Travel-related Diseases Research Articles

Morbidity among child travellers with sickle-cell disease visiting tropical areas: an observational study in a French tertiary care centre

ObjectiveTo examine morbidity among children with sickle-cell disease (SCD) during and after travel to a tropical area.DesignObservational study.SettingTertiary care children; Robert Debré Hospital, Paris, France.PopulationChildren with SCD younger than 18...

Babesia microti:an unusual travel-related disease

BackgroundHuman babesiosis is a rare tick-borne infectious disease. The clinical presentation ranges from an asymptomatic form to a life threatening infection with severe hemolysis. Human babesiosis due to Babesia microti is the most common and is endemic in North America.Case presentationWe report a European patient with severe pancytopenia and reactive hemophagocytosis related to a Babesia microti infection. Babesia infection was acquired during a travel in the USA.ConclusionBabesiosis should be considered in patients who traveled in endemic areas, especially North America for the most common agent Babesia microti.

An Imported Dengue Fever Case in Turkey and Review of the Literature

Dengue fever is an acute viral disease that can affect all age groups in tropical and subtropical countries. The predominant vectors are the mosquitoes namely Aedes aegypti and A.albopictus. Although there have been no case reports in Turkey due to DF, there is seroepidemiological evidence indicating the presence of Dengue virus (DENV) in Turkey. In this case report we presented an imported dengue fever case. The patient was 40 years old, previously healthy male, Switzerland citizen. He had immigrated from Dubai to India two weeks ago and after one week from immigration he attended to a hospital in India because of high fever. The NS1 antigen test (Bio-Rad Laboratories, USA) was found positive and the patient was followed-up with diagnosis of dengue fever in India. During his visit to Turkey, he attended to the hospital for a routine control and his analysis revealed thrombocytopenia (PLT: 48.000/µl), leukopenia (white blood cell: 2800/µL) and elevated liver enzymes (AST: 76 U/L, ALT: 83 U/L). Fever was not detected in follow-up. The patient had petechial rash on his lower extremities. white blood cell and PLT count increased to 4100/µl and 93.000/µl, respectively. Liver function tests revealed a decrease in AST (63 U/L) and ALT (78 U/L) on the third day. The PLT count increased to 150.000/ml. Since the patient had no fever and had normal physical and laboratory findings, he was discharged from the hospital. For the confirmation of dengue fever diagnosis the serum sample was sent to National Public Health Center, Virology Reference and Research Laboratory where IgM and IgG antibodies against DENV types 1-4 were investigated by indirect immunofluorescence method (Euroimmun, Germany). The serum sample yielded positive result at the dilutions of 1/1000 for IgM and 1/10.000 for IgG. The last dilution of type 3 DENV IgM and IgG were determined high density of fluorescein, thus the serotype was identified as "DENV type 3". Travel-related diseases become important with increasing travel opportunities, globalization and transportation, recently. As a result, this imported case with foreign nationality was the first dengue fever case confirmed by clinical and laboratory tests in Turkey.

Travel to Tropical Countries: A Review of Travel-Related Infectious Diseases

Travel to Tropical Countries: A Review of Travel-Related Infectious Diseases

Travel and transplantation

Travel-related diseases may be seen in transplant recipients after travel, after transplant tourism, and via transmission from blood and organ donors, augmented by recent increases in travel, migration, and globalization. Such infections include tuberculosis, Plasmodium (malaria), Babesia, Trypanosoma cruzi (Chagas disease), Strongyloides, Coccidioides, Histoplasma, Leishmania, Brucella, HTLV, dengue, among numerous others. Review of cohorts of transplant recipients show that they tend to have minimal or suboptimal preparation prior to travel, with limited pretravel vaccination, medications, and education, which poses a greatly increased risk of travel-related infections and complications. The epidemiology of such travel-related infections in transplant recipients, along with methods for prevention, including vaccines, chemoprophylaxis, and education may help SOT recipients avoid travel-related infections, and are discussed in this review. Optimizing the understanding of the risk of tropical, geographically restricted, and other unusual or unexpected, travel-related infections will enhance the safety of vulnerable transplant recipients from potentially life-threatening infections.

