A team led by Dr Elizabeth Nava Aguilera of CIETmexico conducted a systematic review and meta-analysis of the scientific literature published between 1994 and 2005 on risk factors associated with recent TB transmission. A systematic review tries to identify, appraise, select and synthesize all high quality research evidence relevant to a research question. A meta-analysis is a statistical technique for estimating the strength of the association between TB and each risk factor according to a measure that standardizes the associations reported by different studies.
Some 137 articles were identified, of which 32 fit the criteria for meta-analysis.
Recent transmission of TB was associated with:
- being a member of an ethnic minority
- being a native of the country where the study took place
- living in an urban area
- being a drug user
- drinking to excess
- being homeless
- having spent time in prison
- being HIV positive or having AIDS
- being young
- having positive results from baciloscopy (examination of sputum smears to detect the TB bacillus)
- drug resistence
- being male
At a global level, identification of these risk factors can help to target programmes for risk prevention, but for developing national and local TB risk prevention strategies further evidence is needed at local levels.
Further details about this study can be obtained from the doctoral thesis of Elizabeth Nava Aguilera, Epidemiología molecular de tuberculosis pulmonar: Factores de riesgo asociados a transmisión reciente de Mycobacterium tuberculosis en Guerrero, México, available from the library
See also: Nava-Aguilera E, Andersson N, Harris E, Mitchell S, Hamel C, Shea B, López-Vidal Y, Villegas-Arrizón A, Morales-Pérez A. Risk factors associated with recent transmission of tuberculosis: systematic review and meta-analysis. The International Journal of Tuberculosis and Lung Disease 2009;13(1): 17-26. Available to institutions and personal subscribers at:http://www.ingentaconnect.com/content/iuatld/ijtld/2009/00000013/00000001/art00005