GLOBAL SCENARIO OF THE AIDS EPIDEMIC
DECEMBER 2004
Number of people living with HIV in 2004 Total 39.4 million (35.9-44.3 million)
Adults 37.2 million (33.8-41.7 million)
Women 17.6 million (16.3-19.5 million)
Children under 15 years 2.2 million (2.0-2.6 million)
People newly infected with HIV in 2004 Total 4.9 million (4.3-6.4 million)
Adults 4.3 million (3.7-5.7 million)
Children under 15 years 640 000 (570 000-750 000)
AIDS deaths in 2004 Total 3.1 million (2.8-3.5 million)
Adults 2.6 million (2.3-2.9 million)
Children under 15 years 510 000 (460 000-600 000)
The ranges around the estimates in this table define the boundaries within which the actual numbers lie, based on the best available information.
Effect of HIV on the immunity system
PATHOGENESIS
The hallmark of HIV disease causes profound immunodeficiency resulting from a progressive deficiency of helper or inducer T-cells (CD4+ T cells). HIV recognizes a CD4 surface molecule on the membrane of the T-lymphocyte, particularly the helper T-lymphocyte. It recognizes the information that identifies this as a "helper" T-lymphocyte. Using this membrane marker to get inside the cell, it employs its reverse transcriptase enzyme to copy its piece of RNA into the cell's genetic material. It will stay there for the life of the cell, eventually causing the death of the cell
HIV mediates the destruction and depletion of mature CD4 T-cells. HIV invades and destroys the immune system by damaging the CD4 lymphocytes, which results in a fall in the number of CD4 lymphocytes with the result that the immune system cannot function normally. As a result the risk of infection and cancer increases. HIV also invades macrophages, which leads to further depression of the functions of the immune system
When the number of CD4+ T cells declines below a certain level, the patient is at high risk of developing a variety of opportunistic infections and neoplasms
Spreading of HIV
Means of HIV Transmission
HIV can be transmitted from an infected person to another through:
Blood (including menstrual blood)
Semen
Vaginal secretions
Breast milk
Blood contains the highest concentration of the virus, followed by semen, followed by vaginal fluids, followed by breast milk
HIV Transmission
Unprotected sexual contact
Direct blood contact, including injection drug needles, blood transfusions, accidents in health care settings or certain blood products
Mother to baby (before or during birth, or through breast milk)
The following are few of the most common routes through which HIV spreads:
Sexual transmission:
HIV is transmitted by both homosexual and heterosexual unsafe contact. Unsafe Heterosexual transmission is the most common mode of infection worldwide, particularly in developing countries. The presence of sexually transmitted diseases further increases the risk of HIV transmission
Sexual intercourse (vaginal and anal): In the genitals and the rectum, HIV may infect the mucous membranes directly or enter through cuts and sores caused during intercourse (many of which would be unnoticed). Vaginal and anal intercourse is a high-risk practice.
A woman can give HIV to a man during vaginal intercourse
Yes. If the woman is infected, HIV is present in vaginal and cervical secretions (the wetness in a woman's vagina) and can enter the penis through the urethra (the hole at the tip) or through cuts or abrasions on the skin of the penis. The presence of other STDs can increase the risk of transmission. The correct and consistent use of a latex condom or female condom can reduce the risk of transmitting HIV during vaginal intercourse.
Oral transmission:
The mouth is an inhospitable environment for HIV (in semen, vaginal fluid or blood), meaning the risk of HIV transmission through the throat, gums, and oral membranes is lower than through vaginal or anal membranes. There are however, documented cases where HIV was transmitted orally, so we can't say that getting HIV-infected semen, vaginal fluid or blood in the mouth is without risk. However, oral sex is considered a low risk practice.
Oral sex
there is considerable debate within the HIV/AIDS prevention community regarding the risk of transmission of HIV through oral sex. What is currently known is that there is some risk associated with performing oral sex without protection; (there have been a few documented cases of HIV transmission through oral sex). While no one knows exactly what that risk is, cumulative evidence indicates that the risk is less than that of unprotected anal or vaginal sex. The risk from receiving oral sex, for both a man and a woman, is considered to be very low.
Currently, risk reduction options when performing oral sex on a man (fellatio) include the use of latex condoms, but also include withdrawal before ejaculation without a condom (avoiding semen in the mouth) and/or refraining from this activity when cuts or sores are present in the mouth.
