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Biomedical subjects

H Hoogstraal

Publications and source records attributed to H Hoogstraal.

At least 37 records · Page 2Linked to original sources

Borrelia crocidurae localization and transmission in Ornithodoros erraticus and O. savignyi.

Borrelia crocidurae infection rates in different organs of adult Ornithodoros (Pavlovskyella) erraticus and O. (Ornithodoros) savignyi were studied at intervals during a 60-day period following an infective meal. The spirochaetes persisted in tick guts for 1 month, were first observed in other organs 1-7 days post-feeding, and persisted for 20-60 days in different organs. The ovaries, Gene's organ, testes and male accessory glands of only O. erraticus were infected. The infection rates in adult and immature O. erraticus and O. savignyi post-feeding on infected hamsters were 26.7-60 X 0% and 26.7-80.0%, respectively. Spirochaete trans-stadial transfer from originally infected larval O. erraticus to first-instar nymphs (N1) was 33.3%; to subsequent N2-N5 it was 40.0-60.0%. Infection rates in the resulting adults were 26.7% (males) and 46.7% (females). In O. savignyi, trans-stadial transfer from originally infected N1 to N2 was 26.7% and to subsequent N3-N7 13.3-33.3%; of the resulting males and females, 20.0% were infected. Transovarial transmission from female O. erraticus infected as adults occurred after the second gonotrophic cycle to 33.3-53.3% of the F1 larvae, and to 26.7 and 46.7% of the F1 males and females, respectively. All infected F1 females transmitted the spirochaetes to 26.7-73.3% of the F2 larval progeny after the first gonotrophic cycle. Transovarial transmission was not observed in O. savignyi.

Animals↗

Observations on the subgenus Argas (Ixodoidea: Argasidae: Argas). 19. Description of the larva of the Palearctic cormorant parasite A. (A.) macrostigmatus.

Larvae of 19 of the 21 species of the Argas subgenus Argas are already described. One of the two exceptions is A. (A.) macrostigmatus; we describe the larva of this species from wet nests of the crested cormorant, Phalacrocorax aristotelis, from Corsica, France. As in the adult and nymphal stages, this larva has an uncovered Haller's organ, a character shared in Palearctic members of this large genus only with A. (A.) polonicus, a Central European parasite of rock pigeons. Available larval samples of both species are indistinguishable. However, adult and nymphal A. (A.) macrostigmatus are unique for their exceptionally large spiracular plates. These are the only Argas (Argas) species which differ distinctly as adults and nymphs but hardly or not at all as larvae. Argas (A.) macrostigmatus was previously known only from a nest of the crested cormorant in the Black Sea. Ukrainian SSR.

Animals↗

The Haller's organ roof and anterior pit setae of Argas ticks (Ixodoidea: Argasidae). Subgenera Secretargas and Ogadenus.

Adults of the Argas subgenera Secretargas (3 species) and Ogadenus (1 species) were studied by scanning electron microscopy. In each species, the anterior pit and Haller's organ are situated in a large dorsal hump of Tarsus I and the 9 setae of the anterior pit are characteristic of the genus Argas in structure and numbers. In A. (S.) transgariepinus, an Ethiopian-Palearctic crevice-dwelling parasite of bats, the Haller's organ capsule roof is solid with a slitlike transverse aperture. In A. (S.) hoogstraali and A. (S.) echinops, Malagasy soil-dwelling parasites of Oplurus (Varanidae) lizards and the hedgehog-tenrec (Insectivora: Tenrecidae), respectively, the Haller's organ is virtually unroofed but partially screened by arborescent dorsal projections from the posterior wall of the capsule, and the open capsule contains numerous fine pleomorphs. In A. (O.) brumpti, a soil-dwelling parasite of the hyrax (Procavia), other terrestrial mammals, and lizards in the Ethiopian Region, the capsule is also virtually unroofed and contains numerous fine pleomorphs. The unroofed capsule is probably phylogenetically primitive and occurs only in these 3 and 2 other Argas species. The soil microhabitat (in Argas confined to 3 of the 4 species recorded here), and the reptile or ancient mammal hosts of these 3 species, as well as the zoogeographical isolation of 2 of the species in the Malagasy Region, are distinctive in this genus of 56 species. The interrelationships between an unroofed Haller's organ capsule and unusual biological properties remain to be determined.

