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Biomedical subjects

H Hoogstraal

Publications and source records attributed to H Hoogstraal.

At least 55 records · Page 3Linked to original sources
PubMed1981

Notes on African Haemaphysalis ticks, XIII. identity of H. (Rhipistoma) cooleyi, a parasite of the rock hyrax in South Africa (Acarina: Ixodidae).

The lectotype male, allotype female, and paratype nymph of Haemaphysalis (Rhipistoma) cooleyi Bedford, 1929, a parasite of the rock hyrax, Procavia capensis, in the Transvaal, are redescribed and illustrated to provide reliable criteria for differentiating between haemaphysaline parasites of hyraxes. Keys are included for identifying adults of these Haemaphysalis ssp. (orientalis Nuttall & Warburton, 1915; bequaerti Hoogstraal, 1956; cooleyi Bedford, 1929; hyracophila Hoogstraal, Walker & Neitz, 1971).

Animals↗
PubMed1980

Bionomics and health importance of fowl tick Argas (Persicargas) persicus (Oken, 1818) (Ixodoidea: ARgasidae).

The fowl tick Argas (Persicargas) persicus occurs in warm areas of Slovakia, where its distribution is limited by the 650-700 mm annual average isohyet and the +8 degrees C annual average isotherm. In Slovakia, larvae hatch from spring to autumn, and nymphal and adult moultings occur chiefly in July and August. Larvae feed for four days, nymphs and adults for less than one hour. The tick develops and reproduces during the warm season in the wild but throughout the year under favourable laboratory conditions in which the life cycle requires 17 months.

Animals↗
PubMed1980

Experimental transmission and field isolation studies implicating Culex pipiens as a vector of Rift Valley fever virus in Egypt.

Attempts were made to isolate virus from wild caught mosquitoes during the 1977 and 1978 Rift Valley fever (RVF) epizootics in Egypt. Over 95% of the 55,126 mosquitoes collected from epizootic areas in the Nile Delta and Valley were Culex pipiens. Two strains of RVF virus were isolated from unengorged female C. pipiens taken in 1978. Laboratory-reared C. pipiens originating from a population sample from the Nile Delta epizootic area transmitted RVF virus. The infection rate of mosquitoes that fed on viremic hamsters was 86.7%; the transmission rate was 40.0% (46.2% based only on infected mosquitoes). From these results, it is suggested that C. pipiens was a vector of RVF virus during the 1977-1978 epizootics in Egypt.

Animals↗
PubMed1980

Histocompatibility-2 system in wild mice. X. Frequencies of H-2 and Ia antigens in wild mice from Europe and Africa.

In this study, data are presented on serologic H-2 typing of 320 wild mice collected in several parts of Europe and Egypt. The sample was typed for 39 class I (K, D) and 16 class II (Ia) antigens. The phenotype frequencies of class I and class II antigens showed high variability in their distribution among different areas, ranging from absence or presence in low frequency in one area to presence in about one-half of the mice in another area. The average phenotypic frequency of class I private antigens was 6.3%; at least 60% of class I alleles (blanks) could not be identified with the available reagents. The data suggest that there might be more than 100 alleles for each class I locus, H-2K and H-2D. The average phenotypic frequencies of Ia-1 private antigens was 10.8%. About 75% of Ia-1 alleles (blanks) could not be identified. The number of Ia-1 alleles was estimated to be in the range of 20 to 50.

Alleles↗
PubMed1980

Ornithodoros (alectorobius) amblus (Acarina: Ixodoidea: Argasidae): identity, marine bird and human hosts, virus infections, and distribution in Peru.

Ornithodoros (Alectorobius) amblus Chamberlin 1920, adults previously were described inadequately. Practically nothing was known regarding the identity, hosts, distribution, and biology of this species. We redescribe both sexes, describe the nymph and larva, and present criteria for differentiating these stages from those of other members of the O. (A.) capensis group in the Western Hemisphere. Samples were collected from 13 localities on the Pacific coast and on offshore islands of Peru. Hosts recorded are the Peruvian Brown Pelican, Peruvian Booby, Blue-footed Booby, Red-legged Cormorant, Guanay Cormorant, and Inca Tern. These birds are not long-distance migrants and more widely distributed species of the O. (A.) capensis group have not been found parasitizing them. The life cycle is characteristic of the O. (A.) capensis group; the first nymphal instar does or does not feed. Humans are attacked eagerly by O. (A.) amblus and suffer afterward from severe inflammation and "incredible" pruritus, and possibly from more severe illness. Viruses infecting this tick are Punta Salinas (Hughes serogroup, family unclassified) and Huacho (Reoviridae, genus Orbivirus, Kemerovo serogroup). Dense tick populations cause breeding birds to desert numerous nests; thus, O. (A.) amblus is economically important to the Peruvian guano industry. Certain spiders and lizards may prey on this tick.

