Bacterial Infection

0

population

Global

percentage

0.1

evidence

reference	supports	snippet	explanation
PMID:35577247	REFUTE	Globally, the prevalence rate of LTBI decreased from 30.66% in 1990 to 23.67% in 2019, with an AAPC of -0.9%.	The prevalence rate of latent tuberculosis infection (LTBI) is much higher than 0.1% globally, at approximately 23.67% as of 2019.
PMID:30454918	REFUTE	An estimated 1.7 billion (23%) of the world's population is infected with Mycobacterium tuberculosis leading to more than 10 million new tuberculosis (TB) cases each year.	The prevalence of tuberculosis infection is around 23%, much higher than the 0.1% suggested in the statement.
PMID:33296141	NO_EVIDENCE	Tuberculosis (TB) is a widespread disease that crosses the human and animal health boundaries, with infection being reported in wildlife, from temperate and subtropical to arctic regions.	This source discusses the prevalence of TB in wildlife but doesn’t provide specific global prevalence rates in humans.
PMID:32324750	NO_EVIDENCE	A TB prevalence of 74.1 (95% CI 48.3-99.3) per 100,000 adult population for smear positive TB and 119.3 (95% CI 78.8-159.9) per 100,000 adult population for bacteriological confirmed MTB was estimated for Rwanda.	This source provides data specific to Rwanda not global prevalence rates.
PMID:23219235	NO_EVIDENCE	Tuberculosis (TB) epidemiology is characterized by significant differences in prevalence between men and women worldwide, with cases among men exceeding those found in women by a ratio of 2:1 in some regions.	This source addresses sex differences in TB prevalence but not the global prevalence rate.

0

phase

Latent

evidence

reference	supports	snippet	explanation
PMID:32978384	PARTIAL	We report that the rate of new mutations in the M. tuberculosis genome declines dramatically after two years of latent infection.	The reference supports that the latent phase of tuberculosis can have variable progression, with the bacteria entering a quiescent state. However, it does not explicitly specify the non-contagious aspect or provide details on variability in duration beyond the decline in mutation rate after two years.
PMID:30021818	PARTIAL	Human TB infection, from latent infection to active disease, exists within a continuous spectrum of metabolic bacterial activity and antagonistic immunological responses.	This reference supports the concept of variable progression within the latent phase but does not explicitly refer to the duration being variable or confirm the non-contagious stage where bacteria are inactive.
PMID:23460007	SUPPORT	Latent tuberculosis infection (LTBI) refers to a circumstance in which viable Mycobacterium tuberculosis (MTB) bacilli are present in an individual but symptoms and signs of active disease are lacking, and the bacilli are relatively inactive metabolically.	The reference directly supports the statement that during the latent phase, tuberculosis is in a non-contagious stage where the bacteria are present but inactive.

notes

Non-contagious stage where the bacteria are present in the body but inactive.

duration

Variable

1

phase

Active

evidence

reference	supports	snippet	explanation
PMID:30021818	SUPPORT	Recent research has clearly demonstrated that human TB infection, from latent infection to active disease, exists within a continuous spectrum of metabolic bacterial activity and antagonistic immunological responses.	This indicates the variable duration of progression from latent to active TB, supporting the statement.
PMID:37094782	SUPPORT	In this cohort, children and adolescents diagnosed with TB experienced symptoms for a median of 85 days (interquartile range: 30, 231 days) prior to treatment initiation.	The variable duration of symptom onset supports the statement.
PMID:35704248	SUPPORT	The system considers demographic structure coupling with the continuous development of disease stage, which is crucial for studying how aging affects tuberculosis dynamics and disease progression.	This implies that TB progression has a variable duration depending on individual factors like age.
PMID:32978384	SUPPORT	Here we report that the rate of new mutations in the M. tuberculosis genome declines dramatically after two years of latent infection.	The variable duration before reaching active TB is implied by observing changes over an extended latency period.

notes

Contagious stage where symptoms appear and the bacteria can be spread to others.

duration

Variable

0

name

Phagocytosis

description

Mycobacterium tuberculosis is engulfed by alveolar macrophages but resists destruction, leading to granuloma formation.

