People in prison are nine times more at risk of developing tuberculosis (TB) than the general population globally.
For the first time ever, researchers have estimated the rate of TB in incarcerated persons, having analyzed data from almost every country in the world (193 out of 195 countries) between 2000 and 2019. The findings have been published in the British medical journal the Lancet Public Health.
Approximately 125,105 of the 11 million people incarcerated globally developed TB in 2019 – a rate of 1,148 cases per 100,000 people per year.
Significantly higher than the global incidence rate among all persons – 127 cases per 100,000 people per year.
Countries in Asia Pacific region with highest incidence per 100,000 persons in prisons: Indonesia: 1,522 cases per 100,000 persons in prisons, Philippines: 3,829 cases per 100,000 persons in prisons, and Thailand: 1,479 cases per 100,000 persons in prisons.
However, the case detection rate was just 53% of all TB cases in prisons globally. Furthermore, the researchers found a strong relationship between country-level tuberculosis incidence rates and overcrowding in prisons, said the Union, world's first global health organisation established in 1920.
“This connection between TB and overcrowding suggests that efforts to limit the number of people who are detained may be one potential public health tool to combat the TB epidemic in prisons,” Leonardo Martinez, study lead from School of Public Health, Boston University, US, was quoted as saying by the Union.
“The high incidence rate globally and across regions, low case detection rates, and consistency over time indicate that this population represents an important, under-prioritised group. Continued failure to detect, treat, and prevent tuberculosis in prisons will result in the unnecessary disease and deaths of many incarcerated persons. And, of course, when incarcerated persons are released from prison, they can take this infectious disease back into the communities in which they live, further contributing to the spread of tuberculosis globally. Greater focus and resources for addressing the tuberculosis epidemic in prisons are needed to protect the health of incarcerated people and their communities.”
The elevated risk of TB among incarcerated populations exceeds that of diabetes, alcohol use disorders, smoking and undernourishment.
The study team, consisting of researchers from across the world, identified that prison TB rates varied greatly by the WHO region in 2019.
The greatest incidence rate in the African region – 2,242 cases 100,000 people per year – almost double the global estimate for this population.
The Americas region, largely driven by Central and South America, had the largest estimated absolute number of TB cases among incarcerated persons – 30,509.
Anthony D Harries, senior adviser at the Union (International Union Against Tuberculosis and Lung Disease), said: “These findings give us a much clearer picture of tuberculosis in prisons than we've ever had before. The high rate of tuberculosis and low rate of detection indicates that current control measures are insufficient for preventing the spread of the disease in prisons globally. Therefore, further research is vital to identify and implement the most effective interventions.”
In the 30 countries including Bangladesh designated by WHO as high burden for tuberculosis, 87,258 incident cases occurred among incarcerated individuals in 2019, representing 70% of the global total in this population. In the 30 countries with the most incarcerated individuals, 93, 717 incident cases, representing 75% of the global total, were estimated to occur.
The five countries with the highest number of incident tuberculosis cases among incarcerated individuals in 2019 included Brazil, (15,266 per 100,000) Russia, China, Philippines, and Thailand. Bangladesh was the 18th among those high-burden countries.
People who are incarcerated are at high risk of developing tuberculosis. We aimed to estimate the annual global, regional, and national incidence of tuberculosis among incarcerated populations from 2000 to 2019, the Lancet said.
“Our estimates suggest a high tuberculosis incidence rate among incarcerated individuals globally with large gaps in tuberculosis case detection. Tuberculosis in incarcerated populations must be addressed with interventions specifically tailored to improve diagnoses and prevent transmission as a part of the broader global tuberculosis control effort.”
There were important differences by WHO region over time. Incidence decreased in several regions (e.g., European, African, and South-East Asian regions) and increased in the Americas region.
Trends in Europe were largely influenced by prisons in Russia which, after targeted interventions in prisons and reductions in incarceration over the past decade, have successfully reduced TB incidence in prisons.
Reasons for the increases in TB burden in the Americas may be multifactorial, The Union said. Mass incarceration has risen dramatically in the Americas likely leading to increased crowding. The strong association found between crowding and TB incidence suggests this may be an important driver of the rising TB incidence in prisons from the Americas, especially in Central and South America.
While estimated incidence rates were high across WHO regions, there were differences within regions as well. For example, in the Americas, incidence in South and Central American countries (both more than 1,200 cases per 100,000 people per year) was considerably higher than those in North America (less than 50 incident cases per 100,000 people per year). Similarly, eastern Europe had a substantially higher incidence than western Europe.
