Immigrants and tuberculosis
===========================

* Wendy Wobeser

The purpose of the immigration medical examination (IME) is to “identify those who may pose a risk to public health or safety, or may place excessive demands on Canadian health and social services.”1 With respect to TB this primarily involves the detection of people with active infectious (i.e., respiratory) TB and not those with extrapulmonary TB or latent TB infection. Applicants identified as having active TB abroad are denied entry to Canada until they have completed a satisfactory course of treatment and have been reassessed. Those with abnormal chest radiography findings that are consistent with latent TB infection or a history of TB are referred for medical surveillance once they arrive in Canada.2 

Despite efforts to identify all cases of active respiratory TB in migrants to Canada through the IME process, some cases of the disease do unfortunately occur in recent migrants. Possible reasons include progression to active disease after a person has undergone the IME but before immigration to Canada or presence of active TB when a person applies for refugee status from within Canada. Although the focus of our article2 was the medical surveillance of recent immigrants, not the IME, Wallace Watson raises a legitimate and frequently asked question regarding the role of tuberculin skin testing as part of the IME. The Immigration Subcommittee of the Canadian Tuberculosis Committee has issued an evidence-based advisory committee statement addressing questions about tuberculin skin testing of new migrants to Canada (see page 1035).3 

Children are also screened for symptoms of active TB disease during the IME, but, as for adults, they are not screened for latent TB infection. As highlighted by Noni MacDonald, a child up to 5 years of age who is infected with *Mycobacterium tuberculosis* has a 2.2 to 5 times greater risk of progression to active TB disease4 than an adult without risk factors for disease progression. Our article2 was a summary of the full guidelines for the investigation and follow-up of individuals placed under immigration medical surveillance. The more comprehensive guideline does discuss young children, recommending that “[y]oung persons (particularly those ≤ 5 years of age) infected with TB who have been identified through investigations of their parent(s) or guardian(s) may be at increased risk of progression to active disease and are likely to tolerate therapy without complications.”5 MacDonald's point about the need for physicians to have information specific to the management of TB in young immigrants and refugees is well taken, and the issue of incorporating specific pediatric recommendations into future Canadian Tuberculosis Committee advisory statements will be raised at the next meeting of the committee.

**Wendy Wobeser** Queen's University Kingston, Ont. **On behalf of the Immigration Subcommittee of the Canadian Tuberculosis Committee**

## References

1.  1. Immigration and Refugee Protection Act, S.C. 2001, c. 27.
    
    

2.  2. Heywood N, Kawa B, Long R, Njoo H, Panaro L, Wobeser W, on behalf of the Immigration Subcommittee of the Canadian Tuberculosis Committee. Guidelines for the investigation and follow-up of individuals under medical surveillance for tuberculosis after arriving in Canada: a summary. CMAJ 2003;168(12):1563-5.
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czoxMToiMTY4LzEyLzE1NjMiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTY5LzEwLzEwMDYuMS5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

3.  3. Menzies D. Screening immigrants to Canada for tuberculosis: Chest radiography or tuberculin skin testing? CMAJ 2003;169(10):1035-6.
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czoxMToiMTY5LzEwLzEwMzUiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTY5LzEwLzEwMDYuMS5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

4.  4. Long R, editor. *Canadian tuberculosis standards. 5th ed*. Ottawa: Canadian Lung Association and Health Canada; 2000.
    
    

5.  5. Immigration Subcommittee of the Canadian Tuberculosis Committee. Canadian guidelines for the investigation and follow-up of individuals under medical surveillance for tuberculosis after arrival in Canada. Can Commun Dis Rep 2001;27 (19): 157-65.
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=11605359&link_type=MED&atom=%2Fcmaj%2F169%2F10%2F1006.1.atom)