Syndrome

The Revised Authoritative Guide To Vaccine Legal Exemptions

Vaccines Have Serious Side Effects

Get Instant Access

Months Years

Figure 29.8 Natural History of HIV Disease Blood levels of infectious virus are very high at the beginning, during the acute retroviral syndrome, and at the end of the disease when AIDS ensues. Antibody tests for diagnosing the disease are often negative in the early stage of the disease even though infected people are highly infectious.The disease steadily progresses in the absence of symptoms, as shown by the rising levels of plasma viral RNA and falling CD4+ cell count.

Months Years

Figure 29.8 Natural History of HIV Disease Blood levels of infectious virus are very high at the beginning, during the acute retroviral syndrome, and at the end of the disease when AIDS ensues. Antibody tests for diagnosing the disease are often negative in the early stage of the disease even though infected people are highly infectious.The disease steadily progresses in the absence of symptoms, as shown by the rising levels of plasma viral RNA and falling CD4+ cell count.

748 Chapter 29 HIV Disease and Complications of Immunodeficiency of sexual HIV transmission. The disease can be contracted by the insertive partner during vaginal or rectal intercourse with an infected person. Saliva is very unlikely to transmit the disease, but there is evidence that oral-genital contact may be risky.

The next most important mode of transmission of HIV is through blood and blood products. Individuals infected with HIV who donated blood before a screening test became available in 1985 unknowingly infected thousands of transfusion recipients. One of the products from pooled donated blood, clotting factor VIII, was used to treat bleeding episodes among hemophiliacs. By 1984, over half of the hemophiliacs in the United States and 10% to 20% of their sexual partners were HIV positive. Fortunately, the risk of HIV transmission by factor VIII was eliminated in 1992 when recombinant factor VIII was licensed. Transmission by blood is still a major factor in the HIV disease pandemic, however, because of sharing of needles by those who abuse injected drugs. In the United States, the population of abusers of injected drugs is estimated to be 1.5 million. Many of them, both men and women, support their drug habits with prostitution. Because HIV is acquired and spread through sexual intercourse and through the sharing of hypodermic needles, drug abusers and their sexual partners have been hard hit by AIDS, but they have also been a big factor in spreading the virus. A study of the first 640,000 AIDS cases revealed that more than one-third were directly or indirectly related to injected-drug abuse.

The third important mode of HIV spread is from mother to infant. Women represent an increasing percentage of the total AIDS cases as heterosexual spread of HIV increases (figure 29.9). An estimated 60% of new AIDS cases in women in 1998 were acquired from heterosexual contact with infected persons, and an estimated 70% of new HIV infections (as opposed to AIDS) in women in the year ending mid-1999 were heterosex-ually acquired. If untreated, about one out of10 pregnant HIVpositive women will miscarry, and of live-born babies, 15% to 40% will develop AIDS. Remarkably, however, in a study of 219 newborn babies positive for HIV by culture or PCR, almost 3%

Figure 29.9 In the United States, a Steadily Rising Percentage of AIDS Cases Occur in Women

cleared their infection without any treatment. Breast feeding carries a significant risk of mother-infant transmission, especially if the mother becomes acutely infected with HIV.

Prevention and Treatment

There is no approved vaccine against HIV infection. Infectious HIV persists in samples of blood plasma for at least 1 week after they are taken from AIDS patients. Most people with HIV disease do not know they are infected, and it is advisable to consider all blood as potentially containing the virus. HIV on objects and surfaces contaminated by body fluids is easily inactivated by commercially available high-level disinfectants and heat at 56°C or more for 30 minutes. Freshly opened household sodium hypochlorite 5.25% bleach diluted 1:10 is a cheap and effective disinfectant for general use. Virus present in dried blood or pus, however, may be difficult to inactivate.

Knowing how HIV is transmitted is a powerful weapon against the AIDS epidemic. This weapon can be far more effective than any vaccine or treatment now on the horizon. HIV is not highly contagious, and the risk of contracting and spreading it can be eliminated or markedly reduced by assuming a lifestyle that prevents transmission of the virus (table 29.3).

Some groups of gay men lowered the incidence of new HIV infections from 10% to 20% annually to only 1% to 2% annually by using condoms and avoiding practices that favor HIV transmission. The improvement in infection rates has not always been sustained, however. Since 1985, the risk of acquiring HIV from blood transfusions has been lowered dramatically by screening potential donors for HIV risk factors and testing their blood for antibody to HIV. The risk is now estimated to be less than

Table 29.3 Lifestyles that Help Control the AIDS Epidemic

1. Not engaging in sexual intercourse.

2. Staying with one faithful sexual partner who you know very well.

3. Avoiding sexual intercourse with persons at risk for HIV infection (see table 29.4).

4. Avoiding trauma to the genitalia and rectum. Small breaks in the skin and mucous membranes allow HIV to infect.

5. Not engaging in sexual intercourse when sores from herpes simplex or other causes are present.They represent sites where HIV can infect.

6. Not engaging in anal intercourse. Receptive anal intercourse carries a high risk of HIV transmission.

7. Using latex condoms from beginning to end of sexual intercourse. Polyurethrane condoms are a reasonable alternative for those allergic to latex. Condoms made from other materials are not reliable for disease prevention, nor are those marketed in many African and other countries outside the United States. Oil-based lubricants are not compatible with latex. Condoms for women are available.

8. Postponing pregnancy indefinitely if you are a woman infected with HIV. If you are not sure of your HIV status, blood tests to rule out HIV disease before considering pregnancy.

9. Using extreme care to avoid needles, razors, toothbrushes, etc., that could be contaminated with someone else's blood.

29.1 Human Immunodeficiency Virus (HIV) Infection and AIDS 749

Was this article helpful?

0 0
You Are What You Eat

You Are What You Eat

Nutrition is a matter that people spend their careers learning about and requires volumes of books to explain. My objective is to instruct you how to consume a healthy nutritional diet that aids your body in burning off fat instead of storing it. You do not require overwhelming science to get this.

Get My Free Ebook


Post a comment