Prevention of travel-related foodborne diseases: Microbiological risk assessment of food handlers and ready-to-eat foods in northern Italy airport restaurants

The focus of this study was to assess the hygienic standards of 44 foodservice facilities located in three Italian International Airports (with an output ranging from 100 to 800 meals a day), by monitoring the microbiological quality and safety of foods ready for consumption (n = 773), food contact surfaces (n = 302), and food handlers (n = 287). The hygienic standard of surfaces was sufficiently high. Only 7.9% of surfaces did not conform with advisory standards in terms of total coliforms, and 2.6% were found to be contaminated with Enterococcus spp. at ≥1.0 log10 CFU/cm2. The hygienic standard of washed and disinfected hands of food workers was not adequately high: the total bacterial count and coagulase positive Staphylococci exceeded the satisfactory limit in 8.4% and 3.5% of cases, respectively. The microbial analysis of foods examined showed an absence of Listeria monocytogenes and Salmonella spp. Food sample analyses highlighted a percentage of samples that did not conform to microbial reference standards: Staphylococcus aureus non-conforming percentages ranged from 2.3% for “fully cooked food” to 9.2% for “raw fruit and vegetables”; Escherichia coli, from 0.0% for “raw fruit and vegetables” to 6.1% for “cooked and uncooked foods”; total coliforms from 14.3% for “fully cooked food” to 79.8% for “cooked and uncooked food”. In conclusion, the results suggest that more effort is needed in the application of HACCP principles. In order to prevent travel-related foodborne infections, various changes in the timing of food preparation and holding temperatures are needed, together with further training of food handlers.

Profile of Travel‐Associated Illness in Children, Zürich, Switzerland

The number of families traveling with their children to their country of origin and/or to tropical destinations has increased in Switzerland and includes a changing profile and multinational range of patients. Defining the profile of reported travel-associated illnesses will help to improve the prevention and treatment of such illnesses in children. This study includes children aged up to 16 years who sought medical advice for a presumed travel-related illness at the emergency room of the University of Zürich Children's Hospital during the period July 2007 to December 2008. We analyzed data on 328 children (58.8% male, mean age: 4.62 y) who presented with travel-associated illness. Our analysis included 155 traditional (mainly tourist) travelers, 162 children who were visiting friends and relatives (VFR), and 11 immigrants. Some 11% were hospitalized. No deaths occurred. The main conditions recorded were diarrheal illness (39%), respiratory (28.7%) and febrile/systemic illness (13.4%). With increasing age, the proportion of children with diarrheal disease increased, while the proportion with respiratory illness declined. There were significant associations between geographic area of exposure and the profile of travel-related disease (p < 0.001). Among 36 children with more serious diseases requiring hospitalization, 12 (3.7% overall) presented with potentially serious diseases: malaria (n = 2), Salmonella typhi (n = 3), Salmonella paratyphi (n = 2), meningococcal meningitis (n = 1), tuberculosis (n = 2), visceral leishmania (n = 1), and hepatitis A (n = 1). Eleven of the 12 children presenting with these potentially serious illnesses were VFR or immigrant children. The main diagnoses for ill-returned Zürich children who presented for emergency care were diarrhea, respiratory, and febrile/systemic illness. A broad spectrum of morbidity was seen including meningococcal meningitis, malaria, tuberculosis, typhoid fever, leishmania, and hepatitis A. Diagnoses varied between geographic regions visited, and VFR child travelers constituted a large proportion of sick-returned children presenting for emergency care.

Health Risks of Travelers With Medical Conditions—A Retrospective Analysis

Traveling the world may result in infection with tropical or other travel-associated diseases. This applies increasingly also to people with immune-compromising and other medical conditions, as well as to elderly individuals. To reduce exposure and susceptibility to health risks, there is a need for appropriate pre-travel advice for these particular groups of travelers. In this observational study, we analyzed the overall risk of health problems among travelers with underlying medical conditions who attended the University of Amsterdam's Academic Medical Center's (AMC) travel clinic from January to October 2010. Telephone questionnaires were administered to 345 travelers with underlying conditions and 100 healthy travelers. The most common underlying medical conditions studied included: (1) diabetes mellitus; (2) impaired immunity due to use of immune-suppressing medication; (3) reduced gastric barrier; and (4) HIV infection. The overall incidence of travel-related diseases (TRDs) was higher among those patients with underlying medical conditions compared to healthy travelers [incidence rate ratio (IRR) 2.26, 95% CI (1.29-3.98)]. Of all diseases reported, gastrointestinal disease, fever, and respiratory problems were reported most frequently. Travel to Central America, South Central Asia, Northeast Asia, and North Africa was associated with increased risk of contracting TRD. Hepatitis B protection was absent or unknown in 75% of these travelers. Travelers with medical conditions had a higher risk of obtaining TRD, predominantly gastrointestinal in nature.

