Archive for the ‘research’ Category

After a Tick Bite, How Long For Disease Transmission?

https://danielcameronmd.com/have-you-been-bitten-by-a-partially-fed-tick/

AFTER A TICK BITE, HOW LONG FOR DISEASE TRANSMISSION?

tick-disease-transmission

A single tick bite can transmit several diseases. But investigators continue to debate how long a tick must be attached before it can transmit the Lyme disease bacterium. While many believe a tick must be attached for at least 36 to 48 hours before transmission can occur, others say it can happen within several hours.

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People often ask: How long does it take for disease transmission to occur after a tick bite? According to investigators, Lyme disease may be transmitted faster if the tick previously fed on another host.

In a 2014 article entitled “Lyme borreliosis: a review of data on transmission time after tick attachment,” Michael J Cook explored the topic. “It is frequently stated that the risk of infection is very low if the tick is removed within 24 to 48 hours with some claims that there is no risk if an attached tick is removed within 24 hours or 48 hours.”

However, in animal models, Cook found, “transmission can occur in less than 16 hours, and the minimum attachment time for transmission of infection has never been established.”

Have you been bitten by a partially fed tick?

Investigators suggest that transmission time may be shorter if a tick has already fed on a host. A study by Shih and colleagues, found that, “Partially fed nymphal ticks transmit spirochetal infection more rapidly than do ticks that have never been attached to a host.”¹

So, how quickly a tick can transmit Lyme disease may depend on whether the tick had been partly fed BEFORE it attached to its second host.

Shih et al. demonstrated that partially fed nymphal ticks (84%) were capable of transmitting spirochetes to a non-infected mouse within 24 hours. The authors discovered it took less time for an infected nymphal deer tick to transmit Lyme spirochetes to a mouse if the tick was partially fed.

Ticks spontaneously detach from hosts

Individuals may mistakenly believe that once a tick bites it will remain attached throughout the entire feeding or until it is removed. But this isn’t the case.

In the mouse study, Shih found that ticks can spontaneously detach during the feeding process. And this action can profoundly impact the time it takes for spirochetes to infect the host.

“Virtually all nymphal ticks that previously had fed for 16 hours reattached efficiently.”¹

“We found that nymphs do detach spontaneously from free-ranging mice in the laboratory, perhaps as frequently as 15% of the time,” the authors report.

“Indeed, about [one tenth] of questing nymphs in nature seem to be distended, and reattachment by partially fed sub-adult ticks commonly occurs.”

In the laboratory, partially fed ticks would reattach to a second host and commence feeding. “Virtually all nymphal ticks that previously had fed for 16 hours reattached efficiently.”

What happens in partially fed ticks?

The tick attaches to a host, feeds and the Lyme bacteria multiply rapidly in the tick’s mid-gut. Normally, the tick eliminates all of the bacteria, leaving behind only those spirochetes that survive in the mid-gut before they molt into an adult.

But, in a partially fed tick, spirochetes multiply in the mid-gut and then move to the salivary glands.

If the tick bites again, the spirochetes residing in the salivary glands can be transmitted more quickly. “Partially fed nymphs [ticks] are able to reattach to another host and Lyme disease spirochetes may be transmitted by partially fed nymphs more rapidly than by nymphs that have not already fed.”

Pet owners: be wary

Their findings are particularly relevant to people who own pets. “These partially fed ticks may already have acquired spirochetal infection and avidly seek other hosts,” writes Shih.

“Pet ownership appears to be a risk factor for human Lyme disease, and this may reflect contact with ticks that have detached from a cat or dog within the household.”

If an unfed tick attaches it can take up to 36 hours to transmit the Lyme spirochetes to a mouse, Shih claims. “The chain of events that culminates in migration of the spirochetes from the gut of the tick to its salivary apparatus begins within the first day of attachment and requires at least another day for completion.”

Note: The study by Shih and colleagues was conducted only with mice and has not been replicated with humans.

UPDATED: June 22, 2021

References:
  1. Shih CM, Telford SR, 3rd, Pollack RJ, Spielman A. Rapid dissemination by the agent of Lyme disease in hosts that permit fulminating infection. Infect Immun, 61(6), 2396-2399 (1993).

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Category:

Activism, research, Ticks, Transmission

New Asian Longhorned Tick Pest Alert Available

https://www.ncipmc.org/connection/

New Asian Longhorned Tick Pest Alert Available

Posted on June 2, 2021 by Jacque Pohl
Asian longhorned tick
Asian longhorned tick. Photo by James Gathany.

