Monkeypox in Montréal: Epidemiology, Phylogenomics, and Public Health Response to a Large North American Outbreak.

BACKGROUND: Monkeypox, a viral zoonotic disease, is causing a global outbreak outside of endemic areas. OBJECTIVE: To characterize the outbreak of monkeypox in Montréal, the first large outbreak in North America. DESIGN: Epidemiologic and laboratory surveillance data and a phylogenomic analysis were used to describe and place the outbreak in a global context. SETTING: Montréal, Canada. PATIENTS: Probable or confirmed cases of monkeypox. MEASUREMENTS: Epidemiologic, clinical, and demographic data were aggregated. Whole-genome sequencing and phylogenetic analysis were performed for a set of outbreak sequences. The public health response and its evolution are described. RESULTS: Up to 18 October 2022, a total of 402 cases of monkeypox were reported mostly among men who have sex with men (MSM), most of which were suspected to be acquired through sexual contact. All monkeypox genomes nested within the B.1 lineage. Montréal Public Health worked closely with the affected communities to control the outbreak, becoming the first jurisdiction to offer 1 dose of the Modified Vaccinia Ankara-Bavarian Nordic vaccine as preexposure prophylaxis (PrEP) to those at risk in early June 2022. Two peaks of cases were seen in early June and July (43 and 44 cases per week, respectively) followed by a decline toward near resolution of the outbreak in October. Reasons for the biphasic peak are not fully elucidated but may represent the tempo of vaccination and/or several factors related to transmission dynamics and case ascertainment. LIMITATIONS: Clinical data are self-reported. Limited divergence among sequences limited genomic epidemiologic conclusions. CONCLUSION: A large outbreak of monkeypox occurred in Montréal, primarily among MSM. Successful control of the outbreak rested on early and sustained engagement with the affected communities and rapid offer of PrEP vaccination to at-risk persons. PRIMARY FUNDING SOURCE: None.

Clinical Characteristics and Outcomes Among Travelers With Severe Dengue : A GeoSentinel Analysis.

BACKGROUND: Dengue virus is a flavivirus transmitted by Aedes mosquitoes and is an important cause of illness worldwide. Data on the severity of travel-associated dengue illness are limited. OBJECTIVE: To describe the epidemiology, clinical characteristics, and outcomes among international travelers with severe dengue or dengue with warning signs as defined by the 2009 World Health Organization classification (that is, complicated dengue). DESIGN: Retrospective chart review and analysis of travelers with complicated dengue reported to GeoSentinel from January 2007 through July 2022. SETTING: 20 of 71 international GeoSentinel sites. PATIENTS: Returning travelers with complicated dengue. MEASUREMENTS: Routinely collected surveillance data plus chart review with abstraction of clinical information using predefined grading criteria to characterize the manifestations of complicated dengue. RESULTS: Of 5958 patients with dengue, 95 (2%) had complicated dengue. Eighty-six (91%) patients had a supplemental questionnaire completed. Eighty-five of 86 (99%) patients had warning signs, and 27 (31%) were classified as severe. Median age was 34 years (range, 8 to 91 years); 48 (56%) were female. Patients acquired dengue most frequently in the Caribbean (n = 27 [31%]) and Southeast Asia (n = 21 [24%]). Frequent reasons for travel were tourism (46%) and visiting friends and relatives (32%). Twenty-one of 84 (25%) patients had comorbidities. Seventy-eight (91%) patients were hospitalized. One patient died of nondengue-related illnesses. Common laboratory findings and signs were thrombocytopenia (78%), elevated aminotransferase (62%), bleeding (52%), and plasma leakage (20%). Among severe cases, ophthalmologic pathology (n = 3), severe liver disease (n = 3), myocarditis (n = 2), and neurologic symptoms (n = 2) were reported. Of 44 patients with serologic data, 32 confirmed cases were classified as primary dengue (IgM+/IgG-) and 12 as secondary (IgM-/IgG+) dengue. LIMITATIONS: Data for some variables could not be retrieved by chart review for some patients. The generalizability of our observations may be limited. CONCLUSION: Complicated dengue is relatively rare in travelers. Clinicians should monitor patients with dengue closely for warning signs that may indicate progression to severe disease. Risk factors for developing complications of dengue in travelers need further prospective study. PRIMARY FUNDING SOURCE: Centers for Disease Control and Prevention, International Society of Travel Medicine, Public Health Agency of Canada, and GeoSentinel Foundation.