Travel risk behaviours and uptake of pre-travel health preventions by university students in Australia

BackgroundForward planning and preventative measures before travelling can significantly reduce the risk of many vaccine preventable travel-related infectious diseases. Higher education students may be at an increased risk of importing infectious disease as many undertake multiple visits to regions with higher infectious disease endemicity. Little is known about the health behaviours of domestic or international university students, particularly students from low resource countries who travel to high-resource countries for education. This study aimed to assess travel-associated health risks and preventative behaviours in a sample of both domestic and international university students in Australia.MethodsIn 2010, a 28 item self-administered online survey was distributed to students enrolled at the University of New South Wales, Sydney, Australia. Multiple methods of distributing links to the online survey were utilised. The survey examined the international travel history, travel intentions, infection control behaviours and self-reported vaccination history.ResultsA total of 1663 respondents completed the online survey, 22.1% were international students and 83.9% were enrolled at an undergraduate level. Half had travelled internationally in the previous 12 months, with 69% of those travelling only once during that time with no difference in travel from Australia between domestic and international students (p = 0.8). Uptake of pre-travel health advice was low overall with 68% of respondents reporting they had not sought any advice from a health professional prior to their last international trip. Domestic students were more likely to report uptake of a range of preventative travel health measures compared to international students, including diarrhoeal medication, insect repellent, food avoidance and condoms (P < 0.0001). Overall, students reported low risk perception of travel threats and a low corresponding concern for these threats.ConclusionsOur study highlights the need to educate students about the risk associated with travel and improve preventative health-seeking and uptake of precautionary health measures in this highly mobile young adult population. Although immunisation is not an entry requirement to study at Universities in Australia, large tertiary institutions provide an opportunity to engage with young adults on the importance of travel health and provision of vaccines required for travel, including missed childhood vaccines.

Salmonellosis and charter tourism: epidemiology and trends of imported human cases to Norway from the Canary Islands and Thailand, 1994–2008

More than 70% of reported human Salmonella infections in Norway are infected abroad. The Canary Islands and Thailand are two of the most popular charter tourist destinations for Norwegians. Using surveillance data for the years 1994-2008, and denominator data on travel to the Canary Islands 2000-2008 and to Thailand 1997-2008, we present the epidemiology and trends of Salmonella infections in Norwegian tourists to these destinations. We found a declining trend in risk of salmonellosis in tourists returning from the Canary Islands, and a change in serovar distribution in travellers to Thailand with more S. Enteritidis infections, similar to that observed in Western European countries. The use of denominator data is important when studying risk of travel-related disease, as surveillance data tend to reflect travel activity more than the risk. Infections among tourists do not always affect the local residents and therefore may not be detected by local public health authorities. Sharing knowledge on the epidemiology of infections in tourists could be useful for observation of changes in trends in the countries visited, and in future outbreak investigations.

Travel-associated zoonotic bacterial diseases

Bacterial zoonoses are increasingly described in association with travel. Some bacterial zoonoses constitute important causes of post-travel illness. We focus on leptospirosis and rickettsiosis - the most common travel-associated bacterial zoonoses. Leptospirosis is regarded to be the most common zoonotic disease worldwide. In industrialized countries recreational exposures, both domestic and overseas, are increasingly becoming a major source of infection. Asymptomatic infection is rare among travelers. Rickettsial diseases account for approximately 1.5-3.5% of febrile travelers. In several series of travel-related rickettsioses, the most common travel-related rickettsial disease is Rickettsia africae. Other rickettsioses including Q fever, scrub typhus and murine typhus are considered rare among travelers. Whereas timely diagnosis of both diseases is still based on exposure history, antigen detection tools to aid the diagnosis during the acute illness are under research and far from being available. Due to these constrains, currently, the true incidence of both diseases is probably underestimated. Both leptospirosis and spotted fever may be rapidly fatal. Empiric doxycycline in severely ill febrile travelers should be considered. There is an urgent need for widely available antigen detection diagnostic tools to improve the detection of leptospirosis and rickettsial infections during the acute illness.