cell_types

• Macrophage
• T Cell

evidence

reference	supports	snippet	explanation
PMID:14745511	SUPPORT	The immune response to Mycobacterium tuberculosis (Mtb) infection is the formation of multicellular lesions, or granulomas, in the lung of the individual.	This reference supports the claim that Mycobacterium tuberculosis infection leads to granuloma formation.
PMID:30306257	SUPPORT	Phagocytosis refers to the process of internalization and degradation of particulate material... One microbe that is particularly successful at surviving within macrophages is the pathogen Mycobacterium tuberculosis, which can efficiently manipulate the macrophage at several levels, including modulation of the phagocytic pathway as well as interfering with a number of immune activation pathways that normally would lead to eradication of the internalized bacilli.	This reference supports the specific involvement of macrophages and the resistance of Mycobacterium tuberculosis to degradation within phagocytes.
PMID:2425678	PARTIAL	The process of granuloma formation in the lung is mediated by an intimate interaction between macrophages and T cells, and this interaction provides the appropriate environment for granuloma formation and the development of fibrosis.	While this reference supports the role of macrophages and T cells in granuloma formation, it does not address the specific mechanisms by which Mycobacterium tuberculosis resists destruction.
PMID:25607549	PARTIAL	Upon invading host cells by phagocytosis, M. tuberculosis can replicate within infected cells by arresting the maturation of the phagosome whose function is to target the pathogen for elimination.	This reference partially supports the claim by highlighting that M. tuberculosis avoids destruction within host cells, though it does not explicitly mention granuloma formation.

downstream

Granuloma Formation

1

name

Granuloma Formation

description

Immune cells form a granuloma to contain the infection, but sometimes the bacteria can break out, causing active TB.

cell_types

• Macrophage
• T Cell

evidence

reference	supports	snippet	explanation
PMID:14745511	SUPPORT	The immune response to Mycobacterium tuberculosis (Mtb) infection is the formation of multicellular lesions, or granolomas, in the lung of the individual.	The reference describes the formation of granulomas in the lung as part of the immune response to Mtb infection, which aligns with the statement.
PMID:28577054	SUPPORT	The typical composition is a center of macrophages/histiocytes with lymphocytes at the border.	The reference indicates the involvement of macrophages and T cells (lymphocytes) in granuloma formation, which supports the statement.
PMID:36920308	SUPPORT	granulomas are pathologically diverse, their tissue-wide heterogeneity has not been spatially resolved at the single-cell level in human tissues.	The reference discusses the diversity of granulomas in the lung and their formation in response to TB, which supports the statement.
PMID:25319335	PARTIAL	Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB), is an intracellular pathogen of mononuclear phagocytes.	While the reference discusses infection of macrophages and various cell types by M. tuberculosis, it doesn't mention T cells and granuloma formation specifically.
PMID:33720848	SUPPORT	Granuloma formation is the pathologic hallmark of tuberculosis (TB).	The reference highlights granuloma formation as a key feature of tuberculosis, supporting the statement.

locations

• Lung

downstream

Tissue Damage

2

name

Tissue Damage

description

Active TB can cause cavitation and destruction of lung tissue.

evidence

reference	supports	snippet	explanation
PMID:32482293	SUPPORT	Cavitation is a dangerous consequence of pulmonary tuberculosis associated with poor outcomes, treatment relapse, higher transmission rates, and development of drug resistance.	The reference explicitly mentions cavitation as a severe consequence of pulmonary tuberculosis, which aligns with the statement.
PMID:27245780	SUPPORT	Human TB lesions are severely hypoxic and M.tb drives HIF-1alpha accumulation, synergistically increasing collagenase activity which will lead to lung destruction and cavitation.	This reference provides evidence that TB lesions result in hypoxia and enzymatic activity that contributes to the destruction of lung tissue and cavitation.
PMID:16136463	SUPPORT	Pulmonary cavitation with cough-generated aerosol is the principle means of spread, and lung remodeling (healed cavitation, fibrosis, and bronchiectasis) is a major cause of lung disability.	This reference discusses the relationship between TB, cavitation, and lung tissue remodeling, underscoring the statement that active TB causes cavitation and tissue damage.
PMID:29491034	PARTIAL	Post-TB lung dysfunction often goes unrecognised, despite its relatively high prevalence and its association with reduced quality of life. Host immune responses probably play a dominant role in lung damage, as excessive inflammation and elevated expression of lung matrix-degrading proteases are common during TB.	This reference discusses post-TB lung dysfunction and general lung damage caused by excessive inflammation and protease activity during TB, although it does not explicitly mention cavitation.
PMID:25361920	SUPPORT	After many months, the affected lung suddenly undergoes caseation necrosis with vanishingly few MTB. The necrotic tissue fragments to produce a cavity or hardens to develop fibrocaseous disease.	This reference explains the process of caseation necrosis leading to cavity formation in the lung, which supports the statement regarding active TB causing cavitation and tissue destruction.

