Clinical presentations, treatments and risk factors for mortality in cats with tick paralysis caused by Ixodes holocyclus: 2077 cases (2008-2016).

Objectives The objective of this study was to describe seasonality, demographics, presentations, treatments, complications and outcomes for cats with Ixodes holocyclus causing tick paralysis, and to identify risk factors for mortality. Methods This was a retrospective single cohort study with 2077 cases occurring between 2008 and 2016, and presenting to one of four emergency clinics in south-eastern Queensland, Australia. Case mortality at 5 days post-presentation could be determined for 1742 cases, and potential risk factors for mortality were assessed using random-effects logistic regression. Results Cases occurred all year round, but there was a marked seasonal pattern with more cases presenting in spring than any other season. Overall, 54/1742 cases (3%) died by 5 days after presentation. Five day mortality incidence for cases that received polyclonal canine tick antitoxin serum (TAS) and recommended treatment was 28/1410 (2%) vs 4/52 (8%) for cases that did not receive TAS ( P <0.001). Mechanical ventilation was recommended for 131/2077 cases (6%). Where mechanical ventilation was recommended but not implemented, mortality incidence was 15/17 (88%), whereas 4/22 cases (18%) that received mechanical ventilation died by day 5. From multivariable analyses, initial gait score (overall P = 0.047) and body temperature on presentation (overall P <0.001) were independently associated with mortality; cases with higher gait scores and those with body temperatures <35°C were at greater risk of death. Cases that had an adverse reaction to TAS were also more likely to die ( P = 0.002). Additional ticks were detected at coat clipping for 80/872 (9%) the cases that were clipped, and coat clipping was associated with a reduced risk of mortality ( P = 0.020). Risk of mortality did not differ significantly by time of year, clinic location, breed, sex, neuter status, age, weight, coat length or number of ticks found. Conclusions and relevance The overall mortality risk for cats treated for tick paralysis caused by I holocyclus is low. Risk factors for mortality include advanced gait and respiratory scores, and hypothermia at presentation. Coat clipping and TAS reduce the risk of mortality, whereas the occurrence of a TAS reaction increases the risk. Mechanical ventilation reduces mortality risk in cats with respiratory failure due to tick paralysis.

Ticks threatening lineage of Anatolian wild sheep (Ovis gmelinii anatolica) and determination of their tick-borne pathogens.

We aimed to determine the ticks of the Anatolian wild sheep and to define their tick-borne pathogens while molecularly studying their relationships with those of the domestic sheep. Furthermore, another aim of this study is to investigate tick paralysis resulting in the death of the Anatolian wild sheep. Ticks and blood samples were collected from the wild sheep whilst tick samples were also collected from hares, guinea fowls, chickens, and a turkey living in the Anatolian wild sheep breeding area. While PCR amplification was carried out for the detection of Babesia spp., Theileria spp. and Anaplasma spp. in blood samples, CCHF virus was screened in the tick samples in addition to the above-mentioned pathogens. Theileria spp. was detected in blood samples of 45 wild sheep. A total of 3494 ticks were collected from 52 Anatolian wild sheep, 5 hares, 5 guinea fowls, 2 chickens, and 1 turkey whereas 98 ticks were collected from the ground. B. ovis and T. ovis were detected in tick pools (Rh. bursa and H. excavatum) that were collected from the wild sheep. The paralysis was diagnosed in both of the hind legs of the newborn lambs infested with a great number of ticks. We also report that the tick species (H. excavatum and Rh. bursa) are determined to cause tick paralysis and tick toxicosis, which are associated with mortality especially in lambs. T. ovis and B. ovis were detected and studied for the first time in Anatolian wild sheep and in their ticks. The results of phylogenetic analyses showed that T. ovis and B. ovis isolates are genetically very close to the isolates that were previously obtained from the domestic small ruminants. We show that the Anatolian wild sheep can play the role of a reservoir for T. ovis. The presence of the CCHF virus has also been clearly shown and it has been observed that this virus, which is very pathogenic for humans, is anywise circulating in the region.

Tick paralysis in spectacled flying-foxes (Pteropus conspicillatus) in North Queensland, Australia: impact of a ground-dwelling ectoparasite finding an arboreal host.

