Nowadays when the whole world is fighting against COVID-19 (coronavirus) pandemic, the news and the authorities are warning us from a new infectious disease which has been reported in China which is caused by a tick-borne virus. The authorities have warned about the possibility of its human-to-human transmission. So let’s discuss what tick borne diseases is and how much we are in risk.
Tick-borne diseases you may be at risk for depend on your area or regions where you are living.
Remember, most ticks do not carry diseases, so don't panic. So many peoples have been bitten dozens of times by ticks. Some people may have nausea, fever, and malaise following a tick bite, but this is usually a reaction to the tick's secretions rather than an actual disease.
If you removed the tick and left the tick's head embedded in your skin than it may fester, and it look infected like a pimple, and then it come out.
Ticks are small, blood-sucking bugs. They can range in size from as small as a pin’s head to as large as a pencil eraser. Ticks have eight legs. They’re arachnids, which means they’re related to spiders.
The different kinds of ticks can range in color from shades of brown to reddish brown and black.
As they take in more blood, ticks grow. At their largest, ticks can be about the size of a marble. After a tick has been feeding on its host for several days, they become engorged and can turn a greenish-blue color.
There are more than 800 known species of ticks found in the world, the common tick (Ixodes ricinus) is the most important for humans or for us. Ticks canbe found all over the globe. The preferred habitats of spider related creatures are mildly damp places in deciduous and mixed forests with an abundance of undergrowth (grasses, shrubs, bushes), in particular overgrown edges of forests, forest clearings and paths, also hedgerows and land with tall growing grasses and bushes. Ticks are rarely to be found in well looked after family gardens, town parks, which are not near forests and pure coniferous forests.
Ticks sit on low growing plants and wait for a passing host and then let themselves be brushed off onto the host. Ticks do not fall from trees! The danger of being bitten in winter is very low, in spring (February to the middle of June) and in autumn (middle of August to October) much higher. These periods can vary from year to year depending on climatic conditions. Hosts for ticks, depending on their stage of development, are small rodents, birds or larger wild animals such as hares, deer, domestic animals (cats and dogs) and in some cases humans.
For a tick to develop it has to suck blood at least once in every phase, first as a larva than as a nymph and than as an adult. With larva this blood sucking process lasts for two to three days, with an adult tick from seven to eleven days. During this time the weight of these 0.5 to 6 mm large creatures can increase a hundredfold. Ticks have a proboscis, a so-called rostrum with which they drill into the skin. With the help of several small teeth, which are used as barbed hooks, they hang on tightly to the skin and are very difficult to remove. With the bite they give off an anaesthetizing substance, which is why it is often not noticed.
Wood ticks pass on germs
Just in Switzerland wood ticks can pass on several germs to humans, a bacterium (Borrelia burgdorferi) and a virus (the tick-borne encephalitis virus (TBEV))
All over Switzerland 5-30% (up to 50%) of ticks are infected with the bacterium Borrelia burgdorferi. An estimated 3’000 people yearly contract the so-called Lyme disease caused by this bacterium. Lyme disease can be treated with antibiotics.
Ticks, which carry the tick-born encephalitis virus, are only to be found in certain areas, so called natural herds (endemic areas). In these endemic areas around 1% (0.5-3%) of ticks carry the virus.
In 2005 the cases of TBE in Switzerland drastically increased with 200 cases, compared to an average of 100 per year during the preceding 5 years. There is a well-tolerated and efficient vaccination against tick-borne encephalitis.
Tick-borne encephalitis (TBE)
The tick-borne encephalitis (TBE) typically manifests itself in two phases of illness. In the first phase around 7 to 14 days after the insect bite certain people show flu like symptoms such as headaches, fever, fatigue, or painful joints. The symptoms disappear after a few days and a connection with the tick bite is seldom made. For most patients the illness is now over and they will most probably be immune for the rest of their life. For approximately 5-15% of patients after a symptom free phase there follows a second phase of illness with an attack on the central nervous system.
The symptoms of this form of meningitis are bad headaches, aversion to light, dizziness, lack of concentration, difficulties of speech, sight and difficulty in walking. These symptoms can last for week’s even months. Certain patients can experience paralysis of arms, legs or facial nerves, which can lead to permanent disabilities. Approximately 1% of the patients die from this disease. With children it usually takes its course harmlessly without any lasting damage. There is no special therapy. The treatment aims at alleviating the symptoms.
Viral encephalitis is inflammation of the brain, caused by any one of a number of viruses. Symptoms include high fever, headache, sensitivity to light, stiff neck and back, vomiting, confusion and, in severe cases, seizures, paralysis and coma. Infants and elderly people are particularly at risk of severe illness. Arboviruses – viruses transmitted through insect bites, are among the most common causes of viral encephalitis, and include Japanese encephalitis and tick-borne encephalitis viruses.
So the pathway for tick-borne encephalitis, for example. would be something like this: Virus in tick saliva -> Insect biting a human -> Virus in human blood & tissue -> Human circulatory system -> Virus crossing the blood-brain barrier -> Into meninges and brain mater (grey & white) itself -> Inflammation & infection of brain (which in this scenario is viral encephalitis)
Lyme disease is a bacterial infection caused by ticks, has a diversity of symptoms. Apart from the skin, the nervous system and the loco motor system the heart can also be affected. There are 3 stages to the illness. The first symptom is often a local inflammation of the skin, the so-called Erythema migrans, a circular rash. Several days after the bite a rash appears, which spreads out and becomes circular in appearance. This symptom only appears with around 30% of patients and is often located at the back of the knee, on the stomach, or on the shoulders. At the same time flu symptoms may occur. The first phase of the illness usually heals by itself within days to weeks. However a treatment with antibiotics is necessary to prevent the virus from spreading to other organs.