Imagine a man who spends a year in a Brazilian prison while awaiting trial. While there, he’s unknowingly exposed to tuberculosis, a deadly, slow-developing airborne bacterial disease. Acquitted, he returns home to his wife and young child, only to develop fever, weakness and, eventually, a cough. He’s diagnosed with TB months later. By then, he’s unwittingly exposed his family and community. 

TB often flies under the radar in the United States, where measures to prevent transmission and treatments for the disease have reduced its threat. Globally, however, the effects are devastating and widespread. The illness sickens more than 10 million people per year and is one of the world’s foremost infectious killers.  

Prisons can be potent TB incubators. Due to overcrowding, poor ventilation, malnutrition and inadequate health care, the infection transmits easily among incarcerated individuals, who may become ill and transmit TB in the community when they’re released. Yet the global burden of TB in prisons is not well understood or tracked by international health organizations. 

This large gap in knowledge and action is damaging global efforts to eradicate TB, said Jason Andrews, MD, an associate professor of medicine and global health faculty fellow. “Remarkably, and dismayingly, global cases of TB in prisons aren’t tracked and reported, and we haven’t had measures of the global burden until now.”  

Andrews, who has been studying TB in Brazilian prisons for more than a decade, and colleagues published a study in June. It provides the largest, most comprehensive global assessment of the rate of tuberculosis among incarcerated individuals. Pulling data from 150 countries, they found a high incidence of TB in prisons around the world and estimate that almost half of all cases go undetected. Globally, they found TB rates in prisons to be ten times higher than those in their surrounding communities. 

Andrews, who recently received a Stanford Global Health seed grant to study low-cost, effective methods for detecting TB and preventing transmission in an Indonesian prisons, discussed the study’s findings and why tracking and treating tuberculosis in prison is critical to combatting the deadly disease worldwide. 

You described this study as possibly the most important scientific endeavor you’ve been a part of. Why?  

If you went to any country in the world and searched for the places with the highest incidence of TB, consistently, it would be prisons. Prisons face overcrowding as well as limited access to medical care, diagnostics, treatment and prevention. Most people who are incarcerated in many of the countries where we work have not even been sentenced yet and are facing these extraordinary health risks.  

Given the rise in mass incarceration in many countries around the world, TB is a rapidly growing problem. Little is being done about the increasing incidence of TB in prisons, and there’s scant recognition of the scale of the problem.  

TB cases are rising in the Americas, which can be entirely attributed to the rapid rise of incarceration. Brazil has the highest number of TB cases in the Americas, and the incarceration rate is seven times the rate of incarceration in the 1990s. More TB cases occur in Brazil’s prisons each year than in the entire population of the United States. The scale of the problem is enormous. 

The goal of the WHO’s End TB Strategy is to reduce the number of new TB cases by 80% by 2030. What role do prisons play in this effort to end TB? 

Often, communities and governments can see health issues in prisons as isolated problems that don’t impact them — and therefore don’t require their attention.  

However, we’ve shown that epidemics in prisons and epidemics in communities are intertwined. People come into prison for a year or two on average, get infected with TB, and could be infectious for a long time before they are diagnosed. Through genome sequencing studies in Brazil and Paraguay, we’ve shown that a substantial proportion of cases that occur in the community can be traced to prison exposure. 

Addressing TB in prisons will have outsized effects on the community. 

What new information does this study reveal about the burden of TB in prisons globally? 

One of the most striking findings was that only 53% of TB cases in prisons are detected. It shows just how far we have to go to improve diagnosis in this setting. 

Worldwide incidence rates are about 130 per 100,000 in the community. In prisons, we saw a rate of 1,148 cases per 100,000 people. These rates were particularly high in some regions of Africa — 2,242 cases per 100,000 people.  

How do you hope this study will impact global efforts to combat TB? 

The first step in addressing any problem is measuring it. Now that we know the scale of TB incidence, we hope other countries will see this information, recognize the scope of this problem, begin to track TB in their prisons more closely and invest resources to better address the problem.  

Photo by methaphum