Infectious diseases Page 7

Infection

Active Vocabulary

1. Read and learn the following words and word combinations:

mean - означать

invasion - инвазия, вторже­ние

saliva – слюна

contaminated -зараженный

skin cuts - порезы

abrasion - абразия

staff – медицинский персонал

defence – оборона

intact - неповрежденный

surface - поверхность

liquid - жидкость

produce - производить

poison – яд

kill – убивать

tears - слезы

sweat - пот

similar - подобный, схожий

inflammation - воспале­ние

2. Read and translate the following words and word combinations:

source : the source of infection, the source of disease, the source of information

surface: an intact surface, a protective surface, tooth sur­faces, a lingual surface, proximal surfaces

to cause : causes, caused, to cause a disease, to cause caries

3. Give Russian equivalents for the following word combinations:

the most common source of infection, direct contact, to enter the body, ancient people, intact surface, protective outer layer, liquid se­cretion, protective surface, mucous membrane, salivary glands, similar effect, fail to prevent

4. Read and translate the text. Be ready to say what you have learnt about in­fection.

Text a. Infection

Infection means invasion of the body by microorganisms which are harmful. 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. If no action were taken infection may enter the body through skin cuts or abrasions or the eyes, it may also be swallowed. Infection from the contamination would be passed on from patient to patient, from patient to staff and from staff to patient. This involvement is called cross-infection.

Even ancient people taught that body's first line of defence against infection was an intact surface, e.g. the outer layer of skin and the protective outer layer of mucous membrane. If infection had passed it the second line of defence started its action. It was the liquid secre­tion produced by the protective surfaces. The mucous membrane and the salivary glands had produced saliva which neutralized some bacte­rial poisons and could kill some microorganisms. Tears and sweat had a similar effect. The acidity of gastric juice killed many bacteria in food. The third line of defence is discovered now. It is immunity.

And we also know that if these defence mechanisms fail to prevent infection, the last line of defence is a response by the body called in­flammation.

Exercises

Exercise 1. Find in the text English equivalents for the following words and word combinations:

1. означать 2. кровь и слюна пациента 3. через порезы на ко­же 4. глотать 5. наружный слой слизистой оболочки 6. продуци­руемая защитной поверхностью 7. яды, вырабатываемые бакте­риями 8. желудочный сок 9. пища 10. ответная реакция

Exercise 2. Quote the sentences of the text in which the following words are used:

direct, abrasion, to teach, to start, to produce, to kill, to discover, mechanism, effect

Exercise 3. Insert prepositions where necessary:

Pathology is the study ... disease. It covers the changes ... normal anatomy and physiology brought about ... disease and body's reaction to it. The skin is the front line of the body which serves to bring addi­tional defences ... a localized area, threatened by either bacterial in­vasion or mechanical injury. The skin forms an effective outer cover­ing ... the organism. It exerts a protective function and warns ... danger.

Exercise 4. Answer these questions:

1. What are the most common sources of infection?

2. How may infection enter the body?

3. What did ancient people teach?

4. When does the second line of defence start its action?

5. What is it produced by?

6. What can saliva do?

7. What effect do tears and sweat have?

8. When was the third line discovered?

9. What is the last line of defence?

Exercise 5. Change the following sentences using Past Perfect.

Model: They have finished the work (by 5 o'clock yesterday). They had finished the work by 5 o'clock yesterday.

1. My friend has prepared the report (by last Monday).

2. The students have done the exercises (by the end of the les­son).

3. Mother has cooked supper (by the time I came home).

4. We haven't seen our teacher (before the bell rang).

5. Have you done the work (before I called you up)?

6. He has translated the article (by this time yesterday). 1. She hasn't bought a present for him (when we came to her place).

Exercise 6. Ask your friend these questions and be ready to answer his.

1. Had you started learning English before you came to study here?

2. Had you finished medical school before you entered the univer­sity?

3. Had your brother studied Anatomy before he entered the Den­tal College?

4. Had you taken your seat by the time the teacher came into the classroom?

5. Did you go to the reading hall after you had finished your classes yesterday?

6. Had you finished your studies by this time last year?

7. Why hadn't you done your homework by Monday?

8. Did you leave for home after you had finished your classes?

Exercise 7. Say what you have learnt about infection.

• Read the text and translate it using a dictionary if necessary. Compose the plan of it.

Text В

In order to prevent cross-infection it is essential to kill all the mi­croorganisms on infected instruments. This process is known as steril­ization and means the killing of all microorganisms: bacteria, spores, fungi and viruses. It is carried out immediately after completion of treatment so that all instruments are sterile again before use on the next patient.

Countless numbers of microorganisms live on the skin and in the mouth, nose and throat. Normally they do no harm to their host as they are living on an external surface and not among delicate internal cells. However, they may become harmful if they are introduced in­side the body tissues, or are transferred from one person to another. This can occur when the tissues are penetrated by a contaminated forceps blade, sealer or syringe needle, and may give rise to a harmful reaction. After each patient has left the surgery, it is the nurse's duty to see that all instruments are properly sterilized before being used again for another patient.

As already mentioned, sterilization means killing not only bac­teria and fungi, but all other microorganisms, including viruses and bacterial spores. Any method which kills bacteria and fungi but allows some spores or viruses to survive cannot be called ster­ilization. The term used for this restricted range of action is disin­fection.

• Read the text and translate it using a dictionary if necessary.

Active Vocabulary

1. to affect – поражать

2. clinical manifestation – клиническое проявление

3. mucus – слизь

4. mucous - слизистый

5. to spread (spread , spread ) – распространять(ся)

6. to multiply – размножать(ся)

7. to discharge from – выделять

8. to ingest - сосать