Endocrine disruptors, travel-associated illness, and media violence: important health considerations for children and adolescents

This article addresses three important topics that are part of contemporary life for children: endocrine disruptors, hazards of international travel, and the impact of media violence on children and adolescents. Practitioners will learn about phthalates and Bisphenol-A as endocrine disruptors. In published studies, elevated phthalates were associated with an increase in pubertal gynecomastia and premature thelarche. Bisphenol-A was judged by the Food and Drug Administration as having some concern for potential effects on brain, behavior, and prostate gland in fetuses, infants, and young children: hence, the decision to take reasonable steps to reduce exposure of infants. In travel-related diseases, diarrheal disease (primarily Campylobacter and Salmonella), dermatologic conditions (animal bites), systemic febrile illness (malaria and dengue fever), and respiratory illnesses predominate. Children and adolescents spend more than 7 h using media per day. The degree to which media violence can be linked to behavior is not conclusive, but the prevention message for practitioners is important because parents can have an important mitigating effect. Endocrine disruptors, travel-related diseases, and media violence are part of modern day life for our children. Pediatricians need to stay abreast of recent findings and have access to up-to-date resources to assist them in providing contemporary advice and guidance to patients and families.

Mosquito‐Borne Illnesses in Travelers: A Review of Risk and Prevention

In 2008, residents of the United States made 12 million visits to developing countries in Asia, South America, Central America, Oceania, the Middle East, and Africa. Due to the presence of Anopheles, Aedes, and Culex mosquitoes, travel to these destinations poses a risk for diseases such as malaria, yellow fever, and Japanese encephalitis that cause significant morbidity and mortality. To gain a better understanding of the major emerging and established travel-related infectious diseases transmitted principally by mosquitoes and the measures for their prevention in U.S. residents who travel to these developing countries, we performed a literature search of the PubMed and MEDLINE databases (January 1950-February 2010). Information from the Centers for Disease Control and Prevention and the World Health Organization and relevant references from the publications identified were also reviewed. Vaccines for the prevention of Japanese encephalitis and yellow fever are commercially available to U.S. travelers and should be administered when indicated. However, the prevention of malaria, dengue fever, chikungunya, and West Nile virus relies on personal insect protection measures and chemoprophylaxis for malaria. As the rate of international travel continues to rise, individuals traveling overseas should be made aware of the risk of various infectious diseases and the importance of prevention. Physicians, pharmacists, nurses, and other practitioners can play a vital role in disease education and prevention, including the administration of vaccines and provision of chemoprophylactic drugs.

Hepatitis E in Italy: A long-term prospective study

In developed countries, hepatitis E is usually associated with travelling to endemic areas, but a growing number of sporadic cases are also seen in patients with no travel history. The aim of this study was to assess the impact and the molecular epidemiology of hepatitis E in Italy. Between January 1994 and October 2009, we analyzed 651 patients with acute non-A-C hepatitis. Diagnosis of hepatitis E was based on the presence of IgM anti-HEV and/or the detection of HEV RNA by RT-PCR. Viral isolates were sequenced and phylogenetically characterized. A total of 134 out of 651 (20.6%) patients tested had acute hepatitis E. All were anti-HEV IgM and IgG positive and 96 (71.6%) were also positive for HEV RNA. Moreover, 39 (6%) patients were anti-HEV IgG positive but negative for both IgM anti-HEV and HEV RNA. A total of 109 (81.3%) patients developed hepatitis E travelling to endemic areas, 3 (2.3%) acquired intra-familial infection from relatives who developed travel-related disease, while 22 (16.4%) patients denied having travelled abroad. In all patients, acute disease had a self-limited course with ALT normalization within 3-6 weeks. Phylogenetic analysis of 39 isolates from patients with a travel-related disease showed that they belonged to genotype 1, while sequences from five patients with autochthonous hepatitis E belonged to genotype 3. In Italy, most cases of hepatitis E are travel related, caused by viral genotype 1, while autochthonous cases are caused by genotype 3. The prevalence of genotype 3 among pigs and boars suggests that HEV infection may have zoonotic origins in non-endemic countries.

