Ticks Spread Plenty More for You to Worry About Beyond Lyme Disease
By Jerome Goddard
When it comes to problems caused by ticks, Lyme disease hogs a lot of the limelight. But various tick species carry and transmit a collection of other pathogens, some of which cause serious, even fatal, conditions.
In fact, the number of tick-borne disease cases is on the rise in the U.S. The range where various species of ticks live in North America may be expanding due to climate change. Researchers continue to discover new pathogens that live in ticks. And new, invasive tick species keep turning up.
In my career as a public health entomologist, I've been amazed at the ability of ticks to bounce back from all the ways people try to control them, including with pesticides. Ticks excel at finding new ecological niches for survival. So people and ticks frequently cross paths, exposing us to their bites and the diseases they carry.
Here are some of the lesser-known, but growing, threats from ticks.
Ticks Can Spread Bacterial Diseases
Certain very small species of bacteria that can cause human diseases, such as rickettsia, ehrlichia and anaplasma, live in ticks. Ticks ingest these bacteria when they drink animals' blood. Then when the ticks take a subsequent blood meal, they pass the bacteria along to the next animal or person they feed on.
Probably the most well known of these bacterial diseases is Rocky Mountain spotted fever, the most frequently reported rickettsial disease in the U.S., with about 6,000 cases each year. The number of diagnoses seems to be increasing nationwide, especially among Native Americans, probably due to exposure on reservations to free-roaming dogs that can carry ticks.
Rocky Mountain spotted fever usually comes with a rash, as on this child.
Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases (NCIRD), CC BY
When people get sick with Rocky Mountain spotted fever, they usually come to a clinic with three things: fever, rash and history of tick bite. They may also report severe headache, chills and muscle pains, and gastrointestinal symptoms such as abdominal pain and diarrhea. A skin rash is usually present after a few days, but not always. Mental confusion, coma and death can occur in severe cases. Untreated, the mortality rate is about 20%; and even with treatment, 4% of those infected die.
Not all tick species are effective transmitters of the rickettsia bacteria. Even within the vector species, often only 1% to 5% of ticks in an area are infected. So getting bitten by a tick that passes rickettsia bacteria on to you is like getting stuck with a needle in a haystack. The primary carriers are the American dog tick in the eastern U.S. and Rocky Mountain wood tick in the West. The brown dog tick has also recently been shown to be a vector.
In most tick-borne diseases, the tick needs to feed for some amount of time before any pathogens it is carrying are transmitted to the animal whose blood it is eating. Rocky Mountain spotted fever organisms generally take between one and three hours for transmission to occur, so attached ticks need to be removed quickly. Doctors usually prescribe the antibiotic doxycycline to treat Rocky Mountain spotted fever, which works quite well if the disease is recognized early.
Ehrlichiosis is another bacterial disease transmitted from ticks to people. In the U.S. it's most commonly caused by Ehrlichia chaffeensis bacteria, carried by lone star ticks which are common in the eastern U.S. Ehrlichia bacteria infect a type of blood cell called leukocytes. Human monocytic ehrlichiosis occurs mostly in the southern and south-central U.S.; 1,642 cases were reported to the CDC in 2017.
Ehrlichiosis patients usually have fever, headache, muscle aches and a progressive low white blood cell count. As opposed to Rocky Mountain spotted fever, people get a rash only about 20% to 40% of the time. Doctors usually treat ehrlichiosis with doxycycline.
Another tick-borne bacterial disease to worry about is human granulocytic anaplasmosis. In human granulocytic anaplasmosis, Anaplasma phagocytophilum bacteria infects a type of white blood cell called granulocytes. It mostly occurs in the upper midwestern and northeastern U.S., and the incidence is increasing, with 5,762 cases of human granulocytic anaplasmosis reported to the CDC in 2017.
Symptoms include fever, headache, muscle aches and progressive low white blood cell count. It's the deer tick Ixodes scapularis — famously also responsible for Lyme disease — that transmits the Anaplasma bacteria to humans. There's the unlucky chance that a bite from a deer tick could infect you with both diseases. Again, recommended therapy is doxycycline.
A female Ixodes scapularis tick.
Dr. Blake Layton, MSU, CC BY-ND
Ticks Can Carry Viruses, Too
People usually think of mosquitoes when they think of insect-transmitted viruses – dengue, Zika or West Nile garner a lot of headlines. But ticks can transmit viruses, too.
Scientists have historically grouped tick-borne viral diseases into two categories. One is diseases similar to dengue fever. The main dengue-like viral disease transmitted by ticks in the U.S. is Colorado tick fever, which occurs in mountainous areas of the West.
