Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLEAS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,747 records · Page 97Linked to original sources
PubMed2003

New perspectives about Hemotrophic mycoplasma (formerly, Haemobartonella and Eperythrozoon species) infections in dogs and cats.

The new perspectives about hemotrophic mycoplasma infections in cats and dogs can be summarized as follows: Haemobartonella and Eperythrozoon species infecting the dog and cat have been reclassified as mycoplasmal parasites and given the names M haemofelis (Ohio or large form of H felis), M haemominutum (California or small form of H felis), and M haemocanis (H canis). The prevalence of hemotrophic mycoplasma infections in anemic cats in the United States is about 25% and usually involves M haemofelis. However, nonanemic cats may also be infected most commonly with M haemominutum. Chronic infections with hemotrophic mycoplasmas may promote myeloproliferative disorders in FeLV-infected cats. M haemocanis infection in dogs may be a widespread latent disease in kennel-raised dogs and is being investigated. The PCR assay is exquisitely sensitive for detection of M haemofelis and M haemominutum, and testing of blood donor cats and perhaps dogs should be done regularly. Fleas are involved in the transmission of M haemofelis to the cat, whereas R sanguines may be involved with transmission of M haemocanis to the dog. Treatment with doxycycline effectively controls acute infection in the cat and dog, and enrofloxacin may also be effective in the cat, but none of the antibiotics tested to date consistently clears the parasites.

Animals↗
PubMed2005

Toxicity and hazard assessment of fipronil to Daphnia pulex.

Hazard assessments based on two measures of toxicity were conducted for the water flea, Daphnia pulex (Leydig) exposed to the insecticide, fipronil. The measures of toxicity obtained were 48 h acute lethal concentration estimates, and a direct measure of population growth rate, the 10-day instantaneous rate of increase (r(i)). Additionally, life tables were developed after exposure to several concentrations to tease out the apparent sublethal effects of this insecticide to D. pulex. The acute LC(50) was estimated to be 0.0156 (0.0088-0.083) mg/L. In the 10-day population growth rate study, extinction of D. pulex populations occurred after exposure to 0.08 mg/L of fipronil, which was equivalent to the 48 h acute LC(75). The NOEC and LOEC for population size after a 10-day exposure to fipronil were 0.03 and 0.05 mg/L, respectively. An expected environmental concentration (EEC) in freshwater lakes/ponds based on an application rate of 250 mg ai/ha (recommended rate for use in Tephritid fruit fly control programs) was estimated to be 0.00017 mg/L. Hazard assessments were developed by dividing the EEC by the LC(50) and NOEC for population size. The assessments based on the LC(50) and NOEC for population size were 0.011 and 0.0057, respectively, indicating that fipronil does not pose a hazard to D. pulex when applied at the rates recommended for control of Tephritid fruit flies. Life tables were developed after exposure to two insecticide concentrations and a control. Exposure to 0.015 mg/L, the approximate 48 h acute LC(50), resulted in only a slight decrease in the net reproductive rate (R(o)), birth rate (b), and intrinsic rate of increase (r(m)) and an increase in generation time (T), death rate (d), and doubling time (DT) compared to the control. Exposure to 0.03 mg/L, the approximate 48 h acute LC(60), and NOEC in the 10-day study, resulted in a 57% decline in the net reproductive rate, a 1.45-fold decrease in birth rate, a 1.5-fold decrease in the intrinsic rate of increase, a 6-day increase in generation time, a 4-fold increase in death rate, and a 1.5-fold increase in doubling time. The stable age distribution (after 60 days) of D. pulex changed after exposure to fipronil. Increasing concentrations of fipronil resulted in a decrease in the percentage of individuals in the first, second, third, and fourth juvenile stages, an increase in the adult stage, and no change in the adolescent stage. These results indicate that certain concentrations of fipronil approaching the LC(50) can negatively affect population parameters of D. pulex, but that EECs, at least for fruit fly control, should be lower than the concentration necessary to cause damage.

