Text A. Infectious diseases of childhood

Infectious diseases are known to be caused by the invasion and growth of microorganisms in the human body. The most common sources of infection in medical practice are direct contact with a patient’s blood and saliva, consequently instruments and equipment used in the treatment become contaminated, the chief source of infection being direct or indirect contact with the patient himself.

According to specific way of invasion contagious diseases may be classified into four groups. Intestinal infections composing the first group are disseminated principally by the intestinal discharges, such as dysentery, typhoid fever, cholera etc. During coughing or talking infection is spread through the respiratory tract. The diseases of this group are diphtheria, smallpox and others. Infectious diseases in which the infecting organism penetrates through an abrasion or wound of the skin or mucous membranes are septicemia, gonococcus infection, toxemia etc. The diseases of the fourth group are spread by living insects. All these diseases, of which encephalitis is an example, are called blood infections.

In order to identify the causative agent bacteriological studies are performed which help to detect such microorganisms by direct examination under the microscope of the patient’s blood, urine, stools, sputum or any pathological material withdrawn from the body. The direct identification of the infecting agent being impossible, the proper test is used.

The characteristic feature of acute infectious diseases is their cyclic course. There are clearly defined stages in the course of infectious diseases: incubation (latent period), prodromal period, invasion period, active period, period of decline, convalescence.

The human organism is known to have a specific capacity of resistance against infection, which is called immunity, it being natural and artificial. It is provided by certain white blood cells which release antibodies and antitoxins into the blood plasma. Natural immunity to certain infections may be transmitted from parent to offspring. A temporary passive immunity is transmitted from mother to her infant both through the placental circulation and through the breast milk. Acquired immunity may follow a spontaneous attack of disease, the artificial inoculation of a modified virus, vaccine injections, injections of antitoxic and antibacterial sera. Immunization against communicable diseases is the most significant primary preventive measure nowadays.

The treatment of infectious disease includes the methods directed against the causative agent and its toxins, as well as the microbes of the secondary complication (treatment with sera, sulfa drugs, antibiotics), and the methods which favourably influence the reactivity of the organism and the patient’s emotional tone (blood transfusion, administration of blood plasma and serum, gamma globulin, physiotherapy, etc.). In addition, the complex of pathogenic therapy includes setting up a hygienic atmosphere for the patient, good care and proper diet.

The principles of pathogenic therapy being applied by pediatric institutions, the mortality from infections has been reduced in our country.

9. Answer the questions using the text:

1. What are infectious diseases caused by?

2. What are the sources of infections?

3. What is the classification of contagious diseases according to the mode of infection?

4. What are the ways of detecting microorganisms?

5. What stages are defined in the course of infectious diseases?

6. What is immunity?

7. What are the kinds of immunity?

8. What is the primary measure of preventing communicable diseases?

9. What does the treatment of infectious diseases consist of?

10. What has helped to reduce the mortality rate from infections?

10. Give the English equivalents to the word combinations in brackets. Translate the sentences:

1. (Заразные заболевания) are classified according to the mode of infection. 2. Bacteriological studies are performed (чтобы определить возбудителя). 3. The cyclic course (острых инфекционных заболеваний) is their characteristic feature. 4. Immunization against contagious diseases is (первостепенная профилактическая мера). 5. (Вследствие врожденного иммунитета) the incidence of scarlet fever is rare during the first six months of life. 6. Scarlet fever may bring about (тяжелые осложнения). 7. If the individual were in a healthy state, a large quantity (заразных микроорганизмов, вторгающихся в тело) would be destroyed. 8. If (определенные гигиенические меры) had been carried out we should have prevented the last year fatal epidemics. 9. In addition to smallpox and yellow fever, viruses cause such human diseases as (свинка, корь, полиомиелит, ветряная оспа), Japanese B encephalitis, infectious hepatitis, influenza and probably the common cold.

11. Replace the word combinations in bold type with active vocabulary. Translate the sentences:

1. Infectious diseases may result from direct contact with patients or from indirect one. 2. Immunization is primary prophylactic measure against contagious diseases. 3. Infecting microorganism may produce poison. 4. If the reaction against entering bacteria is insufficient, vaccine may be injected subcutaneously to produce a more active resistance of the protective mechanisms of the body. 5. The ill person must be given vaccination lest he should become infected. 6. It is likely that the symptoms should recur since the process of inflammation has not been controlled yet. 7. The general symptoms of diphtheria are high temperature, headache, backache, weak and irregular pulse. 8. The bacteriologist was sure that the blood smear would reveal cocci.

12. Choose necessary words. Translate the sentences:

1. (Little, a little) blood is sufficient to carry out the clinical analysis. 2. If (many, much) leucocytes and rapid sedimentation rate are revealed the physician may suggest the presence of infection. 3. During the operation the surgeon noted that (much, many) of the peritoneum had been involved in the pathologic process.