Animals↗

Bat ticks of the genus Argas (Ixodoidea: Argasidae). 13. Haller's organ roof and anterior pit setae in Carios and Chiropterargas.

Adults of 4 of the 6 species constituting the subgenus Carios and of 3 of the 4 species constituting the subgenus Chiropterargas were studied by scanning electron microscopy. All species parasitize Old World cave-dwelling insectivorous bats (Microchiroptera). The anterior pit setae number 10 in Carios and 10 or 11 in Chiropterargas. In most Carios, the setiform seta is replaced by a second serrate seta. In 2 of the 3 studied Chiropterargas species, 1 of the 2 grooved setae is exceptionally long. Porose setae number 3 in Carios and 3 or 4 in Chiropterargas. The Haller's organ roof in both subgenera is solid, lacking perforations; the aperture is narrowly transverse in Carios, irregularly wide or wide and transverse in Chiropterargas; uniquely, 1 or 2 sensilla protrude from the aperture of Chiropterargas species. The protruding sensilla and long grooved seta of Chiropterargas suggest a probably distinctive sensory-behavior pattern common to these ticks. Other morphological characters are discussed and compared to show relationships between these 2 subgenera and the subgenera Argas and Persicargas and distinctive characters present only in adult and/or larval Carios and Chiropterargas.

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A sero-epidemiological survey for certain arboviruses (Togaviridae) in Pakistan.

Complement-fixation test reactions to eight viruses of the family Togaviridae were studied in 372 serum samples (157 rodents, 172 domestic animals, 43 humans) from Pakistan. Antibodies to each tested virus were detected. The highest over-all prevalence rates were for West Nile (WN) (7.8%), Japanese encephalitis (JE) (3.2%) and Zika (ZIKA) (2.4%) viruses, followed by Sindbis (SIN), Chikungunya (CHIK), Uganda S (UGS) and Royal Farm (RF) viruses (1.6 to 1.3%). One human serum (male, age 58 years) reacted with Dengue-1 (DEN) virus antigen (titre 1:32). Antibodies to each virus except RF were detected in human sera; antibodies to RF virus were detected only in rodent and domestic animal sera. The roles of rodents in the epidemiology of WN, JE and ZIKA viruses should be investigated. At least six of these eight viruses cause fevers in humans (fevers of unknown origin comprise about one third of the febrile episodes recorded in Pakistan).

Adult↗

A sero-epidemiological survey for Bunyaviridae and certain other arboviruses in Pakistan.

Complement fixation test reactions to the following viruses were studied in 372 samples (157 rodents, 172 domestic animals, 43 persons) from Pakistan: Bunyaviridae, Phlebovirus: Phlebotomus fever Sicilian (PFS), Phlebotomus fever Naples (PFN), Karimabad (KAR), Salehabad (SAL); Nairovirus: Crimean-Congo haemorrhagic fever (CCHF), Hazara (HAZ), Dera Ghazi Khan (DGK), Dhori (DHO); Uukuvirus: Manawa (MWA); "possible members": Bakau (BAK), Bhanja (BHA). Reoviridae, Orbivirus: Wad Medani (WM). Unclassified: Wanowrie (WAN). Four of these viruses are Phlebotomus-borne (PFS, PFN, KAR, SAL). The other nine ar tick-borne. Antibodies against each virus were detected in sera from rodents. Antibodies against PFS, PFN, KAR, CCHF, DGK, BHA, WM and WAN viruses were detected in sera from domestic animals. Antibodies against PFS, CCHF, DGK, DHO, MWA, BHA, and BHA and WAN viruses were detected in human sera. The presence in Pakistan of KAR, DHO, BHA, and WAN viruses is documented for the first time. Over-all prevalence rates were highest for BHA (12.1%) and WM (10.7%) viruses, followed by DGK, CCHF, PFN and PFS (4.0 to 5.4%) and DHO, KAR, WAN, SAL, MWA, BAK and HAZ (0.3 to 2.1%). Epidemiological factors relating to virus circulation and human disease are discussed.

Adult↗

Observations on the subgenus Argas (Ixodoidea: Argasidae: Argas). 18. Haller's organ roof and anterior pit setae.

