Tick killing in situ before removal to prevent allergic and anaphylactic reactions in humans: a cross-sectional study

BACKGROUND: Tick anaphylaxis is a potentially fatal outcome of improper tick removal and management. OBJECTIVE: To investigate whether killing ticks in-situ with ether-containing sprays or permethrin cream, before careful removal by the mouthparts could reduce this risk. METHODS: This was a prospective study at Mona Vale Hospital Emergency Department (ED) in Sydney, New South Wales, over a 6-month period during the peak tick season of 2016. Tick removal methods, allergic/anaphylactic reactions were recorded for patients presenting with ticks in situ or having already removed the ticks themselves. Primary endpoint was allergic/anaphylactic reaction after tick killing/removal. RESULTS: One hundred twenty-one patients met study inclusion criteria. Sixty-one patients (28 known tick-hypersensitive) had ticks killed with Wart-Off Freeze or Lyclear Scabies Cream (5% w/w permethrin) before removal with fine-tipped forceps or Tick Twister. Three patients (2 known tick-hypersensitive) had allergic reactions (5%), none anaphylactic. The 2 known hypersensitive patients suffered reactions during the killing process and the third patient had a particularly embedded tick meaning it could not be removed solely by mouthparts. Fifty patients presented to the ED posttick removal by various methods, none using either fine-tipped forceps or Tick Twister, of which 43 (86%) experienced allergic reactions – 2 anaphylactic. Five patients suffered allergic reactions before presentation despite no attempt at kill or removal, but ticks had likely been disturbed by some other method. Five patients had live ticks removed in ED – 3 refused killing and had no reaction despite 1 having known hypersensitivity; 2 had ticks on eyelids contraindicating killing, 1 with known hypersensitivity but both had allergic reactions post removal. CONCLUSION: Results support killing ticks in-situ before careful removal by mouthparts to reduce allergic/anaphylactic reactions although further research is still required.

¿Dónde está la garrapata? Crucero & casa (resuelto en Atención Primaria) / Where is the tick? Cruise & home (resolved in primary health care)

Trabajar en Atención Primaria supone pensar en las patologías más frecuentes que se dan en nuestro entorno. Un paciente joven que presenta úlceras genitales nos hace pensar en una infección de transmisión sexual. Sin embargo, la falta de respuesta al tratamiento empírico correcto y los resultados de la serología muestran el diagnóstico definitivo: fiebre botonosa mediterránea, con una localización poco común. Debemos recordar que una enfermedad común en nuestro medio puede parecerse a otra igualmente común, por lo que una correcta historia clínica será fundamental para distinguirlas (AU)

Working in primary health care means thinking about the most common pathologies which we encounter in our workplace. A young patient with genital ulcers makes us think of a sexually transmitted infection. However, the lack of response to the correct empirical treatment and serology results show a definitive diagnosis: Mediterranean spotted fever (also known as boutonneuse fever), with a rare location. It should be remembered that a commonly occurring disease in our environment may resemble another equally common one, thus a correct clinical history is fundamental in order to distinguish them (AU)

Retrospective study of 103 presumed cases of tick (Ixodes holocyclus) envenomation in the horse.

OBJECTIVE: Review 103 cases of presumed tick envenomation in horses. DESIGN: Retrospective study. METHOD: Variables, including date of presentation, age, breed, weight, presence of ticks, gait and respiration scores, duration of recumbency, treatment, outcome and complications were recorded. A series of univariable screening tests were performed and used in a multivariable logistic regression model. RESULTS: There were a total of 103 cases affecting 10 breeds, aged between 1 week and 18 years of age. Horses >6 months old and weighing >100 kg had a higher odds of death than those <6 months old and <100 kg. Cases were seen from North Queensland to the central coast of New South Wales and were more likely to present in the warmer months. There was no association between the number of ticks found on an animal and death. Horses with a higher respiratory score had higher odds of dying, but there was no association between gait score and survival. Horses recumbent >120 h after presentation had higher odds of dying. Complications were reported in 35% of horses. The odds ratio for survival was higher for horses receiving >0.5 mL/kg of tick antiserum. Overall, 74% of horses survived. Multivariable modelling was limited by the small sample size. CONCLUSION: In general, tick envenomation in horses follows the geographic distribution of Ixodes holocyclus. Tick antiserum administered at >0.5 mL/kg increases the odds of survival. It would appear that the complications associated with managing a recumbent horse increase the odds of death.

