II. Check if you remember the meaning of the following words:

Poison; discharge; capable; to multiply; to recognize; to remove; to depend on; to reveal; to suspect; to prove.

III. Using the words given below fill in the gaps in the sentences: 1. Influenza is an ... .2. Influenza is .... 3. Children ... with

influenza get treatment at home. 4. The ... agent penetrates through the skin. 5. You may ... the wound if you do not dress it. 6. Pneumonia is an acute ... disease. 7. This ... is transmitted through the air.

I nfect, infectious, infection, infecting, infected.

IV. Compare the sentences and say in which way they differ in their sense(translation) and grammatically:

1. Infections caused by the pathogenic microorganisms include two types of diseases.

2. These infections are caused by the pathogenic microor­ ganisms.

3. Some infections may be caused by viruses.

4. Bacteriological studies performed to detect the causative microorganism gave positive results.

5. Bacteriological studies were performed in order to detect the causative microorganisms.

6. Bacteriological studies have been performed in order to detect the causative microorganisms.

'V. Answer the questions on the text:

I. What pathogenicagents can cause an infection? 2. What is the classification о{ contagious diseases based on? 3. What are the ways in which the infecting organism penetrates into the human body? 4. What

methods are used to detect the causative microorganism? 5. What kinds of serologic tests are mentioned in the text?

II

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 maximum period of incubation (i.e., the time between the date of exposure to the disease and the beginning of clinical manifestations) of some communicable diseases, e.g., chicken-pox, measles, scarlet fever, small-pox, whooping cough, ranges between 7 to 21 days.

In some cases an increased resistance to certain infections can be observed. The capacity possessed by the body for resisting infection is spoken of as immunity.

Immunity may be natural and acquired. Natural immunity to certain infections may be transmitted from parent to offspring. A temporary passive immunity is transmitted from the 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.

The most significant primary preventive measure is immunization against contagious diseases. Prophylactic measures applied in early childhood and the preschool ages should be directed at combating acute childhood infections.

The medical science is now armed with reliable weapons for preventing infectious diseases. 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 a proper diet.