Animals↗
PubMed2006

Parasitogenic alterations of vector behaviour.

In many parasite-vector systems, alterations of the behaviour of the blood-sucking arthropods result in an increase of the transmission rate, but the underlying mechanisms are elucidated in only some systems. The more sluggish movements of the Trypanosoma rangeli-infected triatomine Rhodnius prolixus might increase the rate of predation by insectivorous mammals but also the transmission rate between the triatomines via cannibalism. Alterations of the feeding behaviour by which the number of attacks on hosts by blood-sucking arthropods can be increased seem to derive from two possible mechanisms. A competition for metabolites in the ingested blood induces an earlier starvation effect than in non-infected specimens and thus a new attempt by the insect to ingest blood. This may be relevant in T. cruzi-infected triatomines. Perhaps this is also the reason for the increased activity of ticks infected with the tick-borne encephalitis virus, resulting in a higher infection rate of ticks collected on humans than from the vegetation. The second, better elucidated mechanism is interference with the ingestion process, which causes a higher number of probings and low ingestion rates and is connected with disturbances of the digestive tract. Cells of the salivary glands are destroyed by the penetration of the parasites in Plasmodium-infected mosquitoes, T. rangeli-infected Rhodnius, and tsetse flies infected with salivarian Trypanosoma species. Some of the latter species attach to mechanoreceptive sensilla, which act as fluid flow meters and/or reduce the diameter of the foregut by a heavy colonization. This colonization effect is even more evident in several Leishmania-sandfly systems and in Yersinia pestis infection of the rat flea.

Animals↗
PubMed2005

Australian ecosystems, capricious food chains and parasitic consequences for people.

Characteristic Australian ecosystems or environments contain numerous food chains some of which may become capriciously side-tracked or appropriated by humans, with parasitic consequences for people in Australia and overseas. Twelve of 13 arboviruses affecting humans are of wildlife origin and all are transmitted by mosquitoes. In this case, transmission is thus associated with aquatic environments, many artificial. Zoonotic trematode (brachylaimiasis) and cestode (rodentoleposis) infections have been reported from semi-arid environments. Scabies and angiostrongylosis are associated with work, recreational and home environments. Four species of Rickettsia endemic in wildlife are acquired by humans from fleas, mites and ticks in bush and semi-urban environments. The enigmatic and life-threatening muspiceoid nematode, Haycocknema perplexum, is known from people associated with the natural environment in Tasmania; whether it comes from vertebrates, invertebrates, plants, soil or water is unknown. Food chains occurring in a range of Australian ecosystems and environments, some associated with feeding arthropods, others with accidental ingestion of invertebrates, may result in human exposure and infection. A range of organisms normally occurring in wildlife, domestic animals or the environment may be involved in causing human disease.

Animals↗
PubMed2004

Prevention of arthropod-related disease.

Arthropods of medical importance include vespids, ticks, mosquitoes, mites, flies, and fleas. They spread illness as disease vectors, are associated with lethal allergic reactions, and produce potentially deadly toxins. Strategies for prevention of illness include avoidance, vector reduction programs, chemoprophylaxis, and repellents. Strategies must be tailored to regional risks.

Anaphylaxis↗
PubMed2004

Ethnobotanical survey and testing of plants traditionally used against hematophagous insects in Eritrea.

An ethnobotanical study was conducted to find plants traditionally used against nuisance insects in three regions of Eritrea: highland, eastern escarpment and wet lowland. Six plants were collected, two of them were reported to be used against mosquitoes (Ocimum forskolei, Lamiaceae and Nicotiana glauca, Solanaceae), two others against fleas (Salvia shimperi, Lamiaceae and Otostegia integrifolia, Lamiaceae) and Neorautanenia mitis (Fabaceae) and Calpurnea aurea (Fabaceae) against animal lice. The effect of fresh leaves and shoots of O. forskolei hanging on walls at the head and foot of beds was tested in Eritrea against Anopheles arabiensis and 53% reduction in mean number of mosquitoes per house was achieved. Blood meals of mosquitoes collected from houses and pit shelters were analysed to determine whether biting diversion occurred due to the use of plants in the houses. No diversion of biting was observed to goats, which are abundant in the test area. Hot water distillates of N. glauca, S. schimperi and O. integrifolia were tested against An. gambiae s.s. in the laboratory using a Hemotek membrane blood feeder with pig skin replacing the parafilm membrane. The approximate doses in microl/cm(2) for 50% repellency with the extracts of S. schimperi, N. glauca and O. integrifolia were 0.97, 1.72 and 2.44, respectively. Even though the plants only achieved partial protection, they have a potential for widespread use as a complement to other control methods.