Tick toxicosis in a dog bitten by Ornithodoros brasiliensis.

Ticks are hematophagous parasites of people and animals and are a public health hazard in several countries. They are vectors of infectious diseases; in addition, the bite of some ticks, mainly from the Ornithodoros genus, may lead to local lesions and systemic illness, referred to as tick toxicosis. In this report, we describe a dog bitten by Ornithodoros brasiliensis, popularly known as the mouro tick. The main clinical findings were disseminated skin rash, pruritus, mucosal hyperemia, lethargy, and fever. Laboratory abnormalities 48 hours after the bites occurred included mild nonregenerative anemia, eosinophilia, basophilia, increased serum creatine kinase activity, increased serum C-reactive protein concentration, and prolonged coagulation times. Tick-borne pathogens were not detected by PCR analysis or serologic testing, supporting the diagnosis of a noninfectious syndrome due to tick bite, compatible with tick toxicosis.

Tick toxicity in cats caused by Ixodes species in Australia: a review of published literature.

Tick toxicity in cats caused by Ixodes holocyclus and related species is a common medical condition on the east coast of Australia. Intoxication typically causes a flaccid ascending neuromuscular paralysis and clinical signs can include anxiety, dysphonia, hind limb weakness and/or ataxia, pupillary dilation, respiratory signs and possible bladder voiding dysfunction. Diagnosis is made with a combination of appropriate clinical signs and visualisation of tick(s) on a thorough body search. Cases are classified clinically using a scoring system, which grades neuromuscular weakness and respiratory compromise. The mainstays of treatment are tick removal, administration of tick antitoxin serum and intensive supportive care. Given a prompt and appropriate management regimen, prognosis is good, according to available literature. Most of the literature concerning tick toxicity in cats is anecdotal in nature and an evidence-based review of what is known of this condition has not previously been published.

Effects produced by the feeding of larvae of Ornithodoros aff. puertoricensis (Acari: Argasidae) on laboratory mice.

The clinical picture produced by the feeding of larvae of Ornithodoros aff. puertoricensis on laboratory mice, was studied using different larval infestation protocols that included 30, 40 or 50 larvae per mouse and control uninfested groups. Clinical effects appeared around 72 h of larval feeding, having a first stage characterized by hyperaemia in both nasal and ocular mucosa, followed by respiratory symptoms (96-120 h) and nervous incoordination (120-144 h). No one mouse evidenced paralysis, and nervous symptoms were never observed in animals infested with only 30 larvae. High mortality (commonly up to 70%) was observed in mice with respiratory symptoms, while 100% of animals in the nervous phase died between 168 and 192 h after the beginning of larval feeding. When some infested mice were treated with a solution of Amitraz the larvae were killed and reversion of symptoms was observed. These effects are ascribed to the presence of a toxin in the saliva of the feeding larvae.

Adaptation of ticks to a blood-feeding environment: evolution from a functional perspective.

Ticks had to adapt to an existing and complex vertebrate hemostatic system from being free-living scavengers. A large array of anti-hemostatic mechanisms evolved during this process and includes blood coagulation as well as platelet aggregation inhibitors. Several questions regarding tick evolution exist. What was the nature of the ancestral tick? When did ticks evolve blood-feeding capabilities? How did these capabilities evolve? Did host specificity influence the adaptation of ticks to a blood-feeding environment? What are the implications of tick evolution for future research into tick biology and vaccine development? We investigate these questions in the light of recent research into protein superfamilies from tick saliva. Our conclusions are that the main tick families adapted independently to a blood-feeding environment. This is supported by major differences observed in all processes involved with blood-feeding for hard and soft ticks. Gene duplication events played a major role in the evolution of novel protein functions involved in tick-host interactions. This occurred during the late Cretaceous and was stimulated by the radiation of birds and placental mammals, which provided numerous new niches for ticks to adapt to a new lifestyle. Independent adaptation of the main tick families to a blood-feeding environment has several implications for future tick research in terms of tick genome projects and vaccine development.

