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COVID-19 is with us indefinitely and air travel is a necessity. Needed research has lagged due to pandemic disruption but must not stall due to COVID indifference. A US government report proposes that national aviation authorities, not health agencies, take the lead. Research priorities and study designs are proposed.

Rationale for review In response to increased concerns about emerging infectious diseases, GeoSentinel, the Global Surveillance Network of the International Society of Travel Medicine in partnership with the US Centers for Disease Control and Prevention (CDC), was established in 1995 in order to serve as a global provider-based emerging infections sentinel network, conduct surveillance for travel-related infections and communicate and assist global public health responses. This review summarizes the history, past achievements and future directions of the GeoSentinel Network. Key findings Funded by the US CDC in 1996, GeoSentinel has grown from a group of eight US-based travel and tropical medicine centers to a global network, which currently consists of 68 sites in 28 countries. GeoSentinel has provided important contributions that have enhanced the ability to use destination-specific differences to guide diagnosis and treatment of returning travelers, migrants and refugees. During the last two decades, GeoSentinel has identified a number of sentinel infectious disease events including previously unrecognized outbreaks and occurrence of diseases in locations thought not to harbor certain infectious agents. GeoSentinel has also provided useful insight into illnesses affecting different traveling populations such as migrants, business travelers and students, while characterizing in greater detail the epidemiology of infectious diseases such as typhoid fever, leishmaniasis and Zika virus disease. Conclusions Surveillance of travel- and migration-related infectious diseases has been the main focus of GeoSentinel for the last 25 years. However, GeoSentinel is now evolving into a network that will conduct both research and surveillance. The large number of participating sites and excellent geographic coverage for identification of both common and illnesses in individuals who have traversed international borders uniquely position GeoSentinel to make important contributions of travel-related infectious diseases in the years to come.

The absence of large numbers of published in-flight transmissions of SARS-CoV-2 is not definitive evidence of safety. All peer-reviewed publications of flights with possible transmission are categorized by the quantity of transmission. Three mass transmission flights without masking are contrasted to 5 with strict masking and 58 cases with zero transmission.

‘Immunity passport’ (also called ''immunity certificate'' or ''immunity license'' has been suggested to certify traveler’ protection from SARS-CoV-2 infection. Some data have demonstrated development of neutralizing antibodies that may protect against reinfection and reduce disease severity in the short-term, and some tests correlate with virus neutralization. More evidence is needed on serologies for such certification to facilitate travel, to protect travelers and their destination countries.

BACKGROUND: Established in the Americas since late 2013, chikungunya is an emerging infection among travellers. OBJECTIVE: To examine demographic and travel correlates of chikungunya among Canadian travellers to establish a detailed epidemiological framework of this infection for Canadian practitioners encountering prospective and returned travellers. METHODS: Data regarding ill returned Canadian travellers presenting to a CanTravNet site between 2006 and 2015 were analyzed. RESULTS: During the study period, 22,387 ill travellers and immigrants presented to a CanTravNet site and, of these, 118 (0.5%) received a diagnosis of chikungunya. Those travelling for tourism were the most well-represented (n=49, 41.5%), followed by those travelling to visit friends and relatives (n=36, 30.5%). The Caribbean was the most likely source region, accounting for 64 (54.2%) diagnoses, followed by South Central Asia (n=18, 15.3%). Haiti was the most well-represented source country, accounting for 22 (18.6%) cases. India, a high-volume destination for Canadians and the next most well-represented source country, accounted for 15 cases (12.7%), as did Jamaica. Median trip duration of those with chikungunya was 14 days, with 51.7% (n=61) having a trip duration of ≤2 weeks and 21.2% (n=25) ≤1 week. Musculoskeletal complaints at presentation were noted in 89% (n=105), followed by fever in 54.2% (n=64). CONCLUSIONS: The present analysis provides an epidemiological framework of chikungunya for Canadian practitioners encountering prospective and returned travellers. It reflects the emergence of chikungunya in the Americas, the risk associated with short-duration travel and substantiates efforts to educate travellers about the need for mosquito avoidance.