Adult↗
PubMed2006

Prevalence of selected infectious disease agents in cats from Arizona.

The objective of this study was to use polymerase chain reaction (PCR) assays to determine the prevalence of Ehrlichia species, Anaplasma phagocytophilum, Mycoplasma haemofelis, 'Candidatus Mycoplasma haemominutum' and Bartonella species from feral and relinquished cats in Phoenix and Nogales, Arizona. DNA from one or more of the organisms was amplified from 31 of 112 blood samples (27.7%). DNA consistent with Bartonella clarridgeiae 15 (13.4%), Bartonella henselae 14 (12.5%), 'Candidatus M haemominutum' 9 (8.0%), and M haemofelis 5 (4.5%) were detected. DNA of Ehrlichia species, Neorickettsia risticii, or A phagocytophilum was not amplified. Failure to amplify DNA of A phagocytophilum may relate to the absence of appropriate tick vectors. Failure to amplify Ehrlichia species DNA suggests that cats were not exposed, exposed but not infected, or infected but the DNA was not detected by the PCR assay used in this study. The Bartonella species and hemoplasma results suggest flea control should be maintained.

Anaplasma phagocytophilum↗
PubMed2006

Prevalence of Bartonella henselae antibodies in serum of cats with and without clinical signs of central nervous system disease.

Bartonella henselae is occasionally associated with neurological dysfunction in people and some experimentally infected cats. The purpose of this study was to determine whether B henselae seroprevalence or titer magnitude varies among cats with neurological disease, cats with non-neurological diseases, and healthy cats while controlling for age and flea exposure. There was no difference in B henselae seroprevalence rates between cats with seizures and cats with other neurological diseases. Cats with non-neurological disease and healthy cats were more likely than cats with neurological disease to be seropositive. While the median B henselae antibody titer was greater in cats with seizures than in cats with other neurological disease, the median B henselae antibody titer was also greater in healthy cats than cats with seizures. The results suggest that titer magnitude cannot be used alone to document clinical disease associated with B henselae infection and that presence of B henselae antibodies in serum of cats with neurological disease does not prove the clinical signs are related to B henselae.

Animals↗
PubMed2006

Density-dependent effects of prey defenses and predator offenses.

Defenses protect prey, while offenses arm predators. Some defenses and offenses are constitutive (e.g. tortoise shells), while others are phenotypically plastic and not always expressed (e.g. neckteeth in water fleas). All of them are costly and only adaptive at certain prey densities. Here, I analyse such density-dependent effects, applying a functional response model to categorize defenses and offenses and qualitatively predict at which prey densities each category should evolve (if it is constitutive) or be expressed (if it is phenotypically plastic). The categories refer to the step of the predation cycle that a defense or offense affects: (1) search, (2) encounter, (3) detection, (4) attack, or (5) meal. For example, prey warning signals such as red coloration prevent predator attacks and are hence step 4 defenses, while sharp predator eyes enhance detection and are step 3 offenses. My theoretical analyses predict that step 1 defenses, which prevent predators from searching for their next meal (e.g. toxic substances), evolve or are expressed at intermediate prey densities. Other defenses, however, should be most beneficial at low prey densities. Regarding predators, step 1 offenses (e.g. immunity against prey toxins) are predicted to evolve or be expressed at high prey densities, other offenses at intermediate densities. I provide evidence from the literature that supports these predictions.

