发布时间：2019-05-15 08:55:59浏览次数：316 次
An estimated 37 million people worldwide are living with HIV, with just under 2 million of those people having recently contracted the virus. In the United States, around 1.1 million people live with HIV, but as many as 15% (or roughly 1 in 7) of those infected do not know they carry the virus. Some groups bare more of the burden of the HIV risk than others, especially racial minorities and men who have sex with other men.
HIV is considered rare in the US with less than 200,000 new infections per year. But for those living with HIV, treatment of the virus becomes a lifelong commitment to medication and maintenance because a reliable cure remains elusive. What makes HIV so hard to eradicate? And how close has science brought us to a cure?
What Is HIV?
The human immunodeficiency virus, or HIV, is a virus that targets the body’s immune system. Within a few weeks of contracting the virus, known as the acute infection stage, people typically experience what feels like a very bad case of the flu as the virus works hard to replicate itself throughout the body. Once this initial surge is over, HIV transitions into a clinical latency stage which means people carrying the virus can go for years without experiencing any symptoms at all.
If left untreated, however, HIV can lead to acquired immunodeficiency syndrome, or AIDS. This occurs once the immune system has become sufficiently damaged or has been weakened enough to allow the contraction of what are called opportunistic illnesses.
Why Is HIV So Hard to Cure?
The first cases of clinically-reported AIDS in the United States occurred in 1981 in Los Angeles. Since then, despite extensive study, we are still without a standard cure. HIV is particularly difficult to combat because it attacks the body’s immune system, the very system meant to fight off infections like HIV.
The virus first hijacks a protein called CD4 found on the cells of our immune system to replicate itself and then eventually kills those cells off. Among those under attack are T cells, the cells typically tasked with seeking out and destroying cells infected with viruses or cancers.
HIV is also be able to kill off immune system cells that it hasn’t even infected yet. The loss of those uninfected cells further leads to the decline in the immune system’s ability to do its job and thus the body’s ability to fight off future infections.
As if all of that weren’t challenging enough, HIV is found to have an extremely high mutation rate in the first 10 days of infection, meaning researchers looking for a cure are chasing down a moving target.
We’ve discussed before how challenging it is to come up each year with the vaccine to fend off the ever-adapting flu virus, and the rapidly mutating HIV is at least an order of magnitude worse.
The virus at work on the body has been likened to an arsonist setting fire to the local firehouse: there is no way to fight the blaze when the tools for that fight are the ones under attack.