Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Mar 18:12:60.
doi: 10.1186/1471-2334-12-60.

Migrant tuberculosis: the extent of transmission in a low burden country

Zaza Kamper-Jørgensen  1 , Aase Bengaard Andersen, Axel Kok-Jensen, Mads Kamper-Jørgensen, Ib Christian Bygbjerg, Peter Henrik Andersen, Vibeke Ostergaard Thomsen, Troels Lillebaek
Affiliations

Migrant tuberculosis: the extent of transmission in a low burden country

Zaza Kamper-Jørgensen et al. BMC Infect Dis. .

Abstract

Background: Human migration caused by political unrest, wars and poverty is a major topic in international health. Infectious diseases like tuberculosis follow their host, with potential impact on both the migrants and the population in the recipient countries. In this study, we evaluate Mycobacterium tuberculosis transmission between the national population and migrants in Denmark.

Methods: Register study based on IS6110-RFLP results from nationwide genotyping of tuberculosis cases during 1992 through 2004. Cases with 100% identical genotypes were defined as clustered and part of a transmission chain. Origin of clusters involving both Danes and migrants was defined as Danish/migrant/uncertain. Subsequently, the proportion of cases likely infected by the "opposite" ethnic group was estimated.

Results: 4,631 cases were included, representing 99% of culture confirmed cases during 1992 through 2004. Migrants contributed 61.6% of cases. Up to 7.9% (95% CI 7.0-8.9) of migrants were infected by Danes. The corresponding figure was 5.8% (95% CI 4.8-7.0) for Danes. Thus, transmission from Danes to migrants occurred up to 2.5 (95% CI 1.8-3.5) times more frequent than vice versa (OR = 1). A dominant strain, Cluster-2, was almost exclusively found in Danes, particular younger-middle-aged males.

Conclusions: Transmission between Danes and migrants is limited, and risk of being infected by the "opposite" ethnic group is highest for migrants. TB-control efforts should focus on continues micro-epidemics, e.g. with Cluster-2 in Danes, prevention of reactivation TB in high-risk migrants, and outbreaks in socially marginalized migrants, such as Somalis and Greenlanders. Fears that TB in migrants poses a threat for resident Danes seem exaggerated and unjustified. We believe this to be true for other low incidence countries as well.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Persons in Denmark and incidence of clustered tuberculosis, according to ethnicity, by time.
See this image and copyright information in PMC

References

    1. Coker R. Compulsory screening of immigrants for tuberculosis and HIV - Is not based on adequate evidence, and has practical and ethical problems. Br Med J. 2004;328(7435):298–300. - PMC - PubMed
    1. Statistics Denmark. Statbank. http://www.statbank.dk/BEF5
    1. European Centre for Disease Prevention and Control/WHO Regional Office for Europe. Tuberculosis surveillance in Europe 2007. Stockholm, European Centre for Disease Prevention and Control. 2009.
    1. Vanembden JDA, Cave MD, Crawford JT, Dale JW, Eisenach KD, Gicquel B. et al.Strain Identification of Mycobacterium-Tuberculosis by Dna Fingerprinting - Recommendations for A Standardized Methodology. J Clin Microbiol. 1993;31(2):406–409. - PMC - PubMed
    1. Bauer J, Andersen AB, Kremer K, Miorner H. Usefulness of spoligotyping to discriminate IS6110 low-copy-number Mycobacterium tuberculosis complex strains cultured in Denmark. J Clin Microbiol. 1999;37(8):2602–2606. - PMC - PubMed

MeSH terms

Substances