Entomopathogenic fungi in flies associated with pastured cattle in Denmark.

Cattle flies, including Musca autumnalis, Haematobia irritans, and Hydrotaea irritans, are pests of pastured cattle. A 2-year study of the natural occurrence of entomopathogenic fungi in adult cattle flies and other flies associated with pastures showed that the four species included in the Entomophthora muscae species complex (E. muscae sensu lato) caused high infection levels in several species of flies. However, only a few specimens of cattle flies were infected by E. muscae sensu stricto despite the fact that cattle flies were observed to perch on spear thistles, which acted as transmission site for all four Entomophthora species. Transmission experiments with E. muscae s.l. supported the field data. Of the two species considered host specific, E. syrphi caused substantial infection in a muscid, and E. scatophagae likewise could be transmitted to a muscid. This emphasizes the need for a revision of the two species. Low prevalences were recorded of another entomophthoralean, Furia americana, and of the hyphomycetes Beauveria bassiana and Verticillium lecanii.

Anticoagulant therapy in deep venous thrombosis. A randomized controlled study.

Ninety patients with venographically proven deep venous thrombosis(DVT) but without clinical signs of pulmonary embolism(PE) were randomized into two different treatment regimens to compare the safety and efficacy of continuous intravenous heparin and oral anticoagulant(AC) treatment versus non-AC treatment. All patients in the two treatment groups were actively mobilized from the day of admission and wore graduated compressing stockings. In the non-AC-group the patients were treated with phenylbutazone for ten days. Treatment with heparin was maintained for 6 days and oral AC treatment was given from the third day and continued for 3 months. Venography was repeated after 30 days. A perfusion-ventilation lung scan was performed on day 1-2, 10 and 60. In fifty-nine patients a revenography was performed, twenty nine in the AC-group and thirty in the non-AC group. For distal veins regression was found in nine and eight respectively (4.4% in favour of AC, 95% confidence limit 27.5% to -18.7%) and in proximal veins regression was found in five and eight, respectively (10.9% in favour of AC, 95% confidence limit 32.0% to -10.1%). No difference in lung scans was found after 10 days (0.8% in favour of AC, 95% confidence limit 21.5% to -19.9%) or after 60 days (3.3% in favour of non-AC treatment, 95% confidence limit 21.8% to -28.5%). In the AC group the incidence of bleeding complications was 8.3%. No side-effects of phenylbutazone was found. The present controlled clinical study demonstrated no effect of AC-treatment on DVT progression in actively mobilized patients wearing graduated compressing stockings when compared to a non-AC treated group receiving analgetic therapy with phenylbutazone. However, the patient population of the study is relatively small with wide confidence intervals for differences between groups. Before more general recommendations can be made, a large scale placebo-controlled study is needed to evaluate the possible effect of AC-treatment in DVT patients, who can be mobilized from the first day.

Variation in density of cattle-visiting muscid flies between Danish inland pastures.

The density of cattle-visiting flies (Muscidae) and the load of black-flies (Simulium spp.) were estimated in twelve and eighteen inland pastures in Denmark in 1984 and 1985 respectively. No differences in the geographical distribution pattern of the predominant cattle-visiting Muscidae were recorded, whilst the relative abundance and density of the species and the total fly-load varied considerably between pastures. In most cases the mean loads of Haematobia irritans (L.) and Hydrotaea irritans (Fall.) on heifers varied significantly in relation to site topography and shelter. These crude site variables explained 65-98% of the variation in densities of horn flies and sheep head flies observed between pastures. Highest densities of Hydrotaea irritans were primarily associated with permanent, low-lying, fairly sheltered grassland sites, whereas the density was low in temporary, dry, wind-exposed pastures. A comparable relationship was found for Haematobia irritans. With Haematobosca stimulans (Mg.) and Morellia spp. no relation between grassland environment and fly density was detected.

Deep vein thrombosis detection by 99mTc-plasmin test and phlebography.

During a 2-year period the diagnostic value of 99mTc-labelled-plasmin test was evaluated in 63 patients admitted with clinical signs of deep vein thrombosis (DVT). In comparison with a conventional phlebography the diagnostic sensitivity and specificity of the plasmin test was 0.97 and 0.55, respectively. The predictive value in positive cases was 0.79 and in negative 0.92. The sensitivity was highest for thrombosis in the calf and popliteal regions, while the specificity was higher for thrombosis in the femoral veins. It is concluded that the 99mTc-labelled-plasmin test is suitable for DVT-screening in groups of high-risk patients and is simple and rapid. In positive cases the DVT diagnosis must be verified by phlebography.

A mass attack by the biting midge culicoides nubeculosus (Mg.) (Dipteria, Ceratopogonidae) on grazing cattle in Denmark. A new aspect of sewage discharge.

A consequence of sewage discharge into a shallow marsh pool was large-scale hatching of the biting midge Culicoides nubeculosus from the recipient and mass attacks by this blood-sucking insect on grazing cattle. Culicoides nubeculosus is a great nuisance due to the painful bite and in Denmark it is a potential vector of pathogenic agents. In the future, these aspects of sewage discharge must be borne in mind.