Showing papers on "Tick published in 1978"
TL;DR: Findings support the hypothesis that erythema chronicum migrans and Lyme arthritis are tick-transmitted, specifically by I. scapularis.
Abstract: Forty-three residents of 12 contiguous Connecticut communities were identified who had the onset of erythema chronicum migrans, Lyme arthritis, or both during the summer and fall of 1977. Nine of them (21%) remembered having been bitten by a tick at the site of the initial skin lesion a median of 12 days (range 3-20) before onset; one patient brought in the tick for identification (Ixodes scapularis). Compared to 64 of their neighbors, significantly more patients had cats and farm animals, and had noted ticks on their pets and tick bites on themselves. The incidence of the illness during 1977 was 2.8 cases per 1000 residents in the three communities on the east side of the Connecticut River, compared to 0.1 cases per 1000 residents in the nine communities on the west side, a difference of almost 30-fold. Taken with the results of a concomitant acarological study on both sides of the river, these findings support the hypothesis that erythema chronicum migrans and Lyme arthritis are tick-transmitted, specifically by I. scapularis.
278 citations
TL;DR: Increasing tourism in endemic areas and the frequent occurrence of prolonged or biphasic illnesses provide the potential for patients with Colorado tick fever to seek medical care anywhere in the United States.
Abstract: During 1973 and 1974, we looked for cases of Colorado tick fever throughout Colorado; 228 cases were identified. Although 90% of the patients reported exposure to ticks before illness, only 52% were aware of an actual tick bite. Typical symptoms of fever, myalgia, and headache were common, but gastrointestinal symptoms were also prominent in 20% of the patients. Twenty percent were hospitalized; no deaths or permanent sequelae were noted. Persistent viremia (greater than or equal to 4 weeks) was found in about half of the cases; this finding was not associated with the occurrence of prolonged symptoms (greater than or equal to 3 weeks), which were also reported in half of the cases. One patient became reinfected with the virus. Increasing tourism in endemic areas and the frequent occurrence of prolonged or biphasic illnesses provide the potential for patients with Colorado tick fever to seek medical care anywhere in the United States.
81 citations
TL;DR: Rabbits and sheep are unable to acquire a resistance to larvae and nymphs of Amblyomma hebraeum, and there is no progressive decline in either the tick yield or the engorged weight of fed ticks after repeated infestation of hosts.
Abstract: Rabbits and sheep are unable to acquire a resistance to larvae and nymphs of Amblyomma hebraeum. After repeated infestation of hosts there is no progressive decline in either the tick yield or the engorged weight of fed ticks. Seasonal fluctuations in engorged weights do occur however, with the weight declining in early to midwinter and increasing in early to midsummer. Changes in hose physiology as a result of low temperature acclimatization appear to be responsible for the fluctuations. Tick yield is determined by the amount of grooming undertaken by hosts. The feedings periods of larvae and nymphs are dependent on the skin temperature of the host.
38 citations
TL;DR: B. theileri is important because infections of invertebrate and vertebrate hosts may interfere with the interpretation of data in various experimental designs, and because it is probably endemic in populations of one or more tick species and their hosts throughout the world.
37 citations
TL;DR: Experiments using glass rod models to represent vegetation showed that ticks selected a position which had greatest substrate curvature and was at rabbit body height, which restricts the tick's host spectrum to rabbits and ground-dwelling or feeding birds.
Abstract: The rabbit tick (Haemaphysalis leporispalustris) is highly host-specific. Adults feed almost exclusively on rabbits. Immatures feed primarily on rabbits but will attack birds. When larvae leave the daytime resting form of the rabbit, they climb up to a position on vegetation where they can encounter a host. Experiments using glass rod models to represent vegetation showed that ticks selected a position which had greatest substrate curvature and was at rabbit body height. This strato-orientation restricts the tick's host spectrum to rabbits and ground-dwelling or feeding birds.
36 citations
TL;DR: The ticks' role as vectors of louping ill may be more important than the harm they do by removing blood and causing inflammation, as some parts of Scotland are in- fested with numerous sheep ticks and Moore (1937) suggested that ticks kill many young grouse.
