TB in the ED: Still Here, Still Sneaky – Think TB!

Tuberculosis (TB) can feel like a disease from a different era; a finals question and something you associate with Victorian novels rather than a Monday morning in resus. The truth is, TB is still very much with us and in a busy urban Emergency Department (ED), you will see it. The real question is whether you think of it before the patient leaves the department, or three months later when they’re back worse.

Fig.1 Think TB poster1

TB is not as rare as you might think. In 2024, there were 5,480 TB notifications in England and numbers have been creeping back up since the post-pandemic dip. London accounts for around 40% of all cases, but rates are rising in other urban centres too. Globally, over 10 million people get TB every year with around 1.25 million deaths, making it the leading infectious disease killer worldwide. This is not a disease that’s going away (not yet at least) and I would urge you to Think TB!

It Doesn’t Always Look Like TB

The classic picture of cough, night sweats, weight loss and haemoptysis is real, but it’s only part of the story. The patients who get missed are the ones who arrive with something that looks like something else. A non-resolving pneumonia. An unexplained pleural effusion. Back pain with a bit of weight loss that gets labelled musculoskeletal.

TB is a bacterial infection but also a systemic disease that can affect almost any organ. Pulmonary TB is the most common accounting for around 60% of cases in England, but extrapulmonary disease is not rare. Lymphadenopathy, bone and joint TB, genitourinary TB, TB meningitis, and abdominal TB all exist and all present to EDs around the country. The pattern is subtle: Chronic, recurrent or just not behaving as expected despite treatment. Thats your cue: Think TB!

Whos highest risk? Immunosuppressed patients. That means patients on high-dose steroids, biologics, those on chemotherapy, and patients with HIV. Poorly controlled diabetes, chronic renal disease, and malnutrition also increase risk. If you have a patient who ticks any of these boxes and has a chronic or unexplained illness, TB should be in your differential.

What the Chest X-Ray Is Telling You

The chest X-ray remains one of the highest-yield tools you have in the ED for picking up TB. The patterns to know are upper lobe shadowing, cavitation, and fibrosis.

Whenever you see a CXR and you see upper lobe changes or cavitation, think TB! Write it in the notes, send samples and isolate. Its an easy thing to do and can dramatically shorten a diagnostic journey that otherwise drags on for months.

Fig. 22

Whos at risk?

TB is not evenly spread across the population. In England, around 70% of cases occur in people born outside the UK, with the highest rates in those from South Asia, sub-Saharan Africa, and Eastern Europe. Social risk factors such as urban deprivation, overcrowded housing, homelessness, and a history of incarceration are all linked to higher rates of TB.

But anyone can get TB.

The UK Health Security Agency specifically flags a cough lasting more than three weeks as a trigger to consider TB. Combined with any systemic features such as weight loss, night sweats, or fatigue Think TB!

Your Job in the ED: Get the ball rolling

Emergency medicine does not need to become a TB service at 2am. What it does need to do is to Think TB! early enough to take the right first steps.

Most TB services nationally will accept referrals directly from the Emergency Department with capacity to see high-risk patients usually within a few days. But a few simple tests can get the journey started:

Routine bloods including inflammatory markers and an HIV test.

Chest X-ray looking for upper zone changes, cavities or maybe a pleural effusion.

Sputum samples for smear and culture. Whether you think the patient can go home or needs admission, try to send the first sputum sample from the ED. Request sputum acid fast bacilli (AFB) for smear and culture to ensure the right tests are done. TB PCR tests are not universally available but can usually be added later if needed.

Refer or admit. Not everyone needs to come in. A patient who is clinically well, has a suitable home situation, and can reliably self-isolate can be discharged, provided there is a clear and documented plan for follow-up with the TB service. Self-isolation means a private room at home, away from vulnerable contacts, and ideally not using public transport.

Fig. 3 RCEMLearning image generated with Google Gemini

Active vs Latent TB: Know the Difference

Active TB means the TB bug is causing disease. This is what presents to the ED, what is infectious, and what needs investigating and treating urgently. Latent TB means the patient has been infected but their immune system has contained it. They have no symptoms, are not infectious, and may never develop active disease.

The interferon-gamma release assay (IGRA), such as QuantiFERON or T-SPOT, tests for immune sensitisation to TB antigens and is used to diagnose latent infection. It is not an ED test. A positive IGRA does not distinguish active from latent disease, and a negative IGRA does not rule out active TB, particularly in immunosuppressed patients.

In the ED, your job is to Think TB! and investigate for active TB with a chest x-ray and sputum samples.

Infection Control: Before You Have a Diagnosis

TB spreads via airborne particles when people with pulmonary or laryngeal disease cough, sneeze, or speak. If TB is a realistic possibility, ensure respiratory isolation precautions are in place. In practice, that means a single side room with the door closed, FFP3 masks for staff entering the room, and minimising patient movement through shared spaces. Where single rooms are not possible, patients sharing that space should be offered FFP3 masks.

If you have been exposed to a patient (aerosol generating or non-aerosol generating) with TB without wearing appropriate FFP3 masks, there is no prophylaxis indicated however contact screening may be required in conjunction with your local TB team, occupational health and infection control. This will depend on the type of exposure and infectiousness of the case. Vaccination is not routinely needed for health care workers. (Remember, TB can stay in the environment for up to eight hours depending on the ventilation of the room- so wear FFP3s for up to eight hours after any aerosol generating procedures in a ?TB patient.) There is no role for surgical masks in reducing TB transmission.

Why It Matters

TB is often forgotten about. It’s slow, easy to defer, and simple to miss if you’re not in the habit of thinking about it.

But picking up possible TB in ED is properly high-value medicine. It massively improves the diagnostic journey, tightens up infection control, gets the right team involved early, and stops patients bouncing through clinics and antibiotics with the wrong label.

We can cure TB and we can prevent TB but it still kills over a million people a year worldwide.

So, keep it simple: Think TB!

References

1. Centers for Disease Control and Prevention (US). Think TB poster [Internet]. Atlanta (GA): CDC; 2024. [Cited on 22 Mar 2026]
2. Gaillard F, Pulmonary tuberculosis. Case study, Radiopaedia.org [Cited on 22 Mar 2026]