The human head louse is, so to speak, a double trouble. By itself, as a parasite, it causes a large number of problems and discomforts, feeding on blood and causing multiple itchy bites. Her saliva and general activity on the scalp can lead to the development of a whole complex of symptoms, which for their specificity in medical practice and theory are isolated in a separate disease - pediculosis.
However, in itself, pediculosis and the presence of lice on the head are only part of the problem. The fact is that the diseases spread by human head louse are not just heavy - they are also deadly.
But first things first…
The human head louse as a parasite
Lice for a person are dangerous even as a parasitic insect. After all, their main food is human blood, which they suck, piercing the skin with jaws that have the form of thin and long stilettos.
Given the small size of parasites and a fairly low density of human infection with lice, the very fact of bloodsucking in most cases does not lead to a measurable decrease in the amount of blood in the capillaries and, even more so, to a change in the composition of the blood itself. However, without this, multiple bites already cause trouble.
First of all, it is an itch caused by each single puncture of the skin, during which the insect enters its saliva into the wound. Such a bite is similar to a mosquito bite, however, in general, the bites themselves occur much more than when attacked by mosquitoes. Specificity of human lice is such that each insect is forced to eat often and gradually. For one day, one louse makes four or five bites, and if there are several dozen parasites on the head, their constant feeding will be associated with hundreds of daily bites.
In addition, lice constantly move around the head and this also irritates the surface of the skin.
However, these are the most insignificant consequences of the presence of lice in a person. Much more serious are the diseases, the causative agents of which lice suffer, and those disorders, the direct cause of which they themselves are.
Pediculosis - the main consequence of infection with lice
Pediculosis is a disease associated with the activity of lice. It is a complex of symptoms, manifested as a result of regular bites by parasites, during which the introduction of saliva containing enzymes occurs, and constant irritation of nerve endings.
The most characteristic symptoms of pediculosis are:
- itching on the head, at a certain stage becoming permanent
- the appearance of bluish-gray spots on the skin
- permanent scalp combs
- excess keratinization of the scalp and dandruff
- as well as the presence on the head of the lice themselves and the presence of nits (louse eggs) attached to the hair at a different distance from the surface of the head.
Such symptoms usually appear one month and a half after the infection itself. During this time, lice caught on the head manage to give the first offspring and significantly increase their number on the head of a person.
It is interesting
In people, the period from infection to the appearance of obvious symptoms of pediculosis is called the incubation period of lice. From the scientific point of view, this term is inappropriate here.
Due to scratching of the scalp in the absence of treatment, pustular inflammation can develop in those places where an accidental infection enters the bloodstream. Such damage is already painful and requires a doctor to develop a treatment plan.
Pediculosis is not a life-threatening disease. But in addition to it, lice are borne by pathogens, which at one time led to huge mass and devastating epidemics.
Lice as carriers of dangerous diseases
Diseases spread by human lice are caused by rickettsia - bacteria from a particular family, some of which are extremely pathogenic. Among these diseases:
- relapsing fever
... and some other related infections.
All types of typhus are characterized by acute leaks, the possibility of a lethal outcome and a weak immune response of the body: even after the transfer of the same recurrent typhus, the immunity is fixed for a short time. Volyn's fever is not a fatal disease, but it is also very unpleasant.
It is interesting
According to doctors' calculations, during the Russian-Turkish wars against typhus, more soldiers were killed than in the actual hostilities. The conditions in which the soldiers lived and were ideally suited for the development of diseases that human head and ward lice suffer.
In most cases it is the louse of the litter that carries the dangerous infections. The likelihood of typhoid infestation from head lice is lower than that of the head lice, but due to the prevalence of the world-wide head lice causes various diseases as a whole not much less often than the louse.
Do lice carry AIDS and hepatitis?
There is a widespread opinion that blood-sucking insects can carry the virus-causing agents of AIDS and hepatitis. Accordingly, in the transfer of these terrible diseases, lice are sometimes suspected.
Lice can not tolerate AIDS or hepatitis. Both of these diseases are caused by viruses that damage cells of internal systems of human organs. The AIDS virus is implanted into the cells of the immune system, and the hepatitis virus enters the liver cells. And these viruses are actually present in the blood of a sick person.
However, these viruses can not infect lice and use them as intermediate hosts. Getting along with human blood in the digestive tract of insects, virions - particles of the virus - are quickly split by enzymes of insects and cease to exist.
On oral organs, viruses are not preserved for a long time and are washed away by mucus, which performs the function of saliva in parasites. Accordingly, even after the bite of a sick person, the viral particles in the parasite cease to exist, and to the next bite, even on a different, healthy person, the louse will already be "clean".
On a note
Similarly, AIDS and hepatitis are not tolerated by mosquitoes and ticks. Parasites can tolerate only those diseases, the causative agents of which in their life cycle one way or another with these parasites are connected. For example - tick-borne encephalitis, malaria (caused not by the virus, but protozoa), sleeping sickness. With lice associated rickettsia, carrying typhus and related diseases. AIDS viruses and all pathogens of hepatitis (including bacterial) are not associated with lice and do not spread by them.
To date, in medical practice, there are no known cases of transmission of AIDS and hepatitis viruses to lice. All speculation about such a way of transmission is considered an imaginary dangers and not confirmed by any studies.
On a note
Another misconception is the myth that with the help of lice it is possible to treat hepatitis. This is also stupid - a louse does not affect the course of the disease, especially since hepatitis can occur for a variety of reasons.
The first signs of infection with lice and typhus
It should always be remembered that typhus and other diseases, of which lice are carriers, have an incubation period less than the time of the manifestation of the lice itself. Simply put, after infection with lice, a person falls ill with typhus (provided that the lice themselves in the specific case were carriers of the pathogen) before they begin to feel serious signs of lice.
The incubation period of typhus is about 2 weeks, and the return period is about 18 days. The first symptoms of the disease are pain in the head and back, fever, chills, fever. During the first week of manifestation of these symptoms with typhus, a pinkish rash appears all over the body, with a return yellowness of the skin. Usually for both diseases are characterized by several attacks, after which the recovery occurs.
On a note
Against typhus, an effective vaccine has been developed that helps protect a vaccinated person for several years. This vaccine is not included in the mandatory list, but when visiting regions where there is a high likelihood of contracting the disease, it is strongly recommended to apply it.
The fatal cases of typhus are caused by disturbances in the circulatory system, most of them occurring due to blockage of the pulmonary artery. Common complications of the diseases are disorders of the nervous system and thrombophlebitis.
Volyn, or trench fever, proceeds similarly, but without pronounced manifestations on the skin. After the second-third attack, a full recovery usually occurs.
At the first such symptoms and the presence of lice on your head, you should immediately go to a medical institution. Self-treatment of such diseases can lead to serious lifelong complications.
All diseases spread by human lice today are very rare. Typhoid and various rickettsiosis manifest themselves almost exclusively in developing countries in conditions of unsanitary conditions and too dense settlement of people. They are typical for the countries of Africa and South America.
It is interesting
One form of typhus is Brill's disease, which is dangerous for its relapses, sometimes recorded in the east of the United States.
In modern conditions, the main guarantee of safety against diseases carried by lice is the prevention of infection by the parasites themselves. To do this, avoid accidental close bodily contacts (hugs, kisses, sexual contacts) with strangers, try not to be in places with a large crowd of people and obvious signs of unsanitary conditions, do not use someone else's hairbrushes, towels and hair care products.
If you do not give the lice a chance to get on your head, then the infection with the corresponding infections can be avoided.
Getting rid of lice and nits at home for 1 procedure: