Travel-related Zika virus cases in Canada: October 2015-June 2017.

BACKGROUND: Zika virus (ZIKV) is an emerging mosquito-borne disease that can cause severe birth defects if contracted congenitally. Since late 2015, there has been a large increase in the number of travel-related cases of Zika virus infection in Canada. OBJECTIVE: The objective of this study was to describe the epidemiology of travel-related Zika cases in Canada from October 2015 to June 2017 and review them in the context of the international outbreak in the Americas. METHODS: Zika virus infections were confirmed by polymerase chain reaction (PCR) detection of viral RNA and/or the serological identification of ZIKV-specific antibodies in serum. Cases of ZIKV infection were identified by provincial and territorial health authorities, and reported on a regular basis to the Public Health Agency of Canada (PHAC). Case information requested included date of illness onset, age category, sex, pregnancy status, and location(s) and dates of travel. Estimates for the monthly number of Canadians travelling outside of Canada to other countries in the Americas were obtained from Statistics Canada and the International Air Transport Association (IATA). Data to produce the epidemic curves of autochthonous cases for each region of the Americas were extracted from country-specific epidemic curves on the Pan American Health Organization website. RESULTS: As of June 7, 2017, 513 laboratory confirmed cases and two Zika-related birth/fetal anomalies were reported across all 10 provinces. Illness in Canadian travellers generally coincided with outbreak intensity in the country of exposure rather than travel volume. There has been no evidence of autochthonous (local) transmission in Canada. Currently, cases are on the decline both in Canada and internationally. CONCLUSION: The surge in Canadian ZIKV infections in 2016 was directly related to the incursion and spread of ZIKV into the Americas. Although cases are now on the decline worldwide, it remains to be seen whether a resurgence of cases in previously affected or new areas will occur. Both outbreak intensity and seasonality of ZIKV transmission should be monitored over time in order to inform the timing of public health education campaigns, as some may turn out to be more effective in the off-peak travel season when the risk of disease transmission may be higher. Ongoing education and awareness among travellers, particularly for pregnant women and those planning pregnancies, is still indicated.

Illness in Canadian travellers and migrants from Brazil: CanTravNet surveillance data, 2013-2016.

BACKGROUND: In light of the 2016 summer Olympic games it is anticipated that Canadian practitioners will require information about common illnesses that may affect travellers returning from Brazil. OBJECTIVE: To identify the demographic and travel correlates of illness among recent Canadian travellers and migrants from Brazil attending a network of travel health clinics across Canada. METHODS: Data was analyzed on returned Canadian travellers and migrants presenting to a CanTravNet site for care of an illness between June 2013 and June 2016. RESULTS: During the study period, 7,707 ill travellers and migrants presented to a CanTravNet site and 89 (0.01%) acquired their illness in Brazil. Tourists were most well represented (n=45, 50.6%), followed by those travelling to "visit friends and relatives" (n=14, 15.7%). The median age was 37 years (range <1-78 years), 49 travellers were men (55.1%) and 40 were women (44.9%). Of the 40 women, 26 (65%) were of childbearing age. Nine percent (n=8) of travellers were diagnosed with arboviruses including dengue (n=6), chikungunya (n=1) and Zika virus (n=1), while another 14.6% (n=13) presented for care of non-specific viral syndrome (n=7), non-specific febrile illness (n=1), peripheral neuropathy (n=1) and non-specific rash (n=4), which are four syndromes that may be indicative of Zika virus infection. Ill returned travellers to Brazil were more likely to present for care of arboviral or Zika-like illness than other ill returned travellers to South America (23.6 per 100 travellers versus 10.5 per 100 travellers, respectively [p=0.0024]). INTERPRETATION: An epidemiologic approach to illness among returned Canadian travellers to Brazil can inform Canadian practitioners encountering both prospective and returned travellers to the Olympic games. Analysis showed that vector-borne illnesses such as dengue are common and even in this small group of travellers, both chikungunya and Zika virus were represented. It is extremely important to educate travellers about mosquito-avoidance measures in advance of travel to Brazil.

Federal public health strategies to minimize the importation of communicable diseases into Canada.

BACKGROUND: The global spread of communicable diseases is a growing concern largely as a result of increased international travel. In Canada, although most public health management of communicable diseases occurs at the front line, the federal government also takes actions to prevent and mitigate their importation. OBJECTIVE: To describe the role of the Public Health Agency of Canada (PHAC) in minimizing the importation of communicable diseases through preventive measures taken before travellers leave Canada and through early detection and prompt containment measures taken when travellers arrive in the country with a potential communicable disease. INTERVENTIONS: PHAC works to minimize the importation of communicable diseases into Canada by developing evidence-based travel health advice and targeted outreach activities geared to the public and to health care professionals. On the basis of the Quarantine Act and the International Health Regulations (2005), PHAC also conducts inspections of conveyances such as aircraft and boats and works with partners to conduct border screening to assess ill travellers entering the country. CONCLUSION: PHAC plays an important role in preventing and minimizing the importation of communicable diseases into Canada in conjunction with clinicians, public health authorities at all levels of government and other federal government departments.