Animals↗
PubMed2004

Priming by natural category membership in the left and right cerebral hemispheres.

The cerebral representation of category information was examined in a single word priming paradigm, during which the N400 component of the event-related potential (ERP) was recorded. The visual half-field paradigm was employed in order to selectively stimulate the two hemispheres. To investigate which aspects of category membership are relevant in producing priming, two types of related stimuli were presented. In one condition pairs of exemplars had a higher amount of feature overlap (e.g., MOSQUITO-FLEA) than in the other (e.g., SOFA-VASE). Significant priming was obtained only for stimuli in the high feature overlap condition and then only when these were presented to the left visual field (LVF)/right hemisphere (RH). This finding was interpreted within our recent model of semantic memory wherein the right hemisphere represents items on the basis of distributed individual features, whereas the left hemisphere (LH) represents semantic information locally, within a spreading activation system, where priming occurs exclusively through associative links. It was concluded that knowledge regarding category membership is maintained in the RH, on the basis of feature coding.

Adolescent↗
PubMed2004

Seroprevalence of and risk factors for Bartonella henselae and Bartonella quintana infections among pet cats in Jordan.

To determine the seroprevalences of Bartonella henselae and Bartonella quintana antibodies in Jordanian pet cats, serum samples from 153 cats from three geographical regions were analyzed. Seroprevalences were determined by indirect immunofluorescence. The true seroprevalences to B. henselae and B. quintana were 32 and 1.5%, respectively. The seroprevalence of B. henselae-specific antibodies in cats from northern Jordan was significantly higher than in cats from the central or southern parts of Jordan. The seroprevalence to B. henselae increased to age 2 years. Odds of seropositivity were higher in cats living outdoors, showing hunting behavior, having a flea infestation and of a mixed breed. No association was detected with sex.

Animals↗
PubMed2005

Generation of therapeutic antibody responses against IgE in dogs, an animal species with exceptionally high plasma IgE levels.

Allergic diseases are common in dogs and the involvement of IgE in the pathogenesis of canine atopic dermatitis (CAD) and flea allergy dermatitis (FAD) is documented. However, many dogs do not achieve sufficient control of their allergic disease, and there is a great need for new treatment strategies. In order to address this issue we first needed to obtain a better picture of IgE-levels in dogs and how plasma IgE-levels are affected by breed, age and health status. IgE is normally present at diminutive concentrations in sera and detection by diagnostic methods has been a technical challenge. Here, we present a new in vitro assay for determining absolute levels of total IgE in sera from dogs. In a panel of 76 adult dogs diagnosed either as healthy or suffering from atopic dermatitis, autoimmunity or infection by skin parasites, we show that levels of IgE range from 1 to 41 microg/ml. This is almost 100 times the level observed in non-atopic humans. However, these exceptionally high IgE-levels in the dogs could not be correlated to either breed or health status. To address the issue of novel treatment strategies, the possibility of reducing the IgE-levels in nine Beagle dogs by immunization with a new therapeutic vaccine was investigated. High levels of anti-IgE antibodies were induced in all dogs, and the IgE-levels were subsequently decreased by a mean of 65%. This shows that the allergy vaccine is potent enough to break the tolerance against IgE, even when the initial IgE-levels are as high as those observed in dogs. Thus, the vaccination treatment may have the potential to serve as a future therapy for dogs with atopic diseases.

Age Factors↗
PubMed2005

Canine visceral leishmaniasis in São José de Ribamar, Maranhão State, Brazil.

