ABOUT TICKS (how to prevent? what to do if bitten by a tick? symptoms of infection after a tick bite)

Blood-sucking ixodid ticks are distinguished from other orders of herbivorous arthropods by a serious change in appearance after satiation with food. They change not only their size, but also their body shape and the color of their chitinous cover. This is due to the structural features of their body and the principles of functioning of the digestive system. In this article we will take a closer look at what a tick that has drunk blood looks like.

It is not difficult to recognize a tick that has drunk blood. Its body takes on the shape of a ball and becomes dense, and the individual itself is clumsy. The tick changes color and increases in size. It is so inactive that it simply falls off the skin onto the ground.

A hungry ixodid tick has an oblong, flat body with a dark chitinous shell (brown, black or brown). The size of an adult does not exceed 3 mm, the female is slightly larger than the male. When the body is saturated with blood, the chitinous shell expands and acquires a lighter (gray, beige) or reddish hue, and the abdomen takes on an oval, convex shape. The size of the tick after consuming blood reaches 11 mm in length. Such changes are due to the following reasons:

The outer shells of the tick consist of microfolds that allow the body to increase in volume. It is possible to see such a structure in ixodid ticks only under a microscope. Aragasidae individuals have a soft body, microfolds are more noticeable as the body increases.
The color of the chitinous shell changes due to the blood entering the digestive tract. It darkens, but when stretched it becomes lighter.
Body sizes can increase tens of times. The tick becomes voluminous and clearly visible on the host's body.

It should be noted that in ixodid parasites only body volume changes. The head part, after replenishing nutritional reserves, has the same size.

GENERAL INFORMATION ABOUT TICKS

Ticks are characterized by seasonality.
The first cases of attacks are recorded in early spring, when the air temperature rises above 00 C, and the last cases - in the fall. Peak bites occur from April to July. Bloodsuckers do not like bright sun and wind, so they lie in wait for their prey in damp, not too shady places, in thick grass and bushes.

During the bite, the parasites inject an anesthetic substance, like mosquitoes, so the suction goes unnoticed. Favorite places to bite are the neck, the area behind the ears, armpits, groin area, and elbow creases.

Attention. Not all ticks carry diseases. But even sterile parasites, and there are 85–90% of them, can cause allergic reactions.

The parasites are not picky when choosing a hunting object; they bite everyone who gets in their way - birds, small and large animals, humans.

Bite sites

As already mentioned, they most often stick to areas with thin skin. Most often this is the head, where there is hair, the back of the head, behind the ears, armpits, groin, knee bends, and stomach.

If we talk about the bite itself, namely the sensations that a person experiences, then this process goes unnoticed for a person. Therefore, it is impossible to detect it before it suctions strongly. This happens for the reason that the parasite’s body produces a special anesthetic enzyme, which it injects when biting, so the person does not experience any pain or discomfort.

The very first symptom is itching, which most often allows you to detect a tick on your body. Less commonly, other symptoms may be observed, for example, drowsiness, general malaise, aching joints, etc.

TICK ATTACK AND BITE

If the tick is a carrier of encephalitis, the pathogen is concentrated in the salivary glands of the bloodsucker and enters the victim’s body at the time of the bite. Therefore, even immediate removal of the attached parasite does not reduce the risk of infection. In the case of Lyme disease, the virus accumulates in the tick's gastrointestinal tract and enters the body when it begins to feed, that is, 5-6 hours after sucking. In this case, early removal of the parasite can prevent infection.

Redness of the skin at the site of the bite does not indicate infection. The color change may appear due to allergies or the presence of the parasite in the victim’s body for many hours. If such symptoms appear, it is better to consult a doctor.

With borreliosis, a tick bite looks like focal erythema up to 20–50 cm in diameter. The shape of the inflammation is most often regular, with an outer border of bright red color. After a day, the center of the erythema turns pale and acquires a bluish tint, a crust appears and soon the bite site is scarred. After 10–14 days, no trace remains of the lesion.

What happens to a tick when it drinks blood?

The structure of the body and limbs of ixodid ticks is maximally adapted for reliable fixation on human skin and animal fur, quickly damaging the outer membranes. The digestive system works like a pump, providing a large volume of blood.

Ixodid ticks have modified limbs. The chelicerae at the end form a proboscis with serrations, with which the individual grabs onto human clothing, animal fur, hair, and the fused pedipalps easily pierce the outer shells of plants and the epidermis of the victim.

