HIV, or the human immunodeficiency virus causes an infectious disease that is spread through the exchange of body fluids, such as blood during sexual intercourse. If left untreated, HIV can lead to AIDS (acquired immunodeficiency syndrome), which in turn can be fatal or result in concomitant opportunistic infection like tuberculosis and cancers such as lymphomas. Currently, no medicine exists that can completely cure HIV/AIDS, although the symptoms can be suppressed to a certain extent through a combination of three or more antiretroviral drugs.
Causes of Infection
HIV (human immunodeficiency virus) is a virus that can cause acquired immunodeficiency syndrome (AIDS). Unlike other viruses, the human body cannot rid itself of HIV, which means that once a person has HIV, they will carry the virus indefinitely. HIV attacks specific cells in the immune system known as CD4+ T cells (named for a type of glycoprotein found on the surface of immune cells). Over time, HIV destroys so many of these cells leading to immunodeficiency condition wherein the body cannot fight off infections or diseases. It is when this happens that HIV infection can then lead to AIDS. HIV can be transmitted via the exchange of body fluids, such as through used intravenous needles, breast milk, and sexual intercourse. People cannot become infected, however, through daily contact, including by sharing objects, food or water or by kissing, hugging, or shaking hands with an infected individual.
Disease Agent：Human immunodeficiency virus (HIV）
While many people infected with HIV do not exhibit any symptoms for up to 10 years or more, some people may develop early flu-like symptoms (sometimes described by patients as “the worst flu ever”) two to four weeks after being exposed. Symptoms can include fever, enlarged lymph nodes, sore throat and rash, which are indeed similar to symptoms of influenza. Since an attack on the patient’s T cells will have begun by the time such symptoms are present, large amounts of HIV will already have been produced in the body, leading to a sharp fall in the T cell counts. Since immunity decreases as the number of CD4+ T cells fall, symptoms such as coughing, weight loss, fever and diarrhea will also begin to appear.
Without treatment, CD4+ T cells counts will continue to fall sharply and may lead to AIDS. Patients may also develop severe illnesses, including TB (tuberculosis), cryptococcal meningitis, and cancers such as lymphoma and Kaposi’s sarcoma. Symptoms can also vary dramatically from person to person. In some cases, no symptoms may appear for 10 years or more following initial infection. It is believed that it can take from 2 to 15 years for patients to develop AIDS.
Diagnosis and Treatment
At this time, an HIV infected person cannot completely get rid of the virus, but with effective medical care, HIV can be suppressed to low levels in the body. One effective HIV infection treatment is called antiretroviral therapy or “ART,” and was introduced in the mid-1990s. ART can dramatically prolong the lives of people infected with HIV and lower their chances of infecting others. But it is nevertheless imperative to diagnose HIV early and treat patients quickly.
The most common HIV diagnostic test is the antibody detection test (immunoassay), which screens for antibodies being made in the body to fight the HIV virus. If a test turns out positive, follow-up diagnostic testing like immuno-blot is usually performed, which includes an antibody differentiation test to distinguish HIV-1 from HIV-2.
Most people have a “window” period of from three to six weeks during which anti-HIV antibodies are still being produced and as such are not yet detectable. In these cases, patients should undergo the same test after six weeks.
HIV can be suppressed by a combination of three or more antiretroviral (ARV) drugs, known as antiretroviral therapy (ART). ART controls viral replication within the body but is not a cure for HIV infection. It allows the immune system to be built up, recovering the ability to fight off infections.
Male and female condoms must be used correctly and consistently. Research has shown that male latex condoms offer 85% or greater protection against sexually transmitted HIV.
Taking two anti-HIV drug tablets daily in what is known as pre-exposure prophylaxis (PrEP), is one preventive option for people who may be at high risk, whether diagnosed as HIV-positive or not. According to a recent study, in cases where an HIV-positive person follows an effective antiretroviral therapy regimen, the risk of transmitting the virus to sexual partners can be reduced by 96%.
Regions at High Risk of Infection
Sub-Saharan Africa is the most affected region, it is estimated that nearly 25 million people are infected by HIV. Sub-Saharan Africa accounts for two-thirds of the global total of new HIV infections. The order of the people who living with HIV is Africa, South-East Asia, Americas, Europe, Western Pacific and Eastern Mediterranean.
Estimated Number of Infected People
It is estimated that in 2015, there were approximately 36.7 million people living with HIV, and 2.1 million people became newly infected globally.
Estimated Number of the Deaths
More than 35 million lives have been lost due to HIV/AIDS so far. In 2015, 1.1million people died from HIV-related causes globally. Tuberculosis (TB) is the most common presenting illness among people with HIV. It is also the leading cause of death among people with HIV- responsible for 1 of every 3 HIV-associated deaths.