Why it matters. Tuberculosis is often assumed to be eradicated in rich countries, yet a top-tier economy like South Korea still battling it shows how the disease persists wherever populations age and live alone — a warning relevant to other wealthy, graying societies.
Background. South Korea joined the OECD in 1996 and has one of the world's fastest-aging populations alongside a rapidly rising share of single-person elderly households, a demographic shift that strains both healthcare and social support. The figures cited come from Korean health data and a clinician at Gachon University Gil Medical Center, a major hospital in Incheon near Seoul.
What to watch next. Watch whether Korea expands outreach to isolated elderly patients and latent-TB screening to finally close the gap with lower-incidence OECD peers.
A Wealthy Nation With a Stubborn Old Disease
South Korea, despite being one of the world’s most advanced economies, still reports more than 80,000 new tuberculosis (TB) cases over the five years from 2020 to 2024 — and held the highest TB incidence rate among OECD member countries until 2022, when it slipped to second place behind Colombia after 27 years at the top. Doctors say the lingering burden shows TB is not a relic of the past but an active public-health threat, especially for an aging society.
Many people assume tuberculosis is a “disease of poverty” from leaner times. The reality in Korea contradicts that. While both case numbers and incidence rates have fallen sharply over the decades, the elderly and people with chronic illness remain highly vulnerable — a growing concern as the population ages.
The Organisation for Economic Co-operation and Development (OECD) is a group of 38 mostly high-income democracies; ranking worst among them on a basic infectious disease has long been an uncomfortable statistic for Korea, which joined the body in 1996.
What Tuberculosis Actually Does
TB is a chronic infection caused by the bacterium Mycobacterium tuberculosis. It most often attacks the lungs, but the bacteria can spread through the bloodstream to the lymph nodes, the membranes around the brain, the spine and the abdomen — meaning it is better understood as a whole-body disease than a simple respiratory illness.
Crucially, infection does not equal illness. Only about 5–10% of infected people develop active TB; the rest carry a latent infection that their immune system keeps in check. But latent does not mean safe — anything that weakens immunity can reactivate the disease. Risk rises sharply with diabetes, malnutrition, chronic illness, heavy drinking and old age.
Professor Park Yoon-sun, an infectious disease specialist at Gachon University Gil Medical Center, explains that TB spreads through the air when an untreated patient coughs or sneezes. Reassuringly, she notes, not everyone infected is contagious, and once proper treatment begins, infectiousness drops dramatically within about two weeks.
Spotting It Early
Early TB is easy to miss because symptoms are mild or resemble a common cold. Warning signs worth checking include a cough lasting more than two weeks, phlegm or coughing up blood, low-grade fever, night sweats, fatigue, loss of appetite and weight loss. Diagnosis relies on sputum smear and culture tests, faster genetic testing, and imaging of the lungs.
Curable — If Patients Finish the Course
TB’s cure rate reaches roughly 98%, so why is it so hard to eliminate? The catch is treatment length. Standard therapy for pulmonary TB requires taking anti-TB drugs for at least six months, because the bacteria multiply very slowly. Stopping early or taking medication irregularly can breed drug-resistant TB, which is far harder and slower to treat.
Side effects can appear over months of treatment: rifampicin can harmlessly turn urine red but may strain the liver, while ethambutol can affect vision in some patients. Professor Park stresses that patients should never stop medication on their own — they should adjust treatment with their doctors.
The bigger message, she says, is social. The treatment “blind spots” today are often elderly people with chronic conditions, particularly those living alone with little support. “TB is more than an individual illness — it is a social infectious disease,” Park said. “Diagnosed early and treated properly, it is completely curable, and transmission can be effectively blocked.”
