Causes of scarlet fever

The causes of scarlet fever are a combination of factors, pathogens, and conditions under which favorable circumstances arise for the infection of a given infection. Each disease is provoked by some pathogens, and scarlet fever is not an exception in this case.

The occurrence of infectious processes is always directly associated with specific pathogens. Under the pathogen refers to pathogenic microorganisms that, when released into the human body, provoke various pathological processes. Infections can be caused by bacteria, viruses or fungi.

Etiological factor of the disease

The causative agent of scarlet fever is a hemolytic type of streptococcal infection belonging to group A. This pathogen causes a large number of various infectious processes in the human body, and under its influence pathologies of the upper respiratory tract, skin, mouth, nasopharynx develop.

Specifically, scarlet fever is caused by highly toxic strains of beta-hemolytic species of group A. Among all 7 types of streptococcus groups, group A is distinguished by increased pathogenicity and, in almost 100% of cases, causes infectious processes when released into the human body. This group of bacteria is represented by 46 serological varieties, which at different times and in different places may exhibit different activities.

Ways of infection

Scarlet fever is very contagious. The path of infection, most often, airborne (by microscopic saliva in the course of a conversation, sneezing, kissing), but can also be spread through the contact-household method through the joint with the diseased dishes, food, articles of general use or hygiene products, as well as sexually and medically.

Pathogen carriers

Carriers of scarlet fever pathogen are most often people who become ill. The contagiousness of the sick person begins to appear after the onset of symptoms of the disease, although sometimes the patient may already be contagious, but still not get sick (rarely, but occurs in medical practice). The incubation period is usually long, more often it is stretched with a latent form of the disease with a worn out symptomatology.

Also, the carrier of the infection can be a completely healthy person, in whose body streptococci are present. Contact-a common way of infection is not as common as airborne, but it is important to remember that streptococci are very tenacious and outside the human body, which means that almost anyone who does not have immunity and who consciously or not contacted with an infected person can get sick.

The incubation period, that is, the period during which the carrier of the infection can spread it to other people lasts from 1 to 10 days, sometimes the patient can be considered sick for up to 12 days. If it is necessary to determine the period of infectiousness of a child with scarlet fever, then it is usually a period from one day to the onset of symptoms (onset of the disease) and all the next 2-3 weeks after that.

In women during pregnancy

Scarlet fever during pregnancy in a woman may be due to various reasons. The main source of transmission of infection remains a sick person, the cause of the pathology of which are streptococci. Infection occurs through airborne droplets when talking, sneezing, and so on.

If a woman becomes ill during pregnancy, the infection can negatively affect the fetus. Therefore, timely antibiotic therapy will prevent it.

In adult patients

The contagion of infectious scarlet fever leads to the fact that in most cases, an adult infection occurs during its contact with a sick child. In this case, the development of pathology becomes possible in adulthood only with the presence of a concomitant factor - a weakened immunity. Most likely the mass distribution of scarlet fever in those seasons when beriberi is clearly felt - autumn, winter, spring.

It is possible to get infected only from person to person, animals are not carriers of streptococci.

The most infectious in the case of scarlet fever tolerance are people:

  • suffering from any streptococcal infections (sore throat, scarlet fever);
  • transferred illness (before the end of the incubation period);
  • healthy carriers of group A streptococci in their own body.

The most infectious is a patient with group A streptococcus in the first days of the illness. However, another 3 weeks after recovery, the patient acts as a carrier of the infection to one degree or another.

Even without feeling the signs of the disease, one can be a carrier of streptococcal infection on the mucous membranes of the oropharynx. When coughing, talking, sneezing, such a person spreads microorganisms into the environment, and they, by airborne droplets on the mucous membranes of another organism, can cause severe infectious processes. About 15% of the total population of the planet is a permanent carrier of streptococci.

Most often, the development of the disease occurs against the background of other infectious processes. Under the influence of microorganisms on the background of a weakened immune system, an inflammatory process develops. Very rarely, pathology can be transmitted through poorly washed or improperly prepared food. Adult patients suffer from scarlet fever once. After that, immunity arises in their bodies, which, however, may not be formed if:

  • man has internal pathologies of a chronic nature;
  • the patient is exposed to radiation, toxins and other negative factors from the outside.

Ways of infection in children

Most often, microorganisms that provoke the development of scarlet fever, penetrate into a foreign body with microscopic particles of mucus or saliva, which is released from the nasopharynx of a sick child during intercourse, crying or sneezing (coughing). Infected particles get into the eyes, nose, mouths of other children. They can also settle down and live for a long time in the external environment on common toys, tableware, towels. This is especially important to understand when it comes to ways to prevent infection in children's groups, where babies can drink from a common glass, bite off a bun and so on. It is impossible to infect from domestic and wild animals scarlet fever.

In children's groups, outbreaks of infection are especially numerous in the autumn-winter period against the background of a decrease in the level of general immunity.


Ways of scarlet fever infection always imply the presence of certain conditions in which the infection will survive and begin to multiply in the human body. The first condition is the direct penetration of the causative agent - a streptococcal infection into the human body by contact-domestic, airborne droplets, and very rarely - sexually or by penetrating the damaged skin.

The second condition for the development of scarlet fever in the human body is the presence of one or more factors that contribute to the weakening of immunity and can lead to the manifestation of a large number of different pathologies. These factors in children include an early age (up to 2 years), during which scarlet fever was transferred for the first time. In this case, a full-fledged immunity was formed in a child only after 2 years, and all infections that the child had been sick with before may not leave a full-fledged immunity in the body, and pathology often recurs. Also provoking factor in scarlet fever is hypothermia, improper work and rest, associated chronic pathologies of an infectious nature (pneumonia, diabetes, sore throats, tuberculosis), vitamin deficiency, sedentary lifestyle, the presence of bad habits, constant stress, abuse of certain drugs.

Despite the immunity that is produced in the human body after scarlet fever, the infection is capable of mutations, so re-infection can never be ruled out. And it is better to observe all precautions if there is a risk to catch scarlet fever.

Scarlet fever responds well to therapy, especially in the early stages. In order not to miss the moment when you need to connect doctors, it is important to know about the symptoms of this infection and be able to notice its complexity in your own body. In the absence of adequate therapy, scarlet fever provokes all sorts of serious consequences and complications.

Article author:
Furmanova Elena Alexandrovna

Specialty: pediatrician, infectious diseases specialist, allergist-immunologist.

Total experience: 7 years.

Education: 2010, SSMU, pediatric, pediatrics.

Experience infectious diseases more than 3 years.

He has a patent on the topic “A method for predicting a high risk of the formation of a chronic pathology of the adeno-tonsillar system in frequently ill children”. As well as the author of publications in the journals VAK.

Other author articles

Watch the video: Scarlet fever visual mnemonic (February 2020).