tb lung latent :: Article CreatorTuberculosis Was Once A Disease In Decline, But A Resurgence In Cases Has Health Officials Puzzled
An outbreak of tuberculosis, or TB – a lung disease that is often accompanied by a hacking cough – began in January 2024 in Kansas City, Kansas, and two nearby counties and continues as of early March 2025. To date, 147 people have been reportedly diagnosed with TB in the outbreak, with 67 becoming ill. The remaining 80 people diagnosed with TB in Kansas contracted the illness but showed no symptoms, which is called a latent infection.
TB is the leading infectious cause of death around the world, outpaced only by COVID-19 during the first three years of the pandemic.
The Conversation asked microbiologists Karen Dobos and Marcela Henao-Tamayo, both from Colorado State University, to explain why this ancient disease seems to be making a comeback.
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What's the history of TB?
Mycobacterium tuberculosis is the organism that causes the disease tuberculosis in humans. The disease has been infecting humans for thousands of years. Researchers found evidence of the disease 9,000 years ago in the excavated remains of people who lived in the Eastern Mediterranean region during that time.
Reports of TB date back to around 410-400 B.C.E., when the physician Hippocrates termed the disease phthisis, an archaic word that means a progressive "wasting away," due to the way people with the disease become emaciated.
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TB was also known as consumption for the same reason. Similarly, it was called the white plague or white death – due to anemia from the disease, with people appearing pallid or chalky – leading to near-certain death. Untreated active TB, meaning cases that are symptomatic, is highly lethal.
About half of all people with untreated active TB die from the disease, whereas treatment reduces the death rate to 12 percent.
One of the more colorful phrases describing TB is "the king's evil." This is a form of TB that also causes neck swelling and lesions, a condition called scrofula. During the Middle Ages, people believed that the touch of a king could cure a person from this form of TB through miraculous intervention.
TB infections, which are typically found in the lungs, have risen since the COVID-19 pandemic.Kateryna Kon/Science Photo Library via Getty Images
Finally, TB was most ominously called the "robber of youth" due to its historical propensity to afflict people 15 to 30 years old.
In 1865, Jean Antoine Villemin, an army physician in Paris, demonstrated that TB could be transmitted from infected animals to healthy ones through inoculation. Before these studies, the cause of TB was presumed to be primarily constitutional, by either an inherent predisposition or from unhealthy or immoral lifestyles.
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The microorganism causing TB was ultimately discovered in 1882 by the German physician Robert Koch. Koch announced his findings on March 24, 1882, a day globally recognized as World TB Day.
How does TB spread?
Tuberculosis is spread by small infectious droplets in the air. A TB patient may emit these droplets by coughing, singing and potentially from regular breathing that occurs during sleep or resting.
One form of TB can be spread through unpasteurized dairy products. While rare, there have been reports of TB transmission through bone grafts, in which healthy, donated bone material is used to replace damaged bones.
Close-up view of an infection by Mycobacterium tuberculosis. Kateryna Kon/Science Photo Library via Getty Images
The origin of the TB outbreak in Kansas remains unknown as of early March 2025. The outbreak has disproportionately affected those in low-income communities, and two people have died from it.
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Importantly, a patient with untreated TB can infect 10 to 15 others.
Could the COVID-19 pandemic be a factor?
The COVID-19 pandemic has played a pivotal role in the resurgence of TB. Cases increased globally by 4.6 percent from 2020 to 2023, reversing decades of steady declines in the disease. In the U.S. Alone, TB cases rose by more than 15 percent from 2022 to 2023.
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During mandatory shutdowns, people were less able to access health care centers for early diagnosis of TB or to fill prescriptions for treatment, perhaps due to the fear of contracting COVID-19 while visiting a medical care facility. COVID-19-related disruptions in care resulted in nearly 700,000 excess deaths from TB.
Access to health care may not be the only factor behind this uptick. Medical supply shortages and delays in shipment may have also played a role. For example, the U.S. Experienced shortages of one of the primary TB drugs between 2021 and 2023.
What are the main treatments?
Multidrug treatment is currently the only way to cure TB and stop its spread.
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Prior to the late 1930s, when the first antibiotic for TB treatment was developed, TB treatments included bloodletting and consumption of cod liver oil. The most popular treatment involved isolated sanatoriums in high-altitude areas such as the Adirondacks and the Rocky Mountains, where the cold, dry air was believed to be a cure. Scholars at the time suggested that the potential for cure was due to these environments being more invigorating for the body and providing more restful sleep. There is no evidence to support these beliefs.
Streptomycin was the first antibiotic treatment to become available for TB, in the 1940s. However, the microorganism quickly became drug resistant. A second antibiotic, called isoniazid, was developed as a first-line treatment against TB in the 1950s. Again, the microorganism became drug resistant.
READ MORE: How Dr. Arthur Conan Doyle cracked the case of the tuberculosis 'remedy'
Two- and four-drug combinations are now used to treat both latent infections and active disease. Treatment of active TB requires at least six months of uninterrupted therapy. Disruptions in treatment result in further spread of TB and the emergence of multidrug resistant TB, which requires additional drugs and more than nine months of treatment.
All TB drugs are toxic; the quality of life for TB patients deteriorates during treatment and remains so throughout their lives. Finding cases and treating TB illness early, before symptoms begin, is important because it not only reduces the spread of disease but also greatly reduces drug toxicity.
What should people be aware of?
People should be aware that TB is still a public health problem across the globe. Education on the transmission, treatment and need for active work to eradicate TB is the best defense.