After the parasite has found a new source of nutrients, it crawls around the body for some time in search of the most vulnerable places with thin skin. The principle of operation of the digestive tract of the ixodid tick resembles a pump that quickly absorbs a large volume of biological fluid. When final saturation occurs, the reverse process begins - the teeth of the oral apparatus disengage, and the suction cups no longer hold the parasite on the skin.

Ticks attack their prey to feed on blood for only two reasons:

to move to the next stage of development;
for reproduction.

What happens to a tick when it drinks blood?
This process is a mandatory preparatory measure for the female to lay eggs. For 10 days, she sits on the victim and drinks blood. At this time, its body increases in size by 1-2 cm. Representatives of the younger generation spend the first stages of development on low vegetation. But for further development they require a regular supply of food. And they begin to look for a host - a vertebrate animal that will supply them with blood until they transform into a nymph. But this is not the last stage of growth. To fully transition into an adult, the nymph again needs to attack the victim and feed on its blood.

Thus, after drinking blood, the tick begins to lay eggs or moves to the next stage of development. For example, the larvae fall off the animal onto the ground, shed their outer cover, and turn into a nymph.

The adult male, after being saturated with blood, fertilizes the female and dies. The female lays eggs before death; she never attacks again.

SIGNS OF A TICK BITE

Most often, an attached parasite is not noticed immediately. Several hours pass before the victim begins to feel unwell and decides to examine himself. The first symptoms of a tick bite in a person are as follows:

there is weakness, a desire to lie down;
chills and fever occur, possibly an increase in temperature;
photophobia appears.

The dynamics of the signs depends on the number of attached parasites and the characteristics of the victim’s body. The symptoms of a bite are especially pronounced in the elderly, children and those suffering from allergic reactions or immunodeficiency pathologies.

Attention. In people of this group, symptoms may be supplemented by low blood pressure, increased heart rate, itching, headache and enlargement of nearby lymph nodes.

In rare cases, difficulty breathing and hallucinations may occur.

Temperature after a bite as a symptom of the disease

An increase in body temperature in the first hours after a tick bite most often does not indicate anything serious. This is how an allergic reaction to the bloodsucker’s saliva manifests itself. You should be wary if fever appears a few days after the parasite has been ingested. This reaction of the body may indicate the onset of the disease.

Each infection caused by a bloodsucker bite has its own characteristics:

With tick-borne encephalitis, relapsing fever appears. The first rise in temperature is recorded 2–3 days after the bite. After two days everything returns to normal. In some cases, a repeated increase in temperature is observed on days 9–10.
Borreliosis is characterized by fever in the middle of the disease, which is accompanied by other symptoms of infection.
With monocytic ehrlichiosis, the temperature rises 10-14 days after the tick bite and lasts about 3 weeks.

Almost all diseases transmitted by bloodsuckers are accompanied by fever.

Description and lifestyle

Ticks, which are common in central Russia, live in the forest among foliage and in garden plots, i.e., wherever there are any plantings. They belong to the order of small arachnids (lat. Acarina), a subclass of arthropods. The size of the tick before the bite is usually 0.4-0.5 mm, occasionally it can reach 3 mm.

The body of the parasite consists of 2 parts and 6 pairs of appendages: 4 of them are legs, a pair are pedipalps, and the most anterior ones are chelicerae, similar to claws, forming a cutting-stabbing mouth, which is clearly visible in an enlarged photo of an ordinary tick.

On a note!
The active period for ticks begins in May-June and continues throughout the warm season; the maximum risk of bites occurs in dry and warm weather. The basis of their diet is human and mammalian blood, which they drink using a special organ, as can be seen in the photo of the tick’s proboscis. They determine the approach of the prey by smell at a distance of 10-15 m.

The danger of tick bites is that they instantly pierce the skin along with the proboscis and head, then begin to suck out blood, which a person cannot always understand that a tick has bitten due to its small size. And only when the parasite inflates from drinking blood, it enlarges and becomes noticeable on the body. Then the victim, having discovered a tick, can begin measures to remove it and treat the bitten area.

Therefore, it is better to know in advance how long it takes for a person to develop symptoms of a tick bite in order to take measures and clarify the possibility of contracting any infections from it.

