Malaria in travellers returning or migrating to Canada: surveillance report from CanTravNet surveillance data, 2004-2014

Abstract

Background: Malaria remains the most common specific cause of fever in returned travellers and can be life-threatening. We examined demographic and travel correlates of malaria among Canadian travellers and immigrants to identify groups for targeted pretravel intervention.Methods: Descriptive data on ill returned Canadian travellers and immigrants presenting to a CanTravNet site between 2004 and 2014 with a diagnosis of malaria were analyzed. Data were collected using the GeoSentinel data platform. This network comprises 63 specialized travel and tropical medicine clinics, including 7 Canadian sites (Vancouver, Calgary, Toronto, Ottawa, Winnipeg and Montréal), that contribute anonymous, delinked, clinician-and questionnaire-based travel surveillance data on all ill travellers examined to a centralized Structure Query Language database. Results:During the study period, 20 345 travellers and immigrants were evaluated, and 93% had a travel-related diagnosis. Of these, 437 (2.1%) patients received 456 malaria diagnoses, the most common species being Plasmodium falciparum (n = 282, 61.8%). People travelling to visit friends and relatives were most well-represented (n = 169, 38.7%), followed by business travellers (n = 71, 16.2%). Sub-Saharan Africa was the most common source region, accounting for 341 (74.8%) malaria diagnoses, followed by South Central Asia (n = 55, 12%). Nigeria was the most well-represented source country, accounting for 41 cases (9.0%). India, a high-volume destination for Canadians, accounted for 40 cases (8.8%), 36 of which were caused by Plasmodium vivax. Of 456 malaria diagnoses, 26 (5.7%) were severe. Of 377 nonimmigrant travellers with malaria, 19.9% (n = 75) travelled for less than 2 weeks, and 7.2% (n = 27) travelled for less than 1 week. Interpretation:This analysis provides an epidemiologic framework for Canadian practitioners encountering prospective and returned travellers. It confirms the importance of preventive measures and surveillance associated with travel to sub-Saharan Africa and India, particularly by travellers visiting friends or relatives. Short-duration travel confers important malaria risk. Abstract Research CMAJ OPENCMAJ OPEN, 4(3) E353 surveillance summary of malaria in a cohort of returned travellers and new immigrants presenting for care at CanTravNet sites over a 10-year period. Methods SettingSeven Canadian sites from 5 provinces (British Columbia, Alberta, Manitoba, Ontario and Quebec), also belonging to the GeoSentinel Global Surveillance Network, constitute CanTravNet, as described. 7 These sites are large referral-based outpatient centres staffed by specialists in travel and tropical medicine, which serve the Greater Vancouver-Victoria, Calgary, Winnipeg, Toronto, Ottawa and Montréal metropolitan areas and could account for service of almost 50% of the Canadian population. Network sites have been accrued over time, with inaugural sites in Toronto (1997) and Ottawa (1997), and more recent additional sites in Victoria-Vancouver (2009), Montréal (2007), Calgary...

Response to fever and utilization of standby emergency treatment (SBET) for malaria in travellers to Southeast Asia: a questionnaire-based cohort study

“…In a retrospective analysis of national notification data from Canada, 9.2% of imported malaria cases originated from India. India displayed the most common source country for vivax malaria cases [36]. Whilst this should be taken into account during pre-travel advice, the notification data to the RKI presented in this study show low and declining numbers of malaria cases imported from South and SEA to Germany.…”

Fever in the Returning Traveler

“…Additionally, severe malaria is more common in children after the first month of travel due to the incubation period of P falciparum (7-90 days), especially in those who visited sub-Saharan Africa. 17,18 Overall, sub-Saharan Africa is one of the most common geographic regions for acquisition, comprising 71.5% of cases according to a GeoSentinel study of travelers migrating or returning to Canada from 2004 to 2014. 19 Malaria should remain on the differential diagnosis for up to a year in an acutely ill, febrile child after travel to an endemic area where P vivax and P ovale strains are present.…”

Travel-Related Parasitic Infections in Travellers to Southeast Asia and Western Pacific Countries

“…Seyahatten dönenlerde görü-len ateşin en yaygın nedeni olan sıtmanın bulaş riskinin bulunduğu 97 ülke/bölgeyi her yıl 125 milyondan fazla uluslararası turist ziyaret etmektedir (10,15). Asya kıtası ise insan hareketlerinin yoğunluğu ile orantılı olarak tüm dünyada sıtma epidemiyolojisi etkileme potansiyeline sahiptir.…”

“…Buna en belirgin örneklerden biri 2003 yılında Çin'de başlayıp Kanada, ABD, farklı Avrupa ve Asya ülkelerine yayılan SARS-Coronavirus'un neden olduğu ölümcül solunum yolları enfeksiyonu olan SARS'dır (SARS: Severe Acute Respiratory Syndrome) (7). Güncel diğer bir örnek ise seyahatten dönen yolcularda ateşin en sık görülme nedeni olan sıtma olarak verilebilir (10). Giardia intestinalis gibi birçok paraziter enfeksiyon ajanı asemptomatik olarak taşınabilir ve hastalığa yakalananlar tedavi edilmezse ülkelerine döndüklerinde farkında olmadan hastalığı yayabilirler (6).…”