Archive for the ‘research’ Category

Study Looks At Deet & Natural Tick Repellents

https://danielcameronmd.com/deet-and-natural-tick-repellents/

STUDY LOOKS AT DEET AND NATURAL TICK REPELLENTS

Ticks patiently hold on to blades of grass and shrubs in a position known as “questing” as they await their next meal or host. “Almost blind, ticks rely on chemosensation to identify and locate hosts for a successful blood meal,” write the authors of “Behavioral responses of Ixodes scapularis tick to natural products: development of novel repellents.”¹

By

As the number of tick-borne diseases grows and the geographical spread of ticks continues, there is increasing interest in what repellents are effective, safe and environmentally friendly. But little is known about how exactly ticks detect odors and what smells repel them.

“Improving our understanding of tick olfactory mechanisms and odor driven behaviors is key to enabling development of new repellents,” writes Faraone.

Given the health concerns over DEET, researchers are turning their attention to plant-based repellents. “Plant-derived essential oils are natural products that exhibit insecticidal and repellent activities and represent a promising alternative to synthetic repellants,” Faraone writes.

Lemongrass essential oil

“In behavioral bioassays we reported that lemongrass essential oil and its main chemical constituents (such as geraniol, β-citronellol and citral), as well as PEA [phenethyl alcohol], were significantly repellent to I. scapularis nymphs,” writes Faraone.

However, “the efficacy of lemongrass essential oil was dose-related, and was effective in repelling up to 76% of I.scapularis nymphs after 10 minutes when applied at the highest tested concentration.”

The substance was more effective at higher concentrations in repelling ticks. But, the effect declined after 2 hours from the first application to 62.5% compared to a DEET-based product of 87.7%.

The authors did not report on the repellent effects outside the lab. And given that the formulation was proprietary, its ingredients were not disclosed.

However, they found that “PEA- and geraniol-based formulas exerted an effective repellent action representing a valid natural alternative to synthetic repellents already available on the market.”

DEET

DEET (diethyltoluamide) repels ticks but its use raises environmental and health concerns. The concentration of DEET also affects its ability to repel ticks, as shown below:

0% of DEET = 8.5% repelled
5% of DEET = 16.6% repelled
10% of DEET = 30.4% repelled
20% of DEET = 68.9% repelled
40% of DEET = 88% repelled

Interestingly, 0% DEET repelled 8.5% of ticks at 10 minutes. This is similar to the placebo effect.

The actual concentration of DEET from the manufacturer is 25% to 30%. The actual concentration on the skin for DEET or the proprietary products was not described in the study.

Most importantly, the study was completed on a paper filter. It remains to be seen how DEET or the natural-based products will work on people.

Related Articles:

Permethrin-treated clothing causes “hot foot” effect in ticks

When do ticks quest, waiting for the next meal?

Killing ticks through controlled burns

References:
  1. Faraone N, MacPherson S, Hillier NK. Behavioral responses of Ixodes scapularis tick to natural products: development of novel repellents. Exp Appl Acarol. 2019 Sep 28.

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**Comment**

Dr. Cameron’s astute comments point out the limitations of this study and we must continue to be careful in our zeal to get answers. Studies have been done on natural products such as stevia and essential oils; however, they are done within a lab with set parameters which may not equate out in the human body and in reality.  Lemon EO oil is in the same camp and caution must be used.

A great point is that most people spend more than 10 minutes outside and we aren’t told what the exact dose is.  How lemongrass EO works after that point isn’t known but we are told effectiveness diminishes.

Most research such as this remains much of a mystery as the authors are hoping for a proprietary formula they can market. All efforts are for that specific outcome.

For more:  https://madisonarealymesupportgroup.com/2019/04/12/tick-prevention-2019/

One inexpensive tick killer is fire:  https://madisonarealymesupportgroup.com/2019/07/18/frequent-prescribed-fires-can-reduce-risk-of-tick-borne-diseases/

Category:

Prevention, research, Ticks, Treatment

Is Exposure to Fleas and Ticks Possible During The Winter?

https://www.galaxydx.com/fleas-and-tick-prevention-in-the-winter/

written on 

Is Exposure to Fleas and Ticks Possible During The Winter?

Research shows that the tick species I. scapularis can remain active at temperatures as low as 30.9 degrees Fahrenheit. In moderate winters, the fact is that flea and tick prevention is a year-round need in most of the world. In general, however, exposure is extremely limited when temperatures are consistently below 40 degrees Fahrenheit.

Exposure to fleas and ticks does tend to be less likely during the winter, but this does not mean they suddenly disappear until spring. Unless it is extremely cold with no shelter, they may be in a dormant state awaiting warmer and wetter weather. Meanwhile, they survive in microenvironments like the soil, leaf litter, or housing structures. When there is a spike in temperature in the winter they can emerge, looking for a meal just as they do in any other season. This has been especially true over the past couple of months for the northeastern region of the United States, where the temperature has fluctuated greatly.