When performing oral sex on a woman (cunnilingus), moisture barriers such as a dam (sheet of latex), a cut-open and flattened condom, or household plastic wrap can reduce the risk of exposure to vaginal secretions and/or blood.
Effectiveness of latex condoms in preventing HIV
Several studies have demonstrated that latex condoms are highly effective in preventing HIV transmission when used correctly and consistently. These studies looked at uninfected people considered to be at very high risk of infection because they were involved in sexual relationships with HIV-infected persons. The studies found that even with repeated sexual contact, 98-100% of those people who used latex condoms consistently and correctly remained uninfected.
Transmission by blood and blood products:
HIV can be transmitted by blood and blood products, both among individuals who share contaminated paraphernalia (needles and syringes) for injection drug use and in those who receive transfusions of blood and blood products
Sharing injection needles: An injection needle can pass blood directly from one person's bloodstream to another. It is a very efficient way to transmit a blood-borne virus. Sharing needles is considered a high-risk practice.
Maternal-fetal/ infant transmission: HIV infection can be transmitted from infected mothers to infants either intrapartum, perinatally, or via breast milk
Mother to Child: It is possible for an HIV-infected mother to pass the virus directly before or during birth, or through breast milk. Breast milk contains HIV, and while small amounts of breast milk do not pose significant threat of infection to adults, it is a viable means of transmission to infants.
Occupational transmission of HIV to health care and laboratory workers: There is a risk of HIV transmission following skin puncture from a needle or a sharp object contaminated with blood from a person with documented HIV infection.
However it dose not spread by
The following "bodily fluids" are NOT infectious:
Saliva
Tears
Sweat
Feces
Urine
Mosquito bite
Any casual contact
By sneezing or coughing
HIV from kissing
Casual contact through closed-mouth or "social" kissing is not a risk for transmission of HIV. Because of the potential for contact with blood during "French" or open-mouth, wet kissing, CDC recommends against engaging in this activity with a person known to be infected. However, the risk of acquiring HIV during open-mouth kissing is believed to be very low. CDC has investigated only one case of HIV infection that may be attributed to contact with blood during open-mouth kissing. In this case both partners had extensive dental problems including gingivitis (inflammation of the gums). It is likely that there was blood present in both partners' mouths making direct blood to blood contact a possibility.
HIV from casual contact
(Shaking hands, hugging, using a toilet, drinking from the same glass, or the sneezing and coughing of an infected person)
No. HIV is not transmitted by day-to-day contact in the home, the workplace, schools, or social settings. HIV is not transmitted through shaking hands, hugging or a casual kiss. You cannot become infected from a toilet seat, a drinking fountain, a doorknob, dishes, drinking glasses, food, or pets.
HIV is a fragile virus that does not live long outside the body. HIV is not an airborne or food borne virus. HIV is present in the blood, semen or vaginal secretions of an infected person and can be transmitted through unprotected vaginal, oral or anal sex or through sharing injection drug needles.
Symptoms of AIDS
One or More of the following could be symptoms of HIV/AIDS
Prolonged, unexplained fatigue
Fever lasting more than 10 days
Chills
Excessive sweating especially night sweats
Mouth lesions including yeast lesions and painful, swollen gums
Sore throat and cough
Shortness of breath
Changes in bowel habits including constipation
Frequent diarrhea
Symptoms of a specific opportunistic infection (such as candida, Pneumocystis, and so on)
Tumor (Kaposi's sarcoma)
Skin rashes or lesions of various types
Unintentional weight loss
General discomfort or uneasiness (malaise)
Headache
Additional symptoms that may be associated with this disease:
Speech impairment
Muscle atrophy
Memory loss
Decreasing intellectual function
Joint swelling
Joint stiffness
Joint pain
Cold intolerance
Bone pain or tenderness
Unusual or strange behavior
Slow, sluggish, lethargic movement
Anxiety, stress, and tension
Groin lump
Generalized itching (pruritus)
Genital sores (female)
Genital sores (male)
Blurred vision
Double vision (diplopia)
Light sensitivity
Blind spots in the vision
Decreased vision or blindness
Chest pain
Flank pain or pain in the sides
Back pain
Abdominal pain
Loss of appetite, indigestion, or other gastrointestinal upset
Muscle pain
Bone pain or tenderness
Numbness and tingling
Seizures