Public health measures were decisive in controlling the SARS epidemic in 2003. Isolation is the separation of ill persons from non-infected persons. Quarantine is movement restriction, often with fever surveillance, of contacts when it is not evident whether they have been infected but are not yet symptomatic or have not been infected. Community containment includes measures that range from increasing social distancing to community-wide quarantine. Whether these measures will be sufficient to control 2019-nCoV depends on addressing some unanswered questions.

Background Tafenoquine, an 8-aminoquinoline, is now indicated for causal prophylaxis against all human malarias and as radical curative (anti-relapse) treatment against Plasmodium vivax and Plasmodium ovale. As with other 8-aminoquinolines, tafenoquine causes hemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency (hemizygous males and homozygous females) and is contraindicated in this population. Those with intermediate G6PD activity (heterozygous females) are also at risk for hemolysis. Awareness of how to prescribe tafenoquine in relation to G6PD status is needed so it can be used safely. Methods A standard literature search was performed on varying combinations of the terms tafenoquine, Arakoda, Kodatef, Krintafel, Kozenis, primaquine, G6PD deficiency, malaria prophylaxis and radical cure. The data were gathered and interpreted to review how tafenoquine should be prescribed in consideration of the G6PD status of an individual and traveller. Results Tafenoquine should only be given to those with G6PD activity >70% of the local population median. Qualitative G6PD tests are sufficient for diagnosing G6PD deficiency in males. However, in females quantitative G6PD testing is necessary to differentiate deficient, intermediate and normal G6PD statuses. Testing for G6PD deficiency is mandatory before tafenoquine prescription. Measures can be taken to avoid tafenoquine administration to ineligible individuals (i.e. due to G6PD status, age, pregnancy and lactation). Primaquine is still necessary for some of these cases. This review provides actions that can be taken to diagnose and manage hemolysis when tafenoquine is given inadvertently to ineligible individuals. Conclusion Attention to G6PD status is required for safe prescription of tafenoquine. A high index of suspicion is needed if hemolysis occurs. Clinicians should seek evidence-based information for the management and treatment of iatrogenicy hemolysis caused by 8-aminoquinolines.

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–Barre 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.

The scope of illnesses that may befall international travelers is broad. A guide to preparing for the preventable causes of illness is provided. Physicians may find it useful in counseling their patients who travel internationally.

The pretravel management of the international traveler should be based on risk management principles. Prevention strategies and medical interventions should be based on the itinerary, preexisting health factors, and behaviors that are unique to the traveler. A structured approach to the patient interaction provides a general framework for an efficient consultation. Vaccine-preventable diseases play an important role in travel-related illnesses, and their impact is not restricted to exotic diseases in developing countries. Therefore, an immunization encounter before travel is an ideal time to update all age-appropriate immunizations as well as providing protection against diseases that pose additional risk to travelers that may be delineated by their destinations or activities. This review focuses on indications for each travel-related vaccine together with a structured synthesis and graphics that show the geographic distribution of major travel-related diseases and highlight particularly high-risk destinations and behaviors. Dosing, route of administration, need for boosters, and possible accelerated regimens for vaccines administered prior to travel are presented. Different underlying illnesses and medications produce different levels of immunocompromise, and there is much unknown in this discipline. Recommendations regarding vaccination of immunocompromised travelers have less of an evidence base than for other categories of travelers. The review presents a structured synthesis of issues pertinent to considerations for 5 special populations of traveler: child traveler, pregnant traveler, severely immunocompromised traveler, HIV-infected traveler, and traveler with other chronic underlying disease including asplenia, diabetes, and chronic liver disease.