Mite

RULES OF CONDUCT IN CASE OF A TICK BITE

So, what to do if you are bitten by a tick? First of all, it is necessary to remove the bloodsucker as soon as possible. This should be done slowly and carefully so as not to damage it or cause infection. Do not use gasoline, nail polish or other chemicals. Vegetable oil or fat will not help either. It is better to use effective and practice-tested methods.

Removing a tick with a thread

The method is simple, but requires a lot of dexterity and patience. It will be useful when extracting large specimens. For the procedure to be successful, it is recommended to perform the following steps:

Take a long and strong thread
Tie a loop at the border between the skin and the body of the parasite and carefully tighten it.
Using rotating, rocking and pulling movements counterclockwise, slowly remove the tick.

The removed bloodsucker must be placed in a glass container with a tight lid and taken to the laboratory for research.

Removing a tick using tweezers

Another simple way to get rid of a tick. Using tweezers you can remove a bloodsucker of any size. The basic manipulations are similar to the thread pulling option. It is better to use tweezers with flat edges, grabbing the parasite at the very base. Then, using careful rotational movements, remove the tick and disinfect the wound.

Attention. When removing the bloodsucker, tweezers must be held strictly parallel or perpendicular to the skin.

It is better to use tweezers with flat edges, grabbing the parasite at the very base.

Tick twisters

Not long ago, the pharmaceutical industry began producing special devices for removing the parasite. The kit includes two tools - a large one and a small one for pliers of different sizes. Using a twister, you can quickly and effectively remove the parasite without damaging it.

The kit includes a test tube into which it is recommended to place a live parasite and store it in the refrigerator for further research.

Other ways to remove ticks

If there are no devices nearby when a tick bites you, you can try to pull the parasite out with your hands. The method is risky, but if you do everything correctly, the result will be good. In this case, you must adhere to the following recommendations:

Wrap your fingers in a handkerchief or gauze to make it easier to hold the tick.
Grab it at the very border with the skin and pull it out with smooth twisting movements.
Disinfect the wound or rinse with water.

If for some reason the tick cannot be preserved for analysis, it should be destroyed by pouring boiling water over it or burning it over a fire.

You can often hear advice from “experienced” people on how to remove a bloodsucker using oil. Despite its apparent simplicity, the method is not only useless, but rather harmful. The parasite, sensing a threat to life, will relax its proboscis and regurgitate the contents of the stomach along with the pathogens back. At the same time, the risk of infection will increase sharply.

Attention. If you cannot remove the bloodsucker yourself, you must contact a medical center.

Medical workers will provide first aid in case of a tick bite: they will professionally remove it and send it for examination, they will disinfect the wound and tell you what to do next. The specialist will definitely inform you what symptoms you should pay attention to in the next month.

WHAT TO DO AFTER REMOVAL OF A TICK?

In people predisposed to allergies, a tick bite can cause a strong response in the body. Facial swelling often develops, difficulty breathing and muscle pain appear. In this case it is necessary:

give the victim an antihistamine: Suprastin, Claritin, Zyrtec;
provide access to fresh air, unbutton clothes;
Call an ambulance.

All other diagnostic and treatment measures are carried out only in a hospital setting.

You can submit a tick for analysis in Tosno at the ETALON medical center at Lenin Ave., building 3. The center is open seven days a week and on holidays.

If the tick could not be preserved, for early diagnosis of the disease it is recommended to donate blood to detect immunoglobulins for infections. The analysis is carried out quickly, the result is usually ready within 24 hours. If you have been vaccinated, you must indicate the date when donating blood. The presence of vaccine antibodies may confuse health care providers.

DISEASES CAUSED BY TICK BITE

So, why is a tick bite dangerous for humans? Infections carried by bloodsuckers can be microbial, viral, rickettsial or protozoal in nature. All of them cause serious illnesses, often resulting in disability and, in rare cases, death. The cause of irreparable disorders in the body is late detection of the parasite and untimely therapy.

For Russia, the most significant diseases from tick bites are tick-borne encephalitis, Lyme borreliosis and zoonotic infections. Let's look at them in a little more detail.

Tick-borne encephalitis

The main carrier of this disease is the ixodid tick. In the wild, the pathogen circulates between bloodsuckers and small animals, usually rodents and birds. In areas developed by humans, livestock—cows and goats—become an additional reservoir. The causative agent of tick-borne encephalitis persists in parasites for a long time and passes to the offspring through eggs.