Biochemical perspectives on paralysis and other forms of toxicoses caused by ticks.

Tick toxicoses, of which paralysis is the most widespread and dominant form, are important elements of pathogenesis induced by ticks. Tick paralysis is the most widespread and dominant form of tick toxicoses. Non-paralytic forms of tick toxicoses do occur and evidence suggests that these forms of toxicoses are not evolutionary related. While functional significance has been suggested for tick toxins, the advantages for tick survival in general are not clear. This review considers the molecular nature of tick toxins, the possibility that tick toxins have originated more than once independently and whether these toxins could have unrecognized benign functions.

Long QT syndrome in dogs with tick toxicity (Ixodes holocyclus).

OBJECTIVE: To evaluate cardiac electrical function in dogs with tick toxicity. DESIGN: A prospective clinical investigation of 39 client-owned dogs treated for naturally occurring tick toxicity. PROCEDURE: An ECG was performed on each dog on several occasions; at admission to hospital with tick toxicity, 24 h later, at discharge from hospital when clinically normal and approximately 12 months later. RESULTS: The mean QT interval corrected for heart rate (QTc) was prolonged at admission, 24 h and at discharge compared to the QTc measured 12 months later. T wave morphology was altered in dogs at admission. All other parameters were within normal limits. CONCLUSIONS: The prolonged QTc interval and altered T wave morphology of dogs with tick toxicity reflects delayed cardiac repolarisation and is comparable with long QT syndrome (LQTS) in people who are predisposed to polymorphic ventricular tachycardia and sudden death. Resolution of ECG changes lagged behind clinical recovery.

[Toxicoses of ticks (Acari: Ixodida)]. / Toksykozy kleszczowe (Acari: Ixodida).

Toxins have been shown to present in the salivary glands, whole body extracts, and eggs of ticks. They cause histological lesions in the skin, and in various organs of tick hosts. Among toxicoses, tick paralysis is of the greatest medical and veterinary importance. Toxins are secreted by cells "b" of acinus II in salivary glands during tick feeding.

[A review of the types of parasite-host relations in ixodid ticks]. / Obzor tipov parazitno-khoziainnykh otnoshenii iksodoidnykh kleshchei.

In the first type of mutual relationships the ixodid ticks expose an evident pathogenicity to vertebrate hosts (tick toxicoses) and in the second type the hosts expose a resistance on a base of organism immune system activisation in a response to blood sucking. In the third type of relationships an interaction between the ticks and hosts have a dynamic character (tolerability of host). The first type of relationships leading to a selective elimination of hosts according to our opinion means a comparatively youth of relationships. The third type represent ancient and long term relationships. The second type probably having been widely spread in a historical past occupies an intermediate position. Depending upon areal the ticks of the same type expose different degree of the pathogenicity. Even an acquired resistance of the host does exist in natural conditions, it is a transient phenomenon.

Characterization of and application of monoclonal antibodies against Rickettsia africae, a newly recognized species of spotted fever group rickettsia.

