In 2011, about 1.2 million people were living with HIV in the US. Unfortunately, 14 percent of those people didn’t know they were infected, according to a CDC report released today. And as of 2012, only five states in the US had met the National HIV/AIDS Strategy objective of making sure that at least 90 percent of people living with HIV know their status by 2015.

When it comes to HIV prevalence and testing, there’s a pretty big gap between the states. In Louisiana, 23 percent of people living with HIV didn't know their status in 2012, compared with just 10 percent of people living with HIV in Connecticut, Colorado, Delaware, Hawaii, and New York.

This is the first time that the CDC has released these estimates, says Irene Hall, chief of the HIV incidence and case surveillance branch at the CDC and one of the authors of the report. "These data really underscore the need to have ongoing efforts that increase testing," she says.

People who don’t know that they have HIV contribute one-third of transmissions, according to the CDC. That means that increasing the number of people who are aware of their status is crucial to reducing transmission rates across the country. Not to mention that "knowledge of one’s HIV status is key to accessing effective HIV treatment," Hall says.

The agency’s estimates were obtained thanks to mathematical modelling. To come up with the percentage of people who are infected with HIV, but don’t know about it, Hall and her colleagues first estimated the total number of infections. From that they subtracted the estimated percentage of diagnosis, which gave them the percentage of undiagnosed cases of HIV. That’s how the researchers were able to figure out that Louisiana wasn't doing nearly as well as Hawaii in 2012, for instance.

The number of infections also varies widely based on location. For example, Iowa saw 110 cases of HIV for every 100,000 people in 2012. But in the District of Columbia, that number was almost 4,000 cases for every 100,000 people. "What I see from the data is that all jurisdictions have room for improvement," Hall says. "States need to monitor their progress, and then focus their prevention efforts."

Additionally, the CDC’s report underscores the fact that gay and bisexual men are still disproportionately affected by HIV. Over 60 percent of people who received an HIV diagnosis in 2011 were gay and bisexual men. And in 2012, the number gay and bisexual men living with HIV ranged from 1,600 in Delaware to about 134,000 in California.

The CDC’s estimates show that, in many areas, increasing the number of people who know their status by 2015 will be an uphill battle. "There is some delay in getting the data reported before we can get it published, so hopefully by 2015 more states will have met the 90 percent standard," Hall says. "but it’s too early to make predictions about that."

National HIV testing day is June 27th. I don’t know about you, but getting a bit of blood drawn sounds like a really good way to spend an hour on Saturday.