International audience

BACKGROUND There is a lack of multicentre analyses of the spectrum of dermatologic illnesses acquired by Canadian travellers and immigrants. Our objective for this study was to provide a comprehensive, Canada-specific surveillance summary of travel-related dermatologic conditions in a cohort of returned Canadian travellers and immigrants. METHODS Data for Canadian travellers and immigrants with a primary dermatologic diagnosis presenting to CanTravNet sites between September 2009 and September 2012 were extracted and analyzed. Data were collected using the GeoSentinel data platform. This network comprises 56 specialized travel and tropical medicine clinics, including 6 Canadian sites (Vancouver, Calgary, Toronto, Ottawa and Montreal), that contribute anonymous, de-linked, clinician- and questionnaire-based travel surveillance data on all ill travellers examined to a centralized Structure Query Language database. Results were analyzed according to reason for most recent ravel: immigration (including refugee); tourism; business; missionary/volunteer/research and aid work; visiting friends and relatives; and other, which included students, military personnel and medical tourists. RESULTS During the study period, 6639 patients presented to CanTravNet sites across Canada and 1076 (16.2%) received a travel-related primary dermatologic diagnosis. Arthropod bites (n = 162, 21.5%), rash (n = 141, 18.7%), cutaneous larva migrans (n = 98, 13.0%), and skin and soft tissue infection (n = 92, 12.2%) were the most common dermatologic diagnoses or diagnostic bundles issued to returning Canadian tourists (n = 754, 70.1% of total sample). Patients travelling for the purpose of immigration (n = 63, 5.9%) were significantly more likely to require inpatient management of their dermatologic diagnoses (p

We thank Dr. Jansz[1][1] for his interest in our surveillance report.[2][2] We recognize that understanding the intricacies of the CanTravNet data would be difficult without first-hand experience of our network and its patient population. CanTravNet is a consortium of post-travel (not pretravel)

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.

Background International travelers were at risk of acquiring influenza A(H1N1)pdm09 (H1N1pdm09) virus infection during travel and importing the virus to their home or other countries. Methods Characteristics of travelers reported to the GeoSentinel Surveillance Network who carried H1N1pdm09 influenza virus across international borders into a receiving country from April 1, 2009, through October 24, 2009, are described. The relationship between the detection of H1N1pdm09 in travelers and the level of H1N1pdm09 transmission in the exposure country as defined by pandemic intervals was examined using analysis of variance (anova). Results Among the 203 (189 confirmed; 14 probable) H1N1pdm09 case-travelers identified, 56% were male; a majority, 60%, traveled for tourism; and 20% traveled for business. Paralleling age profiles in population-based studies only 13% of H1N1pdm09 case-travelers were older than 45 years. H1N1pdm09 case-travelers sought pre-travel medical advice less often (8%) than travelers with non-H1N1pdm09 unspecified respiratory illnesses (24%), and less often than travelers with nonrespiratory illnesses (43%; p

Background: International travel continues to increase, particularly to Asia and Africa. Clinicians are increasingly likely to be consulted for advice before travel or by ill returned travelers. Objective: To describe typical diseases in returned travelers according to region, travel reason, and patient demographic characteristics; describe the pattern of low-frequency travel-associated diseases; and refine key messages for care before and after travel. Design: Descriptive, using GeoSentinel records. Setting: 53 tropical or travel disease units in 24 countries. Patients: 42 173 ill returned travelers seen between 2007 and 2011. Measurements: Frequencies of demographic characteristics, regions visited, and illnesses reported. Results: Asia (32.6%) and sub-Saharan Africa (26.7%) were the most common regions where illnesses were acquired. Three quarters of travel-related illness was due to gastrointestinal (34.0%), febrile (23.3%), and dermatologic (19.5%) diseases. Only 40.5% of all ill travelers reported pretravel medical visits. The relative frequency of many diseases varied with both travel destination and reason for travel, with travelers visiting friends and relatives in their country of origin having both a disproportionately high burden of serious febrile illness and very low rates of advice before travel (18.3%). Life-threatening diseases, such as Plasmodium falciparum malaria, melioidosis, and African trypanosomiasis, were reported. Limitations: Sentinel surveillance data collected by specialist clinics do not reflect healthy returning travelers or those with mild or self-limited illness. Data cannot be used to infer quantitative risk for illness. Conclusion: Many illnesses may have been preventable with appropriate advice, chemoprophylaxis, or vaccination. Clinicians can use these 5-year GeoSentinel data to help tailor more efficient pretravel preparation strategies and evaluate possible differential diagnoses of ill returned travelers according to destination and reason for travel. Primary Funding Source: Centers for Disease Control and Prevention. Accepted version