Strongyloidiasis-related lung involvement: too much of a bad thing.

PURPOSE OF REVIEW: Strongyloidiasis is a soil-transmitted helminthiasis, a neglected tropical disease that affects 300-900 million individuals globally. Strongyloides stercoralis is associated with cutaneous, respiratory, and gastrointestinal clinical manifestations. Chronicity is due to an autoinfective cycle, and host immunosuppression can lead to severe and fatal disease. Lung involvement is significant in severe strongyloidiasis, and Strongyloides has a complex association with a number of lung diseases, which will be discussed in this review. RECENT FINDINGS: The treatment of chronic lung diseases such as asthma and chronic obstructive pulmonary disease with corticosteroids is an important risk factor for Strongyloides hyperinfection syndrome (SHS)/disseminated strongyloidiasis. The use of corticosteroids in the treatment of coronavirus disease 2019 (COVID-19) and potentially COVID-19-induced eosinopenia are risk factors for severe strongyloidiasis. Recent findings have demonstrated a significant immunomodulatory role of Strongyloides in both latent and active pulmonary tuberculosis associated to an impaired immune response and poor outcomes in active pulmonary tuberculosis. SUMMARY: Strongyloides lung involvement is a common finding in severe infection. Prompt recognition of Strongyloides infection as well as prevention of severe disease by screening or presumptive treatment are important goals in order to improve Strongyloides outcomes in at-risk population.

Laboratory Features of Trichinellosis and Eosinophilia Threshold for Testing, Nunavik, Quebec, Canada, 2009-2019.

Prolonged eosinophilia is characteristic of trichinellosis. To determine the optimal eosinophil threshold for reflex Trichinella testing, we examined all 43 cases in Nunavik, Quebec, Canada, during 2009-2019. Using receiver operating characteristic analysis, we determined that eosinophil counts >0.8 × 109 cells/L should prompt consideration of trichinellosis and testing to rapidly identify potential outbreaks.

Efficacy, immunogenicity, and safety of a plant-derived, quadrivalent, virus-like particle influenza vaccine in adults (18-64 years) and older adults (≥65 years): two multicentre, randomised phase 3 trials.

