Although community-onset bloodstream infection (BSI) is recognized as a major cause of morbidity and mortality, its epidemiology has not been well defined in non-selected populations. We conducted population-based laboratory surveillance in the Victoria area, Canada during 1998–2005 in order to determine the burden associated with community-onset BSI. A total of 2785 episodes were identified for an overall annual incidence of 101·2/100 000. Males and the very young and the elderly were at highest risk. Overall 1980 (71%) episodes resulted in hospital admission for a median length of stay of 8 days; the total days of acute hospitalization associated with community-onset BSI was 28 442 days or 1034 days/100 000 population per year. The in-hospital case-fatality rate was 13%. Community-onset BSI is associated with a major burden of illness. These data support ongoing and future preventative and research efforts aimed at reducing the major impact of these infections.

Let A be a unital C*-algebra and let B be an abelian C*-subalgebra containing the identity of A. For any pure state h of B let Fh be the set of states of A which restrict to h on B. Necessary and sufficient conditions are given for an element x in A to have the property that, for each h, x is unable to distinguish between distinct elements of Fh. By specializing, this leads to a new proof of a theorem giving necessary and sufficient conditions for Fh to be a singleton for each h.

It is also shown that if A is postliminal and π(B) is a maximal abelian C*-subalgebra of π(B) for each irreducible representation π of A then Fh is a Choquet simplex for each h.

Observations on the movement of fluids in the vicinity of the mouthparts of actively feeding female Dermacentor andersoni were made with the aid of trans-illuminated live-hamster pouch host-tissue. Following tick attachment and the invasion of ‘attaching cement’ into the outer skin layers, there appeared a progressive release of host blood as the tick settled into a feeding pattern. Short periods of sucking, each followed by an immediate ejaculation of saliva, became lengthened as feeding progressed, as did the resting intervals between sucking. Other movements brought about by the tick included a ‘toying’ of the tissue fluid, a rapid vibration of the same, and a distinct regurgitation of host-blood material. A sudden haemorrhage usually appeared at the feeding site about 2½ h after attachment of partially fed ticks.

Speculations are made concerning the part played by the release of tick saliva and tick water loss, its probable relationship to host paralysis, and its apparent role in tick nourishment.

In Canada eight species of ticks are implicated with ten and possibly seventeen diseases of man and animals. The most important of these, tick paralysis, is caused by Dermacentor andersoni Stiles, and of three hundred human cases in British Columbia since 1910, thirty have been fatal. In livestock, outbreaks have involved up to four hundred cattle in a single herd, with losses of up to fifty head. Other diseases resulting from tick toxins include a paralysis of cattle by Oyobius megnini Dugès, which has caused twelve deaths since 1955; occasional deaths in deer and moose from heavy infestations of Dermacentor albipictus (Packard); and slow-healing sores in man resulting from the bites of Ixodes pacificus Cooley and Kohls.

One of the objectives in the study of tick paralysis at Kamloops was to discover a species of laboratory animal that is consistently susceptible to this disease. Such an animal was needed to explore inconsistencies probably caused by differences in tick virulence or host susceptibility. Observations on infestations of adults of Dermacentor andersoni in tick paralysis areas in British Columbia, and experiments with similar ticks on large and small wild and domestic animals, have revealed the following.

Tick paralysis continues to be one of the most baffling and fascinating tickborne diseases in Canada. It was first reported in this country by Todd in 1912. Since then about 250 human cases, including 28 deaths, have been recorded from British Columbia. Outbreaks in cattle have affected up to 400 animals at a time, with losses in a herd as high as 65 head. Although the disease is most common in the Pacific northwest, where it is caused by the Rocky Mountain wood tick, Dermacentor andersoni Stiles, it has lately been reported as far south as Florida and has been produced by Dermacentor variabilis Say, Amblyomma maculatum Koch, and A. americanum (L.) (Gregson, 1953). The symptoms include a gradual ascending symmetrical flaccid paralysis. Apparently only man, sheep, cattle, dogs, and buffalo (one known instance) are susceptible, but even these may not necessarily be paralysed.

Ixodes signatus Birula, 1895, pp. 357-358, Pl. 1, Figs. 10-13.

Ixodes arcticus Osborn, 1899, p. 553. Synonym, fide Cooley and Kohls, 1945, p. 201.

Ixodes parvirostris Neumann, 1901, p. 284. Synonym, fide Banks, 1908, p. 21, and Nuttall et al., 1911, p. 261.

Ixodes eudyptidis var. signata [Birula], Neumann, 1904, p. 451. Synonym, fide Nuttall et al., 1911, p. 261.

Ceratixodes signatus (Birula), Banks, 1908, p. 21, Pl. II, Figs. 1-3.

The male of Ixodes soricis Gregson was discovered at Silver Creek, British Columbia, in 1948 (Gregson, 1949). The tick was found with its hypostome fully inserted into the lateral body wall of a partially engorged female of the same species. It was not described because the specimen in situ represented an interesting example of either accidental parasitism (Anastos, 1948), or more likely an unsuccessful attempt at copulation, since it is questionable whether the males, like those of some other species of Ixodes, ever feed. The recent discovery, however, by the junior author, of another specimen, in a collection of ticks from a shrew taken at Seattle, Washington, permits the following description of the male of this species.

Preliminary studies of the effectiveness of benzene hexachloride, or more exactly 1, 2, 3, 4, 5, 6–hexachlorocyclohexane, against the paralysis tick, Dermacentor andersononi Stiles, have revealed an acaricide more promising than any hitherto tested by this laboratory.

FEMALE. Dimensions of unengorged holotype–1.2 mm. (to tip of scapula) x .78 mm. Colour–pale, dirty white, engorged specimens pale and yellowish.

Capitulum. Length 340 microns (tip of hypostome io dorsal ridge); width (at cornua) 300 microns. Surface of basis capituli smooth and impunctate. Cornua heavily chitinized but not prominent.

During recent years the tick, Ixodes californicus Banks, has attained considerable prominence as a pest of man, pets and livestock in British Columbia coastlands. This progression from a parasite of relatively little importance to one of major economic significance has been brought about not only by the gradual spread of human settlement into the habitat of the tick, but also by a resulting marked increase in the population of the pest. The present economic status of this tick, as observed by officers of the Dominion Entomological Laboratory at Kamloops during the past eight years, is presented herewith.

Two new species of Ixodes are described herewith. Both have been recognized for the past ten years as differing in certain respects from known species. Published descriptions of them, however, have been withheld pending a fuller knowledge of their distribution and further studies on the stability or certain differences between them and allied species. The acquisition of further study material having shown that differences are constant, the writer now feels justified in erecting two new species, thus differentiating these ticks from allied species with which they have been confused.

A new record for the distribution and environment of Grylloblatta campodeiformis Walker has been established by the recent discovery of this insect in the dry belt of British Columbia at an altitude of 1500 feet. The occurrence of the “ice bug” at this locality is of singular interest. Supposedly an inhabitant of only the coldest regions, such as are found along the margins of glaciers and mountain streams at high altitudes, this discovery shows that Grylloblatta can exist under extremely dry and hot conditions at a relatively low altitude.

A case of a heavy infestation of Cysticercus tenuicollis, terminating fatally in a deer, was recently afforded by one of the experimental animals of the Dominion Entomological Branch (Livestock Insect Investigation Laboratory) at Kamloops, B.C.