Abstract: The number of nymphal ticks (Ixodes ricinus) on red grouse (Lagopus lagopus scoticus) chicks was inversely related to the adult birds' breeding success and population density. Some chicks less than 14 days old were found apparently blinded and dying probably due solely to very high infestations of tick larvae. In addition, tick-borne louping-ill virus, which is known to kill grouse, was probably an important cause of death of grouse chicks in this study. J. WILDL. MANAGE. 42(3):500-505 Population densities of red grouse dif- fer from area to area, depending largely upon differences in the quantity and quality of their main food, heather (Cal- luna vulgaris) (Watson and Moss 1972). However, some parts of Scotland are in- fested with numerous sheep ticks and Moore (1937) suggested that ticks kill many young grouse. This is also the opin- ion of gamekeepers, who complain that grouse are scarce on moors with many ticks. In this study we tested these sug- gestions by comparing the number of sheep ticks found on red grouse chicks with the mortality rate of the chicks and the breeding success and breeding den- sity of adult grouse. Ticks suck blood and body fluids and cause inflammation at their point of at- tachment. They also transmit louping-ill virus (Flavivirus group), which is patho- genic to red grouse (Reid 1975). Hence the ticks' role as vectors of louping ill may be more important than the harm they do by removing blood and causing inflammation. Ticks occur as larvae,
35 citations
TL;DR: The total proportion of larvae finding a host could be expressed as a function of the product of the host-finding rate and the median duration of survival of the larvae.
Abstract: Experimental and theoretical studies on the rates of host finding by larvae of the cattle tick B. microplus are described. At stocking rates of about two beasts per hectare the cattle picked up between 30 and 70% of the larvae in a week, compared with 50 to 85% with five beasts per hectare. Each beast effectively picked up all the ticks from an area of 0.022-0.075 ha each day. The lower values were associated with lower minimum temperatures, a phenomenon which was attributed to reduced activity of the larvae. A simplified model was developed to investigate the sensitivity of the host-finding component of the tick's life system to the parameters controlling the process. It was found that the total proportion of larvae finding a host could be expressed as a function of the product of the host-finding rate and the median duration of survival of the larvae. Pasture spelling for tick control was also considered in relation to the parameters of the model.
34 citations
TL;DR: It is suggested that major physiological changes occur in the salivary glands of I. holocyclus on the third day, which once stimulated continue independently of feeding as well as in ticks fed upon hosts with a previous experience of tick feeding.
28 citations
TL;DR: Nairobi sheep disease was seen principally upon movement of susceptible animals into the enzootic areas and did not occur in epizootic form during the period under consideration.
Abstract: Nairobi sheep disease was seen principally upon movement of susceptible animals into the enzootic areas. This occurred most frequently for marketing purposes near the main centres of population. Other outbreaks followed local breakdowns in tick control measures. The disease did not occur in epizootic form during the period under consideration. Nairobi sheep disease was isolated from pools of Rhipicephalus appendiculatus but not from many pools of other tick species. No virus was isolated from the blood or tissues of a range of wild ruminants and rodents.
28 citations
TL;DR: This report documents the first reported case of ECM acquired in this country in which the tick that caused the disease has been recovered, and an elevated measles titer with a twofold drop on serial determinations was of interest.
Abstract: • Erythema chronicum migrans (ECM) developed in a man after a tick bite; the tick was probablyIxodes pacificus. Despite extensive laboratory evaluation, including bacterial culture of involved skin, viral and rickettsial titers, biopsy and special stains, animal inoculation, and electron microscopy, the causal agent could not be identified. Although probably unrelated, an elevated measles titer with a twofold drop on serial determinations was of interest. To our knowledge, this report documents the first reported case of ECM acquired in this country in which the tick that caused the disease has been recovered. (Arch Dermatol114:253-254, 1978)
TL;DR: Only two species of tick (Ixodes hexagonus and Ixodes canisuga) were found to infest suburban foxes, and even an abnormally high level of infestation found on one fox was not considered to be lethal.