Risk Behaviors and Spectrum of Diseases Among Elderly Travelers: A Comparison of Younger and Older Adults

Elderly travel to the developing world is increasing. Little information is available regarding risk behaviors and health during and after travel in this population. We compared the risk factors and occurrence of travel-related diseases in two populations of Israelis, travelers aged 60 years and older and travelers in the age group of 20 to 30 years. Only people traveling for less than a month were included. Pre-travel, each person received routine counseling regarding travel-associated health risks, was immunized, and given anti-malarial prescriptions as needed. Travelers were surveyed by telephone 6 to 12 months following travel about underlying medical conditions, current medications, and travel history. Risk and preventive behaviors, compliance with anti-malarial prophylaxis, and history of illness during and after travel were assessed. Of patients who visited the clinic from January to June 2008, 191/208 (91%) travelers aged 60 and older and 203/291 (69%) travelers aged 20 to 30 years were contacted by phone and recruited. Fewer elderly travelers drank open drinks, compared to young travelers (8% vs 35%, p < 0.01), and fewer purchased street food compared to young travelers (16.2% vs 37.9%, p < 0.01). More elderly travelers were fully compliant with their anti-malarial chemoprophylaxis regimen (60.7% vs 33.8%, p < 0.01). More elderly travelers took organized tours (61% vs 2%, p < 0.001). Young travelers more often backpacked (50.7% vs 10.4%, p < 0.001). Illness, most commonly diarrhea, was reported by 18.8% of elderly travelers compared to 34.0% of the young travelers (p = 0.001). In a logistic regression model only travel to East Asia (OR 4.66) (95%CI 1.93-11.22) and traveling under basic conditions (OR 1.94) (95% CI 1.42-3.29) remained significantly associated with illness, irrespective of age. Because elderly travelers tend to comply with health-related recommendations better and use less risky travel modes, their risk for illness during travel was lower. Traveling to East Asia and travel mode are associated with illness during travel, irrespective of age.

TB or not TB – Air travel and tuberculosis

Travel is increasingly implicated in the transmission of infectious disease and as travel continues to increase, with 924 million international tourist arrivals recorded in 2008 (decreasing as expected by 4% 880 million in 2009) there are several pertinent travel health issues which require consideration to protect the travelling public, those who work in the travel industry and the public health implications that may ensue with the importation of infectious diseases. Travel by air is one of the most common forms of transport which enables the ease of travel across continents. Aeroplanes are increasing in size in order to accommodate more passengers and they are able to dispatch travellers to their chosen destination even more quickly before and within the incubation period of many infectious diseases in particular, those which are respiratory in nature. One only has to recall the impact of avian influenza and of course, H1N1 pandemic influenza on public health worldwide to understand the importance and indeed requirement for guidelines on prevention of infectious disease associated with travel. The speciality of travel medicine has grown from and considerably since the historical days of the Quarantine and International Health Regulations and it is now recognised as an essential partner in the prevention of travel-related disease alongside the International Health Regulations (WHO). History records the conventional methods applied to prevent the international spread of infectious disease such as cholera in the 19th century, which included establishing border controls to prevent people (or travellers) as well as the transport of merchandise from crossing borders. The International Health Regulations (IHR) under the auspices of the World

Characteristics and risk factors for symptomatic Giardia lamblia infections in Germany.

