For many, tuberculosis (TB) registers as an “old-timey” disease – something that was prevalent during the Victorian era and the Industrial Revolution. Nevertheless, the disease still makes its rounds in present-day America, particularly in low-income areas where factors such as “overcrowding, malnutrition, and poor ventilation” can facilitate the spread of TB. TB itself is highly contagious, transmitted through small, air-borne particles; though symptoms of TB can vary, those with the disease commonly experience breathing troubles, chest pains, and a bloody cough. Without treatment, TB is always fatal. However, in a country where the incidence rate is only 2.9 cases per 100,000 persons, I’d go so far as to say that most Americans rarely think about Tuberculosis, especially when the flu and COVID-19 pose as much more visible threats.
Globally, however, TB takes on a different story. The disease is one of the main causes of death worldwide and is regarded as a global public health emergency, as declared by the World Health Organization (WHO). In 2023, tuberculosis claimed more lives than any other infectious disease, with millions affected worldwide.
Nonetheless, despite its reputation as a deadly disease, TB is both preventable and curable. Typical treatment for TB involves a combination of antibiotics, which generally take between four and nine months to months to complete. However, issues often arise when treatments are interrupted, as is often the case in developing countries, where TB rates are also the highest. Such interruptions, often caused by a complicated mixture of financial barriers, limited healthcare infrastructure, and cultural bias, can increase the risk of developing drug resistant TB. When TB develops drug resistance, an infected person must be treated with more novel regimens over a longer period of treatment, and face higher risk of severe illness and death.
Yet in spite of its staggering global toll, with particular prevalence in countries in Africa, Southeast Asia, and the Pacific, TB remains largely absent in mainstream public health conversations. In many of these regions, health systems already operate under chronic strain and lack the staff, resources, and coordination needed to effectively manage even routine public health needs. Nonetheless, we are also beginning to see how accelerating climate change and environmental degradation are contributing to the rise of new vulnerabilities and exposure pathways that together create the perfect storm for the spread of TB. Rising air pollution, mass displacement, food insecurity, and the breakdown of healthcare systems all directly fuel TB transmission. Climate change will multiply these issues, especially in countries where healthcare infrastructure is already fragmented and overburdened. In ignoring TB today, we are setting ourselves up for a far more severe crisis tomorrow
In fact, there is already evidence that the interplay between natural disasters, mass displacement, and overcrowded living conditions are exacerbating TB transmission. For example, Bangladesh, which has the sixth-highest TB burden in the world and is ranked as the seventh most extreme-disaster risk-prone country in the world, is facing an escalating polycrisis. Although the country has been attempting to build a robust response system to TB, each natural disaster threatens to undermine its progress. The country, which is especially susceptible to the impacts of cyclones, flooding, heatwaves, and sea-level rise, has also experienced massive migrations over the past few years as a result of climate-related disasters. At least 400,00 people move to Dhaka each year, 70% of whom were forced to migrate. Many incoming migrants settle into informal settlements and slums that are poorly ventilated and lack proper sanitation. As a result of increasingly cramped living quarters, the already endemic TB began to spread rapidly between migrant populations.
Beyond displacement and overcrowding, rising levels of air pollution compound the risk of respiratory issues in vulnerable regions, including in Dhaka, which is often regarded by climate experts and global air quality monitoring companies such as IQAir as one of the most polluted cities in the world. In urbanizing cities, air quality often deteriorates due to industrial emissions and the burning of biomass, which increase levels of hazardous pollutants. Studies show a strong correlation between incidence of TB and indoor air pollution from biomass fuel combustion. Pollutants such as fine particulate matter and toxic gases damage lung tissue and weaken the immune system, rendering individuals more susceptible to respiratory infections, including TB.
This combination of pollution and crowded living conditions creates a perfect environment for TB epidemics. For those already infected with TB, exposure to polluted air can exacerbate the severity of TB symptoms and hinder recovery. This cycle of compounding environmental hazards is critically dangerous, especially for vulnerable populations that already lack regular access to adequate health care.
Compounding these challenges is the growing issue of food insecurity. According to studies conducted by the National Institute of Health, undernutrition is amongst the leading risk factors for TB because those who are malnourished face increased risks of developing active TB–the form of the disease in which the bacteria are actively multiplying and is at its most contagious. Those who already have active TB often experience more severe symptoms and treatment complications when undernourished. Several health institutions, including the World Health Organization (WHO), have long advocated for frameworks that address issues with food and water insecurity, a challenge that has intensified with the rising frequency of natural disasters. However, despite these initiatives, implementation remains uneven, and many high-risk regions continue to struggle with persistent food insecurity and limited access to integrated TB care.
As climate change continues to intensify, it becomes increasingly clear how environmental and social conditions facilitating TB transmissions–such as food and water insecurity, pollution, and forced displacement–are all symptoms of broader inequity. Put simply, effective TB control requires considering climate justice: recognizing how unequal exposure to climate-related hazards exacerbate vulnerability to TB. Treating TB without addressing the underlying structural and environmental factors merely addresses the symptoms of a deeper problem.
Addressing this growing threat demands a coordinated global response. This includes assistance from developed nations that may not directly face high TB burdens but will feel its effects nonetheless. Their resources and influence are essential in strengthening prevention and treatment abroad in order to safeguard global stability and health security. However, achieving such global coordination is far from straightforward. With political priorities and competing crises, in addition to systemic inequalities, it will admittedly be difficult to direct resources to where they are most needed. Nonetheless, to handle what seems inevitable requires equitable partnerships between developed and developing countries to protect the world’s most vulnerable populations. Only through shared responsibility can the world hope to contain a disease that respects no borders.