Attention. The virus is transmitted through a tick bite. Transmission of the pathogen through the alimentary route is often recorded - through infected cow's or goat's milk that has not been boiled.

Asymptomatic disease is very common and can reach 85–90% in some areas. Prolonged blood sucking significantly increases the risk of developing pronounced forms of pathology. The virus tolerates low temperatures well, but dies fairly quickly when heated to 80 °C.

Infection with tick-borne encephalitis is seasonal. The first peak of the disease occurs in May-June, the second is recorded in August - early September.

During a bite, the pathogen immediately enters the human blood through the salivary glands of the tick, where it is found in the greatest concentration. After a few hours, the virus penetrates the victim’s central nervous system, and after 2 days it can be detected in brain tissue. The incubation period for encephalitis from a tick bite is 14–21 days, and when infected through milk - no more than a week.

Tick-borne encephalitis

Symptoms of tick-borne encephalitis

The majority of victims have an asymptomatic form of infection, and only 5% have a pronounced form of infection. Tick-borne encephalitis most often begins suddenly with the following symptoms:

increased body temperature to 39-40 °C;
Strong headache;
sleep disturbance;
nausea leading to vomiting;
diarrhea;
redness of the skin of the face and upper body;
weakness, decreased performance.

Such symptoms are characteristic of the febrile form of the disease, which disappears after 5 days. There is no damage to the central nervous system in this case.

Meningeal and meningoencephalitic forms of pathology are much more severe. The patient complains of lethargy, apathy and drowsiness. Hallucinations, delirium, impaired consciousness, and convulsions similar to epileptic seizures appear. The meningoencephalitic form can be fatal, which is very rare in recent years.

Periodic muscle twitching indicates damage to the peripheral nerves. A polyradiculoneuritic form of encephalitis develops, in which general sensitivity is impaired. With the polioencephalomyelitis form of the disease, paresis of the arms and legs is observed.

Lyme disease (Lyme borreliosis)

Borreliosis is common in the northern regions of Russia. The pathogen enters the human bloodstream when bitten by ixodid ticks and can persist in the body for years. The first symptoms of the disease include:

headache;
temperature rise to 38-39 °C;
fatigue, weakness and apathy.

1–3 weeks after a tick bite, a thickening and ring erythema appear at the site of suction, which can reach 20–50 cm in diameter.

Attention. Despite the fact that a few weeks after the bite the red spot disappears without a trace, it is necessary to test for the presence of the causative agent of Lyme borreliosis, since the disease has serious complications and can be transmitted from a pregnant woman to a child.

Often the central nervous system, heart, muscles and ligaments, joints and organs of vision are involved in the pathological process. Late diagnosis and untimely therapy can lead to chronic borreliosis, which often ends in disability.

Lyme disease

Ehrlichiosis

The disease is also transmitted by ixodid ticks. Deer are considered the main reservoir of Ehrlichia, with dogs and horses serving as intermediate reservoirs.

The virus enters the human body during a bite through the parasite's saliva. The incubation period can be up to 3 weeks, and the acute form of the disease lasts 14–21 days. In some cases, the pronounced phase drags on for up to 6–8 weeks.

Ehrlichiosis can be asymptomatic or clinically pronounced, even fatal. Common signs of the disease include:

fever;
increased sweating;
weakness, drowsiness;
nausea to the point of vomiting;
rigor.

In the acute phase of ehrlichiosis, anemia and a decrease in the level of platelets and leukocytes in the blood are observed.

Relapsing tick-borne typhus

The infection is usually recorded in southern Russia, Armenia, Uzbekistan, Tajikistan, Georgia and Kyrgyzstan. The disease always occurs suddenly and begins with a vesicle at the site of the tick bite. Then other symptoms are added to the skin manifestations:

fever;
increased body temperature;
aching joints;
nausea and vomiting;
headache.

Gradually, the bubble becomes bright red, a pronounced rash appears on the patient’s body, the liver enlarges, the skin and whites of the eyes turn yellow.

The disease is wavy in nature. The acute phase usually lasts from 3 to 5 days, then the victim’s condition returns to normal and the temperature drops. A few days later everything repeats again. There can be many such attacks. Each subsequent one occurs with less severity.