locations

• Lung

0

category

Respiratory

name

Chronic Cough

frequency

VERY_FREQUENT

diagnostic

True

evidence

reference	supports	snippet	explanation
PMID:29196066	PARTIAL	Cough is common in pulmonary TB and other chronic respiratory infections.	While cough is indeed a common symptom of pulmonary TB, the statement specifically categorizes chronic cough as very frequent, which is partially supported but not explicitly confirmed by the literature.
PMID:16131501	SUPPORT	A persistent, non-remitting cough was reported in 15/16 (93.8%) children with tuberculosis.	This strongly supports the statement as it shows a high prevalence of a persistent chronic cough in children diagnosed with tuberculosis.
PMID:35710915	SUPPORT	Initial microbiologic burdens and radiographic features also varied, including the presence of cavities and bilateral infiltration, which reflect TB-related severity.	The study identifies chronic cough as a significant symptomatic characteristic among the different TB phenotypes.

1

category

Systemic

name

Fever

frequency

FREQUENT

evidence

reference	supports	snippet	explanation
PMID:11120618	SUPPORT	We describe three patients with recurrent fever thought to be due to tuberculosis, and review the 14 previously reported cases who fulfill the criteria of recurrent fever for at least 1 month's duration.	The literature indicates that fever is a frequent symptom associated with tuberculosis.
PMID:31641790	PARTIAL	Tuberculosis is a bacterial infectious disease that is usually transmitted by inhalation of droplets containing the bacteria.	While this reference does affirm that tuberculosis causes systemic issues, it does not directly specify fever as a frequent phenotype.
PMID:18173876	PARTIAL	SETTING: The diagnosis of tuberculosis (TB) may be rejected in the absence of symptoms such as fever, sweats or weight loss.	This reference notes the association of fever with tuberculosis but also highlights cases where fever may be absent, hence only partially supporting the statement.

2

category

Systemic

name

Night Sweats

frequency

FREQUENT

evidence

reference	supports	snippet	explanation
PMID:31599243	SUPPORT	Cough, night sweat, fever, anorexia were significant presenting features.	The study documents night sweats as a significant symptom in TB patients.
PMID:12643362	PARTIAL	Tuberculosis and lymphoma are diseases in which night sweats are a dominant symptom, but these are infrequently found to be the cause of night sweats in modern practice.	While night sweats are a notable symptom of TB, the reference suggests that in modern practice, they are less frequently the cause of night sweats compared to other conditions.
PMID:21813327	SUPPORT	During therapy, fever, sweats, and dyspnea decreased most rapidly, with near resolution by the end of therapy.	The data supports the presence of night sweats as a frequent symptom in TB, with sweats reducing significantly during therapy.

3

category

Systemic

name

Weight Loss

frequency

FREQUENT

evidence

reference	supports	snippet	explanation
PMID:36451280	SUPPORT	Tuberculosis (TB) is well-known for causing wasting. Patients on treatment gain weight and weight loss is associated with unfavorable treatment outcomes.	This supports the statement that weight loss is a frequently observed systemic phenotype associated with tuberculosis.
PMID:38736083	SUPPORT	Esophageal TB most commonly presents with dysphagia, odynophagia, retrosternal pain, and systemic symptoms like decreased appetite, loss of weight, and low-grade fever as associated or other presentations.	This reference supports the statement by indicating that weight loss is a common systemic symptom of esophageal tuberculosis.
PMID:23531875	SUPPORT	CBA/J mice may model these events, as sick mice share features with TB patients, including weight loss...	Although the study is on mice, it draws parallels with human TB patients, reinforcing that weight loss is a frequently observed phenotype.
PMID:18173876	PARTIAL	The diagnosis of tuberculosis (TB) may be rejected in the absence of symptoms such as fever, sweats or weight loss... In our population, TB, including pulmonary disease, frequently presented without fever, sweats or weight loss and with normal blood inflammatory markers.	This indicates that while weight loss is a known symptom, it is not always present in all TB cases, suggesting that it may be frequent but not ubiquitous.
PMID:8623687	SUPPORT	All patients with a positive reaction to the tuberculin skin test should be evaluated for weight loss, night sweats, fever, chronic cough and other signs of active tuberculosis.	This reference confirms that weight loss is one of the systemic symptoms that are frequently checked for in TB patients.

notes

Also known as consumption historically.