The warmer-than-normal winter weather this year has led to an increased observation of ticks, especially across the US northeast. Local news stations and advocacy groups based in New York have posted warnings of increased tick activity, with experts describing how this may affect tick populations not only now, but also during the upcoming spring. The Cary Institute of Ecosystem Studies, which is working on the TICK Project with partners that include the CDC and NY State Department of Health, warned that the abnormally warm and rainy winter is extremely amenable to the survival of ticks. Without a prolonged cold snap, juveniles and eggs are more likely to survive until the spring. This same trend is likely true for fleas.

So how do they survive in the winter?

Ticks

The lifecycles of Ixodes scapularis and Ixodes pacificus, the primary vectors for Lyme disease in the United States, is generally about 2-3 years and involves distinct developmental stages that each require a blood meal from a new host. This means that survival through seasonal changes is necessary for females to reach adulthood and successfully reproduce.

The Ixodes scapularis (black legged tick) life consists of four distinct stages of development over two to three years. In order to reach adulthood, survival through the winter is necessary (Source: CDC).

After hatching from their eggs, larvae have the main goals of feeding through the summer and fall and surviving the winter. Typically, they do this by remaining in a dormant state within the insulation provided by leaf litter and snow. Unless the ground is frozen for some time, they can survive until the spring, when they will feed on a new host as nymphs. If the weather warms up, however, they can emerge from dormancy at any time to feed. Studies show that Ixodes scapularis can be found questing in New York from January to March when the weather permits. Dermacentor variabilis can become active as early as February.

Interestingly, one species responsible for transmitting tick-borne diseases can complete its entire lifecycle on one indoor host, avoiding the outdoor weather entirely. Commonly called the brown dog tick, Rhicephalus sanguineus is known for residing in kennels and around heated homes year-round. They successfully reproduce just by feeding on dogs, unlike most other species of ticks that require various hosts. Furthermore, they release from the hosts at night rather than during the day, so they easily make it into people’s homes.

Fleas

Unlike most ticks, the survival of eggs or juvenile fleas through cold weather is not necessary to successfully reproduce. This is because fleas generally have a short lifespan of a few weeks to a couple of months. When temperatures are optimal (around 75 degrees Fahrenheit and 70% humidity), cat fleas (Ctenophalides felis, found on cats, dogs and a variety of other hosts in most parts of the world) can complete their entire lifecycle, from egg to adult, on a single host in just a couple of weeks.

Research suggests that adult fleas do not withstand temperature fluctuations in their environment well, but pre-emerged adults residing in cocoons can. They will remain in a protective casing for weeks to months depending on the species. Emergence in an unfavorable environment will not occur until the presence of a potential host is obvious. The flea within the cocoon may be alerted to the presence of a host by vibrations, rising levels of carbon dioxide, and body heat.

Conclusion

Vigilance against fleas and ticks is required year-round. Talk to your veterinarian about flea and tick prevention for your pets and follow best practices to protect yourself from flea and tick exposure, even in winter.

References

Elfenbein, H. (2019). Do fleas die in the winter? PetMD.com. Available at https://www.petmd.com/dog/parasites/do-fleas-survive-winter

Santa Maria, C. (2019). Ticks can survive cold weather, so keep checking your pets. TheWeatherNetwork.com. Available at https://www.theweathernetwork.com/news/articles/ticks-can-survive-winter-and-cold-weather-lyme-disease-deer-tick-pets-cats-dogs-new-boston-new-hampshire/122254/

Silverman, J. et al. (1981). Influence of temperature and humidity on survival and development of the cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae). Journal of Medical Entomology, 18, 78-83. doi:10.1093/jmedent/18.1.78. https://academic.oup.com/jme/article-abstract/18/1/78/2219813?redirectedFrom=fulltext

Gage, K. L. et al. (2008). Climate and vectorborne diseases. American Journal of Preventive Medicine, 35, 436-450. doi:10.1016/j.amepre.2008.08.030 static1.1.sqspcdn.com/static/f/551504/6467299/1270769608913/Gage+et+al.pdf?token=6mCSf%2Fqe2MuEW94lHok5ONl9%2Fhk%3D

Ostfeld, R. (2020, January/February). Ticks in winter. Adirondac Magazine. Available at https://www.adk.org/ticks-in-winter-ostfeld/

WRGB. (2020, February 3). Tick sightings spike during warm January. Available at https://www.weny.com/story/41644769/tick-sightings-spike-during-warm-january#.XjhFtTPZbQM.twitter

Centers for Disease Control and Prevention. (2019). Tick surveillance. Available at https://www.cdc.gov/ticks/surveillance/index.html

Bayer. (n.d.). Companion vector-borne diseases. Available at http://www.cvbd.org/en/flea-borne-diseases/about-fleas/general-aspects/epidemiology/

Ogden, N.H. et al. (2005). A dynamic population model to investigate effects of climate on geographic range and seasonality of the tick Ixodes scapularis. International Journal of Parasitology, 35(4), 375-389. doi:10.1016/j.ijpara.2004.12.013 https://www.sciencedirect.com/science/article/abs/pii/S0020751905000044