Relapsing tick-borne typhus

Coxiellosis

It is one of the most common zoonotic infections in the world. The disease can be transmitted by both farm and wild animals. One of the distributors of the pathogen is the tick, most often the ixodid tick. It is capable of maintaining rickettsiae in the body for a long time and transmitting them to offspring. The first symptoms appear 5–30 days after the tick bite:

increased sweating;
elevated temperature;
dry, exhausting cough;
loss of appetite;
redness of the face and upper body;
migraines, weakness and drowsiness.

KU fever is often accompanied by pneumonia, pain in the lower back and muscles. The temperature in the first days of the disease can change several times during the day. This disease can only be treated in a hospital setting; it responds well to therapy and recovery occurs quickly. Complications are rare, and the outcome of the disease is most often favorable. A person who has recovered from coxiellosis develops a strong immune system.

TREATMENT OF TICK BITE VICTIMS

If a tick has bitten and the test results reveal an infection, the patient is given immunotherapy based on doctor’s prescriptions. Further treatment depends on the type of pathogen that has entered the body.

Treatment of patients with tick-borne encephalitis

There are currently no specific treatments for tick-borne encephalitis. If signs of central nervous system damage appear, the victim must be hospitalized to provide medical care. The treatment regimen includes:

Bed rest during the entire duration of the fever and a week after it ends.
In the first days of the disease, administration of immunoglobulin is indicated. To achieve the best result, it is necessary to apply the product as early as possible, preferably in the first three days after the tick bite.
In general cases, the patient is prescribed corticosteroid drugs and blood substitutes.
For meningitis, increased doses of vitamins B and C are administered.
If respiratory functions deteriorate, the victim is advised to receive artificial ventilation.

During the recovery period, the patient is prescribed nootropics, tranquilizers and testosterone simulators.

As an addition to the main treatment, antibiotics may be prescribed to the bite victim. Antimicrobial drugs are used to suppress pathogenic microflora that can cause various complications.

Therapy for patients with borreliosis

Treatment for Lyme borreliosis involves taking antibiotics. They are used to suppress spirochetes, the causative agents of the disease. The most commonly used drugs are penicillins and cephalosporins. To relieve erythema, antimicrobial agents of the tetracycline group are prescribed.

If neurological disorders appear, the victim is hospitalized. In the hospital, complex therapy is carried out, including:

blood substitutes;
corticosteroids;
testosterone mimics;
nootropic drugs to improve cerebral circulation;
vitamin complexes.

The outcome of borreliosis depends on the timely detection of a tick bite, correct diagnosis and early initiation of therapy. Incompetent treatment often leads to the chronic phase of Lyme disease, which is difficult to treat and can result in disability or death of the victim.

Attention. To treat protozoal infections, medications are used that prevent further growth and development of protozoa.

COMPLICATIONS AFTER A TICK BITE

Summarizing all of the above, we can draw a very disappointing conclusion about the consequences of a tick bite. As you can see, infections affect the most important systems of the body:

lungs - with the development of symptoms of pneumonia and pulmonary hemorrhages;
liver - indigestion, problems with stool (diarrhea);
CNS - with frequent headaches, hallucinations, paresis and paralysis;
cardiovascular system - arrhythmia and blood pressure surges appear;
joints - arthritis and arthralgia are formed.

The consequences of a tick bite can develop in two ways. With a favorable outcome, loss of performance, weakness and lethargy continue for 2–3 months, then all body functions return to normal.

For moderate illness, recovery lasts up to six months or longer. A serious form of the disease requires a rehabilitation period of up to 2–3 years, provided that the disease proceeded without paralysis or paresis.

If the outcome is unfavorable, there is a persistent and long-term (or permanent) decrease in the quality of life of the victim of a tick bite. Manifests itself as a violation of motor function. The clinical picture worsens significantly under the influence of nervous and physical fatigue, pregnancy, and regular alcohol intake.

Persistent disorders in the form of epileptic manifestations and spontaneous convulsions lead to the patient's incapacity.

Disability as a consequence of a tick bite

As you know, there are 3 groups of disabilities. The degree of damage to the body after a tick bite is determined by a special medical commission:

Group III disability - mild paresis of the arms and legs, rare epileptic seizures, inability to perform highly skilled work that requires precision and attention.
Disability of group II - severe paresis of the limbs, partial paresis of muscles, severe epilepsy with mental changes, asthenic syndrome, loss of the ability to self-care.
Group I disability - acquired dementia, severe motor dysfunction, persistent and complete epilepsy, widespread muscle paresis, loss of self-control and inability to move independently.

