifetime, they are parasitic only in one stage (i.e., as larvae) and normally attach to, and feed upon, only one vertebrate and therefore could not acquire an infection from one such host and transmit it later directly to a second, and, finally, the widespread belief that chiggers do not imbibe blood but, instead, feed solely on serum exudate when in the parasitic stage and thus are unlikely to come in contact with pathogens that circulate in the blood of the host.', In the present paper, it is shown that, contrary to general belief, chiggers can acquire R . tsutsugarnushi while feeding on rickettsemic mice and that, when tested by pools of chiggers, this acquisition is relatively frequent. Persistence of acquired rickettsiae for at least 1-2 weeks in the chiggers is demonstrated, and a single case of presumed transovarian transmission to the next generation is reported. The preliminary data presented suggest, somewhat surprisingly, that in nature, under certain conditions, a small but perhaps significant proportion of chiggers may partially feed on one host and then later feed to repletion on a second one, raising the possibility that such "reattached" chiggers may * 91 92 Annals New York Academy of Sciences transmit acquired rickettsiae. These points, coupled with the observation in our laboratory that chiggers may, indeed, imbibe blood on o c~a s i o n ,~~ 5 , l2 indicate that theraphions may perhaps truly be of significance as a source of R. tsutsugumushi infection in chiggers in nature, even though the trombiculids themselves apparently constitute the prime reservoir of chigger-borne rickettsiosis.The approach in this study has primarily been concerned with the acquisition of R. tsrrtsugamushi by chiggers that were presumably free of natural infection; we utilized colonies of six species of chiggers that are known or suspected vectors of chigger-borne rickettsiosis and fed the chiggers on mice that had been inoculated with R. tsutsugumushi. The absence of natural infect...
It has been generally accepted that infected fleas do not pass on Rickettsia mooseri, or indeed any other known pathogen, to their progeny. It is reported here that such transovarial transmission does occur in laboratory-infected Xenopsylla cheopis fleas. By means of the direct fluorescent antibody test, Rickettsia mooseri was observed in cells of the hemolymph of infected fleas. As many as 11 percent of the adults and 2.9 percent of the larvae of the generation reared therefrom, had demonstrable rickettsiae. Moreover, batches of the F1 fleas were capable of transmitting the infection to more than 18 percent of the rats they infested. The data support the contention that Xenopsylla cheopis fleas play an important role in the maintenance of murine typhus in rats in nature.
Jellisonia klotsi Traub.3, 4. Jellisonia hayesi hayesi sp. and subsp. nov. 5.JeUisonia hayesi breviloba sp. and subsp. nov. and Jellisonia dybasi sp. nov. 6, 7.LIST OF ILLUSTRATIONS PLATE 51. Leptopsytta segnis (Schonherr), Orchopeas leucopus (Baker), Stenoponia americana (Baker), and Hystrichopsylla gigas dippiei Rothschild.52. Dasypsyllus gattinulae perpinnatus (Baker), Nosopsyllus fasciatus (Bosc), Diamanus montanus (Baker), and CeratophyUus riparius Jordan and Rothschild.53. XenopsyUa cheopis (Rothschild), Ctenocephalides canis (Curtis), CtenocephcUides felis (Bouch^), Hoplopsyllus anomalus (Baker), and Hoplopsyllus affinis (Baker).54. Opisodasys hollandi Traub, Myodopsylla cottinsi Kohls, Sternopsylla texana (C. Fox),Echidnophaga gattinacea (Westwood), and Tunga penetrans (Linnaeus).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.