Archive for the ‘research’ Category

Lizards May be Protecting People From Lyme Disease in the Southeastern United States

https://www.sciencemag.org/news/2021/02/lizards-may-be-protecting-people-lyme-disease-southeastern-united-states

Lizards may be protecting people from Lyme disease in the southeastern United States

skink_1280p

Lyme disease is one of the most devastating tick-borne infections in the United States, affecting more than 300,000 people each year. It’s also one of the most mysterious: The creature that spreads it—the black-legged tick—lives throughout the country. Yet the northeastern United States is home to far more cases than anywhere else. Now, researchers have identified an unexpected reason: lizards.

Black-legged ticks (Ixodes scapularis), also known as deer ticks, carry corkscrew-shaped bacteria that cause Lyme disease. The ticks pick up the pathogens—spirochetes that belong to the genus Borrelia—when they suck the blood of animals like mice, deer, and lizards. In the next stage of their life cycle, the ticks may latch onto an unlucky human. But every host transmits the microbes differently. Reptiles are worse transmitters than mammals, so ticks that have lived on reptiles are less likely to make people sick.

The north-south divide in Lyme cases is a fairly sharp line right along the border of Virginia and North Carolina. Researchers have hypothesized that disparity in cases stems from ticks feeding on different hosts in the two regions. (See link for article)

_________________________

For more:  

Ulceroglandular Tularemia

https://www.nejm.org/doi/full/10.1056/NEJMicm2031676?query=WB

Ulceroglandular Tularemia

April 8, 2021
N Engl J Med 2021; 384:1349
DOI: 10.1056/NEJMicm2031676

List of authors.

  • Michael Buettcher, M.D.,
  • and Chiara Imbimbo, B.M.


A 5-year-old girl presented to the pediatric emergency department with a 4-week history of painful swelling on both sides of her lower abdomen. Pets that she had regular contact with included a cat and a dog. Six weeks before presentation, her parents had noticed a tick buried in her umbilicus and had removed it with tweezers. Five days later, the patient had fever, loss of appetite, fatigue, and redness around the umbilicus (Panel A). These symptoms abated after 4 days. At the time of this presentation, examination showed marked inguinal lymphadenopathy on both sides (Panel B). Treatment with oral ciprofloxacin was initiated for suspected ulceroglandular tularemia. Serologic testing supported the diagnosis; the Francisella tularensis antibody titer was 1:1280. Two weeks after the completion of treatment, there was a reduction in the lymphadenopathy. After an additional 2 weeks, the swelling had completely resolved.


For more:

According to DHS, tularemia in Wisconsin is rare, with less than one case per year since 1980.  In 2016, a tularemia alert was given for La Crosse due to the death of three infected cats.  And according to this report, while rabbits are the main source of transmission in Wisconsin, aquatic mammals (muskrat, beaver), woodticks, upland game birds: (partridge, pheasant, prairie chicken), cats, squirrels, deer-fly bites, skunks horses, sick dogs which killed rabbits, foxes, possible skunk, mink, muskrat or raccoon are also responsible.  One case was recorded from exposure to a contaminated stream.  It’s been called “Deer-fly Fever.”

Lyme Disease Has the Potential to Emerge in a Wider Range of Habitats Than Previously Thought

https://medicalxpress.com/news/2021-03-lyme-disease-potential-emerge-wider

Lyme disease has the potential to emerge in a wider range of habitats than previously thought

March 21, 2021

scotland
Lyme disease has the potential to emerge in a wider range of habitats than previously thought, suggests University of Liverpool and University of Glasgow research.

A new study, published in Emerging Infectious Diseases found that open, treeless habitats can support similar densities of infected ticks as woodland in the UK, challenging established knowledge of which habitats present the most risk.

Lyme disease—an infection contracted from the bite of an infected – is growing in incidence in people in the UK and large parts of Europe and North America. It is usually associated with forested habitats but over the past decade has, somewhat surprisingly, emerged on treeless islands in the Western Isles of Scotland.

Researchers from the Universities of Liverpool and Glasgow, in collaboration with NHS Western Isles and NatureScot, examined the different human and environmental factors which could have contributed to the rise of Lyme disease in the Western Isles.

Co-lead researcher Dr. Caroline Millins, a research fellow at the University of Liverpool, said: “Superficially, the habitats and the climate of these islands look very similar, yet the incidence of Lyme disease on some islands is 40 times higher than the national average for Scotland, while other nearby islands are relatively less affected. This is really intriguing from an ecological and public health perspective so we wanted to try and understand what could be causing this difference.”