BACKGROUND: Seasonal influenza remains a substantial public health threat despite the availability of egg-derived and other vaccines. Plant-based manufacturing might address some of the limitations of current vaccines. We describe two phase 3 efficacy studies of a recombinant quadrivalent virus-like particle (QVLP) influenza vaccine manufactured in plants, one in adults aged 18-64 years (the 18-64 study) and one in older people aged 65 years and older (the 65-plus study). METHODS: We did two randomised, observer-blind, multinational studies in the northern hemisphere in the 2017-18 (the 18-64 study) and 2018-19 (the 65-plus study) influenza seasons. The 18-64 study was done at 73 sites and the 65-plus study was done at 104 sites, both across Asia, Europe, and North America. In the 18-64 study, inclusion criteria were body-mass index less than 40 kg/m2; age 18-64 years at screening visit; and good health. In the 65-plus study, inclusion criteria were body-mass index of maximum 35 kg/m2; aged 65 years or older at screening visit; not living in a rehabilitation centre or care home; and no acute or evolving medical problems. Participants in the 18-64 study were randomly assigned (1:1) to receive either QVLP vaccine (30 µg haemagglutinin per strain) or placebo. Participants in the 65-plus study were randomly assigned (1:1) to receive QVLP vaccine (30 µg haemagglutinin per strain) or quadrivalent inactivated vaccine (QIV; 15 µg haemagglutinin per strain). The primary outcome in the 18-64 study was absolute vaccine efficacy to prevent laboratory-confirmed, respiratory illness caused by antigenically matched influenza strains. The primary outcome in the 65-plus study was relative vaccine efficacy to prevent laboratory-confirmed influenza-like illness caused by any influenza strain. The primary analyses were done in the per-protocol population and safety was assessed in all participants who received the assigned treatment. These studies are registered with ClinicalTrials.gov (18-64 study NCT03301051; 65-plus study NCT03739112). FINDINGS: In the 18-64 study, between Aug 30, 2017, and Jan 15, 2018, 10 160 participants were randomly assigned to receive either QVLP vaccine (5077 participants) or placebo (5083 participants). The per-protocol population consisted of 4814 participants in the QVLP group and 4812 in the placebo group. The study did not meet its primary endpoint of 70% absolute vaccine efficacy for the QVLP vaccine (35·1% [95% CI 17·9 to 48·7]) against respiratory illness caused by matched strains. 55 (1·1%) of 5064 participants in the QVLP group versus 51 (1·0%) of 5072 in the placebo group had a serious adverse event. Four (0·1%) and six [0·1%] participants had severe treatment-related treatment-emergent adverse events. In the 65-plus study, between Sept 18, 2018, and Feb 22, 2019, 12 794 participants were randomly assigned to receive either QVLP vaccine (6396 participants) or QIV (6398 participants). The per-protocol population consisted of 5996 participants in the QVLP group and 6026 in the QIV group. The study met its primary non-inferiority endpoint with a relative vaccine efficacy of the QVLP vaccine for the prevention of influenza-like illness caused by any strain of 8·8% (-16·7 to 28·7). 263 (4·1%) of 6352 participants in the QVLP group versus 266 (4·2%) of 6366 in the QIV group had serious adverse events (one [<0·1%] vs two [<0·1%] were considered treatment-related); one (<0·1%) versus three (<0·1%) participants had severe treatment-related treatment-emergent adverse events. INTERPRETATION: These efficacy studies are the first large-scale studies of any plant-derived human vaccine. Together, they show that the plant-derived QVLP vaccine can provide substantial protection against respiratory illness and influenza-like illness caused by influenza viruses in adults. QVLP vaccine was well tolerated and no major safety signal arose in participants who received QVLP vaccine across the two studies. FUNDING: Medicago.

Diagnostic Testing for Severe Acute Respiratory Syndrome-Related Coronavirus 2: A Narrative Review.

Diagnostic testing to identify persons infected with severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) infection is central to control the global pandemic of COVID-19 that began in late 2019. In a few countries, the use of diagnostic testing on a massive scale has been a cornerstone of successful containment strategies. In contrast, the United States, hampered by limited testing capacity, has prioritized testing for specific groups of persons. Real-time reverse transcriptase polymerase chain reaction-based assays performed in a laboratory on respiratory specimens are the reference standard for COVID-19 diagnostics. However, point-of-care technologies and serologic immunoassays are rapidly emerging. Although excellent tools exist for the diagnosis of symptomatic patients in well-equipped laboratories, important gaps remain in screening asymptomatic persons in the incubation phase, as well as in the accurate determination of live viral shedding during convalescence to inform decisions to end isolation. Many affluent countries have encountered challenges in test delivery and specimen collection that have inhibited rapid increases in testing capacity. These challenges may be even greater in low-resource settings. Urgent clinical and public health needs currently drive an unprecedented global effort to increase testing capacity for SARS-CoV-2 infection. Here, the authors review the current array of tests for SARS-CoV-2, highlight gaps in current diagnostic capacity, and propose potential solutions.

Serodiagnostics for Severe Acute Respiratory Syndrome-Related Coronavirus 2 : A Narrative Review.