When a parasite finds a new wildlife host, impacts can be significant. In the late 1980s populations of Spectacled Flying-foxes (SFF) (Pteropus conspicillatus), a species confined, in Australia, to north Queensland became infected by paralysis tick (Ixodes holocyclus), resulting in mortality. This Pteropus-tick relationship was new to Australia. Curiously, the relationship was confined to several camps on the Atherton Tableland, north Queensland. It was hypothesised that an introduced plant, wild tobacco (Solanum mauritianum), had facilitated this new host-tick interaction. This study quantifies the impact of tick paralysis on SFF and investigates the relationship with climate. Retrospective analysis was carried out on records from the Tolga Bat Hospital for 1998-2010. Juvenile mortality rates were correlated to climate data using vector auto-regression. Mortality rates due to tick paralysis ranged between 11.6 per 10,000 bats in 2003 and 102.5 in 2009; more female than male adult bats were affected. Juvenile mortality rates were negatively correlated with the total rainfall in January to March and July to September of the same year while a positive correlation of these quarterly total rainfalls existed with the total population. All tick affected camps of SFF were located in the 80% core range of S. mauritianum. This initial analysis justifies further exploration of how an exotic plant might alter the relationship between a formerly ground-dwelling parasite and an arboreal host.

Apparent tick paralysis by Rhipicephalus sanguineus (Acari: Ixodidae) in dogs.

Certain tick species including Ixodes holocyclus can inoculate neurotoxins that induce a rapid, ascending flaccid paralysis in animals. Rhipicephalus sanguineus, the most widespread tick of dogs, is recognized as a vector of several pathogens causing diseases in dogs and humans. A single report suggests its role as cause of paralysis in dogs. This study presents the clinical history of 14 young dogs heavily infested by R. sanguineus (intensity of infestation, 63-328) in an endemic area of southern Italy. During May to June of 2011, dogs were presented at the clinical examination with neurological signs of different degrees (e.g., hind limb ataxia, generalized lethargy, and difficulty in movements). All animals were treated with acaricides and by manual tick removal but ten of them died within a day, displaying neurological signs. The other 4 dogs recovered within 3 days with acaricidal and supportive treatment. Twelve dogs were positive by blood smear examination for Hepatozoon canis with a high parasitemia, two also for Babesia vogeli and two were negative for hemoparasites. Low-grade thrombocytopenia, hypoalbuminemia, and pancytopenia were the haematological alterations most frequently recorded. Other causes of neurological disease in dogs were excluded and the diagnosis of tick paralysis by R. sanguineus was confirmed (ex juvantibus) by early and complete recovery of 4 dogs following acaricidal treatment and tick removal.

A 60-year meta-analysis of tick paralysis in the United States: a predictable, preventable, and often misdiagnosed poisoning.

Tick paralysis (TP) is a neurotoxic poisoning primarily afflicting young girls in endemic regions. Recent case series of TP have described increasing misdiagnoses of TP as the Guillain-Barré syndrome (GBS). A meta-analysis of the scientific literature was conducted using Internet search engines to assess the evolving epidemiology of TP. Fifty well-documented cases of TP were analyzed over the period 1946-2006. Cases were stratified by demographics, clinical manifestations, and outcomes. Misdiagnoses were subjected to Yates-corrected chi-square analyses to detect statistically significant differences in proportions of misdiagnoses between earlier and later reporting periods. TP occurred seasonally and sporadically in individuals and in clusters of children and adults of both sexes in urban and rural locations. The case fatality rate (CFR) for TP was 6.0% over 60 years. The proportion of misdiagnoses of TP as GBS was significantly greater (chi(2) = 7.850, P = 0.005) in more recently collected series of TP cases, 1992-2006, than the proportion of misdiagnoses in earlier series, 1946-1996. TP was a potentially lethal poisoning that occurred in children and adults in a seasonally and regionally predictable fashion. TP was increasingly misdiagnosed as GBS during more recent reporting periods. Such misdiagnoses often directed unnecessary therapies such as central venous plasmapheresis with intravenous immunoglobulin G, delayed correct diagnosis, and tick removal, and could have increased CFRs. TP should be added to and quickly excluded from the differential diagnoses of acute ataxia and ascending flaccid paralysis, especially in children living in TP-endemic regions of the USA.

[Fatal neurological syndrome in a collared dove (Streptopelia decaocto) and fixation of ixodes pari (= I. frontalis) tick (author's transl)]. / Syndrome neurologique mortel chez une tourterelle turque (Streptopelia decaocto) et fixation de la tique (Ixodes pari (= I. frontalis).

Tick paralysis is probably a common condition in wild birds, but rarely observed. The authors report the case of a collared dove (S. decaocto) presenting a fatal neurological syndrome associated with the fixation of a Ixodes pari female above the right eye. Virological studies of bird's tissues and of the tick were negative. These findings were compatible with tick paralysis or a minor equivalent of this syndrome. In addition, it was the first time that a collared dove is found as host for I. pari.

Paralysis in chickens caused by larvae of the poultry tick, Argas persicus.

White Leghorn pullets 20 weeks old submitted to the diagnostic laboratory were found heavily infested with the larval stage of the poultry tick, Argas persicus. The birds were severely depressed and recumbent. The signs were quickly reversed when the tick larvae were removed. The rapid rate of recovery and negative results in detailed diagnostic procedures suggested that the tick larvae caused the paralysis.