Abstract: Only two species of tick (Ixodes hexagonus and Ixodes canisuga) were found to infest suburban foxes The populations of these two ticks were examined, their distributions within the host population described, and infestation levels of I hexagonus discussed in relation to the sex, age and behaviour of the host The most important factor regulating the level of tick infestation is probably the degree of den usage by the host The tick infestations were found to have minimal effect on the host, and even an abnormally high level of infestation found on one fox was not considered to be lethal
TL;DR: Developmental forms of 2 strains of Babesia bovis were studied in the tick vector Boophilus microplus, and it was suggested that continuous blood passaging of the NT strain had resulted in selection of parasites incapable of penetrating gut epithelial cells of the tick.
Abstract: SYNOPSIS. Developmental forms of 2 strains of Babesia bovis (Babes) were studied in the tick vector Boophilus microplus (Canestrini). One strain (designated T) was shown to be infective for the tick, and the other (NT) to have lost infectivity for the tick, because of repeated blood passaging in cattle.
Parasites of the 2 strains in gut contents of adult female ticks were similar during the first 16 h post-repletion (PR), but thereafter their structure differed. From 16–64 h PR, the majority of T strain parasites were spherical and without processes. During the next 32 h elongate forms and vermicules developed. Fission bodies were seen within epithelial cells of the gut by 96 h PR. T-strain parasites in gut contents decreased in number from ∼ 96 h and were difficult to find at 144 h, the time of the final observation.
In contrast, NT strain parasites were plentiful throughout the period of observation. They were predominantly spherical, ranging in diameter from 1.5 to 15 μm. Forms with obvious processes measuring up to 81 μm in length were seen in large numbers at seemingly regular intervals from 16–144 h PR, suggesting that a process of development and divisions was being repeated. No vermicules or fission bodies were seen.
T-strain, but not NT strain parasites, were seen in hemolymph and ova of the ticks and in their larval progeny. It is suggested that continuous blood passaging of the NT strain had resulted in selection of parasites incapable of penetrating gut epithelial cells of the tick.
TL;DR: The severity of tick-induced babesiosis was related to the age of the experimental calves, with more severe reactions and high mortality occurring among older animals, and there would seem to be no objection to using a controlled tick-borne challenge in the laboratory for assessment of susceptibility.
TL;DR: Because of the potential for a fatal outcome, it is imperative to consider tick paralysis in any child with an ascending flaccid weakness or acute ataxia.
Abstract: Reviewed are 3 cases of tick paralysis in children each with a different presentation. One child presented with an ascending flaccid weakness, another with weakness and cerebellar signs, and a third with pure cerebellar signs. Ixodes scapularis, the black-legged deer tick, was the offending tick in Case 3 and apparently has not been previously reported to cause paralysis in humans. Because of the potential for a fatal outcome, it is imperative to consider tick paralysis in any child with an ascending flaccid weakness or acute ataxia.
Journal Article•
TL;DR: An 8% fenvalerate (snythetic pyrethroid) impregnated ear tag was at least equal in controlling Amblyomma maculatum Koch on cattle to those containing 15% stirofos and 10% chloropyrifos, which had been highly effective in extensive evaluations in prior years.
Abstract: An 8% fenvalerate (snythetic pyrethroid) impregnated ear tag was at least equal in controlling Amblyomma maculatum Koch on cattle to those containing 15% stirofos and 10% chloropyrifos, which had been highly effective in extensive evaluations in prior years.
The residual effect of the stirofos impregnated ear tag was adequate to protect animals’ ears from ticks for 11 wks, but when the ear tag was applied 6 wk early, it caused only marginally satisfactory control against a heavy tick population.
TL;DR: Four genera of cattle ticks were found and identified during two tick surveys: Amblyomma, Boophilus, Hyalomma and Rhipicephalus, and the territorial distribution of the ticks is discussed.
TL;DR: It is surprising that some virus-like particles observed during an ultrastructural study of the salivary gland of the cattle tick Boophilus microplus seem to damage the cytoplasm of infected cells, and in extreme cases even to affect the secretory competence of thesalivary glands.
Abstract: TICK-BORNE viruses are generally transmitted into the host's vascular system in infected salivary secretions1, and it was to be expected that virus-like particles (VLPs) would be observed during an ultrastructural study of the salivary gland of the cattle tick Boophilus microplus. But it is surprising that some of these particles, which, are described here, seem to damage the cytoplasm of infected cells, and in extreme cases even to affect the secretory competence of the salivary glands. In view of the economic and medical importance of these arthropods, viruses pathogenic to ticks could have a potential as biological control agents.