Adults of 18 of the 22 species constituting the subgenus Argas, which parasitize birds nesting and resting in rocky habitats in each faunal region of the world (15 species) or in trees (e species) (2 Neotropical, 1 Nearctic), were studies by SEM. In each except three Neotropical species, the nine setae of the anterior pit of tarsus I are arranged in an anterior group (1 serrate, 1 setiform, 1 conical) and a posterior group (2 fine, e porose, 2 grooved), or the two groups are more or less confluent. Abnormally, additional setae may occur on one or both tarsi of a single specimen. In one Neotropical species, only the three anterior group setae are present. In three Neotropical species, only these three setae and a fourth seta are present (whether 6 or 5 additional setae are concealed within the tarsal structure should be investigated). The Haller's organ capsule is entirely open (unroofed) (3 species), roofed posteriorly and open anteriorly (7 species), or mostly roofed by a plate which is pierced by one large aperture and by more or less numerous, small, or medium-sized perforations (8 species plus one other not studied by use). This study suggests that the structure of Haller's organ has evolved in different lines in response to a multiplicity of biologic al factors related to the behavior and habitat of individual species.

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The subgenus Persicargas (Ixodoidea: Argasidae: Argas). 38. Haller's organ roof and anterior pit setae in Persicargas and Microargas.

Adults of 13 of the 17 species constituting the subgenus Persicargas (parasitizing birds nesting in trees) and the single species of the subgenus Microargas (parasitizing the Galapagos giant tortoise) were studied by scanning electron microscopy. The setae of the anterior pit of tarsus I number nine(1 serrate, 1 setiform, 1 conical, 2 fine, 2 porose, 2 grooved) in Persicargas. The single, serrate seta arises from an anterior section of the pit, the other eight setae arise from a posterior section. Abnormally, fewer or more setae occur on one or both tarsi of a single specimen. The setal arrangement is similar in Microargas, but the total number is eight (setiform seta absent). The capsule roof of Haller's organ in Persicargas is typically flat and platelike with a circular central aperture and few to moderately numerous small perforations. Thus, this roof is more solid than in other subgenera of Argas, except in Microargas and subgenera associated with cave-dwelling bats (Carios and Chiropterargas). The roof structure is quite variable in samples of A. (P). radiatus. The roofs of two Persicargas species differ from the typical pattern, the A. (P.) minatus roof is more extensively perforated and in some specimens of A. (P.) streptopedia the roof is netlike. The Microargas roof, on a sloping surface bounded by a transverse anterior groove, is more solid than those of Argas and has a circular aperture surrounded by small perforations. The biological implications of these structural properties should be investigated.

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Haemaphysalis (Garnhamphysalis) rusae (Ixodoidea: Ixodidae): identity, deer and pig hosts, and distribution in Luzon and Mindanao.

Haemaphysalis (Garnhamphysalis) rusae Kohls, previously known only from three male ticks from Mindanao, Philippines, is a seldom collected but probably common parasite of the Philippine deer, Cervus (Rusa) philippinus, and wild pig, Sus celebensis philippensis, in forests of Mindanao and Luzon. A single female taken from a wallaby in Papua New Guinea is presumed to result from an introduction with the Philippine deer. The male, originally briefly described, is redescribed to provide criteria for comparing this species and other members of the subgenus Garnhamphysalis. The female and nymph are described for the first time. The male H. (G.) rusae and H. (G.) calvus Nuttall and Warburton are structurally quite similar, differing only in palpal length:breadth ratio and size of the trochanter IV spur. Females differ more widely in the presence (rusae) or absence (calvus) of a large retrograde spur extending from the posteroventral margin of palpal segment 2. Conversely, qualitative and quantitative structural differences between most Haemaphysalis species are greater in males than in females.

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Hyperparasitism in Ornithodoros erraticus.