Here, we describe the situation of canine visceral leishmaniasis in two villages of São José de Ribamar in Maranhão State/Brazil, where human cases have been registered. Blood samples of 36 household crossbred dogs from Sergio Tamer village and 43 dogs from Quinta village were collected and the serum used for serological diagnosis. An Indirect Fluorescent Antibody Test (IFAT) and enzyme-linked immunosorbent assay (ELISA) were used to detect antibodies against Leishmania. The clinical examination showed that 25% of the canine population of Quinta presented a poor body condition and in 39%, ectoparasites (ticks and fleas) were detected. In both tests, serology revealed that 21% (9 out of 43) of the dogs presented antibodies against Leishmania (55% were asymptomatic and 45% were symptomatic). In the Vila Sérgio Tamer, 25% (9 out of 36) of the dogs were seropositive for Leishmania (66.67% were asymptomatic and 33.33% were symptomatic), 33% presented poor body condition, and 22% have ectoparasites. The clinical signs more frequent were skin lesions. The statistical analysis showed that there was no statistical difference (p>0.05) between the seropositivity of the dogs from the two villages. The same was observed when the clinical signs were compared (p>0.05). Both villages have favorable conditions to maintain the cycle of leishmaniasis.

Animals↗
PubMed2006

Ectoparasites of free-ranging pumas and jaguars in the Paraguayan Chaco.

Ectoparasites were collected from seven puma (Puma concolor) and seven jaguar (Panthera onca) live-captures (each representing six different animals) in the Paraguayan Chaco from 2002 to 2004. The same five species of ectoparasites were recovered from both host species: the flea, Pulex simulans (total on both hosts combined=30 male, 49 female), and the ticks, Amblyomma cajennense (1 male, 4 female, 46 nymphs, 241 larvae), Amblyomma parvum (42 male, 25 female), Amblyomma tigrinum (1 male, 7 female, 34 larvae) and Amblyomma triste (4 male). There were no statistical differences between the prevalences (percent of hosts infested) for any of these ectoparasite species between the two host species, and only P. simulans showed a significantly higher mean intensity (mean no. of each ectoparasite species per infested host) on one of the host species (jaguar). Clearly, these two large carnivores share similar ectoparasite faunas in the Paraguayan Chaco. However, both carnivores occupy large geographical distributions in the New World and this study, combined with the few previous studies, suggests that their ectoparasite faunas differ slightly in different parts of their respective ranges.

Animals↗
PubMed2006

Accuracy of an anaemia scoring chart applied on goats in sub-humid Kenya and its potential for control of Haemonchus contortus infections.

We tested the practical application of an anaemia scoring chart (the FAMACHA chart) as a method for controlling Haemonchus contortus in goats kept under smallholder conditions in a sub-humid area of Central Kenya. The objectives were: (1) to test the accuracy of the FAMACHA chart in identifying anaemic goats (PCV< or =18); (2) to quantify the proportion of goats left untreated at farm level when using the chart. On each of two farms, Small East African goats of various ages were allocated to two treatment groups; a FAMACHA group (F1 (n=34) and F2 (n=31) on farms 1 and 2, respectively) and a control group (C1 (n=34) and C2 (n=30)). In F1 and F2 goats with a FAMACHA score of 3, 4 or 5 were treated with anthelmintic after scoring. In C1 and C2 goats were treated every 4 weeks from 15 February to 20 July. Every 2 weeks all goats were scored with the FAMACHA chart and weighed. Furthermore, faecal samples were collected for faecal egg counts (FEC) and blood samples were collected for packed cell volume (PCV) determination. H. contortus was found to be the predominant nematode on both farms. The mean FECs were higher on farm 1 compared to farm 2, while in contrast the mean PCV levels were lowest on farm 2. The latter was most likely due to the presence of Fasciola spp., flea and tick infections on farm 2. The accuracy of the chart was evaluated by using PCV as the gold standard for anaemia (PCV< or =18%). The mean percentage of false-negative scorings per sampling was 0.7% on farm 1 and 1.6% on farm 2, while the mean percentage of false-positive scorings was 9.7% and 21.4%, respectively. It is most likely that the accuracy of the chart was negatively affected by the concurrent parasite infections on farm 2. The mean proportion of untreated goats per sampling was 89% and 77% on farm 1 and farm 2. It was concluded that the FAMACHA chart can be a valuable tool for decision-making in control of H. contortus in goats kept under smallholder conditions, without morbidity or mortality unacceptable to the farmer. The application may further reduce the risk of development of anthelmintic resistance by increasing refugia. However, caution should be taken under conditions where other anaemia-causing parasites are present (e.g. Fasciola spp. and ecto-parasites), since this possibly decreases the accuracy of the FAMACHA chart.