To describe patient characteristics and disease spectrum among foreign visitors to Haiti before and after the 2010 earthquake, we used GeoSentinel Global Surveillance Network data and compared 1 year post-earthquake versus 3 years pre-earthquake. Post-earthquake travelers were younger, predominantly from the United States, more frequently international assistance workers, and more often medically counseled before their trip than pre-earthquake travelers. Work-related stress and upper respiratory tract infections were more frequent post-earthquake; acute diarrhea, dengue, and Plasmodium falciparum malaria were important contributors of morbidity both pre- and post-earthquake. These data highlight the importance of providing destination- and disaster-specific pre-travel counseling and post-travel evaluation and medical management to persons traveling to or returning from a disaster location, and evaluations should include attention to the psychological wellbeing of these travelers. For travel to Haiti, focus should be on mosquito-borne illnesses (dengue and P. falciparum malaria) and travelers' diarrhea.

Using the GeoSentinel database, an analysis of ill patients returning from throughout sub-Saharan Africa over a 13-year period was performed. Systemic febrile illness, dermatologic, and acute diarrheal illness were the most common syndromic groupings, whereas spotted fever group rickettsiosis was the most common individual diagnosis for travelers to South Africa. In contrast to the rest of sub-Saharan Africa, only six cases of malaria were documented in South Africa travelers. Vaccine-preventable diseases, typhoid, hepatitis A, and potential rabies exposures were uncommon in South Africa travelers. Pre-travel advice for the travelers to the 2010 World Cup should be individualized according to these findings.

Among ill returned travelers to Schistosoma-endemic areas reported to the GeoSentinel Surveillance Network over a decade 410 schistosomiasis diagnoses were identified: 102 Schistosoma mansoni, 88 S. haematobium, 7 S. japonicum, and 213 Schistosoma unknown human species. A total of 83% were acquired in Africa. Unlike previous large case series, individuals born in endemic areas were excluded. Controlling for age and sex, those traveling for missionary or volunteer work, or as expatriates were more likely to be diagnosed with schistosomiasis. Sixty-three percent of those with schistosomiasis presented within six months of travel. Those seen early more often presented with fever and respiratory symptoms compared with those who presented later. One-third of patients with schistosomiasis were asymptomatic at diagnosis. Half of those examined for schistosomiasis were diagnosed with infection. Screening for schistosomiasis should be encouraged for all potentially exposed travelers and especially for missionaries, volunteers, and expatriates.

A family is planning a safari that includes 3 days in Cape Town, 3 days in Kruger National Park, South Africa, and 3 days in Victoria Falls, Zambia. The 31-year-old husband takes no medications, but recently he discontinued fluoxetine for depression. His 29-year-old wife is healthy and 15 weeks pregnant. Their 7-year-old child is in good health. How should the risk and prevention of malaria be managed in this family?

Selected data collected for travelers to China from 1998 through November 2007 by the GeoSentinel Surveillance Network were used to provide an evidence base for prioritizing recommendations for Olympic and other future travelers to China. Respiratory illness and injuries were common among patients seen during their travel; acute diarrhea and dog bites were common among those seen after travel. Tropical and parasitic diseases were rare. Pre-travel consultation for China travelers should be individualized according to these findings.

