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Why Tuberculosis Bacilli Love the Climate Crisis

A person traveling and a close up of Tuberculosis bacterium

[Editor’s Note: Tomorrow, March 24th, is World TB Day. Migrant Clinicians Network has a long history of working with migrant patients with TB. Read more on MCN’s Tuberculosis page.]

Climate disasters are wrecking crops, flooding neighborhoods, burning down infrastructure, and destroying economies. When combined with political instability, gang violence, economic collapse, or the simple yearning for better life circumstances, climate change pushes people to leave their countries of origin. Migration is a natural human response when conditions are not conducive to a safe and healthy life. This is evidenced in well over a hundred thousand years of human migration around the planet, starting with the original migrations across and then out of Africa. Worldwide migration is accelerating as the climate crisis destabilizes already-fragile livelihoods. And, even though it is a natural phenomenon, migration brings significant increased health risks for those who move.

Tuberculosis (TB) cases, for example, are higher among migrants to the US than the general population. Some migrants may have been exposed in their country of origin, as TB is commonplace in war-torn countries and in many lower-income nations across the world, but many more are exposed to the highly infectious airborne bacteria en route or after migration because of congregate living arrangements.

A refugee camp in Turkey

During migration, particularly after a disaster when a region experiences a mass exodus, many people seek shelter in informal camps, refugee centers, or other substandard shelters because they have few alternatives to protect themselves from harsh weather conditions. Overcrowding and poor ventilation in such locations increase the risk of infection, should a fellow migrant have active TB. Throughout their journeys, most migrants have little to no access to health services. Additionally, treatment for TB is long and requires ongoing surveillance to ensure treatment adherence and completion. While treatment for TB has improved and can now take as little as six months even for highly resistant strains of TB, uninterrupted treatment is essential. The person under treatment must be monitored for adverse effects and have the administration of medications directly observed. Migration is not conducive to such intensive treatment regiments, unless paired with MCN’s Health Network, a virtual case management system that is proven cost-effective and lifesaving for TB patients.

After migration, many newly arrived migrants and asylum seekers may continue to be subject to a heightened risk of TB. Many detention centers and prisons in the US have significant overcrowding and poor ventilation, partnered with poor infection control practices, a decrease in individual immune response secondary to stress and poor diet, and limited or delayed access to health care. Those who are able to stay in the country discover that their access to health care is severed; newly arrived asylum seekers who are awaiting their immigration hearings and those without an immigration status are ineligible for public health insurance in most states, and private health insurance is prohibitively expensive for this low-earning segment of the population. While TB treatment is provided without cost in the US, a person with active TB would need to encounter the health system or other social services in order to access screening and treatment. Many migrants are wary of accessing health services for the belief that it may jeopardize their immigration status or result in deportation. Asylum seekers, unlike refugees, are not guided through an arrival process that includes medical screening and access to social services. Many remain unaware of local services that may be available to them. Others may be aware of the services but linguistic and cultural barriers, lack of transportation, and poverty may prevent them from reaching out even when ill.

Migrants on a boat in the ocean

As the climate crisis progresses almost unabated, migration will become a necessity for millions of people as large swaths of land become uninhabitable, and basic survival, untenable. Some forecasters estimate that the climate crisis will soon lead to upwards of a billion climate migrants – one in seven people on the planet – by 2050. Climate disasters result in large numbers of people leaving simultaneously, straining resources and leading to overcrowding in shelters. TB bacilli, seeking to infect as many people as possible, are huge beneficiaries to this type of increase in migration – unless cross-border and intra-border TB control and care interventions are increased and systematized. 

Since its inception, Migrant Clinicians Network has sought to reduce the health risks that migrants take on as a result of their migration. An early rendition of MCN’s highly effective virtual case management program, Health Network, was developed specifically for TB patients who needed to move and could not keep up their TB treatment as a result. In addition to projects like Health Network, universal health coverage is a necessity for all people in the US, regardless of immigration status, to ensure access to medical services so that anyone with active TB or latent TB infection can get the treatment they need.

A clinician checks on a child being held by their parent

Now, we encounter a new obstacle. Tuberculosis, an ancient disease, is butting up against our most modern of disasters: human-induced climate change. In this scenario, with millions more migrants, and ever-more crowded migrant camps and detention centers, tuberculosis will almost certainly win. In addition to universal health care and cross-border systems to ensure treatment access and completion among the growing number of migrants, a rapid reduction in greenhouse gas emissions to stabilize the climate is the urgently needed -- because the best way to prevent tuberculosis among migrants is to prevent the climate disasters that force people to migrate in the first place. 

Read more:

TB and COVID-19 in migrants - the need to focus on both conditions

Coronavirus? Or TB? An Effective Public Health Approach Would Address Both

Tuberculosis: Migration Doesn’t Have to Be A Barrier