Accurate serologic tests to detect host antibodies to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) will be critical for the public health response to the coronavirus disease 2019 pandemic. Many use cases are envisaged, including complementing molecular methods for diagnosis of active disease and estimating immunity for individuals. At the population level, carefully designed seroepidemiologic studies will aid in the characterization of transmission dynamics and refinement of disease burden estimates and will provide insight into the kinetics of humoral immunity. Yet, despite an explosion in the number and availability of serologic assays to test for antibodies against SARS-CoV-2, most have undergone minimal external validation to date. This hinders assay selection and implementation, as well as interpretation of study results. In addition, critical knowledge gaps remain regarding serologic correlates of protection from infection or disease, and the degree to which these assays cross-react with antibodies against related coronaviruses. This article discusses key use cases for SARS-CoV-2 antibody detection tests and their application to serologic studies, reviews currently available assays, highlights key areas of ongoing research, and proposes potential strategies for test implementation.

Epidemiological and Clinical Characteristics of International Travelers with Enteric Fever and Antibiotic Resistance Profiles of Their Isolates: a GeoSentinel Analysis.

Enteric fever, caused by Salmonella enterica serovar Typhi (S Typhi) and S. enterica serovar Paratyphi (S Paratyphi), is a common travel-related illness. Limited data are available on the antimicrobial resistance (AMR) patterns of these serovars among travelers. Records of travelers with a culture-confirmed diagnosis seen during or after travel from January 2007 to December 2018 were obtained from GeoSentinel. Traveler demographics and antimicrobial susceptibility data were analyzed. Isolates were classified as nonsusceptible if intermediate or resistant or as susceptible in accordance with the participating site's national guidelines. A total of 889 travelers (S Typhi infections, n = 474; S Paratyphi infections, n = 414; coinfection, n = 1) were included; 114 (13%) were children of <18 years old. Most individuals (41%) traveled to visit friends and relatives (VFRs) and acquired the infection in South Asia (71%). Child travelers with S Typhi infection were most frequently VFRs (77%). The median trip duration was 31 days (interquartile range, 18 to 61 days), and 448 of 691 travelers (65%) had no pretravel consultation. Of 143 S Typhi and 75 S Paratyphi isolates for which there were susceptibility data, nonsusceptibility to antibiotics varied (fluoroquinolones, 65% and 56%, respectively; co-trimoxazole, 13% and 0%; macrolides, 8% and 16%). Two S Typhi isolates (1.5%) from India were nonsusceptible to third-generation cephalosporins. S Typhi fluoroquinolone nonsusceptibility was highest when infection was acquired in South Asia (70 of 90 isolates; 78%) and sub-Saharan Africa (6 of 10 isolates; 60%). Enteric fever is an important travel-associated illness complicated by AMR. Our data contribute to a better understanding of region-specific AMR, helping to inform empirical treatment options. Prevention measures need to focus on high-risk travelers including VFRs and children.

First Human Case of Metacestode Infection Caused by Versteria sp. in a Kidney Transplant Recipient.

Cestodes are emerging agents of severe opportunistic infections among immunocompromised patients. We describe the first case of human infection, with the recently-proposed genus Versteria causing an invasive, tumor-like hepatic infection with regional and distant extension in a 53-year-old female kidney transplant recipient from Atlantic Canada.

Decision Tool for Herpes B Virus Antiviral Prophylaxis after Macaque-Related Injuries in Research Laboratory Workers.

Macaque-related injuries among primate workers can lead to a potentially fatal B virus encephalomyelitis. We describe a decision tool for evaluating the need for antiviral postexposure prophylaxis and provide a retrospective review of the injuries assessed in our center after its implementation in 2010. Among the injuries studied (n = 251), 40.6% were categorized as high-risk (prophylaxis recommended), 44.2% moderate-risk (consider prophylaxis), and 15.1% low-risk (prophylaxis not recommended). Ten percent of low-risk and 98% of high-risk injuries received prophylaxis (p<0.001). Compared with using universal postexposure prophylaxis, using a decision tool can lead to a standardization of practice and a reduction in prescriptions for antiviral medication.

Cutaneous leishmaniasis in the 21st century: from the laboratory to the bedside.

