Chapter 5.5 – Prevention in special hosts - Migrants and those visiting friends and relatives: Canadian recommendations for the prevention and treatment of malaria

An Advisory Committee Statement (ACS) from the
Committee to Advise on Tropical Medicine and Travel (CATMAT)

Preamble

The Committee to Advise on Tropical Medicine and Travel (CATMAT) provides the Public Health Agency of Canada (PHAC) with ongoing and timely medical, scientific, and public health advice relating to tropical infectious disease and health risks associated with international travel. PHAC acknowledges that the advice and recommendations set out in this statement are based upon the best current available scientific knowledge and medical practices, and is disseminating this document for information purposes to both travellers and the medical community caring for travellers.

Persons administering or using drugs, vaccines, or other products should also be aware of the contents of the product monograph(s) or other similarly approved standards or instructions for use. Recommendations for use and other information set out herein may differ from that set out in the product monograph(s) or other similarly approved standards or instructions for use by the licensed manufacturer(s). Manufacturers have sought approval and provided evidence as to the safety and efficacy of their products only when used in accordance with the product monographs or other similarly approved standards or instructions for use.

Chapter 5: Prevention in special hosts

5.5 Migrants and those visiting friends and relatives (VFR)

Migrants

Risk for malaria exists for migrants after their arrival in Canada from a malaria-endemic country. While some refugees may receive pre-departure pre-emptive treatment for malaria in refugee camps, such treatment is by no means universal. Most cases of malaria will develop within three months of last exposure, but residual risk may persist for one year or longer, with the longest reported relapses occurring decades later. As such, the diagnosis of malaria should be considered for migrants new to Canada for at least 12 months after their arrival.

Recent clinical guidelines published in Canada include chapters on migrant malariaReference 1, Reference 2. Overall, there are no data on the number of migrant malaria cases diagnosed in Canada; however, there are limited data on severe malaria cases reported to the Canadian Malaria Network. Between 2001 to 2012, just under 20% of all cases of severe malaria in Canada had reported immigration as the reason for travel, and 65.7% of these cases were under 18 years old (Personal communication, A. McCarthy and J. Geduld, Domestic Response Unit, Malaria Branch—Division of Parasitic Diseases, US Centers for Disease Control and Prevention, 2012).

Visiting friends and relatives

According to the 2007 Census, almost 20% of the Canadian population is made up of people not born in CanadaReference 3, and large numbers are part of families who came to Canada in recent generations. The increased ease of international travel means that that more travellers can and do return to their country of origin to visit friends and relatives. Those visiting friends and relatives (VFRs) are a unique group with distinct characteristics and behaviours, and resultant risks of disease acquisition while travelling. Malaria is a specific risk for VFRs, with some studies suggesting as much as a 4.5-fold greater risk of malaria for VFRs compared with tourist travellersReference 4. VFRs routinely represent a significant proportion (21%–68%) of the cases of imported malaria in various countriesReference 5. Canada does not have data on the overall numbers of VFR cases seen. However, VFRs account for approximately 25.1% of cases of severe malaria from 2001 to 2012, and 8.8% (4 of 45 cases) were among those aged less than 18 years (Personal communication, A. McCarthy and J. Geduld, 2012).

In the United States 2,483 malaria cases reported to the Centers for Disease Control and Prevention (CDC) between 2006 and 2010 were VFRs, representing 32.9% of all cases. Among these travellers, 15.8% were aged 18 years and under (Personal communication, K. Cullen and P. Arguin,2012). In the same timeframe, 8.1% (n = 616) of all the malaria cases reported to the CDC were among immigrants or refugees, and 45.0% were among those 18 years of age or under.

Characteristics of the travel destination, the traveller, and travel health beliefs and behaviours predispose VFRs to a heightened risk of malaria acquisitionReference 5. VFRs tend to travel to destinations different to those travelled to by tourists: they often go to rural locations with a higher transmission risk of malaria (and of other tropical diseases) than in urban centresReference 6. Accommodations are more likely to be with local family members than in air-conditioned and well-screened hotelsReference 6. VFRs tend to be younger and often travel with their Canadian-born children, remaining in their countries of origin for longer than tourist travellers travel to their destinationsReference 6. Sometimes, travel plans are made at the last minute because of urgent situations such as returning to visit a sick relative or to attend a funeralReference 6. They also tend to be less likely to seek out or comply with preventive travel health adviceReference 7, Reference 8, Reference 9, including malaria chemoprophylaxis and personal protective measures (PPM)Reference 5, Reference 6, Reference 7, possibly because of financial or time restrictions, misconceptions about immunity against malaria and reliance on advice from family members or local providers at their destinationReference 6, Reference 10, Reference 11, Reference 12, Reference 13. For these reasons, risk of malaria acquisition in VFRs can sometimes approach that of local residents, but the risk of severe disease is higher due to loss of partial immunity after having lived abroadReference 6.

