Hygiene

Many infections such as gastroenteritis 1..... E coli, hepatitis A, typhoid and cholera are water-borne and can 2..... a holiday into a nightmare. Travellers 3..... be advised to give careful attention to personal 4....., sterilization of drinking 5..... and to the hygiene with which food has been prepared. Breast feeding 6..... a safe, uncontaminated supply of food and water for 7..... and can usually be continued even if the mother 8..... an infection. For 9..... babies, supplies of a ready-to-feed pre-packed formula are ideal. Scrupulous 10..... must always be paid to sterilization of bottle feeds and equipment. Water should be 11....., as should milk if not pre-packed. Sterilizing water with chlorine tablets is an 12..... method.

Hand 13..... before and after using toilet or changing nappies, sanitary wear or stoma bags is a sensible 14...... If water is not 15....., a supply of disposable moist antiseptic cloths is 16...... Make sure that disposable items are safely wrapped before disposal.

____________________________

1. babies; 2. available; 3. hygiene; 4. turn; 5. useful; 6. due to; 7. boiled; 8. precaution; 9. water; 10. provides; 11. attention; 12. contracts; 13. alternative; 14. washing; 15. bottle-fed; 16. should.

F. САМОСТОЯТЕЛЬНОЕ ЧТЕНИЕ.

A brief overview of AIDS

Although we know that AIDS is caused by Human Immunodeficiency Virus (HIV), it was originally observed by its effects on the immune system. An important clue was that AIDS patients often had a lung infection or pneumonia caused by a member of the fungi family of organisms called Pneumocystis carinii. This infection is very rare in healthy individuals but patients with cancers of the immune system itself (lymphomas) are susceptible to this disease. Lymphomas are usually treated by chemotherapy, which is intended to destroy the cancer cells. However, chemotherapy, which is intended to destroy many healthy immune cells along with the cancerous lymphoma cells. Thus, this type of pneumonia predominantly occurs in patients with a damaged immune system. Examination of the immune system in AIDS patients confirmed that the cells of their immune systems were damaged. It had been known for some time that other various virus infections could damage as seen with AIDS was unprecedented. Although it was suspected early on that AIDS resulted from infection by a virus, it was not until 1984 that this virus was finally isolated by both French and American researchers. That virus is now known as HIV.

In addition to pneumonia, AIDS is associated with numerous other infections. These secondary infections are caused by various bacteria, protozoa, other fungi and other viruses. Usually, it is these infections (known as opportunistic infections) that cause death in AIDS patients. In addition to secondary infections AIDS patients frequently develop cancers, including lymphomas and an otherwise rare cancer called Kaposi’s sarcoma. HIV infection also can result in damage to brain cells. This leads to loss of mental function, referred to as AIDS dementia. A more complete description of the clinical features of AIDS is presented further. Most of these opportunistic infections and some other effects of HIV infection can be explained by damage to the immune system by HIV infection.

HIV has a very insidious nature in causing a disease. The early stages of infection are often unapparent, without any visible symptoms. The infected person may feel healthy and appear to be completely normal during this time, known as the incubation period, but such a person is able to transmit the infection. The HIV incubation period is of variable duration, and can be quite long (more than 5 years). Therefore, it is not possible to distinguish infected from uninfected people solely by the time since possible exposure to the virus. In contrast, for most common virus infections, such as colds or influenza, an incubation period of several days will be closely followed by an apparent disease. This adds greatly to the difficulty in studying and controlling AIDS because many people who have the virus have not developed the disease yet.

THE AIDS EPIDEMIC. Despite the many different clinical symptoms associated with AIDS, medical investigations have already learned a great deal about how AIDS is spread in our population. For example, it is now clear that HIV transmission requires close contact and that infection occurs by one of only three routes; blood, birth, or sex. Casual contact does not lead to disease transmission. AIDS epidemiology will be further discussed..

Between 1981 (the beginning of AIDS epidemic) and the early part of 1988 about 57,000 cases of AIDS have been reported to the National Center for Disease Control (CDC) in Atlanta, Georgia. Of these cases, about 32,000 (56%) have died.

Promiscuous homosexual males were the major afflicted group and represent about 63% of these reported cases. Another 18% of the cases were intravenous drug users, and 7% were both male homosexuals transmissions, or by blood transfusion during the period when American blood supply was not monitored for HIV antibodies (1981-1985).

The AIDS epidemic is not restricted to the USA. It can be found in all continents and hence is considered a pandemic. There may be as many as ten million people in sub-Saharan Africa who are infected with HIV. In Africa, HIV transmission appears to result from heterosexual contact and other modes as well. Given the relatively poor medical support available in much of Africa, the number of infected people is expected to increase significantly. As there is no current cure for AIDS these numbers are alarming. They indicate the clear potential of AIDS to spread unchecked, in spite of recent advances in modern medicine, epidemiology, virology, and recombinant DNA technology. This reminds us of previous eras when major infectious diseases devastated human populations. How can we control this epidemic? An overview of the relationship between epidemics and human populations may shed some light on this.