4

category

Hematologic

name

Hemoptysis

frequency

OCCASIONAL

evidence

reference	supports	snippet	explanation
PMID:31970731	SUPPORT	Hemoptysis, or coughing up blood, is an uncommon but recognized cause of pulmonary tuberculosis complications.	The text explicitly states that hemoptysis is a recognized, though uncommon, complication in pulmonary tuberculosis.
PMID:21597515	SUPPORT	A man, 56 years of age, presents to his general practitioner after coughing up half a cupful of fresh, bright red blood every day for 1 week. He reports previous pulmonary tuberculosis 12 years ago.	The case report discusses a patient with a history of pulmonary tuberculosis presenting with hemoptysis, suggesting it as a possible phenotype.
PMID:12816036	SUPPORT	The most common causes of hemoptysis are tuberculosis, lung carcinoma, bronchiectasis but idiopathic forms are frequent.	The text states that tuberculosis is one of the most common causes of hemoptysis, supporting the statement.
PMID:913138	SUPPORT	Massive hemoptysis in patients with tuberculosis … we describe herein five cases characterized by hemoptysis on admission... leading to death, probably from asphyxiation.	Describes cases of hemoptysis in TB patients, supporting its association as a hematologic phenotype.
PMID:11837465	PARTIAL	Other haematological abnormalities of the white blood cells include leucopenia, neutropenia, lymphocytopenia, monocytopenia, leukocytosis, neutrophilia, lymphocytosis, and monocytosis.	While it mentions a comprehensive list of haematological abnormalities, hemoptysis, though not directly mentioned, is still indirectly supported through related abnormalities.

notes

Coughing up blood.

name	presence	evidence	notes
Tuberculin Skin Test (TST)	Positive	TRUNCATED	Indicates TB infection, not necessarily active disease.
Interferon-Gamma Release Assay (IGRA)	Positive	TRUNCATED	Blood test indicating TB infection.

0

name

Isoniazid

description

First-line antibiotic for TB treatment.

evidence

reference	supports	snippet	explanation
PMID:33106268	SUPPORT	Isoniazid (INH), one of the first-line drugs used for the treatment of tuberculosis, is a prodrug which is activated by the intracellular KatG enzyme of Mycobacterium tuberculosis.	The description of Isoniazid as a first-line antibiotic for TB treatment and its activation by the KatG enzyme is supported. This aligns with the provided mechanism of prodrug activation.
PMID:12164478	SUPPORT	The drugs shown to inhibit mycolic acid biosynthesis are isoniazid, ethionamide, isoxyl, thiolactomycin, and triclosan.	The inhibition of mycolic acid biosynthesis by Isoniazid aligns with the described mechanism of action in the statement.

notes

It's important to note that resistance to isoniazid can develop through mutations in the katG gene, which reduces the activation of the drug, or in the inhA gene, which decreases the binding affinity of the activated drug to the InhA enzyme. To minimize the risk of resistance, isoniazid is typically used in combination with other antitubercular drugs, such as rifampicin, ethambutol, and pyrazinamide.

mechanism

name	description
Prodrug Activation	Isoniazid is a prodrug that requires activation by the bacterial enzyme catalase-peroxidase (KatG). KatG couples the isonicotinic acyl with NADH to form an isonicotinic acyl-NADH complex.
Inhibition of InhA	The activated form of isoniazid binds to and inhibits the enoyl-acyl carrier protein reductase (InhA), an enzyme involved in the fatty acid synthase II (FAS-II) pathway. This pathway is essential for the synthesis of mycolic acids.
Depletion of mycolic acids	By inhibiting InhA, isoniazid prevents the synthesis of mycolic acids, which are long-chain fatty acids that make up a significant portion of the mycobacterial cell wall. Mycolic acids provide structural integrity and help the bacteria resist the host's immune response.
Cell wall disruption	The depletion of mycolic acids leads to the weakening and disruption of the bacterial cell wall. This makes the bacteria more susceptible to the host's immune defenses and other antibiotics.
Reactive oxygen species	In addition to inhibiting mycolic acid synthesis, the isoniazid-NAD adduct can also generate reactive oxygen species (ROS) and nitric oxide (NO) within the bacteria. These reactive species can cause damage to various bacterial components, including DNA, proteins, and lipids, contributing to the bactericidal effect.
Bactericidal action	The combination of cell wall disruption and the production of reactive oxygen and nitrogen species ultimately leads to the death of the M. tuberculosis bacteria.