Hyperparasitism is common in laboratory colonies of Egyptian Ornithodoros erraticus whether the ticks are on or off the rodent host. Sex, recent engorgement, and size appear to be major factors in this feeding relationship. Males, and nymphs that produced males (N-male), parasitized females and nymphs that produced females (N-female) more frequently than they parasitized males and N-male. Females and N-female seldom parasitized females and N-female and did not parasitize males or N-male. Engorging and recently engorged, large ticks attracted smaller unfed ones. No preferred attachment site was observed. Hyperparasitizing females and parasitized females weighed less, had a longer preoviposition period, and produced fewer eggs than normally feeding, unparasitized females. About 30% and 80% of the females parasitized by males and females, respectively, died within 3 mo; only 7% of unparasitized females died within the same period. The proximity of replete or engorging ticks may be sufficient stimulus for hyperparasitism. Additional factors may include production of an attracting kairomone by fed ticks or the absence under certain conditions of a deterrent to hyperparasitism normally produced by fed ticks. Borrelia crocidurae spirochetes are transmitted during hyperparasitism.

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Blisters, pruritus, and fever after bites by the Arabian tick Ornithodoros (Alectorobius) muesebecki.

A biologist was bitten by Ornithodoros (Alectorobius) muesebecki Hoogstraal, an endemic tick parasite of nesting and resting marine birds on islands in eastern Arabia. Irritating bullae developed and for four months he experienced intermittent inflammation and irritation. Two years earlier, after being bitten by the same tick species on a different island, he had experienced only irritation lasting no more than a fortnight. Petroleum-industry labourers on another island were admitted to hospital for about two weeks with bullae at numerous bite sites, intense pruritus, headache, and fever. Zirqu virus (Bunyaviridae, Nairovirus) has been isolated from O. (A.) muesebecki samples from Abu Dhabi. The role of Zirqa virus and/or of salivary toxins in producing irritation and illness, as well as individual sensitivity to the tick and the seasonal dynamics of toxicity or infectivity, should be investigated.

Bites and Stings↗

Haemaphysalis (Garnhamphysalis) mjoebergi: identity, structural variation and biosystematic implications, deer hosts, and distribution in Borneo and Sumatra (Ixodoidea: Ixodidae).

Haemaphysalis (Garnhamphysalis) mjoebergi Warburton was reported from four male specimens from Sarawak, Borneo. We redescribe herein the male, from three specimens from Sarawak and 24 from Lampung District, Sumatra, and describe the female from 24 specimens from Lampung. Male structural variation in the dental formula and development of the coxa IV spur and segments of legs III and IV is unusual or unique in the genus Haemaphysalis. "Atypical" males might easily be misidentified. This species provides an ideal model for experimental study of population genetics and evolutionary processes and of biological factors influencing body size and structural variation in the genus Haemaphysalis. The sambar deer, Cervus unicolor brookei Hose (Sarawak) and C. unicolor equinus Cuvier (Sumatra), appears to be the chief host in humid, marshy, lowland forests and secondary growth. Single collections were from a human and a domestic cow. The dynamics and vector potential of this tick should be investigated in environments being exploited for human settlement and cattle breeding.

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Hyalomma (Hyalommina) arabica sp. n. parasitizing goats and sheep in the Yemen Arab Republic and Saudi Arabia.

Hyalomma (Hyalommina) arabica sp. n. is described from 62 adults (29 males, 33 females) taken throughout the year from 23 goats and two sheep, mostly at 200 m altitude in the southern tihama foothills of Ta'izz Province, Yemen Arab Republic. One female from a goat at 2,300 m altitude in this Province may have attached to the host elsewhere and a male from Mecca, Saudi Arabia, was on a goat imported from an unknown source for the traditional religious pilgrimage feast. We postulate that the original host of adults was the Nubian ibex, Capra ibex nubiana F. Cuvier (Artiodactyla: Caprinae). This parasite is most closely related to H. (H.) kumari Sharif, which infests chiefly wild and domestic Caprinae from India to northwestern Iran and Tadzhik, SSR. It also shows relationships to H. (H.) punt Hoogstraal, Kaiser and Pedersen, which parasitizes gazelles and domestic mammals in Somalia and Ethiopia, but differs more widely from the third African-Arabian member of this subgenus, H. (H.) rhipicephaloides Neumann, which feeds on the Nubian ibex and gazelles in the Red Sea and Dead Sea areas. The Hyalomma subgenus Hyalommina now contains seven species, four confined to the Indian subcontinent (including Nepal, Burma, India, Sri Lanka, Pakistan, and Afghanistan) and Southwest Asia, and three in eastern Africa north of the equator and Arabia.

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