The other group of tick-borne diseases resemble mosquito-borne encephalitis. Most of these illnesses, characterized by brain inflammation, are not found in the U.S. Powassan encephalitis is the one that is, occurring in the northeastern U.S. and adjacent regions of Canada.
Powassan is a relatively rare but serious human disease, characterized by sudden onset of fever with temperature up to 104 degrees Fahrenheit, along with convulsions. Brain inflammation is usually severe, with vomiting, respiratory distress and prolonged fever.
Fewer than 100 cases of Powassan have been reported in North America, with about half of them fatal. Its incidence seems to be increasing; there were 34 cases of Powassan reported during 2017. POW is maintained in a natural cycle when ticks — primarily Ixodes cookei — infect animals with the virus via their bites. Then these infected animals may serve as what scientists call disease reservoirs, infecting new ticks when they feed on their blood.
Tiny larval lone star ticks next to a penny.
In the last decade, researchers have found additional new tick-borne viruses in the U.S. About 30 cases of Heartland virus have thus far been identified. It's associated with the lone star tick and has been recognized in Missouri, Oklahoma, Kentucky and Tennessee.
A few cases of a new Thogotovirus called Bourbon virus have been identified in the Midwest and southern U.S. The lone star tick may be the vector of Bourbon virus as well.
A Food Allergy Triggered by a Tick Bite
Maybe the most bizarre threat from ticks is the "red meat allergy" scientists have recently traced back to tick bites. People can become allergic to eating meat when a tick's saliva passes on the carbohydrate galactose-α-1.3-galactose it had previously picked up in a blood meal from an animal. If prone to allergies, the person can get sensitized to that alpha-gal molecule that's found in animal blood and other tissues.
Then days or weeks later, he or she may develop hives, swollen skin and lips, or even life-threatening anaphylactic shock three to six hours after eating red meat. Meats containing alpha-gal include beef, pork, lamb, squirrel, rabbit, horse, goat, deer, kangaroo, seal and whale. People who become sensitized to alpha-gal may still eat chicken, turkey and fish.
Overall, people should be aware of what tick-borne diseases are present in their area and use personal protection techniques whenever outdoors in tick-infested areas. Remember that ticks often come into close contact with people via pet dogs or cats. It's a good idea to inspect yourself for ticks after being outdoors in tick-infested areas. Reducing the number of tick bites and the amount of time ticks remain attached can go a long way to protecting you from tick-borne diseases.
Invasive Tick Spreads to Ninth State, CDC Warns of 'New and Emerging Disease Threat' https://t.co/9r4yqpJvxJ— EcoWatch (@EcoWatch) December 3, 2018
Jerome Goddard is an extension professor of biochemistry, molecular biology, entomology and plant pathology at Mississippi State University.
Disclosure statement: Jerome Goddard does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond his academic appointment.
Reposted with permission from our media associate The Conversation.
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By Zahida Sherman
Cooking has always intimidated me. As a child, I would anxiously peer into the kitchen as my mother prepared Christmas dinner for our family.
Falling in Love With Food All Over Again<p>Slowly, through my most intimate relationships with friends and partners, I began to see the beauty — and rewards — of cooking.</p><p>I got tired of giving in to defeat and always bringing chips or paper products to social gatherings. I started asking my mom to send me her Christmas and Thanksgiving recipes. I even volunteered to host Thanksgiving dinner at my place.</p><p>Each time I heard my loved ones sing the praises of the foods I prepared for them, I felt a tinge more confident that I could carry out our traditions my way.</p><p>In reaching out to other relatives for their favorite recipes, I learned that they had a little help of their own. They didn't rely solely on their ancestral cooking instincts. They turned to Black chefs for guidance.</p><p>These 7 cookbooks by Black chefs have inspired my family and fed us in nutrients, joy, and spiritual sustenance. They're also helping me overcome my personal fears of cooking.</p>
Get CookingWhether you're in recovery from cooking fears like me, or are just looking to expand your culinary confidence with dishes honoring Black heritage, these Black chefs are here to support you on your journey.Turn on some music, give yourself permission to make mistakes, and throw down for yourself or your loved ones. Glorious flavors await you.
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By Tara Lohan
The conclusion to decades of work to remove a dam on the Middle Fork Nooksack River east of Bellingham, Washington began with a bang yesterday as crews breached the dam with a carefully planned detonation. This explosive denouement is also a beginning.
