Tuberculosis risk factors: Difference between revisions
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Primary [[TB]] disease (1-5% cases) occurs soon after [[infection]], however, the majority of cases occur with latent infection, where there are no obvious [[symptoms]]. The dormant [[bacilli]] can cause [[tuberculosis]] in 2 to 23% of the latent cases, often many years after [[infection]].<ref name=Parrish_1998>{{cite journal |author=Parrish N, Dick J, Bishai W |title=Mechanisms of latency in Mycobacterium tuberculosis |journal=Trends Microbiol |volume=6 |issue=3 |pages=107-12 |year=1998 | pmid = 9582936}}</ref> The risk of reactivation increases with [[immunosuppression]], such as that caused by [[infection]] with [[HIV]]. In patients co-infected with [[HIV]], the risk of reactivation increases to 10% per year. | Primary [[TB]] disease (1-5% cases) occurs soon after [[infection]], however, the majority of cases occur with latent infection, where there are no obvious [[symptoms]]. The dormant [[bacilli]] can cause [[tuberculosis]] in 2 to 23% of the latent cases, often many years after [[infection]].<ref name=Parrish_1998>{{cite journal |author=Parrish N, Dick J, Bishai W |title=Mechanisms of latency in Mycobacterium tuberculosis |journal=Trends Microbiol |volume=6 |issue=3 |pages=107-12 |year=1998 | pmid = 9582936}}</ref> The risk of reactivation increases with [[immunosuppression]], such as that caused by [[infection]] with [[HIV]]. In patients co-infected with [[HIV]], the risk of reactivation increases to 10% per year. | ||
The following people are at higher risk for active [[TB]]:<ref name=CDC>{{cite web | title = Tuberculosis Fact Sheet | url = http://www.cdc.gov/tb/publications/factsheets/drtb/mdrtb.htm }}</ref> | The following people are at higher risk for active [[TB]]:<ref name=CDC>{{cite web | title = Tuberculosis Fact Sheet | url = http://www.cdc.gov/tb/publications/factsheets/drtb/mdrtb.htm }}</ref><ref name=Griffith_1996>{{cite journal |author=Griffith D, Kerr C |title=Tuberculosis: disease of the past, disease of the present |journal=J Perianesth Nurs |volume=11 |issue=4 |pages=240-5 |year=1996 | pmid = 8964016}}</ref> | ||
* People who live in areas where the disease is more common | |||
* Elderly | * Elderly | ||
* Infants | * Infants | ||
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]
Overview
The risk factors for the development of tuberculosis include: weakened immune system (patients taking immunosuppressive medication or with immunosuppressive diseases, such as HIV or diabetes); history of contact with infected patients, bad hygiene conditions, and evidence of previous disease. Risk factors for multidrug-resistant TB include: non-adherence to treatment regimen, inadequate medication for that strain of bacteria, and contact with patients with multidrug-resistant TB.
Risk Factors
Primary TB disease (1-5% cases) occurs soon after infection, however, the majority of cases occur with latent infection, where there are no obvious symptoms. The dormant bacilli can cause tuberculosis in 2 to 23% of the latent cases, often many years after infection.[1] The risk of reactivation increases with immunosuppression, such as that caused by infection with HIV. In patients co-infected with HIV, the risk of reactivation increases to 10% per year.
The following people are at higher risk for active TB:[2][3]
- People who live in areas where the disease is more common
- Elderly
- Infants
- IV drug users
- People with weakened immune systems, such as:
- AIDS
- Diabetes
- Silicosis
- Malignancy, such as head and neck cancers
- Hematologic and reticuloendothelial disease, such as leukemia and hodgkin's disease
- Or those taking medications, such as:
- Chemotherapy
- Immunosuppressive medications, such as prolonged corticosteroid therapy, tumor necrosis factor-alpha blockers[4]
The risk of contracting TB increases in cases where there is:[2]
The following factors may increase the rate of TB infection in a population:[2]
- Chest X-ray with evidence of previous TB disease (fibrotic lesions and nodules)
- Increase in HIV infections
- Increase in number of homeless people
- The appearance of drug-resistant strains of TB
Multidrug-Resistant Tuberculosis
Drug resistance is more common in people who:[5]
- Do not take their TB medicine regularly
- Do not take all of their TB medicine as told by their doctor or nurse
- Develop TB disease again, after having taken TB medicine in the past
- Come from areas of the world where drug-resistant TB is common
- Have spent time with someone known to have drug-resistant TB disease
References
- ↑ Parrish N, Dick J, Bishai W (1998). "Mechanisms of latency in Mycobacterium tuberculosis". Trends Microbiol. 6 (3): 107–12. PMID 9582936.
- ↑ 2.0 2.1 2.2 "Tuberculosis Fact Sheet".
- ↑ Griffith D, Kerr C (1996). "Tuberculosis: disease of the past, disease of the present". J Perianesth Nurs. 11 (4): 240–5. PMID 8964016.
- ↑ Mutlu G, Mutlu E, Bellmeyer A, Rubinstein I (2006). "Pulmonary adverse events of anti-tumor necrosis factor-alpha antibody therapy". Am J Med. 119 (8): 639–46. PMID 16887405.
- ↑ "Multidrug-resistant tuberculosis".