eiving treatment have less than 600 CD4 cells per microliter of blood. AIDS patients, who have CD4 cell counts that are lower than 200, have the greatest risk of developing opportunistic infections that may be fatal.
HIV is transmitted from person to person via bodily fluids including blood, semen, vaginal secretions, and breast milk. Therefore, it can be transmitted through sexual contact with an infected person, by sharing needles/syringes with someone who is infected, through breastfeeding, during vaginal birth or, less commonly (and rare in countries where blood is screened for HIV antibodies), through transfusions with infected blood.
Symptoms: Many patients experience no symptoms when they first become infected with HIV. After one or two months, an estimated 80-90% of HIV patients develop flu-like symptoms including headache, fever, fatigue, and enlarged lymph nodes. These symptoms usually disappear after one week to one month and are often mistaken for another viral infection, such as the flu. Despite having minimal or no symptoms during this stage, individuals are very infectious because the virus is present in large quantities in bodily fluids.
After the initial infection with HIV, the next stage is called clinical latency. Although patients experience few or no symptoms during the clinical latency stage, the infection may still be passed to others. Once infected with HIV, the clinical latency stage may last 10 or more years in adults or up to two years in children who are born with HIV infection. The length of this asymptomatic period varies in individuals. Some people may start to experience more serious symptoms within a few months, while others may be symptom-free for several years. The virus can also hide inside infected cells and lay dormant. Patients can still transmit the virus to others when the virus is dormant.
As the immune system continues to weaken many symptoms appear, including inflamed lymph nodes (swollen glands) that may be enlarged for longer than three months. Other symptoms often experienced months to years before the onset of AIDS include fatigue, weight loss, frequent fevers and sweats, persistent or frequent yeast infections (oral or vaginal), persistent skin rashes, flaky skin, pelvic inflammatory disease (PID) in women that does not respond well to treatment, and short-term memory loss.
In addition, some individuals develop a painful nerve disease called shingles or frequent and severe herpes infections that cause sores to develop on the mouth, genitals, or anus. Infected children may be sick often, grow or gain weight slowly, or take longer to develop important mental and motor skills.
Although treatment can slow the progression of HIV, nearly all patients eventually develop AIDS. Once the patient's CD4 T-cell count is less than 200 cells per microliter of blood, their condition has progressed to AIDS, the final stage of the disease. Some patients are diagnosed with AIDS after they developan AIDS-defining illness, such as Pneumocystis jiroveci pneumonia (formerly called Pneumocystis carinii or PCP). The first symptoms of AIDS often include moderate and unexplained weight loss, recurring respiratory tract infections, and oral ulcerations.
Patients with AIDS have the greatest risk of developing opportunistic infections and tumors. Opportunistic infections and tumors may include tuberculosis, thrush, herpes viruses, shingles, Epstein-Barr virus, pneumonia, and a type of cancer called Kaposi's sarcoma (KS). In the last stages of AIDS, it is common for individuals to develop respiratory infections, including cytomegalovirus or mycobacterium avium complex (MAC) infections.
Diagnosis: HIV is diagnosed after HIV antibodies or HIV itself is detected in the patient's body. As soon as the virus enters the body, the immune system produces antibodies, which are proteins that detect and bind to HIV. The presence of these antibodies, which may take months to build up to detectable levels in the blood, oral fluid, and urine, can be used to determine whether HIV is in the body.
It may take some time f