1

name

Rifampicin

description

Bactericidal antibiotic used for TB treatment.

evidence

reference	supports	snippet	explanation
PMID:11290327	SUPPORT	Rifampicin (Rif) is one of the most potent and broad spectrum antibiotics against bacterial pathogens and is a key component of anti-tuberculosis therapy, stemming from its inhibition of the bacterial RNA polymerase (RNAP).	This reference explains that Rifampicin is a key component of anti-tuberculosis therapy due to its inhibition of bacterial RNA polymerase.
PMID:27553018	SUPPORT	For the treatment of TB, administration of multiple antibiotics such as isoniazid, rifampicin, pyrazinamide, and ethambutol is required for a long period of time to kill bacteria.	This reference confirms that rifampicin is used for the treatment of TB.
PMID:34400805	SUPPORT	Rifamycins exhibit bactericidal activity against many Gram-positive and Gram-negative bacteria by inhibiting RNA polymerase (RNAP).	This reference supports the statement by confirming that Rifamycins, including rifampicin, exhibit bactericidal activity by inhibiting RNA polymerase.
PMID:33199626	SUPPORT	Rif targets the enzyme RNA polymerase (RNAP).	This reference affirms the mechanism of rifampicin targeting RNA polymerase, which validates its use in TB treatment.
PMID:28803492	SUPPORT	Rifamycin antibiotics, like rifampin and rifapentine, have unique sterilizing activity against M.tb.	This reference supports the use of rifampicin (a Rifamycin antibiotic) for TB treatment due to its sterilizing activity against Mycobacterium tuberculosis.

notes

Rifampicin is a broad-spectrum antibiotic that is particularly effective against mycobacteria, including M. tuberculosis, as it can easily penetrate the lipid-rich cell wall.

mechanism

name	description
Inhibition of bacterial RNA polymerase	Rifampicin binds to the beta subunit of DNA-dependent RNA polymerase, preventing the initiation of RNA synthesis.
Disruption of bacterial transcription	By inhibiting RNA polymerase, rifampicin disrupts bacterial transcription, which is essential for protein synthesis and bacterial survival.

2

name

Ethambutol

description

Bacteriostatic antibiotic used for TB treatment.

evidence

reference	supports	snippet	explanation
PMID:16209089	SUPPORT	Ethambutol (EMB), the first line drug in the treatment of tuberculosis, is an inhibitor of the biosynthesis of the cell wall compound - arabinogalactan.	The literature states that ethambutol interferes with the biosynthesis of arabinogalactan, supporting the mechanism described in the statement.
PMID:32327601	SUPPORT	The arabinosyltransferases EmbA, EmbB, and EmbC are involved in Mycobacterium tuberculosis cell wall synthesis and are recognized as targets for the anti-tuberculosis drug ethambutol. These structures show how ethambutol inhibits arabinosyltransferases by binding to the same site as both substrates in EmbB and EmbC.	The literature specifically notes that ethambutol inhibits the enzyme arabinosyl transferase, aligning with the mechanism described in the statement.
PMID:9949810	PARTIAL	Isoniazid is the most widely used antituberculosis drug.	The statement specifies ethambutol as a bacteriostatic antibiotic used for TB treatment, whereas this reference talks about isoniazid. It is partially relevant since ethambutol is also an antituberculosis drug, but this reference does not fully address ethambutol's function.
PMID:37289062	SUPPORT	In combination with TB antibiotics, wollamide B1 synergistically enhances the activity of several antibiotics... and wollamide B1 did not compromise the antimycobacterial activity of the isoniazid/rifampicin/ethambutol combination.	This reference confirms that ethambutol is used in combination with other antitubercular drugs, aligning with the notes in the statement about preventing the emergence of drug resistance.

notes

Ethambutol is specific to mycobacteria and is often used in combination with other antitubercular drugs to prevent the emergence of drug resistance.

mechanism

name	description
Inhibition of arabinogalactan synthesis	Ethambutol interferes with the biosynthesis of arabinogalactan, a key component of the mycobacterial cell wall.
Inhibition of arabinosyl transferase	Ethambutol inhibits the enzyme arabinosyl transferase, which is responsible for the polymerization of arabinose into arabinan, a precursor of arabinogalactan.
Compromised cell wall integrity	By disrupting the synthesis of arabinogalactan, ethambutol compromises the integrity of the cell wall, making the bacteria more susceptible to host defenses and other antibiotics.