A new Pest Alert from the North Central IPM Center focuses on the Asian longhorned tick, which is native to East Asia. This tick targets livestock and can reproduce even in the absence of male ticks.

“A single individual tick has the potential to establish entire new populations almost anywhere in the US, but if we are vigilant, we may be able to eradicate this tick from new locations,” said Scott Larson, co-leader for the Public Tick IPM Working Group and assistant entomologist for the Metropolitan Mosquito Control District.

The Asian longhorned tick pest alert includes details about the tick’s life cycle, identification, and management options. These ticks are a threat to livestock because large tick infestations on one animal can lead to stress, blood loss and even death. There is also concern that these ticks may be able to spread disease as they feed on multiple hosts throughout their lives.

“We felt this pest alert was needed to increase awareness of the Asian longhorned tick” said Leah McSherry, community IPM coordinator at the IPM Institute of North America, Inc and member of the Public Tick IPM Working Group. “We are optimistic that increased awareness of the Asian longhorned tick will lead to increased management and better control.”

The Tick IPM Working Group formed in 2013 and works to support a network of experts and interested partners that cooperate to reduce tick populations and reduce tick-borne disease risk. More details about this team can be found on the Public Tick IPM Working Group website.

The Public Tick IPM Working Group produced this pest alert with support from the IPM Institute and the USDA National Institute of Food and Agriculture, Crop Protection and Pest Management Program through the North Central IPM Center (2018-70006-28883).

Pest Alerts are published by the North Central IPM Center as new species arrive in the United States and create new management challenges. They are often written by working groups or by interested researchers or Extension personnel.  A list of Pest Alerts created by the North Central IPM Center and instructions for starting a new one are available here.

https://www.ncipmc.org/projects/pest-alerts1/asian-longhorned-tick-haemaphysalis-longicornis/

Asian Longhorned Tick (Haemaphysalis longicornis)

Contact ncipmmedia@gmail.com for free printed copies.  Include in email: 1) Pest Alert name, 2) number of packs desired (only available in packs of 50) and, 3)  the date they will be needed.

A printable pdf is available.

Contact northcentral@ncipmc.org for free printed copies.  Include in email: 1) Pest Alert name, 2) number of packs desired (only available in packs of 50) and, 3)  the date they will be needed.

Introduction

The Asian longhorned tick (ALT) is primarily a pest of concern in livestock (cattle, goats, sheep) and studies suggest there is a potential for the ALT to vector pathogens that cause Rocky Mountain spotted fever and other tick-borne illnesses. In its native range, the ALT can transmit Rickettsia japonica, which causes Japanese spotted fever, and the potentially fatal, severe fever with thrombocytopenia syndrome (SFTS) virus, among others.

Asian Longhorned Tick Facts
  • Females can reproduce without mating with a male, which makes male ticks quite rare.
  • Ticks have one blood meal during each life cycle stage.
  • Females can lay up to 2,000 eggs.


Asian longhorned tick (Haemaphysalis). Image by James Gathany.

Origin and Distribution

The ALT is native to East Asia, with established populations in China, Japan and South Korea, and is considered invasive in Australia, New Zealand and the United States. The ALT was first believed to be discovered in the United States in August of 2017 on a tick-infested female Icelandic sheep in New Jersey. An unidentified
tick specimen archived in Union County, New Jersey, now identified as an ALT, has moved the assumed introduction date to 2013. As of 2021, the ALT has been detected in primarily mid-Atlantic and southern states. For the current distribution, visit the USDA-APHIS website.

Size of Asian longhorned tick compared to a dime. Image by James Gathany at CDC.

Life Cycle

There are four life stages of the ALT. The ALT begins its life as an egg. The second life stage is the larval stage. At this point, the ALT is six-legged. The next life stage is an eight-legged nymph. The next and last life stage is the adult. Ticks take one blood meal as they transition to the next life stage. After each successful blood meal, the tick releases from its host, molts and then begins to quest for a new host. An interesting aspect of the ALT is that females can reproduce without mating with a male. This process is called parthenogenesis and as a result, male Asian longhorned ticks are rare.

asian longhorned tick life cycle

Identification

The adult ALT resembles the adult brown dog tick shown below (Rhipicephalus sanguineus). To differentiate the two species, look for the presence of “eyes” on the sides of its body near the second row of legs, which is present on the brown dog tick.