One of the reasons why education and awareness about TB are so important is that a person with latent TB may be unknowingly harboring the microorganism for years. In the absence of symptoms, these people are unlikely to seek care and will not be diagnosed and treated unless identified as part of an outbreak, as was the case for more than half of the patients in Kansas.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
NHS Alert Over Cough Infection That Can Spread To The Brain - Signs To Spot
11:04, 24 Mar 2025Updated 14:10, 24 Mar 2025
CDC explains how tuberculosis can be transmitted
The NHS has issued a warning over a slow-developing bacterial infection that usually starts with a cough. While the illness isn't generally as contagious as a common cold, it can be far more serious, potentially requiring antibiotics for at least six months.
"Tuberculosis (TB) is a bacterial infection that usually affects the lungs," the health body stressed on X earlier this morning. "It can be treated with antibiotics but can be serious if not treated. Learn more about the symptoms and treatments of this condition."
As the NHS implies, TB is caused by the spread of bacteria. When someone with active TB coughs, sneezes or speaks, tiny germs are released into the air, which others may inhale.
TB symptoms typically come on gradually, often starting with a cough that lasts more than three weeks. This cough may contain mucus or phlegm with blood in it. High temperatures, exhaustion, and weight loss may accompany this, too, with the latter often associated with a lack of appetite.
Although TB commonly affects the lungs, it can spread to other body parts, including the lymph nodes, bones, or even the brain. If this occurs, you may then notice an array of other uncomfortable symptoms, including the following:
Rash on the legs, face or other part of the body Nausea and vomiting Swollen ankles and joints Swollen glands Confusion Headaches Stiff neck Stomach or pelvis pain Constipation Aching body and pains Dark or cloudy pee
However, experts at the University of Edinburgh also saysome cases of TB are entirely symptomless. "Not everyone with TB is infectious," they wrote in a previous blog.
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"People with a TB infection that occurs outside the lungs (extrapulmonary TB) don't spread the infection. In most healthy people, the immune system is able to destroy the bacteria that cause TB.
"In some cases, the bacteria infect the body but don't cause any symptoms (latent TB), or the infection begins to cause symptoms within weeks, months or even years (active TB). Up to 10% of people with latent TB eventually develop active TB years after the initial infection."
Individuals with TB symptoms are encouraged to see a GP for further advice and examinations. These may involve mucus sampling, X-rays, CT scans, or tissue biopsies from the affected area.
Anyone may contract the illness, but it is more common among people who spend a lot of time around others with active TB or who live in an area where TB is more common. Regular smoking, drinking and having a weakened immune system can worsen your risk as well.
NHS guidance adds: "The main treatment for tuberculosis (TB) is to take antibiotics for at least six months. If TB has spread to your brain, spinal cord or the area around your heart, you may also need to take steroid medicine for a few weeks.
"If you have TB but do not have symptoms (latent TB), you usually need to take antibiotics for three to six months." It also stresses: "It's important to take your antibiotics correctly and until you've completed the course, even if you feel better. If you stop your treatment early, TB could come back."
For more information, head to the NHS website.
Latent Vs Active Tuberculosis: Key Differences Explained
Early diagnosis and treatment of active Tuberculosis is utmost priority, but identifying the latent TB, especially among the high risk groups is an essential step towards ending this disease.
Tuberculosis (TB) remains a significant public health challenge in India, with around 27% of global TB burden. It is a contagious disease caused by the bacteria Mycobacterium tuberculosis, which does not respond to conventional antibiotics because of unique structure of its cell wall. Patients infected with TB can develop symptoms like persistent cough, haemoptysis, fever, night sweats, weight loss, sometimes chest pain, shortness of breath, fatigue or anorexia and can shed the bacteria in their cough and sneezes.
Burden Of Tuberculosis And Its Transmission
Such symptomatic cases are known as active TB cases, which can be detected through clinical examination, chest X-ray or sputum examination. A person with active pulmonary TB can release infectious aerosols containing bacteria, that can stay airborne for hours in poorly ventilated spaces, increasing the risk of inhalation by others. The active TB cases are managed with weight-band based anti-tubercular treatment regimens consisting of 2 months of HRZE followed by 4 months of HRE, which may be extended or individualized based on patient's clinical or radiological cure.
Latent TB Infection And Its Significance
When a person with good immunity gets exposed to active TB cases, he may develop latent TB infection (LTBI), which is nothing but, a state of persistent immune response to Mycobacterium tuberculosis antigens. Such individuals harbour the bacteria in their body, but do not develop symptoms of active TB and hence are not infective to others. From the pool of latent TB cases, 5-10% mostly develop active TB disease over the course of their lives, usually within the first 5 years depending on the patient's immunological status. Various tests like Interferon Gamma Release Assay (IGRA) and Tuberculin skin test are recommended for screening the patients for LTBI. However, routine screening of LTBI is not recommended as they give positive results in both TB infected and exposed population.
Screening And High-Risk Groups For LTBI
These screening tests are used only in certain risk groups like, adults and children living with HIV, household contacts of active TB cases with immunosuppressed status such as, those on chemotherapy or immunomodulators, patients receiving dialysis, or those preparing for an organ or haematological transplant and patients with chronic lung conditions. If found positive, these groups are started on TB Preventive Treatment (TPT), because of their high risk of progression to active TB.
TB Preventive Treatment (TPT) And Its Importance
WHO, CDC and Government of India have recommended TPT, in form of Isoniazid monotherapy for 6 months Or Rifampicin or rifabutin plus isoniazid daily for 3 months for the LTBI cases. However, it is always essential to rule out active TB before initiating TPT, else it can lead to sub-optimal clinical response in active TB, later on leading to disseminated disease involving multiple organs and even drug resistance. Management of active TB and LTBI is available free of charge through national programmes.
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