Hiroyuki Takaoka

Bio: Hiroyuki Takaoka is an academic researcher from University of Malaya. The author has contributed to research in topics: Simulium & Black fly. The author has an hindex of 28, co-authored 354 publications receiving 3788 citations. Previous affiliations of Hiroyuki Takaoka include Oita University & Chiang Mai University.

Andean leishmaniasis in Ecuador caused by infection with Leishmania mexicana and L. major-like parasites.

Abstract: Between 1986 and 1988, epidemiologic studies were carried out in a small rural community in an Andean region of Ecuador, where cutaneous leishmaniasis is highly endemic. A total of 25 human cases, positive for Leishmania parasites by culture and/or smear, were examined. Fourteen of the cases were in infants less than one year of age, suggesting intradomiciliary transmission of the disease. Clinically, many of these cases were similar to descriptions of “uta,” a form of cutaneous leishmaniasis which occurs in Andean regions of Peru and is reportedly caused by L. peruviana. Of the 11 positive cultures obtained from human cases in the present study, eight were identified by molecular characterization as L. mexicana and three were identified as L. major-like. Two additional isolates of L. mexicana were also made from an infected dog and from a sand fly, Lutzomyia ayacuchensis, living in the region, thus implicating the latter species as possible reservoir and vector, respectively, of L. mexicana in this highland community. The significance and validity of recent isolates of L. major-like parasites from the New World are also discussed.

Morphotaxonomic revision of Simulium Gomphostilbia Diptera Simuliidae in the Oriental Region

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Infective larvae of Cercopithifilaria spp. (Nematoda: Onchocercidae) from hard ticks (Ixodidae) recovered from the Japanese serow (Bovidae).

Abstract: Hard ticks taken from the Japanese serow, Capricornis crispus, in Yamagata Prefecture, Honshu, har- boured infective larvae of onchocercid filariae after incubation from the 22nd to the 158th day. Haemaphysalis flava and H. japonica contained one to eight filarial larvae; females, males and a nymph of the ticks were infected. The 44 infective larvae recovered were 612-1,370 lm long, and 11 of them, 930-1,340 lm long, were studied in detail. The larvae possessed the morphologic characteristics of the larvae of the genus Cercopithifilaria, namely an oesoph- agus with a posterior glandular part, no buccal capsule and a long tail with three terminal lappets. Five types (A to E) of infective larvae were identified based on the morphologic characteristics. While to date five species of Cercopithifilaria have been described from the Japanese serow, a specific identification of the larvae found in this study was generally not possible. Only type E larvae could be tentatively assigned to Cercopithifilaria tumidicervicata, as they had a cer- vical swelling similar to that of the adults of this species. A key for the identification of the five larval types is pre- sented. The study presents circumstantial evidences indicating that H. flava and H. japonica may transmit Cercopithifilaria spp. to Japanese serows. It also suggests the possibility that such filarial larvae will be found in hard ticks anywhere, because Cercopithifilaria is distributed worldwide, though this genus generally goes unnoticed, as its microfilariae occur in the skin, not in the blood, of host animals.

Seasonal abundance and daily flying activity of black flies (Diptera: Simuliidae) attracted to human baits in Doi Inthanon National Park, northern Thailand

Abstract: The seasonal abundance and daily flying activity of adult black flies were investigated at four different altitudes (400 m, 860 m, 1,360 m and 2,460 m> in Doi Inthanon National Park, northern Thailand. Collections were carried out at each altitude twice a month from 0600 to 1800 hours from August 2003 to July 2004, and adult b]ack fiies attracted to a human bait were captured by a hand net. The numbers of black flies collected were 2,599, 24,O1O, 7,996 and 4,496 at altitudes of 400 m, 860 m, 1,360m and 2,460m, respectively. A total of 39,101 adult black flies comprising 39,060 females. 37 males and 4 sex mosaics of 23 species of the genus Simutium Latreille s. L were identified. Simuliid species composition and abundance varied according to altitude, Three species, i.e., S. (Gomphostilbia) as hoae Takaoka and Davies, S. (Simulium) nifibasis Brunetti and S. {S.) nigrogitvum Summers, were regularly attracted to a human bait in this order of predominance, Simulium (G,) asaleoae was captured from low to rnedium altitudes, while S, {S.) rafibasis was captured mostly at high altitude, and S.

A new species

Abstract: We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

Leishmaniases of the New World: current concepts and implications for future research.

Abstract: Recent epidemiologic studies indicate that leishmaniasis in the Americas is far more abundant and of greater public health importance than was previously recognized. The disease in the New World is caused by a number of different parasite species that are capable of producing a wide variety of clinical manifestations. The outcome of leishmanial infection in humans is largely dependent on the immune responsiveness of the host and the virulence of the infecting parasite strain. This article reviews current concepts of the clinical forms, immunology, pathology, laboratory diagnosis, and treatment of the disease as well as aspects of its epidemiology and control. Recommendations for future research on the disease and its control are made.