Summary of recommendations on malaria issues in special hosts.

BACKGROUND: On behalf of the Public Health Agency of Canada, the Committee to Advise on Tropical Medicine and Travel (CATMAT) developed the Canadian Recommendations for the Prevention and Treatment of Malaria Among International Travellers for Canadian health care providers who are preparing patients for travel to malaria-endemic areas and treating travellers who have returned ill. OBJECTIVE: To provide guidelines on malaria issues related to special hosts. METHODS: CATMAT reviewed all major sources of information on malaria prevention, as well as recent research and national and international epidemiological data, to tailor guidelines to the Canadian context. The evidence-based medicine recommendations were developed with associated rating scales for the strength and quality of the evidence. RECOMMENDATIONS: All people visiting malaria endemic regions should use effective personal protective measures (PPM; topical repellants, bed nets, behavioural choices) and the prescribed chemoprophylaxis. Chemoprophylaxis for pregnant and breastfeeding women and for children requires careful consideration in the context of the pregnancy trimester, the age or size of the infant/child as well as their glucose-6-phosphate dehydrogenase (G6PD) status. Recommendations for long-term travellers, expatriates and people visiting friends and relatives (VFRs) do not differ markedly from those for short-term travellers. Some underlying medical conditions may make individuals more vulnerable to malaria. In addition, some conditions or their treatment may preclude the use of one or more antimalarial medications.

Travel-acquired infections in Canada: CanTravNet 2011-2012.

BACKGROUND: Important gaps remain in our knowledge of the infectious diseases people acquire while travelling and the impact of pathogens imported by Canadian travellers. OBJECTIVE: To provide a surveillance update of illness in a cohort of returned Canadian travellers and new immigrants. METHODS: Data on returning Canadian travellers and new immigrants presenting to a CanTravNet site between September 2011 and September 2012 were extracted and analyzed by destination, presenting symptoms, common and emerging infectious diseases and disease severity. RESULTS: During the study period, 2283 travellers and immigrants presented to a CanTravNet site, 88% (N=2004) of whom were assigned a travel-related diagnosis. Top three destinations for non-immigrant travellers were India (N=132), Mexico (N=103) and Cuba (N=89). Fifty-one cases of malaria were imported by ill returned travellers during the study period, 60% (N=30) of which were Plasmodium falciparum infections. Individuals travelling to visit friends and relatives accounted for 83% of enteric fever cases (15/18) and 41% of malaria cases (21/51). The requirement for inpatient management was over-represented among those with malaria compared to those without malaria (25% versus 2.8%; p<0.0001) and those travelling to visit friends and relatives versus those travelling for other reasons (12.1% versus 2.4%; p<0.0001). Nine new cases of HIV were diagnosed among the cohort, as well as one case of acute hepatitis B. Emerging infections among travellers included hepatitis E virus (N=6), chikungunya fever (N=4) and cutaneous leishmaniasis (N=16). Common chief complaints included gastrointestinal (N=804), dermatologic (N=440) and fever (N=287). Common specific causes of chief complaint of fever in the cohort were malaria (N=47/51 total cases), dengue fever (14/18 total cases), enteric fever (14/17 total cases) and influenza and influenza-like illness (15/21 total cases). Animal bites were the tenth most common diagnosis among tourist travellers. INTERPRETATION: Our analysis of surveillance data on ill returned Canadian travellers provides a recent update to the spectrum of imported illness among travelling Canadians. Preventable travel-acquired illnesses and injuries in the cohort include malaria, enteric fever, HIV, hepatitis B, hepatitis A, influenza and animal bites. Strategies to improve uptake of preventive interventions such as malaria chemoprophylaxis, immunizations and arthropod/animal avoidance may be warranted.

CHIKUNGUNYA OUTBREAK IN THE CARIBBEAN 2013-2014.

BACKGROUND: In December 2013, the local transmission of the mosquito-borne chikungunya virus was confirmed for the first time in several Caribbean islands. OBJECTIVE: To outline what is known to date on the outbreak of chikungunya in the Caribbean, and identify what is being done to detect and limit this infection. RESULTS: PAHO/WHO has recommended that chikungunya surveillance be set up in countries where there is existing dengue surveillance. Prospective travellers should be advised to take personal protective measures to avoid mosquito bites to decrease risk of exposure. Patients typically present with fever and arthralgia. If there is a positive travel history, serology for both chikungunya and dengue virus infection should be considered after consultation with local public health officials. Treatment is supportive. Transmission in Canada is not expected. CONCLUSION: Clinicians and public health professionals in Canada should be on the alert for sporadic cases of chikungunya virus in patients who present with fever and arthralgias after a stay in an affected Caribbean island.