Table 5.5.1: Evidence-based medicine recommendations
Recommendation EBM rating
Test for malaria in migrants with unexplained fever for at least for at least 12 months after their arrival in Canada. C III
Consider malaria screening in asymptomatic new arrivals from highly endemic areas, with treatment of those cases that have parasitemia (apart from the presence of gametocytes only) in blood smears. C III
Ask migrants from malaria-endemic countries about future travel plans. Doing so may provide the opportunity for  anticipatory guidance about malariaReference 6. C III
Inform Canadian VFRs travelling to malaria-endemic countries of the risk of malaria, including the loss of partial immunity from living abroad and the increased risk for severe disease in children and pregnant womenReference 6. C III
Counsel Canadian VFRs travelling to malaria-endemic countries about PPM (repellants, bed nets, behavioural choices) and chemoprophylaxisReference 6. C III
Discuss the affordability of chemoprophylaxis with Canadian VFRs travelling to malaria-endemic countries, taking cost into account in the weighing of different choicesReference 6. C III

Abbreviation: EBM, evidence-based medicine; PPM, personal; protective measures; VFR, visiting friends and relatives.

Note: For a description of the categories and quality of evidence of the recommendations, see Appendix IV.

References

Reference 1

Pottie K, Greenaway C, Feightner J, Welch V, Swinkels H, Rashid M, et al. Evidence-based clinical guidelines for immigrants and refugees. CMAJ 2011 Sep 6;183(12):E824–E925.

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Reference 2

McCarthy AE, Varghese S, Duggan A, Campbell G, Pottie K, Kuhn S. Appendix 9: Malaria: evidence review for newly arriving immigrants and refugees. CMAJ 2011.

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Reference 3

Statistics Canada.2007. Population by immigrant status and period of immigration, 2006 counts, for Canada and census metropolitan areas and census agglomerations - 20% sample data (table). Immigration and Citizenship Highlight Tables, 2006 Census. Ottawa.; 2012. Report No.: Statistics Canada Catalogue no. 97-557-XWE2006002.

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Reference 4

Leder K, Tong S, Weld L, Kain KC, Wilder-Smith A, von SF, et al. Illness in travelers visiting friends and relatives: a review of the GeoSentinel Surveillance Network. Clin Infect Dis 2006 Nov 1;43(9):1185–93.

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Reference 5

Pavli A, Maltezou HC. Malaria and travellers visiting friends and relatives. Travel Med Infect Dis 2010 May;8(3):161–8.

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Reference 6

Bacaner N, Stauffer B, Boulware DR, Walker PF, Keystone JS. Travel medicine considerations for North American immigrants visiting friends and relatives. JAMA 2004 Jun 16;291(23):2856–64.

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Reference 7

dos Santos CC, Anvar A, Keystone JS, Kain KC. Survey of use of malaria prevention measures by Canadians visiting India. CMAJ 1999 Jan 26;160(2):195–200.

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Reference 8

Van HK, Van DP, Castelli F, Zuckerman J, Nothdurft H, Dahlgren AL, et al. Knowledge, attitudes and practices in travel-related infectious diseases: the European airport survey. J Travel Med 2004 Jan;11(1):3–8.

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Reference 9

Hagmann S, Neugebauer R, Schwartz E, Perret C, Castelli F, Barnett ED, et al. Illness in children after international travel: analysis from the GeoSentinel Surveillance Network. Pediatrics 2010 May;125(5):e1072–e1080.

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Reference 10

Centers for Disease Control and Prevention. CDC Health Information for international travel 2012. Atlanta: US Department of Health and Human Services, Public Health Service; 2012.

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Reference 11

Angell SY, Behrens RH. Risk assessment and disease prevention in travelers visiting friends and relatives. Infect Dis Clin North Am 2005 Mar;19(1):49–65.

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Reference 12

Campbell H. Imported malaria in the UK: advice given by general practitioners to British residents travelling to malaria endemic areas. J R Coll Gen Pract 1987 Feb;37(295):70–2.

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Reference 13

McCarthy M. Should visits to relatives carry a health warning? Lancet 2001 Mar 17;357(9259):862.

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