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At least 127 records · Page 7Linked to original sources
PubMed2004

Zoonotic Babesia: possibly emerging pathogens to be considered for tick-infested humans in Central Europe.

The three host-tick Ixodes (I.) ricinus is regarded as an important vector of tick-borne microorganisms pathogenic for humans in central Europe and is primarily known as the main vector of Borrelia (B.) burgdorferi and the virus causing tick-borne encephalitis (TBE), the most clinically relevant tick transmitted pathogens for humans in European countries. Furthermore, it is now well established that I. ricinus also transmits Ehrlichia (E.) phagocytophila, Babesia (Ba.) divergens, and Ba. microti, all agents of zoonotic infections in dear, sheep, cattle, dogs, and horses. In addition to their known zoonotic potential, recent molecular-epidemiological and seroepidemiological surveys as well as increasingly reported clinical cases of infections caused by these tick-borne organisms other than B. burgdorferi (TOBB) also strongly suggest a possible relevance of Babesia, Ehrlichia and Rickettsia for humans at risk in Europe. However, there are few medical microbiological investigations and epidemiological data on the distribution and relevance of Babesia for humans in our part of the northern hemisphere. There is also very little diagnostic and clinical knowledge on human babesiosis in many regions of Europe. Furthermore, sophisticated diagnostic tools designed for the reliable detection of the underlying pathogens, are not yet generally available to the microbiological laboratory. This review aims to provide basic information on human babesiosis and the most relevant causative pathogens of the disease in Europe and to draw attention to this parasitic infection as a possibly emerging and probably under-diagnosed disease in this part of the northern hemisphere.

Animals↗
PubMed1986

Tick infestation simulating a traumatized, papillomatous nevus.

A patient is described who had a five-week history of agonizing pain in a "mole" on his left inner thigh that clinically was thought to be a traumatized, papillomatous nevus. Biopsy disclosed the presence of the body parts of a hard tick. Much has been written about ticks as agents or vectors of disease. This case demonstrates the less well-described ability of a blood-engorged tick to clinically simulate a traumatized or infarcting skin growth, and it represents the second reported case of the development and persistence of a tick bite nodule following complete surgical removal of all tick parts.

Animals↗
PubMed1975

Transstadial transmission of Theileria annulata through common ixodid ticks infesting Indian cattle.

Transstadial transmission of Theileria annulata with Hyalomma anatolicum anatolicum, H. dromedarii and H. marginatum isaaci, and Haemaphysalis bispinosa, Rhipicephalus haemaphysaloides haemaphysaloides and Boophilus microplus was determined. It was found that the infection was successfully transmitted by H. a. anatolicum from larva to nymph and nymph to adult in all attempts. When larvae were fed on an infected calf the succeeding adults transmitted the infection when the intervening nymphs fed on a rabbit (non-susceptible host) but not when fed on a calf (susceptible host). Infective adult ticks transmitted the parasite during the first 24 h of feeding on a calf. When the feeding was interrupted after 24 h, and the tick transferred to another calf, the infection was transmitted to the latter as well. H. dromedarii successfully transmitted the infection from larva to nymph and from nymph to adult. Larvae of H. marginatum isaaci did not feed on calves but the infection was successfully transmitted from nymph to adult. Haemaphysalis bispinosa, Rhipicephalus h. haemaphysaloides and Boophilus microplus did not transmit Th. annulata from larva to nymph to adult.

Animals↗
PubMed1995

Mechanisms of eosinophilia in mice infested with larval Haemaphysalis longicornis ticks.

Infestation of larval Haemaphysalis longicornis ticks induced a threefold increase of eosinophils in the peripheral blood of normal WBB6F1- +/+ mice 2 days after tick infestation. In genetically mast cell-deficient WBB6F1- W/Wv mice, a threefold increase of blood eosinophils was observed 6 days after the tick infestation. However, marked infiltration of eosinophils was detected in the tick infestation sites of the WBB6F1- +/+ mice but not the WBB6F1- W/Wv mice. When the mast cell deficiency of WBB6F1- W/Wv mice had been rescued locally by intradermal injections of WBB6F1- +/+ mouse-derived cultured mast cells, a rapid increase of blood eosinophils and tissue infiltration of eosinophils were revealed following tick infestation. The intravenous (i.v.) injection of immune spleen or lymph node cells obtained from WBB6F1- +/+ mice 10 days after tick infestation led to significant eosinophilia in naive recipient mice. Treatment with anti-Thy-1.2 or anti-CD4 monoclonal antibody (mAb) and complement (C) completely abolished the eosinophilia; the early response (2 days after tick challenge) is dependent on mast cells at the feeding site, and the late response (6 days after tick challenge) is dependent on T lymphocytes. Since amplified interleukin-5 (IL-5) cDNA was detectable in the spleen cells 4 days after tick infestation, the late response might be mediated by IL-5. The infiltration of eosinophils at the feeding site of skin appeared to be dependent on mast cells.

