Questing by Tick Larvae (Acari: Ixodidae): A Review of the Influences That Affect Off-Host Survival.

Questing is a host-seeking behavior in which ticks ascend plants, extend their front legs, and wait poised for a chance to attach to a passing host. Hard ticks are ectoparasites of terrestrial vertebrates and because some species vector disease, they are among the most medically important of arthropod pests. All ixodid ticks require blood to survive and reproduce with the number of blood-hosts needed to complete their life cycle varying among species. The vast majority are three-host ticks requiring a different host for each developmental stage: larva, nymph, and adult. A few, including some of the most economically important species, are one-host ticks, that quest only in the larval stage. Questing is a rate-limiting behavior critical to tick survival and disease transmission. For the off-host larval stage, survival is highly dependent on ecological and physiological factors. Yet, off-host larval ecophysiology is often overlooked for the more obvious adult and nymphal tick-host interactions. This review summarizes the literature on ixodid larval questing with emphasis on how specific biotic and abiotic factors affect off-host survival.

Prospecting Local Treatments Used in Conjunction with Antivenom Administration Following Envenomation Caused by Animals: A Systematic Review.

Envenomation caused by venomous animals may trigger significant local complications such as pain, edema, localized hemorrhage, and tissue necrosis, in addition to complications such as dermonecrosis, myonecrosis, and even amputations. This systematic review aims to evaluate scientific evidence on therapies used to target local effects caused by envenomation. The PubMed, MEDLINE, and LILACS databases were used to perform a literature search on the topic. The review was based on studies that cited procedures performed on local injuries following envenomation with the aim of being an adjuvant therapeutic strategy. The literature regarding local treatments used following envenomation reports the use of several alternative methods and/or therapies. The venomous animals found in the search were snakes (82.05%), insects (2.56%), spiders (2.56%), scorpions (2.56%), and others (jellyfish, centipede, sea urchin-10.26%). In regard to the treatments, the use of tourniquets, corticosteroids, antihistamines, and cryotherapy is questionable, as well as the use of plants and oils. Low-intensity lasers stand out as a possible therapeutic tool for these injuries. Local complications can progress to serious conditions and may result in physical disabilities and sequelae. This study compiled information on adjuvant therapeutic measures and underscores the importance of more robust scientific evidence for recommendations that act on local effects together with the antivenom.

Survival of off-host unfed Rhipicephalus (Boophilus) annulatus (Acari: Ixodidae) larvae in study arenas in relation to climatic factors and habitats in South Texas, USA.

The cattle fever tick, Rhipicephalus annulatus (Say), is an economically destructive arthropod because of its ability to vector bovine babesiosis. Cattle fever ticks can spend more than 90% of their life cycle as questing larvae, but the effect of climatic factors on their off-host behavior and survival is unclear. The goal of this study was to measure the effects of specific ecological factors on off-host larvae in nature. The study was conducted in a south Texas pasture over a 20-mo period, during which time larval populations were surveyed and ambient weather variables - relative humidity and temperatures - were recorded. Oviposition success and larval survival varied between cattle fever tick cohorts and was affected by relative humidity and canopied (with tree cover) versus exposed habitat. The results show that relative humidity and the interaction of relative humidity and inhabiting canopied habitats play a key role in oviposition success. Additionally, canopied habitats have a positive influence on off-host larval survival in the spring and summer.

Population Dynamics of Off-Host Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) Larvae in Response to Habitat and Seasonality in South Texas.

The cattle tick, Rhipicephalus microplus (Canestrini), is an economically destructive arthropod because of its ability to vector bovine babesiosis. It is known that cattle ticks can spend 80-90% of their lifecycle as questing larvae, yet the effect of climatic factors on their off-host behavior and survival is unclear. The goal of this study was to measure the effects of specific ecological factors on off-host questing larvae in nature. The study was conducted in a south Texas pasture over a two-year period, during which time larval populations were surveyed. Simultaneously, weather variables-precipitation, relative humidity, and ambient temperatures-were recorded. Larval survival rates varied among seasons, with the overall highest populations recorded in the spring and the lowest in the fall by a ratio of 20:1. In the winter, the larger numbers were collected from exposed habitats at a ratio of 6:1. Conversely, canopied habitats in the summer had 10-fold larger larval numbers. In the spring, exposed and canopied habitats showed no difference in tick larval survival rates. The results show that the interaction between season and habitat strongly influence off-host questing tick survival. Relative humidity was a key weather variable.

Cattle fever tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae): Potential control on pastures by the application of urea fertilizer.

The southern cattle fever tick, Rhipicephalus (Boophilus) microplus, spends as much as 80-90% of its life cycle as a larva questing for a host. Standard control methods are limited to on-host applications, leaving a need for methods directed at the pasture infesting stages. Reports from Brazil indicate that pasture fertilization can reduce tick numbers. Granular urea was tested using standard pesticide efficacy methods in both the laboratory and field trials to determine if there was a significant impact on adult reproduction and larval survival. Under the conditions of this present study, there was no detectable effect on either female adults or larval stages. Ammonification in the soil may be a key factor limiting the impact of fertilizer treatments.

Mondor's disease in a patient previously treated for breast carcinoma in situ: a case report.

Mondor's disease is a thrombophlebitis that affects mainly the superficial veins of the breast. The aetiology of Mondor's disease is multifaceted and there are reports in the literature of an association between Mondor's disease and breast cancer. This disease occurs more commonly in women than men, mainly in the third and fourth decades of life, leading to a spontaneous remission in most cases. We report a case of a 45-year-old female patient that had been treated for breast carcinoma in situ.