Rickettsia africae is a newly described species which causes African tick bite fever. Mediterranean spotted fever caused by R. conorii is endemic in the same regions of Africa as tick bite fever, and differentiation of the two syndromes by characterization of their etiological agents is important for epidemiological studies. R. africae and R. conorii are, however, difficult to distinguish, and therefore, our aim was to produce monoclonal antibodies to address this problem. Monoclonal antibodies were produced against R. africae by fusing splenocytes from BALB/C mice immunized with purified rickettsial organisms and SP2/0-Ag14 myeloma cells. A total of 355 hybridomas producing monoclonal antibodies to R. africae were identified by initial screening with six different antigens by microimmunofluorescence assay. A panel of 23 representative monoclonal antibodies were selected and subcloned. This panel was screened with a further 17 different spotted fever group (SFG) rickettsial reference antigens. Of these 23 monoclonal antibodies, 1 cross-reacted with only R. parkeri, whereas the others cross-reacted with more than two different antigens. Immunoblotting indicated that all the monoclonal antibodies were directed against the epitopes on two major high-molecular-mass heat-labile proteins, of which the molecular masses were 128 and 135 kDa, respectively. This monoclonal antibody panel was used successfully to identify R. africae in the blood culture of an infected patient, in infected cells within shell vials, and in infected ticks collected from Africa. Furthermore, the cross-reactivity of each SFG rickettsia with each of these 23 monoclonal antibodies was scored and was used to build a dendrogram of taxonomic relatedness between R. africae and the other SFG rickettsiae on the basis of Jaccard coefficients and unweighted pair group method with arithmetic mean analysis. The relatedness was generally consistent with that obtained by other methods of comparison.

Sweating sickness: relative curative effect of hyperimmune serum and a precipitated immunoglobulin suspension and immunoblot identification of proposed immunodominant tick salivary gland proteins.

Although of low morbidity, sweating sickness is readily induced in calves by infestation with positive Hyalomma truncatum adult ticks. This epitheliotrophic disease has no specific cure except by the administration of hyperimmune serum obtained from animals which have recovered and are subsequently immune to the disease. Treatment with hyperimmune serum, however, has associated problems of donor availability, possible serum contamination and i.v. administration of a relatively large volume. This paper compares the treatment and cure of sweating sickness using unrefined hyperimmune serum and that of an experimental suspension. The latter proved relatively inefficient probably due to a low concentration of effective immunoglobulins. Immunoblot analyses of the sera of affected animals, using tick salivary glands as antigen during the course of the trial revealed 4 tick salivary gland proteins with molecular masses of between 27-33 kDa. These are proposed as being associated with sweating sickness immunodominance.

Tick-borne diseases.

Ticks may transmit a variety of human pathogens and are second in importance only to the mosquito as a vector of human disease. The majority of tick-borne diseases are nonspecific in their initial clinical and laboratory presentation and may be confused with a variety of more common illnesses. A history of tick exposure is frequently not available. Although specific serologic tests exist for confirming the diagnosis of many of these diseases, the time required for confirmation of results makes them of little use in the acute situation. Recognition of the epidemiology of tick-borne pathogens and clinical suspicion are of key importance in making the appropriate diagnosis. Early and specific therapy is a principal factor in reducing the morbidity and mortality associated with these diseases.

[Life-threatening complications caused by Argas reflexus (Ixodoidea, Argasidae)]. / Lebensbedrohliche Komplikationen durch Argas reflexus (Ixodoidea, Argasidae).

Injuries to health by Argas reflexus (Ixodoidea, Argasidae) are known and have been published since about the middle of 19th century. Argas reflexus was on outsider in health pests for a long time, but biological and medical interests increased during last years. The greatest part of injuries by far, brought about by stings of this parasite, takes either a harmless course or there are appearances of middle severity, which can be easy controlled by a physician. In some cases however, at often happened exposition in the main, there may be complications dangerous for one's life, the causes of which often are not recognised sufficient by general practitioners. Beside a casuistry the article contains references to prompt measures--especially for the first-aid doctor-and following tasks for public hygienic executive organs.

Severe tick-bite fever in young children. A report of 3 cases.

Tick-bite fever in young children is usually a mild illness with few complications and no mortality. That it may assume a severe form is illustrated by the occurrence of 3 cases admitted to Johannesburg Hospital within 1 week in which 2 patients, 3 and 5 years old respectively, had severe involvement of the central nervous system with epileptiform fits and deep coma and loss of power of speech on recovering consciousness. The third patient, aged 5 years, developed an incipient haemorrhagic state as well as serious involvement of the central nervous system. The severe form of the disease in these patients appears to have been due to unusually virulent strains of Rickettsia conorii, probably acquired from dog ticks in their homes. All patients recovered on appropriate treatment. Two regained their normal speech after many weeks while the third patient's incipient haemorrhagic state rapidly resolved.