PURPOSE OF REVIEW: Despite modern advances in molecular diagnostic tools and a better understanding of its complex pathophysiology, cutaneous leishmaniasis, a neglected tropical disease, remains a major global health problem. Laboratory methods to inform prognosis and treatment are not widely available, the therapeutic options are limited and have significant adverse effects, and emergence of drug resistance is a further complication. New advances in the understanding of the role of Leishmania RNA virus (LRV) as a prognostic factor, speciation methods and antimicrobial resistance testing and their limitations will be discussed. RECENT FINDINGS: LRV, an intracytoplasmic endosymbiont found mostly in Leishmania spp. associated with more severe disease, appears to play a role in modulating the host immune response and has been associated with treatment failure in some Viannia subgenus species. Proper speciation is an important guide to management. However, recent findings have demonstrated significant heterogeneity of results related to differences in genotyping methods. SUMMARY: Recognition of the role of LRV in immune modulation and response to treatment along with more accessible tools for its detection to guide management at the bedside should allow a better individualized approach. Improving accessibility and standardization of speciation methods and antimicrobial susceptibility testing should be major goals to improve cutaneous leishmaniasis management in the 21st century.

Emerging concepts in the diagnosis, treatment, and prevention of travelers' diarrhea.

PURPOSE OF REVIEW: Traveller's diarrhea, though not life-threatening. is often a vexing problem, which impacts overall function of the traveller while on holiday. Increasing data is available regarding molecular diagnostic techniques, which may help obtain an early etiologic diagnosis. Use of antibiotics for traveller's diarrhea is controversial in this era of multidrug resistance and microbiome disruption. RECENT FINDINGS: Travel to the tropics promotes gut colonization with drug-resistant bacteria and this risk increases after treatment with antibiotics, leading to potential ecological impacts in the country of residence. SUMMARY: Traveller's diarrhea is common and can impact a traveller's itinerary leading to significant inconvenience, and occasional longer term sequelae. Though bacterial causes predominate, recommended treatment is conservative in mild-to-moderate cases. Molecular techniques for early diagnosis of traveller's diarrhea may help with appropriate management. Treatment with antibiotics is sometimes required but is associated with gut colonization by multidrug-resistant bacteria.

Area of exposure and treatment challenges of malaria in Eritrean migrants: a GeoSentinel analysis.

BACKGROUND: Recent reports highlight malaria as a frequent diagnosis in migrants who originate from Eritrea. A descriptive analysis of GeoSentinel cases of malaria in Eritrean migrants was done together with a literature review to elucidate key attributes of malaria in this group with a focus on possible areas of acquisition of malaria and treatment challenges. RESULTS: A total of 146 cases were identified from the GeoSentinel database from 1999 through September 2017, with a marked increase in 2014 and 2015. All patients originated from Eritrea and the main reporting GeoSentinel sites were in Norway, Switzerland, Sweden, Israel and Germany. The majority of patients (young adult males) were diagnosed with malaria following arrival in the host country. All patients had a possible exposure in Eritrea, but may have been exposed in documented transit countries including Ethiopia, Sudan and possibly Libya in detention centres. Most infections were due to Plasmodium vivax (84.2%), followed by Plasmodium falciparum (8.2%). Two patients were pregnant, and both had P. vivax malaria. Some 31% of the migrants reported having had malaria while in transit. The median time to onset of malaria symptoms post arrival in the host country was 39 days. Some 66% of patients were hospitalized and nine patients had severe malaria (according to WHO criteria), including five due to P. vivax. CONCLUSIONS: The 146 cases of mainly late onset, sometimes severe, P. vivax malaria in Eritrean migrants described in this multi-site, global analysis reflect the findings of single-centre analyses identified in the literature search. Host countries receiving asylum-seekers from Eritrea need to be prepared for large surges in vivax and, to a lesser extent, falciparum malaria, and need to be aware and prepared for glucose-6-phosphate dehydrogenase deficiency testing and primaquine treatment, which is difficult to procure and mainly unlicensed in Europe. There is an urgent need to explore the molecular epidemiology of P. vivax in Eritrean asylum-seekers, to investigate the area of acquisition of P. vivax along common transit routes and to determine whether there has been re-introduction of malaria in areas, such as Libya, where malaria is considered eliminated, but where capable vectors and Plasmodium co-circulate.