The History<p>The Middle Fork Nooksack drains glacier-fed headwater streams that run off the icy summit of 10,778-foot Mt. Baker. The Middle Fork joins the North Fork and then the mainstem of the Nooksack River, which travels to Bellingham Bay and Puget Sound. The entire Nooksack watershed stretches 830 square miles across Washington and into British Columbia.</p>
A Plan Comes Together<p>The Middle Fork dam is not a pool dam built for water storage. Much of the time, water flows over the top until dam operators drop a floodgate to divert water to new locations. That water travels about 14 miles through tunnel and pipeline to Mirror Lake, then Anderson Creek, and to Lake Whatcom before finally being delivered to residents' taps.</p><p>Before removing the dam, engineers had to move the water intake 700 feet upstream and situate it at an elevation that still enabled city water withdrawals throughout the year, regardless of flow conditions.</p><p>They also needed to make sure that the rushing water didn't sweep up fish and accidentally send them through the water-supply system.</p><p>"The solution required a fairly complex design in the intake structure, including a fish exit pipe out of that structure to put fish back into the river in a way that meets current environmental permit standards," explains LaCroix.</p>
Project layout for the removal of the Middle Fork Nooksack diversion dam and rebuilding of water intake. City of Bellingham<p>Despite the cost and the work, she says, being able to continue to meet their municipal water obligations while opening up habitat for threatened species has been a win-win.</p><p>"I think there's a lot of benefits to having a dam removal versus fish passage — the main one being that you get a free-flowing river that can be a dynamic ecosystem and change over time," she says. "A static fish ladder just can't provide that same level of ecosystem benefit."</p>
Restoration Success<p>Despite local authorities' championing dam removal on the Middle Fork, the project has largely flown under the radar, overshadowed in the Pacific Northwest by heated discussions about a much larger potential project — removing <a href="https://www.seattletimes.com/seattle-news/feds-reject-removal-of-4-snake-river-dams-in-key-report/" target="_blank">four federal hydroelectric dams on the lower Snake River</a>, a major tributary of the Columbia River.</p><p>Proponents of dam removal there see it as the best chance for recovering threatened salmon populations, including Chinook, which could help starving Southern Resident killer whales. Those dams also provide irrigation water, barge navigation and hydropower, so there's been more pushback against removal efforts.</p><p>Previous dam removals around the country, however, have proved successful at aiding fish recovery and river restoration.</p><p>Most notably the 1999 demolition of <a href="https://therevelator.org/edwards-dam-removal/" target="_blank">Edwards Dam on Maine's Kennebec River</a> restored the annual run of alewives, a type of herring essential to the food web. The fish run has gone from zero to 5 million in the two decades since dam removal. Blueback herring, striped bass, sturgeon and shad have also extended their reach. And the resurgence has brought back osprey, bald eagles and other wildlife, too.</p><p>The overwhelming success of river restoration on the Kennebec helped to spur a nationwide dam removal movement that's now seen 1,200 dams come down since 1999. Last year a record <a href="https://www.americanrivers.org/conservation-resource/a-record-26-states-removed-dams-in-2019/" target="_blank">90 dams</a> were removed in 26 states, including <a href="https://therevelator.org/cleveland-forest-dam-removal/" target="_blank">20 dams in California's Cleveland National Forest</a>.</p>
Spider excavators remove on dam on San Juan Creek in California's Cleveland National Forest. Julie Donnell, USFS<p>The results have been seen in the Pacific Northwest, as well, which boasts the largest dam removal thus far in the country. In 2011 and 2014, the demolition of <a href="https://therevelator.org/elwha-dam-removal/" target="_blank">two dams</a> on Elwha River, which runs through Washington's Olympic National Park, opened up 70 miles of habitat that had been blocked for a century. Scientists have started seeing all five species of salmon native to the river coming back, particularly Chinook and coho. Bull trout, they've observed, have increased in size since the dams were removal.</p>
Benefits on the Middle Fork Nooksack<p>McEwan hopes to see a similar outcome on the Middle Fork.</p><p>Like the Elwha the Middle Fork Nooksack is a relatively pristine river with little development, and dam removal is expected to provide a big boost to fish. The additional miles of spawning habitat are important, but so is the temperature of that water.</p><p>The dam removal will open access to cold upstream waters, which are ideal for salmon and getting harder to come by as climate change warms waters and reduces mountain runoff.</p><p>"This is really great for the climate change resiliency for these species," says McEwan.</p><p>Steelhead will get back 45% of their historic habitat in the river, and scientists expect Chinook populations to increase in abundance by 31%.</p><p>That <em>could</em> help Southern Resident killer whales.</p><p>"When you get to the ocean, it's a little bit of a black box in terms of what you can model and say definitively is going to help, but more fish is better for orcas," McEwan says.</p><p>Upstream habitat will see benefits, too.</p><p>Oceangoing fish like salmon enrich their bodies with carbon and nitrogen while at sea. When they return to their natal rivers to spawn and die, the marine-derived nutrients they carry back upriver become important food and fertilizer for both riverine and terrestrial ecosystems — aiding everything from trees to birds to bears.</p><p>"Once the fish start making their way back, it will start changing the whole ecological system," says Delgado.</p><p><span></span>But any ecological benefit from salmon restoration, either in the ocean or the upper watershed, won't be immediate.<br></p><p>"The population of salmon on the Middle Fork is so low that we expect it's going to take quite a while to rebound," she says. "But the big picture is that what's good for salmon is good for the region — our history and our destiny are intricately intertwined."</p><p>After decades of work, that process of restoration has finally begun.</p>
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A new tool called The Food Systems Dashboard aims to save decision makers time and energy by painting a complete picture of a country's food system. Created by the Johns Hopkins' Alliance for a Healthier World, the Global Alliance for Improved Nutrition (GAIN), and the U.N. Food and Agriculture Organization (FAO), the Dashboard compiles food systems data from over 35 sources and offers it as a public good.
