by MACOR Industries Inc.

About Ticks and Tick-borne Diseases

Diagnosis—Treatment and Prevention

Dr. Chris Riemann, M.D.

Introduction

Despite promising developments in both the prevention and treatment, incidents of debilitating tick-borne afflictions continue to occur at record levels. According to the Center for Disease Control and Prevention, more than 16,000 cases are recorded annually, with possibly as many as three to five times more cases unreported.

Tick-borne diseases are, unfortunately, here to stay. They are endemic around the world, have great reservoirs in the natural animal populations and are highly resistant to any form of widespread control efforts. As more medical and veterinary practitioners become familiar with tick-borne diseases, we predict with a great deal of confidence that the recognized incidence rate of these diseases will increase dramatically.

What makes these diseases even more dangerous is that the symptoms are frequently overlooked. Their ability to mimic so many other diseases often leaves them undiagnosed and consequently untreated. Prevention and early treatment are the only ways to avoid the often-serious secondary consequences of these diseases. Best is, of course, to locate and remove ticks quickly, if encountered, to avoid infections.

Tick season is generally from March to October, peaking in July and August, pending on location. Many species of ticks exist throughout the world. They can affect the health of people and animals by the direct effect of secretions released into the host during feeding or by transmission of disease-causing organisms. Tick saliva may contain anticoagulants or substances that destroy host cells in order to enlarge the feeding area. The saliva may also contain toxins that can affect the host’s general metabolism or cause flaccid paralysis.

In the United States, ticks transmit the causative organisms of Lyme Borreliosis, Rocky Mountain Spotted Fever, Ehrlichiosis and other less common diseases. They are zoonotic (diseases shared by humans and animals).

Lyme Disease

Lyme Disease was first identified in 1977, when a peculiar form of arthritis was found among children near Lyme, Connecticut. It is the most common tick-borne disease in the United States, caused by a spirochete called Borrelia Burgdorfer and can be transmitted by various species of ticks, primarily by deer ticks. Dogs and humans are the main victims. Human symptoms include a red rash around the bite (this does not always occur) and early signs involve flulike symptoms. In dogs, lameness and fever are the predominant signs; loss of appetite, fatigue and swollen glands can also be seen.

 

Red rash after Lyme infection

Lyme disease is treated with antibiotics, the earlier the better. Humans and dogs do appear frequently to be fully recovered within 24 hours of antibiotic treatment. The penicillin and tetracycline families of antibiotics currently are the best therapeutic drugs. If not diagnosed and treated from its early and generally nonsymptomatic stages, Lyme frequently becomes a chronic “for life” condition.

Rocky Mountain Spotted Fever

RMSF often is misdiagnosed because of the variability and severity of its range of possible symptoms. The etiological is Rickettsia rickettsii, usually transmitted by the American dog tick and seen mainly during tick season.

In people, the symptoms are primarily flulike and include headache, fever, chills, pain and nausea. Sometimes, a rash appears on the ankles and wrists. Symptoms occur within two days to two weeks of the tick bite.

In dogs, the symptoms range from swollen lymph nodes to coughing, from diarrhea and vomiting to neurological abnormalities and kidney failure.

Without treatment, the disease can be fatal in pets and people. Treatment of patients with RMSF is mainly supportive and includes intravenous fluid therapy, transfusion of whole blood or platelet-rich plasma, short-term treatment with corticosteroids and antibiotic therapy.

Ehrlichiosis

Ehrlichiosis canis is an infectious blood parasite and causes a disease that attacks white blood cells and the ability of the immune system to make new blood cells. Once thought to be strictly a canine disease, ehrlichiosis has attacked at least 400 humans since 1987.

Diagnosis is difficult in humans and dogs, but the symptoms are similar for both. Stage 1 appears as a mild viral infection. Fever, depression and loss of appetite are common symptoms. Stage 2 is more acute, accompanied by pneumonia, disorientation, increased thirst and urination and weight loss. During Stage 3, the parasite moves into the bone marrow, making the disease chronic and irreversible. At this stage, massive internal hemorrhaging, heart attack, stroke, venal failure or liver failure may occur, all resulting in death.

Treatment of the disease is with antibiotics. During the acute phase, clinical signs and hematological measurements may improve within 24 to 48 hours after initiation of antibiotic therapy. Unfortunately, little can be done if it progresses much further.

Ticks, Infection and Incubation

Tick attached to skin, taking blood meal

Ticks relish blood. Related to spiders, there are more than 650 species of the eight-legged “Ixodidae” family of hard ticks worldwide. Most are brown to gray with oval shaped, hard, flat bodies that plump like tiny blood-filled balloons when attached and feeding. Unlike fleas, hard ticks spend 90 percent or more of their lifetime off the host. Most have a three-host cycle, with each stage preferring a specific host.

Adult ticks need a blood meal before mating, then drop off the host to lay 1,000 to 4,000 eggs, depending on the species. Eggs hatch into “seed ticks,” tiny six-legged larvae that crawl onto vegetation to await a passing host. Larvae feed several days before dropping off the host to molt into eight-legged nymphs. Nymphal ticks again seek an appropriate host and after another blood meal they drop off and molt into adults. Hosts during the development stages through larvae and nymph are exclusively small mammals such as mice and birds. Only adult ticks attack larger hosts.

