Prisoners around the world and people who were formerly incarcerated have a higher burden of HIV and other infectious diseases than the general population, worsening the spread of diseases inside and outside of prison, according to new research.

In a series of six papers in medical journal the Lancet, researchers from the Johns Hopkins Bloomberg School of Public Health analyzed the prevalence of infectious diseases including HIV, hepatitis C, hepatitis B and tuberculosis between 2005 and 2015.

They broke down how many of the 10.2 million people incarcerated worldwide had which illnesses. Based on the most recent data, from 2014, they estimate that 3.8 percent had HIV, 15.1 percent had hepatitis C, 4.8 percent had chronic hepatitis B and 2.8 percent had active tuberculosis.

The series noted that the spread of disease is usually low while someone is incarcerated, and people typically have access to treatment while incarcerated. However, it is difficult for them to continue their treatment once they are released.

Chris Beyrer, one of the researchers and a professor of public health and human rights, said the lack of resources is often a reason for a person becoming more infectious.

“What you have is treatment interruptions and gaps in care, and that’s because it’s very hard for people to access services,” he said.

Newly released prisoners with HIV often see their viral loads spike, which makes them more infectious to sexual partners and to people with whom they share drug needles.

Beyrer points out that criminal-justice policies that affect certain groups can have a big impact on how infectious diseases spread. He said that in much of the world, a substantial number of people are jailed because of drugs or drug-related offenses. In 27 countries, according to the analysis, drug users often don't receive treatment and are kept in unsanitary areas that can promote the spread of disease.

In the United States, researchers estimated that 1.3 percent of prisoners have HIV and 16.4 percent of prisoners have hepatitis C.

Drug use across America is pretty much the same for many demographics, Beyrer said, but who is actually punished for drug use or drug-related offenses varies greatly by race.

The series notes that black men are nine times more likely to be incarcerated for drug offenses than white men are, and they represent a disproportionate share of the U.S. prison population. Moreover, the high rates of black men in prison could be contributing to the high rate of HIV among all black Americans, according to one of the papers.

Researchers recommend reforming police practices, changing health-care management in prisons and decriminalizing drug use and the possession of drug across all nations. Doing so, they say, will mean compliance with the global standards of health care for prisoners.

William Schaffner, medical director at the National Foundation for Infectious Disease and professor of preventive medicine at Vanderbilt University School of Medicine, agrees with many of the findings and recommendations of the series. He suggests improving treatment after incarceration. “I should like to see prisoners [screened] when they enter prison and then the problems identified,” he said. “As they’re discharged, I’d like to see an actual link to post-discharge care.”

Brad Brockmann, executive director of the Center for Prisoner Health and Human Rights, supports many of the points leading to incarceration in the study. However, he thinks one of the studies doesn't emphasize enough just how rampant hepatitis C is among prisoners and the rest of the population, especially in the U.S.

“The hep C epidemic has been woefully under-addressed,” he said. “The funding for HIV in this country dwarfs the funding that is available for hep C.”

Brockmann said 90 percent of prisons and jails in the United States offered antiretroviral therapy for prisoners with HIV.

Like Schaffner and Beyrer, Brockmann said the public should be concerned about the health of its prisoners.

“The population in the country with the highest health burden is our prison population,” he said. “Over 90 percent of that population is going to be released.”