Gray, J et al. (2013). Systemics and ecology of the Brown Dog Tick, Rhipicephalus sanguineus. Ticks Tick Born Dis. 4(3), 171-180. doi: 10.1016/j.ttbdis.2012.12.003. https://www.ncbi.nlm.nih.gov/pubmed/23415851

Rust, Mk et al. (1997). The biology, ecology, and management of the cat flea. Annu Rev Entomol. 42, 451-73. https://www.ncbi.nlm.nih.gov/pubmed/9017899

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For more:  https://madisonarealymesupportgroup.com/2016/01/20/polar-vorticks/

https://madisonarealymesupportgroup.com/2019/04/12/tick-prevention-2019/

 

Category:

research, Ticks, Transmission

Experts Harvest Ticks Along American River Parkway (CA)

https://www.kcra.com/article/experts-harvest-ticks-along-american-river-parkway-test-lyme-disease/30734749# Article and numerous videos here

By Vicki Gonzalez

SACRAMENTO COUNTY, Calif. —

The American River Parkway is more than 30 miles of trails and draws over 10 million visitors each year.

But Sacramento’s backyard jewel is also a popular destination for ticks.

Peak tick season runs from December to May, according to Sacramento-Yolo Mosquito Vector Control District….(See link for article)

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**Comment**

Here we see a tick in the middle of the sidewalk on a blade of grass – also in CA:  https://madisonarealymesupportgroup.com/2019/05/17/video-showing-questing-ticks-in-the-middle-of-the-sidewalk/

Ticks are in unlikely places:  https://madisonarealymesupportgroup.com/2018/06/07/ticks-on-beaches/ (see comment section)

https://madisonarealymesupportgroup.com/2019/06/19/a-creepy-bed-time-story-from-stephen-king/

Ticks have been found:

Category:

research, Ticks

Tick-borne Relapsing Fever: An Unrecognized Cause of Fever in Travelers

https://www.ncbi.nlm.nih.gov/pubmed/32014353/

2020 Jan 31. pii: S0248-8663(20)30010-2. doi: 10.1016/j.revmed.2019.12.022. [Epub ahead of print]

Tick-borne relapsing fever : An unrecognized cause of fever in travelers

[Article in French]
Ahmed Yahia S1, Faibis F2, Benmoussa M3, Lantohasina N3, Dupont A4, Ait Abdesselam T4.

Abstract

INTRODUCTION:

Tick-borne relapsing fever is a usual cause of fever in West Africa. Except relapsing febrile episodes, there are no pathognomonic signs and diagnosis is difficult because Borrelia density in patient’s blood is low.

CASE REPORTS:

Tick-borne relapsing fever was revealed by the presence of spirochetes in a blood sample to search malaria in two men, 24 and 31 year-old, returned from Mali.

CONCLUSION:

This diagnosis should be evocated in patients having fever after a trip in infested area, as malaria, both infections can be associated.

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**Comment**

I got news for you.  Borrelia density is low in many patients’ blood.  This is a common problem and one of the reasons why patients continue to test negative.

Category:

Borrelia Miyamotoi (Relapsing Fever Group), research

Lyme Disease & Heart Transplantation: Presentation of a Clinical Case and a Literature Review

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6992363/

. 2019; 26(3): 173–180.
PMCID: PMC6992363
PMID: 32015672

Language: English | Lithuanian

Lyme disease and heart transplantation: presentation of a clinical case and a literature review

Audrius Aurelijus Pilypas,1 Giedrutė Raišelienė,2 and Jurgita Valaikienė3
Author information

Abstract

Background.

Lyme disease, the most common anthropozoonosis, is a transmissible natural focal infection affecting various organs and systems. Also known as Lyme borreliosis, it is caused by Borrelia spirochetes, which are distributed by ticks of the genus Ixodes. Early diagnosis is difficult due to frequent occurrence of atypical symptoms, unnoticed tick bites, the absence of migratory erythematous lesions, and symptoms occurring during the non-tick season. If not diagnosed and treated in time, dissemination of the infection occurs and various complications develop since borrelias damage not only the skin but also the nervous system, joints, and, in rare cases, the heart and eyes.

Materials and methods.

This article presents a clinical case of Lyme borreliosis-induced myocarditis, which led to the development of dilated cardiomyopathy and, consequently, urgent cardiac transplantation. According to our data, this is one of the first described cases of this complication in the world.

Results and conclusions.

When diagnosed in time and treated properly, the prognosis of Lyme myocarditis is usually good. In most cases, the atrioventricular block disappears within 1–2 weeks of antibiotic treatment and the implantation of a temporary pacemaker is rarely needed. In those rare cases of a chronic Borrelia burgdorferi infection, dilated cardiomyopathy may develop; thus if a sudden atrioventricular block occurs, the physician should be vigilant and perform the necessary tests to exclude the diagnosis of Lyme disease.

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**Comment**

When you consider how many people are turned away on a daily basis due to negative testing you begin to see that stating this is “rare,” is a bit premature.  So many are undiagnosed or misdiagnosed.

Category:

Heart Issues, Lyme, research