Brown dog tick (Rhipicephalus sanguineus)  with “eyes” on the sides of body. Image by Herlberto Verdugo M. & Darby S. Murphy.

Human Health Concerns

The first human ALT bite in the U.S. was reported in 2018 in Westchester County, New York, and did not result in the subject becoming ill. The ALT has not been found on rodents including white-footed mice, shrews and chipmunks, which are natural reservoirs for tick-borne pathogens. In one study, 120 ALTs were tested for pathogens that cause human disease including species in the following genera: Anaplasma, Babesia, Borrelia and Ehrlichia; all were found to be negative. In lab settings, ticks have been reported to transmit Rocky Mountain spotted fever. Further testing is necessary to determine the maintenance and transmission of this pathogen in nature. In a recent study, 263 ticks were tested, and one adult female was positive for Borrelia burgdorferi, a bacterial species that causes Lyme disease. Continued observation and testing of the ALT is imperative to monitor its threat to public health.

Animal Health Concerns

The United States Department of Agriculture and animal health officials have noted their concern about the ALT’s impact on livestock. The ALT is notorious for large-scale infestations with multiple ticks on one animal, which leads to stress on the animal and reductions in growth and production. A serious infestation can lead to death of the animal due to blood loss. The ALT has been linked to the death of five cows in Surry County, North Carolina, with one bull having over 1,000 attached ticks. Cattle tested positive for Theileria orientalis Ikeda at a Virginia farm where the ALT was found. The ALT is referred to as the “cattle tick” in New Zealand, where it has been linked to Theileria orientalis Ikeda outbreaks among cattle.

Integrated Tick Management Strategies

The strategies for avoiding the ALT are similar to techniques used for other tick species, including avoiding wading through the woods or grassy areas. If walking along a path, try to stay near the middle to avoid questing ticks along the grassy edges. It is also important to check clothes and pets after coming in from outdoors, especially after walking through wooded, brushy or grassy areas. Throwing clothes in the dryer on high heat for 10 minutes will kill any ticks that remain hidden on clothes. Check any items for ticks that cannot go in a dryer such as backpacks and shoes. The next suggested strategy is to take a shower and check your body for ticks. Be sure to inspect armpits, ears, bellybutton, back of knees, hair, between legs and waist. Lastly, Asian longhorned ticks can be avoided by purchasing and wearing permethrin-treated clothing or spraying clothes with an EPA-registered insect repellent such as DEET, picaridin, insect repellent (IR) 3535 or oil of lemon eucalyptus. If bitten by a tick, remove immediately by grabbing the tick by the head with a tweezers as close to the skin as possible and pull upwards. Be sure to clean the bite with soap and water or rubbing alcohol.

Integrated tick management strategies for livestock include trimming grass, weeds and branches in and around pastures and ensuring wooded areas are at least 10 feet from fences. Visually check for ticks on animals daily on their chest, jaw, belly, ears, eyelids and elbows and use your hands to feel for embedded ticks. If ticks become a problem, apply a low-risk, EPA-registered insecticide while closely following the label instructions. Area-wide acaricides are another management strategy used to reduce tick populations.

For more information on the Asian longhorned tick, visit the USDA-APHIS website.

Collaborators

Authored by the Public Tick IPM Working Group. For more information see: tickipmwg.wordpress.com

Funding

This work is supported by the USDA National Institute of Food and Agriculture, Crop Protection and Pest Management Program through the North Central IPM Center (2018-70006-28883).

For information about the Pest Alert program, please contact Jacqueline Pohl, communications specialist for the North Central IPM Center at northcentral@ncipmc.org.

April 2021

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**Comment**

According to this study, the ALT contributes minimally, if at all, to transmission of Lyme disease spirochetes in the United States.

Please remember they’ve said this exact same thing about other ticks.

Transmission can still happen and if you are the sorry sucker it happens to – it makes all the difference in the world.  Here’s the deal – ticks are not your friends.Take each and every tick bite as seriously as a heart attack.  Little is known about the Asian Longhorned tick but in Asia it’s bite KILLS 15% of those whom contract it. Don’t take this lightly.

https://madisonarealymesupportgroup.com/2019/06/09/first-us-human-bite-from-worrying-longhorned-tick-noted-but-its-actually-the-second-human-bite/

Excerpt:

Several other human pathogens have been detected in the ticks, but it’s not clear the Asian longhorned species are able to transmit them to humans. They include Anaplasma, Ehrlichia, Rickettsia, and Borrelia species. Lyme disease is caused by Borrelia burgdorferi bacteria.