Animals↗
PubMed1984

Significant changes in epidermal Langerhans cells of guinea-pigs infested with ticks (Dermacentor andersoni).

Resistance to tick feeding has previously been shown to be an acquired, immunologically mediated phenomenon in guinea-pigs, associated with cutaneous basophil hypersensitivity to tick antigens. In this study, Langerhans cells (LC) in the epidermis of guinea-pigs were monitored during tick infestations of susceptible and resistant animals. A specific adenosine triphosphatase (ATPase) staining technique was used to identify epidermal LC. The numbers of LC decreased significantly around the sites of tick attachment during primary infestations. Early in the secondary infestations, increases in numbers of LC were observed in the epidermis surrounding tick mouth-parts. These changes in LC populations resemble those previously described in contact dermatitis reactions of guinea-pigs.

Adenosine Triphosphatases↗
PubMed1985

Effects on cattle of artificial infestations with the tick Rhipicephalus appendiculatus.

Groups of ten cattle were exposed to 0, 40 and 400 adult Rhipicephalus appendiculatus feeding once a week for 24 weeks. Although no differences in cumulative percentage weight gain were found at the end of the experiment, animals free of ticks performed better during the first 12 weeks. A marked recovery of the 400-tick group was recorded during weeks 13-24 and after ticks were removed. Haemoglobin and packed cell volume values were lowered in tick-infested animals but no clear trends were observed in red and white blood cells. No differences between the percentages of ticks feeding in the 2 tick-infested groups on day 2 were observed but higher numbers of females were feeding on the 40-tick group on day 5. More ticks were found on day 5 after tick application to the cattle during weeks 1-6 than in the rest of the experiment. Significant correlations were found between lymph node enlargement and ear damage when they were tested against tick load. R. appendiculatus nymphs feeding on the formerly tick-infested cattle were fewer, lighter and engorged in a shorter time than those on the control animals. The possible causes for the reduction in ticks feeding, the changes in cattle weights, blood composition and development of host resistance are discussed.

Analysis of Variance↗
PubMed1981

The transmission of Babesia bovis in herds of European and Zebu x European cattle infested with the tick, Boophilus microplus.

Transmission of Babesia bovis by the tick Boophilus microplus was studied in 4 breeding herds of European and Zebu x European cattle under different levels of tick infestation. The observations consisted of weekly counts of female ticks on the cattle, monthly serological tests for antibodies to B. bovis, examination of tick larvae from the pasture to determine B. bovis infection rates and comparison of the suitability of paddocks for tick reproduction. The rate of transmission (inoculation rate) was estimated in terms of the daily probability of infection and consisted of the product of the mean daily tick infestation head-1 and the babesial infection rate in tick larvae. The theoretical value of the minimum inoculation rate required to produce stability of babesiosis is 0.01. This value was exceeded only in a herd of European cattle with minimal tick control and grazing on a pasture favourable for tick reproduction. Instability of babesiosis occurred in the other herds of European cattle after tick numbers had been reduced by pasture spelling and strategic dipping and after reduction in the babesial infection rate in ticks apparently caused by unfavourable environmental conditions. Over a period of years, the tick infection rates also declined as a consequence of the reduction in numbers of ticks. The Zebu x European cattle failed to generate inoculation rates greater than the minimum level, even though no tick control measures were applied. This was attributed to lower babesial infection rates in the ticks than those observed in a comparable herd of European cattle and to the high tick resistance of the Zebu crosses which maintained the tick populations at low levels. Both factors combined to produce a low inoculation rate.

Administration, Oral↗
PubMed2006

Dermal mast cell counts in F2 Holstein x Gir crossbred cattle artificially infested with the tick Boophilus microplus (Acari: Ixodidae).

The role of dermal mast cells (DMC) in the host resistance to ticks has been studied but it is not totally explained yet. Studies have proposed that zebuine cattle breeds, known as highly resistant to ticks, have more DMC than taurine breeds. In the present study, we compared the number of adult female ticks Boophilus microplus and the mast cells' countings in the skin of F(2) crossbred Gir x Holstein cattle, before and after tick infestation. F(2) crossbred cattle (n = 148) were divided into seven groups and artificially infested with 1.0 x 10(4) B. microplus larvae and, 21 days afterwards, adult female-fed ticks attached to the skin were counted. Skin biopsies were taken and examined under light microscopy with a square-lined ocular reticulum in a total area of 0.0625 mm(2) in both the superficial and deep dermis. Results demonstrated that infested F(2) crossbred cattle acquired resistance against the cattle-tick B. microplus probably associated to an increase in the dermal mast cell number. It is concluded that the tick infestation may lead to an environmental modification in the dermis of parasitized hosts due to the massive migration of mast cells or their local proliferation.

Animals↗