Providing optimal pretravel advice requires travel medicine practitioners to perform an epidemiologic and host‐related risk assessment so that preventive measures can be appropriately prioritized for each traveler.1,2 Individual host characteristics and itinerary details must be considered to properly balance the efficacy, side effects, and costs of various interventions against estimates of the incidence and severity of the disease(s) they can prevent. Most preventable travel‐related diseases are associated with relatively low risks, generally of the order of 1 of 100,000 to 100 of 100,000. Consequently, decisions regarding intervention measures that minimize risks will depend on the risk threshold, such that diseases with poor or fatal outcomes will undoubtedly be associated with less tolerance of even small risks than diseases leading to only mild morbidity. The patient’s own perception of risk and their attitude toward the reassurance provided by the intervention measure versus its potential side effects or costs is also a vital consideration when tailoring individual pretravel advice. Research providing data on the risk factors for specific adverse health outcomes during travel enables high‐risk travelers to be identified and preventive measures to be optimally targeted.1 In addition to benefiting risk management in the individual traveler, improved understanding of the health risks faced according to individual traveler characteristics and itineraries and up‐to‐date data regarding the epidemiology of specific infections also provide guidance regarding possible differential diagnoses following travel to specific areas. This facilitates assessment and quantification of disease risks if a traveler returns with an illness and helps guide diagnostic measures and rapid empiric treatment interventions. Reliable data regarding the burden of travel‐related illness also have the potential for significant public health impact by facilitating the recognition and limitation of disease transmission across international borders. Until recently, the evidence base for travel recommendations has largely relied on case reports, case … Corresponding Author: Dr Karin Leder, FRACP, Department of Epidemiology and Preventive Medicine, Monash University, Alfred Hospital, Melbourne 3004, Victoria, Australia. E‐mail: karin.leder{at}med.monash.edu.au

Fil: Heymann, David L. London School of Hygiene & Tropical Medicine; Reino Unido. The Royal Institute of International Affairs; Reino Unido Fil: Hodgson, Abraham. Ghana Health Service; Ghana Fil: Sall, Amadou Alpha. Senegal Institut Pasteur de Dakar; Senegal Fil: Freedman, David O. University of Alabama at Birmingahm; Estados Unidos Fil: Staples, J Erin. Centers for Disease Control and Prevention; Estados Unidos Fil: Althabe, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Efectividad Clínica y Sanitaria; Argentina Fil: Baruah, Kalpana. Ministry of Health and Family Welfare; India Fil: Mahmud, Ghazala. Quaid i Azam University; Pakistán Fil: Kandun, Nyoman. Ministry of Health; Indonesia Fil: Vasconcelos, Pedro F C. Evandro Chagas Institute; Brasil Fil: Bino, Silvia. Institute of Public Health; Albania Fil: Menon, K U. Ministry of Communications and Information; Singapur

BACKGROUND Approximately 8 percent of travelers to the developing world require medical care during or after travel. Current understanding of morbidity profiles among ill returned travelers is based on limited data from the 1980s. METHODS Thirty GeoSentinel sites, which are specialized travel or tropical-medicine clinics on six continents, contributed clinician-based sentinel surveillance data for 17,353 ill returned travelers. We compared the frequency of occurrence of each diagnosis among travelers returning from six developing regions of the world. RESULTS Significant regional differences in proportionate morbidity were detected in 16 of 21 broad syndromic categories. Among travelers presenting to GeoSentinel sites, systemic febrile illness without localizing findings occurred disproportionately among those returning from sub-Saharan Africa or Southeast Asia, acute diarrhea among those returning from south central Asia, and dermatologic problems among those returning from the Caribbean or Central or South America. With respect to specific diagnoses, malaria was one of the three most frequent causes of systemic febrile illness among travelers from every region, although travelers from every region except sub-Saharan Africa and Central America had confirmed or probable dengue more frequently than malaria. Among travelers returning from sub-Saharan Africa, rickettsial infection, primarily tick-borne spotted fever, occurred more frequently than typhoid or dengue. Travelers from all regions except Southeast Asia presented with parasite-induced diarrhea more often than with bacterial diarrhea. CONCLUSIONS When patients present to specialized clinics after travel to the developing world, travel destinations are associated with the probability of the diagnosis of certain diseases. Diagnostic approaches and empiric therapies can be guided by these destination-specific differences.