Diagnosis and Management of Systemic Endemic Mycoses Causing Pulmonary Disease.

Systemic endemic mycoses cause high rates of morbidity and mortality in certain regions of the world and the real impact on global health is not well understood. Diagnosis and management remain challenging, especially in low-prevalence settings, where disease awareness is lacking. The main challenges include the variability of clinical presentation, the fastidious and slow-growing nature of the fungal pathogens, the paucity of diagnostic tests, and the lack of options and toxicity of antifungal drugs. Coccidioidomycosis and paracoccidioidomycosis are restricted to the Americas only, and while histoplasmosis and blastomycosis also occur predominantly in the Americas, these mycoses have also been reported on other continents, especially in sub-Saharan Africa. Talaromycosis is endemic in tropical and subtropical regions in South-East Asia and southern China. Systemic endemic mycoses causing pulmonary disease are usually acquired via the airborne route by inhalation of fungal spores. Infections can range from asymptomatic or mild with flu-like illnesses to severe pulmonary or disseminated diseases. Skin involvement is frequent in patients with paracoccidioidomycosis, blastomycosis, sporotrichosis, and talaromycosis and manifests as localized lesions or diffuse nodules in disseminated disease, but can also occur with other endemic mycoses. Culture and/or characteristic histopathology from clinical samples is the diagnostic standard for endemic mycoses. Immunological assays are often not available for the diagnosis of most endemic mycoses and molecular amplification methods for the detection of fungal nucleic acids are not standardized at present. The first-line treatment for mild to moderate histoplasmosis, paracoccidioidomycosis, blastomycosis, sporotrichosis, and talaromycosis is itraconazole. Severe illness is treated with amphotericin B. Patients with severe coccidioidomycosis should receive fluconazole. Treatment duration depends on the specific endemic mycosis, the severity of disease, and the immune status of the patient, ranging between 6 weeks and lifelong treatment.

Travel-Related Infections Among Pregnant Travellers to the Tropics: An Overview.

Infectious diseases acquired during travel pose a significant health risk to pregnant travellers, who are more susceptible to both acquiring certain infections and developing severe complications. A review of the literature focusing on recent evidence-based guidelines was conducted with attention to tropical infections in the pregnant patient. A summary meant to serve as a succinct reference for health care professionals caring for pregnant women is presented. Magnitude of risk, clinical features, management, and preventive strategies of major travel-acquired infections of pertinence to the pregnant traveller are summarized, including malaria, arboviral infections, foodborne infections, helminthic infections, and influenza. Tables with details on specific infections within each group and guidance for reducing travel-related health risks in the pregnant patient are presented.

Travel-Associated Zika Virus Disease Acquired in the Americas Through February 2016: A GeoSentinel Analysis.

Background: Zika virus has spread rapidly in the Americas and has been imported into many nonendemic countries by travelers. Objective: To describe clinical manifestations and epidemiology of Zika virus disease in travelers exposed in the Americas. Design: Descriptive, using GeoSentinel records. Setting: 63 travel and tropical medicine clinics in 30 countries. Patients: Ill returned travelers with a confirmed, probable, or clinically suspected diagnosis of Zika virus disease seen between January 2013 and 29 February 2016. Measurements: Frequencies of demographic, trip, and clinical characteristics and complications. Results: Starting in May 2015, 93 cases of Zika virus disease were reported. Common symptoms included exanthema (88%), fever (76%), and arthralgia (72%). Fifty-nine percent of patients were exposed in South America; 71% were diagnosed in Europe. Case status was established most commonly by polymerase chain reaction (PCR) testing of blood and less often by PCR testing of other body fluids or serology and plaque-reduction neutralization testing. Two patients developed Guillain-Barré syndrome, and 3 of 4 pregnancies had adverse outcomes (microcephaly, major fetal neurologic abnormalities, and intrauterine fetal death). Limitation: Surveillance data collected by specialized clinics may not be representative of all ill returned travelers, and denominator data are unavailable. Conclusion: These surveillance data help characterize the clinical manifestations and adverse outcomes of Zika virus disease among travelers infected in the Americas and show a need for global standardization of diagnostic testing. The serious fetal complications observed in this study highlight the importance of travel advisories and prevention measures for pregnant women and their partners. Travelers are sentinels for global Zika virus circulation and may facilitate further transmission. Primary Funding Source: Centers for Disease Control and Prevention, International Society of Travel Medicine, and Public Health Agency of Canada.