In especially severe cases, with inadequate treatment of infections caused by a tick bite or complete lack of therapy, death is possible.

What can you get infected with?

Of the extensive list of infections carried by these creatures, encephalitis leads. This disease is aimed at damaging the human nervous system (possibly death, disability, severe pain). Borreliosis usually causes damage to the nervous and motor systems. Often affects the heart and blood vessels (possible disability). Fever and other infections - timely detection and treatment will help completely avoid negative consequences.

It is important to remember that you need to take precautions, if you still need to go to places where these parasites are concentrated, you need to dress to the maximum without leaving any exposed areas on yourself. This way, the tick will not immediately get on your skin and, most likely, you will shake it off on the ground yourself.

PREVENTION OF TICK BITES

The main and main measure to prevent diseases transmitted by bloodsuckers is vaccination, but it does not protect 100% and not against all diseases transmitted by ticks. But the event significantly reduces the risk of infection after tick bites.

There are two vaccination options:

Preventive vaccination. Helps protect against tick bites for a year, and after additional vaccination - for at least 3 years. Revaccinations are carried out every three years.
Emergency vaccination. Allows you to protect yourself from tick bites for a short period of time. For example, such a procedure will be necessary for an urgent trip to regions with high tick-borne activity. While staying in epidemiologically dangerous areas, it is recommended to take iodantipyrine.

How to protect yourself from a tick bite?

When going to an unfavorable area, you should choose clothes in light colors:

a shirt or jacket with cuffs and a tight-fitting collar, trousers tucked into boots;
anti-encephalitis suit;
a thick hood with ties that protects the ears and neck from ticks;
It is advisable to treat clothes with insecticidal agents.

When hiking, it is recommended to avoid ravines and tall grass; it is better to walk in the middle of the path. When leaving the forest, you need to carefully examine yourself for ticks. In this case, it becomes possible to detect and remove the parasite before the bite.

To repel ticks, special insecticidal products based on DEET are produced, but repellents are not effective enough and require application every 2 hours. They can be used on exposed areas of the body and clothing.

Acaricides are more effective. The drugs are used for contact destruction of ticks. They can only be used on outerwear worn over underwear.

Attention. Acaricides for application to the skin are often found on sale. However, they should be used very carefully. A severe allergic reaction and poisoning is possible.

How to recognize an encephalitis tick

In fact, such a type of insect as the encephalitis mite does not exist in nature. There is a common forest one that carries the infection. In the western part of Russia, the carrier of the dangerous virus is the dog tick, in the eastern part it is the taiga tick.

However, this does not mean that all insects of this species, without exception, can infect the encephalitis virus. In order to become a carrier, he must drink the blood of a sick person or animal.

Outwardly, this will not manifest itself in any way: the insect will look exactly the same. There are no signs of the presence of a pathogen. Only a well-fed tick differs visually from a hungry one: after drinking, it increases from 2-3 mm tens of times.

Finding out whether a particular insect carried the virus can only be done in a laboratory. The only condition is that it must remain alive. It should be delivered to the study site within two days after the bite.

INSURANCE AGAINST TICK-BORNE ENCEPHALITIS

Recently, insurance for expenses associated with possible encephalitis after an “encounter” with a tick has become widespread. This measure is often used as an addition to vaccination or as an independent measure.

Insurance will help pay for expensive treatment for tick-borne encephalitis and other infections carried by bloodsuckers.

The irreparable consequences of a tick bite can be prevented if you seek medical help in time and begin treatment. Remember, an attached parasite does not immediately transmit the infection. The longer it stays on the body, the greater the risk of contracting tick-borne encephalitis or Lyme borreliosis.

How long does a tick drink human blood?

The parasite can fall off at any time after it has become attached to the skin. The duration of meals often varies from a few hours to several weeks. On average, the pest remains on the human body for 3-8 days, the maximum period is 14 days. A tick that has drunk blood falls off on its own. But this does not always happen within the specified time frame.

The duration of the meal is also determined by how hungry the parasite is. If it has not been fed for several months/years, it may well remain on the skin much longer. Sooner or later, the parasite filled with blood disappears. During this time, it will most likely be detected, since within a few weeks of parasitism this pest develops more severe symptoms.