The paper by Jelinek and colleagues1 in this issue examines the short-term immunogenicity of an accelerated Vero cell-derived Japanese encephalitis vaccine (JE-VC) regimen administered at Days 1 and 8. This regimen is compared with the conventional Days 1 and 29 administration schedule;2 this latter interval frustrates many pre-travel advisors who well know of the high proportion of travelers presenting in close proximity to departure. In an increasingly fast-paced world, this study addresses part of a long-standing larger desire to prepare all travelers for their trips if there is only a week to do so prior to departure. With much of the adult population in many countries already immunized against hepatitis B,3 the remaining usual travel vaccines that require more than a single dose are then restricted to Japanese encephalitis and rabies. It is a well-established principle of vaccinology that once you find an appropriate vaccine antigen and if you administer a large quantity of antigen in a single dose or multiple doses very quickly, you will get an antibody response, and often at very high-titers, very rapidly.4,5 The issue then becomes how long that antibody response will last at protective levels. Conventional vaccine regimens are typically designed to give a durable antibody response, ideally for life, or at least for an interval of several years before boosting is required. … Corresponding Author: David O. Freedman, MD, W.C. Gorgas Center for Geographic Medicine, Division of Infectious Diseases, University of Alabama at Birmingham, 845 19th St. S. #203, Birmingham, AL 35294-2170, USA. E-mail: dfreedman{at}shoreland.com

Background Sexual behavior of travelers to Latin America and the sexual behavior of US travelers in general are poorly characterized. Goal The goal of the study was to evaluate sexual risk factors of travelers to Peru. Study design Anonymous written questionnaires were administered to 442/507 (87%) of the individuals approached in the international departures area of the Lima airport. Results Of the 442 respondents, 54 (12.2%) had new sex partners during their stay. Sex with a local partner (35/52; 67.3%) was more frequent than sex with other travelers (18/52; 34.6%) or with sex workers (4/52; 7.7%). Risk factors for a new sex partner included male sex (relative risk, 1.94), single marital status (relative risk, 2.59), duration of stay longer than 30 days (relative risk, 5.05), traveling alone or with friends (relative risk, 2.88), and bisexual orientation (relative risk, 4.94). Frequency of sexual activity among US travelers was greater than that among travelers from other countries (15.2% [22/145] versus 10.6% [30/282]; NS). Condoms were consistently used by 12/50 (24%) and sometimes used by 10/50 (20%), including 8/20 United States travelers and 13/29 travelers from other countries. Conclusion Behaviors and risk factors are similar to those described for travelers to Africa, Asia, and Eastern Europe. Behavior of US travelers did not differ from that of other travelers.

Important gaps remain in our knowledge of the infectious diseases people acquire while travelling and the impact of pathogens imported by Canadian travellers.To provide a surveillance update of illness in a cohort of returned Canadian travellers and new immigrants.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.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%; p0.0001) and those travelling to visit friends and relatives versus those travelling for other reasons (12.1% versus 2.4%; p0.0001). 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.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.