3

name

Directly Observed Therapy (DOT)

description

Health worker observes and records patients taking their medication to ensure adherence.

evidence

reference	supports	snippet	explanation
PMID:17943789	SUPPORT	Directly observed therapy (DOT), which involves people directly observing patients taking their antituberculous drugs.	The abstract clearly states that DOT involves someone directly observing patients taking their antituberculous drugs to ensure adherence.
PMID:29461901	SUPPORT	The World Health Organization (WHO) propagates Directly Observed Therapy Short-course (DOTS) as an effective way to stop the spread of TB in communities with a high burden.	The abstract indicates that DOTS is endorsed by WHO as a method to ensure patients adhere to TB treatment.
PMID:25368721	SUPPORT	To evaluate this clinic, records of all patients with tuberculosis followed-up there were compared with patients with tuberculosis observed in the other clinics over a nine-year period.	It mentions observation of TB patients, aligning with the description of DOT, although it focuses on clinic follow-up rather than the specific method.
PMID:28410705	SUPPORT	A flexible, patient centered approach where a family member can act as the DOT provider with guidance from a trained health worker was evolved as the most acceptable and comfortable mode of treatment to the majority of the TB patients.	The abstract reinforces the involvement of a health worker in observing DOT, even if it's flexible to involve family members.
PMID:27598709	SUPPORT	To best ensure compliance, directly observed therapy (DOT) is considered the standard of practice.	Emphasizes DOT as a standard practice to ensure compliance by observing the patient directly.

4

name

Latent TB Treatment

description

Isoniazid or rifapentine used to prevent latent TB from becoming active.

evidence

reference	supports	snippet	explanation
PMID:29910114	SUPPORT	The 3-month isoniazid-rifapentine regimen is as safe and effective as other recommended latent tuberculosis infection regimens and achieves significantly higher treatment completion rates.	This source supports the statement mentioning that a regimen of isoniazid and rifapentine is used for latent TB infection.
PMID:19496388	SUPPORT	The treatment of choice for LTBI is isoniazid for nine months.	This source supports the use of isoniazid for the prevention of latent tuberculosis infection (LTBI).
PMID:32551948	SUPPORT	The World Health Organization recommends the use of isoniazid (INH) alone or in combination with rifapentine to treat latent tuberculosis infections.	This supports the statement by specifying that WHO recommends isoniazid and rifapentine for the treatment of latent tuberculosis infections.
PMID:35869842	SUPPORT	weekly treatments with isoniazid and rifapentine for 3 months reduced active M. tuberculosis infection and LTBI.	This supports the statement by showing the efficacy of isoniazid and rifapentine in reducing latent TB infection as well as active TB.

name	evidence	description
Mycobacterium tuberculosis	TRUNCATED	A bacterium that primarily affects the lungs but can affect other organs.

name	description	evidence
Airborne Transmission	Spread through the air when individuals with active TB cough, sneeze, or speak.	TRUNCATED

0

name

Sputum Microscopy

presence

Positive

evidence

reference	supports	snippet	explanation
PMID:30054578	PARTIAL	We developed and evaluated an operator-independent microscopic examination of sputum smears for the automated detection and enumeration of acid-fast bacilli using a ZEISS Axio Scan.Z1 microscope.	The study supports that sputum microscopy can detect acid-fast bacilli. It emphasizes an automated method but still aligns with the use of sputum microscopy for diagnosis.
PMID:15535337	PARTIAL	The chest radiographs showed 'typical' changes of tuberculosis in 62% while in the other 38% the radiological features were 'not typical'. Sputum direct smear was positive for acid-fast bacilli in only 22.8% of patients and 11.2% were diagnosed based on positive sputum culture.	This study confirms that sputum microscopy can detect acid-fast bacilli, but it also highlights instances where sputum may be negative even in TB patients.
PMID:27847013	PARTIAL	Of the 100 ZN positive specimens, 74 were FDA positive of which 70 were reported positive by both the readers.	Sputum microscopy positivity for acid-fast bacilli is mentioned but the study's focus is on the FDA staining method.
PMID:10734523	PARTIAL	Forty three (24.2%) were sputum smear positive for acid fast bacilli (AAFB).	The study supports sputum microscopy for TB diagnosis but only in 24.2% of cases verified by smear.
PMID:35180496	PARTIAL	The SFV-CSSM showed higher sensitivity than DSSM (79.4% versus 60.5%) and less background interference.	The study supports sputum microscopy but highlights an advanced method with higher sensitivity.
PMID:21333111	PARTIAL	Although sputum smear microscopy is the primary method for tuberculosis (TB) diagnosis in low-resource settings, it has low sensitivity.	Sputum microscopy is acknowledged as the primary method but with limitations in sensitivity.