Once ticks get on a host to take a blood meal, they do not hop off and go for another blood meal. That means people do not get tick-borne diseases from their pets, but removing ticks with bare hands can cause exposure to infection.

Not all ticks carry diseases. Estimates of the number that do, range from five to twenty percent. Four to six hours after the bite, the blood meal begins, lasting several days, with the tick growing into the size of a cherry pit. During this time, the tick is continuously injecting saliva into the host, as mentioned above. This is the dangerous part. The saliva contains two substances—one to prevent the blood from coagulating, the other to numb the nerves in the skin and, therefore, can pass on the disease if the tick is infected. Infection of the host does not occur immediately, but usually after several hours.

The incubation period is 3 to 30 days, following the bite and infection.

Preventing Infections by Ticks

Tick repellent products for animals (flea and tick collars) and topical preventive medication offer, in general, limited and short-term results only. No such products are currently available for humans. Therefore, the best defense in preventing infection caused by ticks is awareness about ticks and tick-borne diseases, checking ourselves and family members thoroughly, in particular after outdoor activities and, most importantly, the immediate and complete removal of ticks.

Unfortunately, there is little knowledge about the correct method to remove ticks from humans and animals and facts about tick removal in general. The results of this are frequently very messy and dangerous “tick-pulling” procedures, making things worse instead of better.

Ticks should never be removed by using force and pulling, trying to burn them, using oil, glue, alcohol—or even worse methods.

Not knowing how to proceed to remove a tick frequently causes worries, sometimes panic and concern. Most of us really hate everything about ticks and tick removal.

Removing ticks by force and a pulling motion will very frequently result in a broken-off mouthpart, the hypostome, leaving parts imbedded in the skin of the host. This condition requires surgical removal to avoid additional infections, discomfort/itching for up to six months or worse complications, until the tissues of the body finally absorb these parts.

Further, the use of force, tweezers and hemostats (forceps) will frequently rupture ticks, in particular if imbedded or engorged, causing a really ugly situation.

To perform effective tick removal is, in fact, very simple and safe, providing it is done correctly. The hooks on the mouthpart of the tick (head) do resist pulling but not turning. A gentle turning motion (3 to 4 revolutions) will loosen the grip, by loosening the “hooks” and enlarging the hole in the skin. After a few gentle turns, the tick will slide out of the skin, completely, without leaving parts imbedded.

Our wrist does not allow a turning motion of more than 180 degrees. Therefore, this method requires an instrument that is capable of holding the tick without destroying it, and allowing the turning motion.

Tests have shown only two devices that were designed to perform this procedure correctly:

1. The De-Ticker, very easy to use with consistent results, cost under $5.00.

2. The O’Tom hook, similar function, but more difficult to hold and turn, cost under $7.00.

There are numerous “tick pullers” available. All of the ones we have seen and tested do use force and pulling and are, therefore, unsuitable for safe tick removal. Actually, these devices have given tick-removing devices a bad reputation.

Conclusion

If a tick is encountered, it is too late to try to find a suitable device to remove it correctly. Therefore, having a well-designed tick remover readily available in the medicine cabinet is the best assurance to remove ticks immediately and correctly as soon as discovered. The De-Ticker even has a pocket clip, making it handy to take along to the outdoors.

Awareness, knowledge, being observant and careful, combined with a suitable device, which allows immediate and correct tick removal by turning, not pulling, is currently the best protection available against complications from tick encounters and infections with tick-borne diseases. Following these guidelines will bring to an end—finally—the ugly part of ticks and tick removal, which was so much disliked by most of us in the past.

Dr. Chris Riemann is a physician at the Cincinnati

Eye Institute, Cincinnati, Ohio. He is particularly

interested in developing more effective methods of

prevention through education and treatment

of parasite diseases.

References:

· Cupp EW: Biology of ticks. Vet Clin North Am Small Anim Pract 21(1):1-26, 1991.

· Corner KM: Rocky Mountain spotted fever. Vet Clin North Am Small Anim Pract 21(1):37-44, 1991.

· Hoskins JD: Tick-borne zoonoses: Lyme disease, ehrlichiosis, and Rocky Mountain spotted fever. Semin Vet Med Surg Small Anim 6(3):236-2243, 1991.

· Greene CE, Breitschwerdt EB: Rocky Mountain spotted fever and Q fever, in Greene CE (ed): Infectious Diseases of the Dog and Cat. Philadelphia, WB Saunders Co, 1990, pp. 419-430.

· Greene RT: Lyme borreliosis, in Greene CE (ed): Infectious Diseases of the Dog and Cat. Philadelphia, WB Saunders Co, 1990, pp. 508-514.

· Mather TN, Fish D, Coughlin RT: Competence of dogs as reservoirs for Lyme disease spirochetes (Borrelia burgdorferi), JAVMA 205:2, 1994.

· Malik R, Farrow BRH: Tick paralysis in North America and Australia. Vet Clin North Am Small Anim Pract 21(1):157-172, 1991.