Anemia↗
PubMed2006

Cloning and characterization of the retinoid X receptor from a primitive crustacean Daphnia magna.

Terpenoid hormones function as morphogens throughout the animal kingdom and many of these activities are mediated through members of the retinoid X group of nuclear receptors (RXR; NR2B). In the present study, RXR was cloned from the water flea Daphnia magna, a primitive crustacean of the class Branchiopoda, and characterized with respect to phylogeny, developmental expression, and hormonal regulation. The full length daphnid RXR cDNA was cloned by initial PCR amplification of a cDNA fragment from the highly conserved DNA-binding domain followed by extension of the fragment using RACE PCR. The full length cDNA was 1888 base pairs in length and coded for a 400 amino acid protein that exhibited the five-domain structure of a nuclear receptor superfamily member. The RXR protein shared significant identity with other NR2B group members. Phylogenetic analyses of the ligand-binding domain of the receptor revealed that daphnid RXR clustered with RXR from decapod crustaceans on a branch of the phylogenetic tree that was distinct from RXRs known to bind retinoic acids and juvenile hormones. Daphnid RXR mRNA levels were greatest in embryos that were early in development and progressively declined through the initial five stages of embryo development. Adult females expressed higher levels of RXR mRNA than did males and exposure of females to the terpenoid mimic pyriproxyfen reduced RXR mRNA to levels approaching levels in males. RXR mRNA levels in males were refractory to pyriproxyfen. These results show that branchiopod crustaceans dynamically express RXR which should be evaluated as a candidate receptor for the terpenoid hormone methyl farnesoate which functions as a sex determinant in these organisms.

Amino Acid Sequence↗
PubMed1988

Radioactive artifacts: historical sources of modern radium contamination.

Radium has been distributed in a wide variety of devices during the early part of this century. Antique objects containing significant amounts of radium turn up at flea markets, antique shows, and antique dealers, in a variety of locations. These objects include radium in devices which were used by legitimate medical practitioners for legitimate medical purposes such as therapy, as well as a wide variety of "quack cures." These devices may contain anywhere from a few nanocuries to as much as several hundred microcuries of radium. In addition to medical sources, a large variety of scientific instruments utilize radium in luminous dials. These instruments include compasses, azimuth indicators, and virtually any object which might require some form of calibration. In addition, the consumer market utilized a large amount of radium in the production of wrist watches, pocket watches, and clocks with luminous dials. Some of these watches contained as much as 4.5 microCi of radium, and between 1913 and 1920 about 70 gm was produced for the manufacture of luminous compounds. In addition to the large amount of radium produced for scientific and consumer utilization, there were a number of materials produced which were claimed to contain radium but in fact did not, further adding to the confusion in this area. The wide availability of radium is a result of the public's great fascination with radioactivity during the early part of this century and a belief in its curative properties. A number of objects were produced in order to trap the emanations of radium in water for persons to drink in order to benefit from their healing effects. Since the late 20s and early 30s the public's attitude towards radiation has shifted 180 degrees and it is now considered an extremely dangerous and harmful material. However, even as late as the 1950s, there were still some items produced containing radioactivity which today would be unthinkable. The "Buck Rogers Mystery Ring" of the 1950s was activated with polonium. With the shift in public attitudes towards radioactivity, and increasing problems in disposal of radioactive materials, the disposal of radium presents a particularly perplexing problem. The radium which was produced in the early part of the century is still around in various forms and is extremely difficult to dispose of. All objects discovered claiming to contain radium should be taken seriously and should be properly surveyed.(ABSTRACT TRUNCATED AT 400 WORDS)

Equipment and Supplies↗