For the study, the researchers sampled ticks from different habitats on islands with high Lyme disease incidence and on islands with low incidence to determine tick numbers and infection rates. None of these islands had any forests. They also analyzed survey responses from 522 local adult residents to understand the social and behavioral factors that influence when and where people are exposed to tick bites.

The proportion of infected ticks was found to be around 6% on islands with high numbers of Lyme disease cases, compared to less than 1% on islands with low numbers of cases.

On islands with a high incidence of Lyme disease, the researchers found that open habitats, including grassland and domestic gardens, had similar tick density and prevalence of infected ticks as forested mainland sites in Scotland.

Co-lead researcher Dr. Roman Biek, from the University of Glasgow, said: “This is a striking finding and suggests that microclimatic conditions in these open habitats, possibly driven by the milder oceanic climate on the Western Isles, can be as conducive to tick survival as conditions in woodlands.

“Our study highlights the potential for Lyme disease to emerge in habitats with a suitable climate other than forests so we should be looking at non-forested habitats more broadly both in the UK and globally.

The survey results found that residents on islands with a high incidence of Lyme disease were more likely to be bitten by ticks, with most people being bitten close to their home or in their gardens. Residents also reported increasing problems with ticks, with many suggesting increasing numbers of deer, and deer coming closer to people’s homes, as a potential driver.

“When we visited the and attended community meetings, there were significant concerns raised by residents about frequent tick bites in their gardens.”

Dr. Millins said: “Our surveys support residents’ concerns and show that spillover of infected ticks into people’s gardens is very common. These findings can suggest ways we might be able to reduce exposure risk, for example by managing garden environments to reduce tick numbers. We have also started to investigate how deer move across the landscape and how that might affect where ticks are found.”

NatureScot’s Outer Hebrides Operations Manager Johanne Ferguson said: “This important piece of research confirms what many in the Uist community have been reporting for some time—that infected ticks are being found much closer to home. The Lyme Disease Research project is carrying out ongoing research into this, which will inform NatureScot’s work with the Uist community, the Uist Deer Management Group and others to find ways to reduce the tick burden in and around villages.”

Isabell MacInnes, a public health nurse specialist with NHS Western Isles said: “We are aware of the increasing numbers of cases of Lyme disease being reported in people living in the Western Isles, and we welcome the evidence provided through this research, which we will use to guide future public health actions.”


More information: Caroline Millins et al. Emergence of Lyme Disease on Treeless Islands, Scotland, United Kingdom, Emerging Infectious Diseases (2021). DOI: 10.3201/eid2702.203862
Journal information: Emerging Infectious Diseases

1st Report of Deer Ticks Parasitizing a North American Porcupine in Canada

https://www.mdpi.com/2673-6772/1/2/6/htm

First Report of Ixodes scapularis Ticks Parasitizing a North American Porcupine in Canada

by John D. Scott
 
 
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
Academic Editor: Theo De Waal
Parasitologia 2021, 1(2), 45-49; https://doi.org/10.3390/parasitologia1020006
Received: 16 February 2021 / Revised: 18 March 2021 / Accepted: 25 March 2021 / Published: 1 April 2021

Abstract

Adult females of the blacklegged tick, Ixodes scapularis (Acari: Ixodidae), were collected from a North American porcupine, Erethizon dorsatum, in eastern Ontario, Canada. This porcupine parasitism indicates that an established population of I. scapularis is present in the local vicinity. This tick species is known to parasitize more than 150 different vertebrate hosts, including the North American porcupine. The presence of I. scapularis ticks parasitizing a North American porcupine constitutes a new tick-host record in Canada.

1. Introduction

The North American porcupine, Erethizon dorsatum (Rodentia: Erethizontidae), also known as the Canadian porcupine, is a herbivore rodent. This meso-mammal is one of the largest members in the rodent family, and has wide distribution across continental North America. This woodland denizen is native to coniferous and mixed forests across southern Canada, and its distribution extends southward into northeastern, north-central, and western United States as far south as the northern fringe of Mexico. Ecologically, free-ranging porcupines have a home range of up to 28 ha. This arboreal herbivore is covered with a coat of quills that arm it from predators. Once a porcupine is threatened, it will hide its face, swat its tail at its assailant, and thrust an arsenal of quills in multiple directions to strike its attacker. The sharp, needle-like quills are painful, and prudent attackers retreat. In the spring and summer, porcupines feed on berries, seeds, grasses, leaves, roots, and stems. In the winter, North American porcupines feed on the inner bark of trees. As these herbivore rodents forage for food, they make direct contact with low-lying vegetation where ticks are questing.
Blacklegged ticks, Ixodes scapularis (Acari: Ixodidae), are indigenous across North America east of the Rocky Mountains [1]. Ixodidae, commonly referred to as hard ticks, are predominantly blood-feeding ectoparasites of mammals and birds although several species feed on reptiles [1]. Tiny ticks maintain a stealth presence in the natural environment, and covertly parasitize North American porcupines. These quill-laden rodents are primarily nocturnal, but will defend themselves at any time of day. In Wisconsin, wildlife rehabilitators collected I. scapularis adults from several North American porcupines [2].
 