Malaria after international travel: a GeoSentinel analysis, 2003-2016.

BACKGROUND: More than 30,000 malaria cases are reported annually among international travellers. Despite improvements in malaria control, malaria continues to threaten travellers due to inaccurate perception of risk and sub-optimal pre-travel preparation. METHODS: Records with a confirmed malaria diagnosis after travel from January 2003 to July 2016 were obtained from GeoSentinel, a global surveillance network of travel and tropical medicine providers that monitors travel-related morbidity. Records were excluded if exposure country was missing or unascertainable or if there was a concomitant acute diagnosis unrelated to malaria. Records were analyzed to describe the demographic and clinical characteristics of international travellers with malaria. RESULTS: There were 5689 travellers included; 325 were children <18 years. More than half (53%) were visiting friends and relatives (VFRs). Most (83%) were exposed in sub-Saharan Africa. The median trip duration was 32 days (interquartile range 20-75); 53% did not have a pre-travel visit. More than half (62%) were hospitalized; children were hospitalized more frequently than adults (73 and 62%, respectively). Ninety-two per cent had a single Plasmodium species diagnosis, most frequently Plasmodium falciparum (4011; 76%). Travellers with P. falciparum were most frequently VFRs (60%). More than 40% of travellers with a trip duration ≤7 days had Plasmodium vivax. There were 444 (8%) travellers with severe malaria; 31 children had severe malaria. Twelve travellers died. CONCLUSION: Malaria remains a serious threat to international travellers. Efforts must focus on preventive strategies aimed on children and VFRs, and chemoprophylaxis access and preventive measure adherence should be emphasized.

Surveillance report of Zika virus among Canadian travellers returning from the Americas.

BACKGROUND: Widespread transmission of Zika virus in the Americas has occurred since late 2015. We examined demographic and travel-related characteristics of returned Canadian travellers with Zika infection acquired in the Americas to illuminate risk factors for acquisition and the clinical spectrum. METHODS: We analyzed demographic and travel-related data for returned Canadian travellers who presented to a CanTravNet site between October 2015 and September 2016 for care of Zika virus acquired in the Americas. Data were collected with use of the GeoSentinel Surveillance Network data platform. RESULTS: During the study period, 1118 travellers presented to a CanTravNet site after returning from the Americas, 41 (3.7%) of whom had Zika infection. Zika infection from the Americas was diagnosed at CanTravNet sites as often as dengue (n = 41) over the study period. In the first half of the study period, Zika virus burden was borne by people visiting friends and relatives in South America. In the latter half, coincident with the increased spread of Zika throughout the Caribbean and Central America, Zika virus occurred more often in tourists in the Caribbean. Forty (98%) of the travellers with Zika infection acquired it through probable mosquito exposure, and 1 had confirmed sexual acquisition. Congenital transmission occurred in 2 of 3 pregnancies. Two (5%) of those with Zika had symptoms resembling those of Guillain-Barré syndrome, 1 of whom also had Zika viral meningitis. INTERPRETATION: Even in this small cohort, we observed the full clinical spectrum of acute Zika virus, including adverse fetal and neurologic outcomes. Our observations suggest that complications from Zika infection are underestimated by data arising exclusively from populations where Zika is endemic. Travellers should adhere to mosquito-avoidance measures and barrier protection during sexual activity.