In 1998, the Centers for Disease Control and Prevention was notified of severe illnesses and one death, temporally associated with yellow fever (YF) vaccination, in two elderly U.S. residents. Because the cases were unusual and adverse events following YF vaccination had not been studied, we estimated age-related reporting rates for systemic illness following YF vaccination. We found that the rate of reported adverse events among elderly vaccinees was higher than among vaccinees 25 to 44 years of age. We also found two additional deaths among elderly YF vaccinees. These data signal a potential problem but are not sufficient to reliably estimate incidence rates or to understand potential underlying mechanisms; therefore, enhanced surveillance is needed. YF remains an important cause of severe illness and death, and travel to disease-endemic regions is increasing. For elderly travelers, the risk for severe illness and death due to YF infection should be balanced against the risk for systemic illness due to YF vaccine.

BACKGROUND Single dose diethylcarbamazine (DEC) as used in control programmes is effectively microfilaricidal for periods of up to a year or more but has incomplete ability to kill Wuchereria bancrofti adult parasites. These regimens can be effective in breaking transmission by suppression of circulating microfilariae available to mosquito vectors. Whether prolonged or aggressive therapy with DEC has a significant effect on adult worms, which may live up to 12 years or more, and is important in the context of the treatment of individual patients, is still incompletely understood. METHODS METHODS In order to investigate the adulticidal effect of aggressive therapy, DEC was given at 6 mg/kg/day for 12-day courses at 0, 6, 12, and 18 months and Og4C3 antigenaemia followed over two years in 38 CAg + Brazilians in a W. bancrofti endemic area. RESULTS RESULTS At two year follow-up, the median level of antigenaemia was 21% of the pre-treatment value. 92% of individuals had antigen levels < 50% of pretreatment values, but only 26% had completely cleared antigenaemia. The clearance rate at 24 months was only 12% (3/26) in the asymptomatic CAg + patients but 58% (7/12) in those with clinical manifestations of filariasis. The latter individuals cleared significantly more antigen (median of 0% pretreatment antigenaemia vs. 26%; Pa 0.02) than asymptomatic but infected individuals. CONCLUSION CONCLUSION Aggressive repeated therapy with DEC alone is ineffective in consistently eradicating adult W. bancrofti, especially in infected but asymptomatic individuals. Prolonged courses of combination therapy with other antifilarial drugs should be investigated for treatment of individual patients with the means to pursue aggressive personal medical care.

A study was conducted in Lima, Peru to determine if patients with Strongyloides hyperinfection had human T cell lymphotropic virus type-1 (HTLV-I) infection. The study included patients with Strongyloides hyperinfection and a control group consisted of sex- and age-matched asymptomatic healthy individuals whose stools were negative for Strongyloides. A third group included patients with intestinal strongyloidiasis. Sera from each study subject were tested for HTLV-1/2I by an ELISA and Western blot. The HLTV-1 infection rates (85.7%, 18 of 21) were significantly (P0.001) associated with Strongyloides hyperinfection compared with the control group (4.7%, 1 of 21). The HTLV-1 rate (10%, 6 of 62) for patients with intestinal strongyloidiasis was significantly (P0.001) lower than patients with Strongyloides hyperinfection, but did not differ significantly (P0.05) from the control group. The association of HTLV-1 infection was observed among 17 of 19 patients more than 20 years of age and one of two younger patients. None had HTLV-2 infection. In conclusion, Strongyloides hyperinfection among Peruvian patients was highly associated with HTLV-1 infection.

As travel medicine practices expand and multiply, practitioners increasingly need to be familiar with constantly changing disease epidemiology and drug resistance patterns in over 220 different countries. Nowadays, keeping current means utilizing the wide array of resources available on the internet. This article contains background information on the most relevant travel medicine-oriented Internet sites and provides their universal resource locators in a convenient table.