The locality where the free-ranging porcupine was found is in the Great Lakes-St. Lawrence forest region which consists primarily of red pine, eastern white pine, eastern hemlock, yellow birch, sugar maple, and red oak [3]. In a tick-host study conducted across Ontario with veterinarians, wildlife rehabilitators, and the public, acarologists previously detected I. scapularis ticks on domestic dogs, cats, and humans in the same precambrian area (Canadian Shield) [4]. Although porcupines have feeding activities in trees, these spiny rodents will have direct contact with low-lying vegetation when they are feeding at ground level. If present, this is where I. scapularis ticks are questing. Depending on the time of year and their developmental life stage, I. scapularis ticks conduct host-seeking activities anytime through the day. Several blacklegged ticks collected within a single collection period (a single year) indicate that a reproducing population of I. scapularisis present [5,6].

2. Results

The North American porcupine was found on the side of the road north of Westport, Ontario on County Road 10 (44.687° N, 76.385° W), which is situated within the Canadian Shield (Figure 1). The injured porcupine was taken to Sandy Pines Wildlife Centre, Napanee, Ontario, and a wildlife rehabilitator examined it. Since the head had visible trauma, it is believed that the porcupine was struck by a passing vehicle. Based on a x-ray, veterinary technicians also found a diaphramatic hernia. Due to the severity of trauma, the North American porcupine was promptly euthanized upon arrival, and five partially engorged I. scapularisfemales were collected.

3. Discussion

The collection of five engorged I. scapularis females feeding on a North American porcupine is a novel discovery in Canada (Figure 2). Based on a literature search [2,7,8,9] and the Canadian National Collection, the author affirms that this mammalian parasitism is the first documentation of I. scapularis parasitizing a North American porcupine in Canada. (See link for full article)

New Lyme Disease Test Distinguishes Between Early and Late-Stage Disease

ihttps://medicalxpress.com/news/2021-04-lyme-disease-distinguishes-early-late-stage

New Lyme disease test distinguishes between early and late-stage disease

April 7, 2021

Lyme disease

For those who live in an area blighted by ticks, the threat of Lyme disease can cast a shadow over the joy of spring and summer. These blood-sucking arachnids can transmit bacteria into the bloodstream of their unsuspecting host, causing the disease. Early treatment is essential, but current tests are not usually sensitive enough to detect the disease in early-stage patients. A recent study in open-access journal Frontiers in Microbiology reveals a new test for Lyme disease, which is the first to reliably distinguish between early- and late-stage patients. The test detects a genetic sequence left by a virus that resides in Lyme-causing bacteria, and can detect just one bacterial cell in a small blood sample.

As the most common tick-borne infection, Lyme affects nearly 500,000 people in the U.S. every year. Symptoms include fever, fatigue, joint pain, and a distinctive ‘bullseye’ rash, but if left untreated, the disease can cause paralysis and even death. As such, is important, but difficult.

“Early diagnosis of Lyme disease is absolutely vital in reducing suffering, because early Lyme can be treated, but late Lyme is very difficult to treat,” explained Dr. Jinyu Shan of the University of Leicester, lead author on the study. “Current tests cannot typically detect the low numbers of bacteria in early-stage patient blood samples. Our goal was to design a highly sensitive to help doctors to identify Lyme disease as early as possible.” (See link for article)

______________________

Study here: https://madisonarealymesupportgroup.com/2021/03/31/targeting-multicopy-prophage-genes-for-the-increased-detection-of-borrelia-burgdorferi-sensu-lato-the-causative-agents-of-lyme-disease-in-blood/

Evidently the test is unique in that it is based on prophages that have a genetic sequence inserted into the bacteria by a virus which can escape the bacteria, and is more likely to be picked up in the blood due to having multiple copies within cells.

They found the test is sensitive and can detect one bacterial cell in .3 mL of blood.  Infected patients have between 1-100 bacterial cells per mL of blood.

The test is the first to distinguish between healthy, early-stage, and late-stage samples.


I must admit that the debacle with PCR testing for COVID has made me extremely skeptical and wary.  I hope that this isn’t too good to be true.  Time will tell.