The medical world is filled with jargon, long words, and complicated definitions. And acronyms trying to make it all less confusing. That’s true at Partners In Health (PIH) too, but our hope is to make things clear, for supporters and patients alike.
When we talk about tuberculosis (TB), many of those words arise. Simply put, TB is a common infectious disease. However, there are other related terms we often use that are important to know and understand.
In the alphabetized list below, learn about 14 TB terms, and how they show up in PIH’s everyday work:
1. Active TB
What It Means: If a person has active TB, this means the bacteria is “awake” unlike with a TB infection (explained below) and likely causing lung damage, possibly transmitting to and making other people sick, and needing treatment urgently.
In Our Work: In 2024, there were 3,200 people with active TB who successfully completed treatment across PIH care delivery sites.
2. Chest X-ray
What It Means: A chest X-ray is an imaging test used to view the lungs, heart, and other structures. It helps diagnose TB in people with or without symptoms; and monitor progress.
In Our Work: Modern X-ray machines are available across most PIH care delivery sites. Recently, Socios En Salud as PIH is known in Peru received 28 X-ray machines equipped with artificial intelligence for the detection of abnormal chest films.
3. Co-infection
What It Means: A person with TB may also be diagnosed with another infectious condition, such as HIV.
In Our Work: Nearly 75% of patients treated at PIH-supported Botšabelo Hospital in Lesotho are co-infected with TB and HIV.
4. Directly Observed Therapy Plus (DOTS-Plus)
What It Means: It’s an evidence-based strategy where a trained person either a health care worker or treatment supporter supports a patient through complex treatment and delivers care in the home or another location convenient for the patient.
In Our Work:In 1998, PIH Co-founders Drs. Paul Farmer and Jim Yong Kim introduced the idea of DOTS-Plus to expand the World Health Organization recommendation for treatment of TB. Beyond the WHO’s limited scope of first-line treatment and watching people take their medications (known as DOT or directly observed therapy), PIH included additional drug regimens necessary to cure drug-resistant TB coupled with supportive care. PIH proved this model in Haiti and Peru and then expanded it to Russia and beyond.
5. endTB
What It Means: The endTB project a partnership among PIH, Médecins Sans Frontières, and Interactive Research and Development, funded by Unitaid utilizes clinical trials of new drugs and shorter treatment regimens to dramatically improve the treatment of multidrug-resistant tuberculosis.
In Our Work:In 2024, the World Health Organization approved new, safe, and effective TB treatments which were studied in a PIH-led endTB clinical trial. The resulting recommendations represent the culmination of nearly a decade of scientific research and patient care across 18 countries.
6. Extensively drug-resistant tuberculosis (XDR-TB)
What It Means: It’s a form of TB caused by bacteria resistant to at least four common medications.
In Our Work: PIH clinicians across most care delivery sites have experience treating XDR-TB, the most rare and difficult-to-treat form of the disease. In Kazakhstan, Peru, and Lesotho, PIH led a clinical trial specifically for people with pre-XDR-TB, an early form of the disease; and cured patients, including a mother-daughter duo whom you can read more about in this blog.
7. GeneXpert
What It Means: It’s a machine that tests clinical samples to quickly identify infectious diseases, such as TB.
In Our Work: PIH-supported Botšabelo Hospital first started using the GeneXpert around 2012 and was the first facility in Lesotho to have the machine. PIH now has GeneXpert machines across seven additional hospitals and clinics in Haiti, Peru, Malawi, Rwanda, Liberia, Sierra Leone, and Kazakhstan.
8. Multidrug-resistant tuberculosis (MDR-TB)
What It Means: It’s a form of tuberculosis caused by bacteria resistant to at least two common medications.
In Our Work: In partnership with the government, PIH Sierra Leone opened the country’s first MDR-TB treatment center at Lakka Government Hospital in 2017. Since then, over 1,100 patients have been enrolled in the program.
9. Prophylaxis
What It Means: It refers to measures such as antibiotics or routine wellness visits used to prevent diseases before they occur.
In Our Work: In many of the communities where PIH works, families often live in overcrowded houses which makes it easier for TB to spread. If someone has TB and the rest of the family tests negative, PIH staff may still recommend they take daily preventative medication, known as TB prophylaxis, for one to three months depending on their medical history.
10. Sputum
What It Means: It’s a thick mucus that can accumulate in the airways in people with respiratory disease. Testing it helps identify and diagnose TB.
In Our Work: Community health workers collect sputum samples during home visits. A person coughs deeply, coughs the sputum into a container, then the sample is tested in a laboratory.
11. TB infection
What It Means: It’s when TB bacteria are present in the body, but inactive. The person has no symptoms and cannot spread the disease to others. A person can be infected for weeks or even years before the bacteria becomes active. Treatment of TB infection virtually guarantees that TB disease will not occur and will not be spread to others.
In Our Work: To detect TB infections early, Socios En Salud as PIH is known in Peru and other care delivery sites conduct active screening in vulnerable communities using portable X-ray machines and molecular tests.
12. Treatment success rate
What It Means: It is the percentage of patients who finish their entire TB treatment with a positive outcome and are clinically better.
In Our Work: Between 2019-2023, community health workers in Liberia completed 171,693 home visits. Those visits and referrals include TB treatment, in which PIH has become a nationwide leader, and have also pioneered artificial intelligence-based testing leading to a 92% treatment success rate in 2021.
13. Treatment supporter
What It Means:Treatment supporters are non-clinical individuals oftentimes a person with TB’s neighbor or friend who provide at-home support with medication routines, appointments, and more.
In Our Work: Between 2021 and 2024, PIH Lesotho worked with 483 treatment supporters to reach hundreds of patients with MDR-TB
14. Universal search, treat, and prevent
What It Means: It’s a three-part approach designed to eliminate TB. Standard approaches focus more heavily on one pillar typically “treat” and often cannot reach the full population. At PIH, we are reenvisioning the approach to simultaneously carry out each pillar for a wider group of people what we refer to as “universal access search, treat, and prevent.”
In Our Work: In Lesotho, PIH is launching the universal access search, treat, and prevent approach in a full district. We believe it is our moral imperative to end TB and through this approach we can detect and treat thousands more people with TB.