What is Tick-borne Typhus in Children?
Tick-borne typhus is an abbreviation for tick-borne relapsing fever, also known as tick-borne spirochetosis or tick-borne relapsing fever. This is an acute infectious disease, the foci of which are in the wild.
The disease is caused by spirochetes, which are transmitted by ticks. Tick-borne typhus in children is manifested by repeated bouts of fever with periods of apyrexia (the period when the patient’s temperature drops for some time before the next bout of fever).
The infection is stored in the organisms of rodents, sandstones, jerboas, porcupines, hamsters, jackals and other animals. Ticks of the genus Omiihodoros spirochetes are transmitted to humans. Ticks are considered reservoirs of infection, because in their organisms the pathogen lasts a lifetime. Spirochetes are transmitted to the offspring of these insects transviral.
After a bite of infected ticks, a child (like an adult) becomes ill. On the territory of the CIS countries there are such epidemic foci of tick-borne relapsing fever: southern regions of Ukraine, the republics of Transcaucasia, Central Asia. Relapsing tick-borne typhus does not cause epidemics, unlike relapsing tick-borne typhus.
Causes of Tick-borne Typhoid in Children
At the moment, science has more than 15 types of spirochetes that provoke tick-borne typhus in the human body. In morphological and biological properties, they are similar to borrelia of recurrent lice fever, but they are immunologically different. On nutrient media they grow poorly. According to Romanovsky, they are painted in purple.
Pathogenesis during Tick-borne Typhus in Children
The pathogenesis and pathological anatomy of tick-borne spirochetosis are close to those with recurrent lousy fever. Spirochetes, when ingested in the internal environment of a child’s body, settle in the cells of the lymphoid-macrophage system. Their reproduction takes place there. Then spirochetes enter the bloodstream. Blood has bactericidal properties, because the infection partially dies, while releasing endotoxin, which damages the central nervous system and the circulatory system. Toxicosis is accompanied by fever, and foci of necrosis appear in the spleen and liver. There is a violation of local blood circulation, which leads to hemorrhagic heart attacks.
After the first period of fever, tick-borne typhoid antibodies form antibodies against spirochetes of the first generation. Under the influence of these antibodies, microbial aggregates with a platelet load appear and most of the infection dies. This will lead to the onset of remission. Since some pathogens change antigenic properties, they acquire resistance to antibodies and can be stored further in the child’s body. This new generation of spirochetes begins to multiply, getting into the blood, which causes a new increase in temperature. Antibodies begin to form again, but they cannot completely eliminate the causative agent. Resistant pathogens that have changed antigenic specificity, multiplying, again give a relapse of the disease. Such processes are repeated. Recovery occurs only when a spectrum of antibodies appears in the blood that lyse all antigenic variants of borrelia.
After the disease is transferred, the child does not have strong immunity, since the antibodies that have formed remain for a short time.
Symptoms of Tick-borne Typhus in Children
From 5 to 15 days, the incubation period lasts when a child is infected with tick-borne typhus. The disease has an acute onset, characterized by an increase in temperature to the level of 39-40 ° C. The leading symptoms of the onset of the disease are chills, headaches, and muscle pain. The patient’s face is hyperemic, sclera is injected. At the site of a tick bite, primary affect can often be detected. At first it manifests itself as flushing of the skin, after a day a nodule appears on this part of the body, which after 2 days turns into a papule, which is surrounded by hyperemic skin. This primary affect persists for several weeks from the onset of the disease.
At the peak of a fever, there is a weak ictericity of the skin and sclera, the lining of the tongue, an increase in the spleen and liver. There is a likelihood of bronchitis and digestive tract disorders. The condition of the child may be serious. However, in general, the disease is much easier than recurrent lousy fever.
Fever during the first attack most often lasts 2-4 days, then the temperature drops sharply, increased sweating begins. The patient’s condition is rapidly improving. The duration of the febrile period is from 2-4 days to 3-4 weeks.
The next similar attack has a sudden onset, the body temperature “jumps”, all the characteristic symptoms return. But repeated attacks have a milder and shorter course. Periods of apyrexia, on the contrary, lengthen. With tick-borne spirochetosis, 10 seizures or more are possible. The disease can last several months before recovery.
Recurrent tick-borne typhus differs from lousy in the list of symptomatic manifestations. It should be noted that there are more attacks, they last less, the general condition of the patient is easier. But in the peripheral blood, the changes are the same as with recurrent lousy fever.
Diagnosis of Tick-borne Typhus in Children
In order to accurately diagnose relapsing fever, primary affect is detected at the site of the bite. The paroxysmal course of the disease, an increase in the liver and spleen are also noted.
To confirm the diagnosis, a blood test of a sick child is used using methods similar to those with lousy relapsing fever.
In the laboratory, sometimes blood poisoning of a patient in experimental guinea pigs is used. Serological reactions are not practical. Differential diagnosis of tick-borne typhoid fever with brucellosis, malaria, relapsing fever typhus is carried out. With these diseases, there is no primary affect at the site of the tick bite, but with tick-borne relapsing fever in children – there is.
Treatment of Tick-borne Typhus in Children
Treatment is carried out with penicillin preparations.
Prevention of Tick-borne Typhoid Fever in Children
Preventive measures focus on combating ticks and protecting people from attack in the natural habitats of these insects. At the same time, measures are taken to combat rodents.