She warned that the organisms are present in states where longhorned ticks have been found and that it’s possible that the tick—known to be an aggressive biter—might be able to transmit Heartland virus, given its close relationship to SFTS virus.

Pritt said it’s clear that the invasive species is here to stay for the foreseeable future, and next steps should include public awareness campaigns that incorporate the new information, easy-to-use resources for labs to identify the tick, and more research to understand the implications of the new findings.

For a great read on this aggressive biter which can clone itself and is found in sunny open locations:   https://madisonarealymesupportgroup.com/2018/09/12/three-surprising-things-i-learned-about-asian-longhorned-ticks-the-tick-guy-tom-mather/.  This picture demonstrates how if you brush against a blade of grass a literal cluster bomb of ticks explodes onto you.  To downplay this is really short sighted.three_surprising_4.png-2

Category:

Activism, research, Rocky Mountain Spotted Fever, Ticks

Can Powassan Virus Cause Encephalitis or Other Neurologic Damage?

https://danielcameronmd.com/no-neurologic-damage-three-children-lyme-disease-powassan-virus/

CAN POWASSAN VIRUS CAUSE ENCEPHALITIS OR OTHER NEUROLOGIC DAMAGE?

Child with Powassan virus and encephalitis getting temperature taken

Over the past ten years, there have been 75 cases of Powassan virus reported in the United States, according to the Centers for Disease Control and Prevention (CDC). [1] Most cases have been confined to the Northeast and Great Lakes region. That, however, may change. As Lyme disease continues to spread throughout the country, so too may this potentially deadly virus.

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The Powassan virus (POWV) can be transmitted in as little as 15 minutes and is spread primarily through the bite of an infected deer tick. There is no treatment for the Powassan virus, yet it can cause devastating neurologic damage including encephalitis, meningitis or even death.

“About 15% of patients who are infected and have symptoms are not going to survive,” Dr. Jennifer Lyons, chief of the Division of Neurological Infections and Inflammatory Diseases at Brigham and Women’s Hospital in Boston told CNN. [2] “Of the survivors, at least 50% will have long-term neurological damage that is not going to resolve.”

In 2017, two men from Cape Code died from the virus. In 2019, a man from upstate New York died, along with a former US senator from North Carolina. The 66-year-old woman died “nearly three years after she was first hospitalized with what doctors later said was encephalitis” caused by the Powassan virus. [3]

With so much media attention focused on the deaths caused by Powassan virus, both parents and the public are understandably worried. However, a new study published in the journal Emerging Infectious Diseases provides a more optimistic outlook, finding not all subjects had neuroinvasive disease.

3 children with Lyme disease and Powassan virus

Frost and colleagues, from the Marshfield Clinic in northern Wisconsin, looked at serologic evidence of Powassan virus from 95 patients who tested positive for Borrelia burgdorferi, the causative agent of Lyme disease. The patients had visited their clinic between July and August of 2015. [4]

Clinical data was available for only 51 of the 95 patients (53.7%) suspected of having a tick-borne illness. Out of the 51 patients, 3 were children, all of whom had IgM evidence of Powassan virus, as well as IgM and IgG evidence of B. burgdorferi.

However, none of the children, who were all female, had neuroinvasive disease (i.e. encephalitis). [4]

  1. Age 14: 3-day history of urticarial rash. She was treated with doxycycline for 14 days.
  2. Age 4: 1-week history of fever (103°F), listlessness, headache, fatigue, and a maculopapular rash. She was treated with amoxicillin for 21 days.
  3. Age 3: 1-week history of intermittent fever, fussiness, and erythema migrans rash. After developing a urticarial rash on cefuroxime, she was treated with amoxicillin for 21 days.

“In POWV-endemic regions, up to 7% of ticks carry the virus, and seroprevalence among small mammalian hosts can exceed 90%,” the authors point out. Meanwhile, the seroprevalence of the Powassan virus in some regions of North America ranges from 0.5% to 3.3%. [4]

The authors’ conclusion is encouraging:

“The spectrum of disease is broader than previously realized, with most patients having minimally symptomatic infection.”