BackgroundIn developed countries, giardiasis is considered a travel related disease. However, routine surveillance data from Germany indicate that >50% of infections were acquired indigenously. We studied the epidemiological characteristics of symptomatic Giardia infections acquired in Germany and abroad, and verified the proportion of cases acquired in Germany in order to investigate risk factors for sporadic autochthonous Giardia infections.MethodsWe identified Giardia cases notified by 41 local health authorities between February 2007 and January 2008 and interviewed them on their clinical symptoms, underlying morbidities, travel abroad and potential risk factors for the disease. We conducted a case-control-study including laboratory-confirmed (microscopy or antigen-test) autochthonous Giardia cases with clinical manifestations (diarrhoea, cramps, bloating) and randomly selected controls from the local population registry matched by county of residence and age-group (0-5, 6-19, ≥20 years). Secondary cases, controls with diarrhoea and persons who had travelled outside Germany in the three weeks prior to disease onset (exposure period) were excluded. We calculated adjusted odds ratios (aOR) with 95% confidence intervals (CI) using conditional logistic regression.ResultsOf 273 interviewed cases, 131 (48%) had not travelled abroad during the defined exposure period. Of these 131, 85 (65%) were male, 68 (54%) were living in communities with >100,000 inhabitants and 107 (83%) were aged 20 years or older. We included 120 cases and 240 controls in the case-control study. Cases were more likely to be male (aOR 2.5 CI 1.4-4.4), immunocompromised (aOR 15.3 CI 1.8-127) and daily consumers of green salad (aOR 2.9 CI 1.2-7.2). Contact with animals (pets/farm animals) and exposure to surface water (swimming/water sports) were not associated with symptomatic disease.ConclusionsA substantial proportion of Giardia lamblia cases in Germany are indigenously acquired. Symptomatic cases are significantly more likely to be immunocompromised than control persons from the general population. Physicians should consider Giardia infections among patients with no recent history of travel abroad, particularly if they have immune deficiencies. Green salads may be an important vehicle of infection. Information campaigns highlighting this food-borne risk should emphasise the risk to persons with immune deficiencies.

Multicenter EuroTravNet/GeoSentinel Study of Travel-related Infectious Diseases in Europe

We analyzed prospective data on 17,228 European patients who sought treatment at GeoSentinel sites from 1997 to 2007. Gastrointestinal illness (particularly in tourists), fever (those visiting friends and relatives [VFRs]), and skin disorders (in tourists) were the most common reasons for seeking medical care. Diagnoses varied by country of origin, region visited, or categories of travelers. VFRs who returned from sub-Saharan Africa and Indian Ocean islands were more likely to experience falciparum malaria than any other group. Multiple correspondence analysis identified Italian, French, and Swiss VFRs and expatriate travelers to sub-Saharan Africa and Indian Ocean Islands as most likely to exhibit febrile illnesses. German tourists to Southeast and south-central Asia were most likely to seek treatment for acute diarrhea. Non-European travelers (12,663 patients from other industrialized countries) were less likely to acquire certain travel-associated infectious diseases. These results should be considered in the practice of travel medicine and development of health recommendations for European travelers.

Global health surveillance and travelersʼ health

Monitoring disease trends among travelers can inform both pretravel advice and posttravel management. Data from sentinel travelers upon their return to medically sophisticated environments can also benefit local populations in resource-limited countries. Provider-based surveillance of travelers is increasingly sophisticated. Recently, networks such as GeoSentinel have provided cumulative trends in travel-related illness to assess pretravel risk for a mass gathering event--the Beijing Olympic Games. Data provided by the GeoSentinel also helped in determining the seasonality of dengue by region of travel and risk of acquiring schistosomiasis after a single short exposure. For chikungunya fever, detailed study of returned travelers exposed new clinical aspects of a disease previously studied in the tropics only. Clusters of hepatitis A, a vaccine-preventable disease, among European travelers, illustrated continued gaps in the preparation of the traveling public. Plasmodium knowlesi has emerged as the fifth human malaria parasite and is now a consideration in the diagnosis of febrile travelers from Asia. Automated global news scanning software is increasingly being able to detect and prioritize disease events. Every year millions of travelers visit countries where they are exposed to pathogens that are usually rare in their home countries. Global surveillance of travel-related disease represents a powerful tool for the detection of infectious diseases. These data should encourage clinicians to take a detailed travel history during every patient encounter.

Epidemic intelligence and travel-related diseases: ECDC experience and further developments

The European Centre for Disease Prevention and Control (ECDC) started to work on information gathering for early detection of public health threats in June 2005. Since then, based on a framework including events and data-based surveillance, EDCD has been learning by doing. The internal tools and procedures for epidemic intelligence (EI) were developed while screening signals. Information including relevant epidemiological data, media news detected and actions taken are recorded in a specific event information system (Threat Tracking Tool). We describe the main elements, process and outputs of EI activities at ECDC. We also describe the main results regarding travel-related diseases. Efforts are needed to better identify and gather information about travellers coming to the EU with imported diseases with a potential for further spread inside our territory.