01 Jan 1978
TL;DR: Tick infestation occurs over 1.3 x 106 km2 in northern Australia and has been difficult to estimate the economic effects of ticks due to a lack of information on their effects on growth and reproduction.
Abstract: Tick infestation occurs over 1.3 x 106 km2 in northern Australia. It has been difficult to estimate the economic effects of ticks due to a lack of information on their effects on growth and reproduction (Anon 1975).
12th Biennial Conference. February 1978. Melbourne, Victoria
TL;DR: A direct correlation between the infectivity of the ticks and the volume of T. annulata -infected blood sucked by them during their preceding instars is suggested.
TL;DR: The results support the hypothesis of cholinergic neurotransmitter involvement in the overall nervous control of ixodid tick salivary gland function and suggest that normal salivARY gland function is disrupted.
Journal Article•
TL;DR: The microsporidian experimentally inoculated into the hemocele of half-engorged females of D. reticulatus caused acute infection and death of the host and the importance of Nosema infection in ticks in nature is discussed.
Abstract: A total of 6,199 adult ticks (Haemaphysalis intermis, Dermacentor reticulatus, D. marginatus and Ixodes ricinus) collected in three localities in Slovakia were examined for microsporidian infection. The spores of Nosema slovaca were found in six D. reticulatus (0.097%). The microsporidian experimentally inoculated into the hemocele of half-engorged females of D. reticulatus caused acute infection and death of the host. The infection can be transmitted also to other tick species from the same region. The yield of spores from one tick ranges from 3 X 10(5) to 52 X 10(7) depending on the infection dose and tick species. Peroral infection of some butterfly larvae with the microsporidian pores was unsuccessful. The importance of Nosema infection in ticks in nature is discussed.
Journal Article•
Journal Article•
01 Dec 1978-Journal of The South African Veterinary Association-tydskrif Van Die Suid-afrikaanse Veterinere Vereniging
TL;DR: A series of in vitro trails confirmed resistance in the three-host tick, Amblyomma hebraeum Koch, to the organophosphorus ixodicides, dioxathion, chlorfenvinphos, quintiofos, bromophos-ethyl and a dioxATHion/chlorfenvinPhos combination.
Abstract: A series of in vitro trails confirmed resistance in the three-host tick, Amblyomma hebraeum Koch, to the organophosphorus ixodicides, dioxathion, chlorfenvinphos, quintiofos, bromophos-ethyl and a dioxathion/chlorfenvinphos combination. The results of a routine survey showed that a resistance factor of greater than 100x was present in the offspring of ticks in six of 115 field isolates tested. These six isolates were confined to the lowveld areas of the province of Natal, Republic of South Africa, and Swaziland. Ticks in a further 59 isolates were less susceptible than the reference strain. Resistance was present in all three tick instars. This is the first recorded resistance to the organophosphorus group of ixodicides by multi-host ticks in Africa.
TL;DR: Two siblings with Rocky Mountain spotted fever are described, which was diagnosed in an nonendemic area, Wisconsin, and the younger sibling, a 6-month-old, contracted the disease in infancy, an event infrequently recorded but apparently associated with marked morbidity and mortality.
Abstract: The incidence of Rocky Mountain spotted fever (RMSF) in the United States has been increasing over the past 15 years. 1 This disease had noticeable seasonal and geographic predilection, being most prevalent in the spring and summer and in the southeastern United States. 1 About 70% of the cases occur in children 3 to 15 years of age. 2 The purpose of this report is to describe two siblings with the disease, which was diagnosed in an nonendemic area, Wisconsin. The younger sibling, a 6-month-old, contracted the disease in infancy, an event infrequently recorded but apparently associated with marked morbidity and mortality. 3-5 Report of Cases . —Case1.—In May 1977, this 6-month-old male infant visited relatives in northern Mississippi. Twelve days before admission, fever and a generalized maculopapular rash developed. He was exposed to a neighbor's dog known to have ticks, but had no known tick bites. He slept