UPDATED: June 15, 2021

Related Articles:

Powassan virus infection causes polio-like illness

Prevalence of Borrelia infections and Powassan virus in Maine

Maine woman dies from deer tick virus

References:
  1. Centers for Disease Control and Prevention (CDC). https://www.cdc.gov/powassan/index.html
  2. CNN. https://www.cnn.com/2017/05/03/health/powassan-tick-virus/index.html
  3. Outbreak News Today. Powassan virus complications the cause of death of former Sen. Kay Hagan: Report. http://outbreaknewstoday.com/powassan-virus-complications-the-cause-of-death-of-former-sen-kay-hagan-report-71829.
  4. Frost HM, Schotthoefer AM, Thomm AM, et al. Serologic Evidence of Powassan Virus Infection in Patients with Suspected Lyme Disease. Emerg Infect Dis. 2017;23(8):1384-1388.

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Category:

research, Viruses

Tick Season 2021: Why Researchers Are Focusing on Staten Island Backyards

https://www.silive.com/news/2021/06/tick-season-2021-heres-why-researchers-are-focusing-on-staten-island-backyards.html

Tick season 2021: Here’s why researchers are focusing on Staten Island backyards

STATEN ISLAND, N.Y. — For the last four years, researchers from Columbia University have been studying the rise in tick populations and Lyme disease on Staten Island — and the work continues this summer as they drag for ticks, set up hair traps and place trail cameras in residents’ backyards.

The researchers are studying both parks and residential areas to better understand the ecology of ticks and the risk of tick-transmitted diseases in urban environments. And ticks are now being found across all of Staten Island, not just in the southernmost parts.

Most notably, the Asian longhorned tick continues to spread across the borough.

(See link for article)

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**Comment**

For more on Diuk-Wasser’s work.

Category:

Anaplasmosis, Ehrlichiosis, Lyme, research, Rickettsia, Rocky Mountain Spotted Fever, Ticks, Transmission

Eva Sapi, Lyme Disease Research Group on Antibiotic Resistance of Borrelia burgdorferi

Public Tick IPM WG Call Notes – 6.9.2021  Go here for Dr. Sapi’s presentation

A recording of this webinar is available by visiting this link: https://photos.app.goo.gl/vrvbX7HbhcVkrnq37

Dr. Eva Sapi teaches Biology at the University of New Haven and has a research group that studies Borrelia burgdorferi.

Lyme disease numbers are going up with approximately 476,000 of Americans diagnosed and treated for Lyme disease from CDC surveillance data covering 2010-2018.

In vitro and clinical data observing the efficacy of antibiotics against Borrelia burgdorferi found that antibiotics, in some cases, do not work against Borrelia burgdorferi. In the mid-90s, in vivo studies found evidence that antibiotics such as tetracycline, erythromycin or doxycycline, failed to eradicate acute Borrelia burgdorferi infections. Studies turned to a stronger antibiotic, ceftriaxone. These studies also showed antibiotic resistance of Borrelia burgdorferi. These results led to the question of why Borrelia burgdorferi cannot be killed and if any other form(s) exist that are resistant to therapy.

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**Comment**

Very interesting webinar on the persistence of Lyme.

Sapi is also known for her in vitro work with Stevia. When I inquired about dosages, she stated those have not been determined. Dr. Horowitz and many other LLMD’s are using stevia as a biofilm and cyst form disruptor. The new kid on the block is liposomal oregano oil (some also use clove and cinnamon or a combination of the three) based on Dr. Zhang’s work.) When I inquired about these, she stated that these same doctors are also finding results using them but results are anecdotal. Dr. Phillips mentions it in his book “Chronic.” Dr. Ross also mentions it.

I’ve previously used cinnamon, clove, and oregano essential oils (EO’s) put with black seed oil in capsules. When I questioned herbalist Greg Lee on dosage, he agreed with my treatment of a total of 6 drops of EO’s taken twice a day. I never herxed or noticed any recognizable results on this treatment and relapsed on it. Lee spoke about liposomal oils years ago at an ILADS convention, but they were hard to find at the time.

I am currently using the liposomal form of oregano as part of my Bartonella treatment with (Rifampin/Clarithromycin). I’m hoping this combination works and has lasting results. The brand “Doctor Inspired Formulations” within the link can be found cheaper elsewhere, but they are all pretty expensive. I do not have a financial affiliation with anyone. Please note the other liposomal forms they create as well.

Category:

Herbs, Lyme, research, Treatment