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It can grow to a maximum of six inches (16 centimeters), change color depending on mood and habitat, and, like all seahorses, the White's seahorse male gestates its young. But this tiny snouted fish is under threat.
Building an Ocean Seahorse Destination<p>Seahorses are found in tropical and temperate coastal water worldwide, but are most abundant around Australia, China and the Philippines. </p><p>Trade in the tiny creatures is strictly regulated because of their use in traditional medicine, aquariums and their sale as dried curios. But because they are poor swimmers and cannot easily move elsewhere, habitat loss is a particular threat for these curious animals. </p><p>Seahorses wrap their tails around seagrass and corals to avoid being carried away on currents. They use the habitat to spawn and hide from predators such as crabs, while also feeding on riches of plankton and small crustaceans living in the reef.</p><p><span></span>Where corals aren't available, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/aqc.1217" target="_blank">scientists</a> found seahorses taking up residence in fishing nets and old crab traps abandoned at the bottom of the ocean. </p>
Mixing With the Locals<p>Baby seahorse mortality is high in the wild because they are easily caught, so those bred in the protected environment of the aquarium weren't ready to be released into the wild until early May.</p><p>The team released 90 new arrivals into Sydney Harbor, placing some directly into the purpose-built hotels, and others onto a net that wild seahorses had already settled on.</p><p>Before setting them free, the researchers marked each young seahorse with a fluorescent tag with unique IDs inserted just beneath the skin to track how they get on in the different environments. </p><p>"The most exciting part was being able to put these animals into the wild and then go back a month later and still see them surviving and growing," said McCracken. </p><p>The seahorses will be old enough to mate and reproduce around October or November 2020. And researchers hope that by then, they will be able to breed with the wild population. </p>
Building a Global Seahorse Hotel Chain<p>With seahorses everywhere facing the loss of their coral reef homes, similar projects have sprung up in places like Greece and South Africa, home to the world's most endangered seahorse, the Knysna seahorse. </p><p>"The endangered South African seahorse is benefiting from something quite similar, even though it wasn't intentional," said Peter Teske, professor at the Department of Zoology, University of Johannesburg.</p><p>In the South African <a href="https://www.researchgate.net/publication/322649251_An_endangered_seahorse_selectively_chooses_an_artificial_structure" target="_blank">case</a>, seahorses have bedded down in "Reno mattresses" — wire cages filled with rocks — that were used to build a new marina. Researchers from NGO Knysna Basin Project found the structures acted as a refuge for the animals.<span></span></p><p><span></span>While Teske describes the seahorse hotels as "a positive news story" and a great way to create public awareness of conservation, he added that establishing artificial habitats in some areas will only prevent the extinction of local populations.</p><p>"For a complete recovery, it is necessary to give the natural habitat a chance to regenerate," said the seahorse expert. </p>
Underwater Mascot<p>In Australia, the researchers hope the project could provide an opportunity to raise awareness not only of the plight of the Sydney seahorses but the other animals with which it shares its ocean habitat.</p><p>The waters around Sydney and the east coast are rich in biodiversity and include several threatened species like the weedy seadragon — a relative of the seahorse — and the grey nurse shark. Like the seahorse, they're also under pressure from pollution, ocean traffic and habitat loss through storms and coastal construction. </p><p>"It's a good thing to get people's support and interest. The seahorses are a useful vehicle to get people concerned if the harbor is in trouble," said David Booth, professor of marine ecology at the University of Technology Sydney who is also working on the project. </p><p>The hotels have become an attraction for divers hoping to catch a glimpse of these small but near mythical creatures. </p><p>"Everyone loves seahorses," added Booth, "they are so popular." </p>
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