In 2012, the number of international tourist arrivals worldwide was projected to reach a new high of 1 billion arrivals, a 48% increase from 674 million arrivals in 2000. International travel also is increasing among U.S. residents. In 2009, U.S. residents made approximately 61 million trips outside the country, a 5% increase from 1999. Travel-related morbidity can occur during or after travel. Worldwide, 8% of travelers from industrialized to developing countries report becoming ill enough to seek health care during or after travel. Travelers have contributed to the global spread of infectious diseases, including novel and emerging pathogens. Therefore, surveillance of travel-related morbidity is an essential component of global public health surveillance and will be of greater importance as international travel increases worldwide.September 1997-December 2011.GeoSentinel is a clinic-based global surveillance system that tracks infectious diseases and other adverse health outcomes in returned travelers, foreign visitors, and immigrants. GeoSentinel comprises 54 travel/tropical medicine clinics worldwide that electronically submit demographic, travel, and clinical diagnosis data for all patients evaluated for an illness or other health condition that is presumed to be related to international travel. Clinical information is collected by physicians with expertise or experience in travel/tropical medicine. Data collected at all sites are entered electronically into a database, which is housed at and maintained by CDC. The GeoSentinel network membership program comprises 235 additional clinics in 40 countries on six continents. Although these network members do not report surveillance data systematically, they can report unusual or concerning diagnoses in travelers and might be asked to perform enhanced surveillance in response to specific health events or concerns.During September 1997-December 2011, data were collected on 141,789 patients with confirmed or probable travel-related diagnoses. Of these, 23,006 (16%) patients were evaluated in the United States, 10,032 (44%) of whom were evaluated after returning from travel outside of the United States (i.e., after-travel patients). Of the 10,032 after-travel patients, 4,977 (50%) were female, 4,856 (48%) were male, and 199 (2%) did not report sex; the median age was 34 years. Most were evaluated in outpatient settings (84%), were born in the United States (76%), and reported current U.S. residence (99%). The most common reasons for travel were tourism (38%), missionary/volunteer/research/aid work (24%), visiting friends and relatives (17%), and business (15%). The most common regions of exposure were Sub-Saharan Africa (23%), Central America (15%), and South America (12%). Fewer than half (44%) reported having had a pretravel visit with a health-care provider. Of the 13,059 diagnoses among the 10,032 after-travel patients, the most common diagnoses were acute unspecified diarrhea (8%), acute bacterial diarrhea (5%), postinfectious irritable bowel syndrome (5%), giardiasis (3%), and chronic unknown diarrhea (3%). The most common diagnostic groupings were acute diarrhea (22%), nondiarrheal gastrointestinal (15%), febrile/systemic illness (14%), and dermatologic (12%). Among 1,802 patients with febrile/systemic illness diagnoses, the most common diagnosis was Plasmodium falciparum malaria (19%). The rapid communication component of the GeoSentinel network has allowed prompt responses to important health events affecting travelers; during 2010 and 2011, the notification capability of the GeoSentinel network was used in the identification and public health response to East African trypanosomiasis in Eastern Zambia and North Central Zimbabwe, P. vivax malaria in Greece, and muscular sarcocystosis on Tioman Island, Malaysia.The GeoSentinel Global Surveillance System is the largest repository of provider-based data on travel-related illness. Among ill travelers evaluated in U.S. GeoSentinel sites after returning from international travel, gastrointestinal diagnoses were most frequent, suggesting that U.S. travelers might be exposed to unsafe food and water while traveling internationally. The most common febrile/systemic diagnosis was P. falciparum malaria, suggesting that some U.S. travelers to malarial areas are not receiving or using proper malaria chemoprophylaxis or mosquito-bite avoidance measures. The finding that fewer than half of all patients reported having made a pretravel visit with a health-care provider indicates that a substantial portion of U.S. travelers might not be following CDC travelers' health recommendations for international travel.GeoSentinel surveillance data have helped researchers define an evidence base for travel medicine that has informed travelers' health guidelines and the medical evaluation of ill international travelers. These data suggest that persons traveling internationally from the United States to developing countries remain at risk for illness. Health-care providers should help prepare travelers properly for safe travel and provide destination-specific medical evaluation of returning ill travelers. Training for health-care providers should focus on preventing and treating a variety of travel-related conditions, particularly traveler's diarrhea and malaria.