Summary of recommendations for the prevention of malaria by the Committee to Advise on Tropical Medicine and Travel (CATMAT).

BACKGROUND: On behalf of the Public Health Agency of Canada, the Committee to Advise on Tropical Medicine and Travel (CATMAT) developed the Canadian Recommendations for the Prevention and Treatment of Malaria Among International Travellers for Canadian health care providers who are preparing patients for travel to malaria-endemic areas and treating travellers who have returned ill. OBJECTIVE: To provide guidelines on risk assessment and prevention of malaria. METHODS: CATMAT reviewed all major sources of information on malaria prevention, as well as recent research and national and international epidemiological data, to tailor guidelines to the Canadian context. The evidence-based medicine recommendations were developed with associated rating scales for the strength and quality of the evidence. RECOMMENDATIONS: Used together and correctly, personal protective measures (PPM) and chemoprophylaxis very effectively protect against malaria infection. PPM include protecting accommodation areas from mosquitoes, wearing appropriate clothing, using bed nets pre-treated with insecticide and applying topical insect repellant (containing 20%-30% DEET or 20% icaridin) to exposed skin. Selecting the most appropriate chemoprophylaxis involves assessment of the traveller's itinerary to establish his/her malaria risk profile as well as potential drug resistance issues. Antimalarials available on prescription in Canada include chloroquine (or hydroxychloroquine), atovaquone-proguanil, doxycycline, mefloquine and primaquine.

Summary of recommendations for the diagnosis and treatment of malaria by the Committee to Advise on Tropical Medicine and Travel (CATMAT).

BACKGROUND: On behalf of the Public Health Agency of Canada, the Committee to Advise on Tropical Medicine and Travel (CATMAT) developed the Canadian Recommendations for the Prevention and Treatment of Malaria Among International Travellers for Canadian health care providers who are preparing patients for travel to malaria-endemic areas and treating travellers who have returned ill. These recommendations aim to achieve appropriate diagnosis and management of malaria, a disease that is still uncommon in Canada. OBJECTIVE: To provide recommendations on the appropriate diagnosis and treatment of malaria. METHODS: CATMAT reviewed all major sources of information on malaria diagnosis and treatment, as well as recent research and national and international epidemiological data, to tailor guidelines to the Canadian context. The evidence-based medicine recommendations were developed with associated rating scales for the strength and quality of the evidence. RECOMMENDATIONS: Malarial management depends on rapid identification of the disease, as well as identification of the malaria species and level of parasitemia. Microscopic identification of blood samples is both rapid and accurate but can be done only by trained laboratory technicians. Rapid diagnostic tests are widely available, are simple to use and do not require specialized laboratory equipment or training; however, they do not provide the level of parasitemia and do require verification. Polymerase chain reaction (PCR), although still limited in availability, is emerging as the gold standard for high sensitivity and specificity in identifying the species.

Testing for HIV among patients with tuberculosis in Montreal.

OBJECTIVE: To determine the rate of HIV testing among patients with tuberculosis (TB) in Montreal, and to identify patient characteristics associated with physician screening patterns. Knowledge of local patterns of HIV testing among patients with TB could be used to facilitate the development of strategies to improve compliance with recommendations that all patients with TB be screened for HIV. DESIGN: Retrospective chart review. PATIENTS: All patients with TB reported to the Montreal Public Health Unit from 1992 to 1994 (ages 19 to 50) and from 1992 to 1995 (ages 18 and under) and for whom a chart could be reviewed. OUTCOME MEASURES: Patients with TB screened versus not screened for HIV infection, analyzed to determine which variables independently predict the likelihood of screening for HIV infection. RESULTS: Of the 376 patients with TB for whom data were available, 192 (51%) were screened for HIV. Of those, 33 (17%) had been tested before having received the diagnosis of TB. Multivariate analysis revealed that patients with TB who were male, aged 30 to 39, had a positive sputum smear, displayed at least 1 clinical symptom, received the TB diagnosis from a microbiologist or infectious disease specialist, or reported 1 or more HIV risk factors were more likely to be screened for HIV. CONCLUSIONS: HIV screening of patients with TB is selective, depending on both patient and physician characteristics. Physicians' awareness of recommendations needs to be increased to improve the diagnosis and treatment of TB/HIV co-infection.