The risk of progression of HIV infection into AIDS is very high in the absence of treatment. However, the progression might be very slow or may not occur, in a very small number of affected people. Such people are called nonprogressors.

While some of the people exposed to this virus may not show any signs, there are others who experience certain symptoms after 2 to 4 weeks or up to 3 months after exposure to the virus. This phase of acute illness is referred to as the primary HIV infection or acute retroviral syndrome (ARS). This is basically the body's response to the rapid HIV replication. During this phase, the infected person experiences flu-like symptoms. Unfortunately, the affected individuals might consider the illness to be a case of flu. During this phase, the amount of virus circulating in the blood (viral load) is high, which increases the possibility of transmission of the virus considerably, in comparison to the next phase of the infection. The risk of transmission of the virus is very high, if the infected person indulges in unprotected sex during this phase. Statistics show that one in five infected persons, is unaware of his/her condition, which is why people in the high-risk groups are often urged to go for HIV screening tests. The symptoms of the acute retroviral syndrome include: ➞ Fever ➞ Chills ➞ Night sweats ➞ Muscle aches ➞ Fatigue ➞ Headache ➞ Rash ➞ Sore throat ➞ Mouth ulcers ➞ Enlarged lymph nodes In case of people affected by ARS, the symptoms might resolve within a few weeks. After the ARS phase, comes the asymptomatic or latency phase, wherein the affected individuals don't experience symptoms for several years. Not everyone exposed to the virus gets affected by ARS or the primary HIV infection. In some people, there are no specific symptoms. These people have a clinical latent infection, that may last for a duration of 8 - 10 years or longer. However, some of the people in this phase might have swollen lymph nodes. During this asymptomatic period, HIV multiplies fast, thereby destroying the immune cells. Infected individuals begin to experience symptoms as the immune system weakens. As the virus destroys immune cells, the infected individuals begin to develop mild infections, and experience symptoms such as: ➞ Fever ➞ Fatigue ➞ Swollen lymph nodes ➞ Diarrhea ➞ Unexplained weight loss ➞ Cough and shortness of breath ➞ Progression of the HIV infection to AIDS In the absence of treatment, the disease can progress to AIDS in a few years. By the time AIDS develops, one's immune system has been severely damaged, thereby increasing the risk of opportunistic infections or diseases that wouldn't affect a person with a healthy immune system. The signs and symptoms of some of these infections may include: ➞ Soaking night sweats ➞ Shaking chills ➞ Fever that lasts for more than 10 days ➞ Cough and shortness of breath ➞ Diarrhea ➞ Nausea ➞ Vomiting ➞ Sores on the tongue or in the mouth ➞ Headaches ➞ Persistent, unexplained fatigue ➞ Vision-related problems ➞ Weight loss ➞ Skin rashes ➞ Easy bruising ➞ Genital sores ➞ Oral thrush ➞ Joint pain This virus can get transmitted to others through sexual contact, or direct contact with the infected blood in case of a blood transfusion. Having unprotected sex with multiple sex partners or indulging in other risky behavior like sharing a drug-injecting syringe can put a person at a greater risk. Sexual intercourse is the most common method of the transmission. During sexual contact, HIV can enter a body through the lining of vagina, penis, rectum, or mouth. Although there is no evidence of HIV being spread by saliva, there are possibilities of contact with blood through cuts or sores in mouth. HIV can spread from one person to other through the sharing of infected needles that carry a small amount of blood. Transmission could occur through blood transfusions, if there is any negligence during the transfusion process. An infected woman can transmit the virus to her unborn child during pregnancy. The risk of transmission of the virus from the mother to the unborn child can be lowered, if the mother takes the anti-HIV drug called zidovudine during pregnancy. The risk is further reduced if the delivery is done by Cesarean section. Breastfeeding can also cause the virus to spread from an infected mother to the child. HIV can only be transmitted through intimate contact with infected blood or body fluids. Some of the ways in which HIV does not spread include touching or hugging, contact with sweat, tear, or respiratory secretions of an infected person, sharing household items like utensils, towels, bedding, sharing facilities like swimming pools, saunas, hot tubs or toilets, etc.