Animals↗
PubMed1979

An epizootic of Rift Valley fever in Egypt in 1977.

A disease causing increased mortality and abortion in domestic animals during a 1977 epizootic in Egypt was identified as Rift Valley fever (RVF) virus. The epizootic included extensive human involvement reflected clinically as either an acute febrile, ocular, encephalitic, or fatal haemorrhagic form of RVF disease. The virus was again isolated from humans and animals during a second RVF epizootic in the summer of 1978.

Animals↗
PubMed1979

The Rift Valley fever epizootic in Egypt 1977-78. 2. Ecological and entomological studies.

Epidemiological factors related to the introduction, spread and maintenance of Rift Valley fever (RVF) virus were studied during the 1977-78 epizootic in Egypt, Culex pipiens is the most ubiquitous and prevalent mosquito species in the Nile Valley and Delta. Isolation of RVF virus from unengorged C. pipiens, and demonstration of laboratory transmission of the virus by this species, strongly implicate it as the chief vector in Egypt. Virus transmission to man also occurs by contamination when handling infected meat and by inhaling natural virus aerosols. Wild rodents apparently do not serve as RVF virus reservoirs. Domestic sheep, cattle, buffaloes, camels, goats, donkeys and dogs act as amplifying hosts. Over 30% of the camels sampled at the southern border of Egypt were serologically positive for antibodies to RVF virus and it appears likely that the virus was introduced into Egypt, either by these animals or by other vehicles from the south.

Animals↗
PubMed1979

Ticks and spirochetes.

The concept is expressed that Borrelia developed as symbionts of ticks (especially Argasidae) but act as parasites in mammals and birds ... borrelial reservoirs and amplifiers following bites by infected ticks. Certain tick borreliae may multiply in lice but one Borrelia has evolved into a n independent species (B. recurrentis) associated only with lice and humans. Seventeen argasid tick species are known as vectors of Borrelia species and 4 ixodid tick species are known as vectors of B. theileri.

Animals↗
PubMed1979

Observations on the subgenus Argas (Ixodoidea: argasidae: Argas). 17. Argas (A.) polonicus sp. n. parasitizing domestic pigeons in Krakow, Poland.

Argas (A.) polonicus sp. n. is described from males, females, nymphs, and larvae from the steeple tower of St. Mary's Church, Karkow, Poland, where it feeds on domestic rock pigeons, Columba livia Gmelin. This species is related to the widely distributed Eurasian A. (A.) vulgaris Filippova and to certain other species of the eastern area of the Palearctic Faunal Region; it differs distinctly from A. (A.) reflexus (Fabricius) of western Europe. Comparative study under the light microscope. and especially under the scanning electron microscope, reveals numerous structural differences in adult and immature stages of these species, chiefly in the Haller's organ roof of each stage, adult body shape and integumental formations, dental formulae, and setal lengths and numbers on the larval dorsum.

Animals↗
PubMed1979

The Ornithodoros (Alectorobius) capensis group (Acarina: Ixodoidea: Argasidae) of the palearctic and oriental regions. O. (A.) coniceps identity, bird and mammal hosts, virus infections, and distribution in Europe, Africa, and Asia.

Ornithodoros (Alectorobius) coniceps (Canestrini 1890), which was briefly described from adult specimens from St. Mark's Cathedral, Venice, Italy, has been a confusing taxon. We redescribe and illustrate the adult and immature stages from St. Mark's Cathedral (topotypes) and elsewhere, list criteria to distinguish this species from others in the O. (A.) capensis complex, and provide data for 36 collections, chiefly from nest sites of wild and domestic pigeons in humid, rocky situations, and from a nest of the pallid swift, in Italy, France, Egypt, Kenya, Israel, Jordan, Afghanistan, Ukrainia, and Turkmenia. Other collections of small-sized adults and nymphs, lacking larvae, from pigeon, swallow, and swift nest in Nepal, India, and Sri Lanka, are tentatively assigned to this taxon. This is the only member of the O. (A.) capensis group not associated with marine or wading birds. Humans bitten by O. (A.) coniceps in buildings or caves may suffer from pain, edema, chills, and fever. BAku virus (Reoviridae) has been isolated from this tick in Uzbekistan, but most reports of other viruses and infectious agents are clouded by probable misidentification of O. (A.) maritimus as O. (A. coniceps. Published data on the life cycle and dynamics are reviewed briefly. Previously, this tick has not been reported from the Ethiopian Faunal Region (Kenya).

Africa↗