notes

Detection of acid-fast bacilli.

1

name

Chest X-Ray

evidence

reference	supports	snippet	explanation
PMID:24429302	SUPPORT	The chest radiograph (CXR) is a key initial tool in the diagnosis of many lung conditions, including pulmonary tuberculosis (TB). With proper use of anti-tuberculosis drugs, TB can be treated effectively and many CXR changes are limited.	This reference establishes that chest radiographs (CXRs) are key tools in diagnosing pulmonary tuberculosis, supporting the statement that chest X-ray is used in the diagnosis of TB.
PMID:37977833	SUPPORT	Follow-up CT showed CS progressing to a cavitatory shadow and GS intensification. The detection of Mycobacterium tuberculosis (M. tuberculosis) in a subsequent sputum analysis prompted treatment with antitubercular drugs, leading to symptom relief.	This reference supports the statement regarding the use of chest X-rays in diagnosing TB as it discusses how chest CT (an advanced form of X-ray) shows cavitary lesions, which are indicative of active pulmonary TB.
PMID:8553964	SUPPORT	Radiographic findings consistent with active pulmonary TB were present in all patients.	This reference reinforces the use of radiographic imaging (including chest X-rays) in identifying active pulmonary TB.
PMID:26634258	SUPPORT	Evaluation for pulmonary TB in children with positive isolated TSTs should be made primarily with PA chest X-ray.	This further supports the statement by emphasizing that chest X-rays (PA chest X-ray) are a primary diagnostic tool for evaluating pulmonary TB.

notes

Shows cavitary lesions and other signs of active pulmonary TB.

2

name

Sputum Culture

presence

Positive

evidence

reference	supports	snippet	explanation
PMID:10970761	PARTIAL	However, the sensitivity of sputum smear for acid-fast bacteria is only approximately 50% and sputum culture has a relatively long turnaround time.	While sputum culture is considered important for TB diagnosis, it has limitations such as long turnaround time which may affect its utility in confirming TB diagnosis promptly.
PMID:31666021	PARTIAL	Pulmonary tuberculosis (TB) with detectable Mycobacterium tuberculosis in the sputum is a major source of transmission.	Although this article acknowledges the importance of sputum smear for transmission evaluation, it also highlights that viable bacteria may still be present in some 'cured' patients, indicating a limitation in using sputum alone for confirming cure.
PMID:32755530	SUPPORT	Poor-quality cough specimens (n=61) from presumptive tuberculosis cases were cultured and GeneXpert MTB/RIF (Xpert) successfully performed on samples transferred by flocked swab into PrimeStore molecular transport medium (PS-MTM). Mycobacterium tuberculosis was grown in culture from 13 (21.3 %).	Supports the idea that sputum culture can confirm TB diagnosis, even from poor-quality specimens.
PMID:8758132	SUPPORT	Confirmation of tuberculosis in young children is difficult as they seldom expectorate sputum... Mycobacterium tuberculosis was cultured from three of them.	Indicates that sputum culture is a useful method for confirming TB diagnosis.
PMID:27727131	PARTIAL	Culture, the accepted reference standard for pediatric TB diagnostics, has a low and variable yield that impacts how diagnostic studies should be reported as well as everyday clinical care.	While culture is a standard for pediatric TB diagnostics, the low yield suggests it might not confirm all cases.
PMID:34397866	NO_EVIDENCE	Patients with a positive culture for non-mycobacteria were significantly older and had lower levels of physical activity...	This study focuses on non-mycobacterial cultures and does not specifically address the role of sputum culture in TB diagnosis.

notes

Confirms TB diagnosis.