GeoSentinel surveillance of illness in returned travelers, 2007-2011

Travel to malaria-endemic areas: using digital geo-location to assess potential exposure risks and health behaviours

BACKGROUND

Travellers frequently visit popular destinations like Brazil, India, Peru, Thailand and Tanzania, each presenting varying malaria risks. The extent to which travellers enter high-risk malaria-endemic areas in destinations with heterogeneous malaria risk remains unclear. We used geo-location via a smartphone application to (i) describe where travellers go within countries with heterogeneous malaria risk (Brazil, India, Peru, Thailand) and (ii) compare mosquito bite prevention behaviours between these destinations and Tanzania, considered entirely high risk for malaria.

METHODS

This analysis is a sub-study of the Tracking of Urgent Risks in Swiss Travellers (TOURIST2) cohort, which prospectively recruited 1000 travellers (≥18 years, travelling ≤4 weeks) from Swiss travel clinics (Zurich and Basel) between September 2017 and April 2019. We included 734 travellers to Brazil, India, Peru, Thailand and Tanzania who provided geo-location data. Daily health and geo-location data were collected using a smartphone application. Malaria risk was categorized using 2022 malaria maps from the Swiss Expert Committee for Travel Medicine.

RESULTS

Of the 734 travellers, 525 travelled to Brazil, India, Peru and Thailand and 225 to Tanzania. In Brazil, India, Peru and Thailand, only 2% (n = 13) visited high-risk malaria areas. In Peru, 4% (n = 4) visited a high-risk area; in Brazil, 3% (n = 6); in Thailand, 2% when crossing the border into Myanmar (n = 3); and in India, 0%. Travellers to high-risk areas were more often male (62%), slightly older (median age 42.0) and planned longer trips (median 23.0 days) than other travellers. No participants were diagnosed with malaria. Travellers to Brazil, India, Peru and Thailand used mosquito bite prevention measures less frequently than travellers to Tanzania. Those in Tanzania had higher, but still suboptimal, use of insect spray (65% of travel days).

CONCLUSIONS

Travellers to Brazil, India, Peru and Thailand rarely visited high-risk malaria areas, and their adherence to mosquito bite prevention measures was generally low. In Tanzania, adherence was higher but still suboptimal.

The impact of climate change on travel-related vector-borne diseases: A case study on dengue virus transmission

INTRODUCTION

Climate change significantly affects global health, particularly through the increased transmission of vector-borne diseases like dengue fever. This study examines how climate change influences the geographical spread of Aedes aegypti mosquitoes, the main carriers of dengue, highlighting its implications for public health worldwide.

MATERIALS AND METHODS

This study employed a comprehensive approach to evaluate the effect of climate change on dengue transmission dynamics. It included environmental data analysis, mosquito population surveys, and dengue case reports. Remote sensing data was used to track changes in temperature, precipitation, and humidity in dengue-prone areas. Field surveys measured mosquito density, while molecular techniques assessed viral load in Aedes mosquitoes. Additionally, mathematical modeling predicted dengue's future spread under various climate scenarios.

RESULTS

The findings indicate a significant correlation between rising temperatures, changing rainfall patterns, and the expansion of Aedes aegypti habitats, resulting in increased mosquito populations in previously non-endemic areas. This ecological shift is linked to a rise in dengue incidence in regions affected by climate change. Projections suggest a 25 % increase in dengue spread by 2050, especially in Southeast Asia, sub-Saharan Africa, and parts of South America.

DISCUSSION

The study highlights the significant effects of climate change on mosquito distribution and the increasing rates of dengue fever. Warmer temperatures and altered rainfall patterns enhance mosquito growth and virus transmission, while global travel aids the spread of the virus. It emphasizes the necessity for early intervention strategies, including better surveillance, vector control, and adaptations to climate changes, to tackle future dengue transmission issues.

Imported fever in returning travellers and migrants in Spain, 2009-2021. Analysis by the +REDIVI network

BACKGROUND

Travellers and migrants commonly present to health services with febrile syndrome, which can have different causes, including some that are life-threatening. A better understanding of these causes may help guide management and determine appropriate empirical treatments.

OBJECTIVES

The aim was to identify the leading causes of fever and to assess their association with the region of travel and type of travellers.

METHODS

This prospective, multicentre study was conducted within the +REDIVI network. Data were collected on febrile syndrome cases among migrants, travellers, and people visiting friends and relatives (VFRs) from 2009 to 2021. Comparative analyses were performed according to patient categories and regions of travel/origin.

RESULTS

Of the 4186 patients with febrile syndrome, the most frequent diagnosis was malaria (31.0 %), followed by dengue fever (12.0 %) and nonspecific fever of less than three weeks' duration (11.6 %). Malaria predominated in people coming from sub-Saharan Africa (58.4 %), while dengue fever was more common in the rest of the regions (19.0 % in South America, 25.0 % in Central America and the Caribbean, 34.2 % in Southeast Asia, and 18.1 % in South-Central Asia). By type of traveller, tuberculosis was more frequent in migrants, malaria in VFRs, and dengue and other arboviral infections in travellers and VFRs.

CONCLUSIONS

Geographical area of travel and type of traveller are the main determinants of imported fever aetiology. Malaria remains the most common cause of febrile syndrome, especially in VFRs from sub-Saharan Africa, while dengue fever prevails in the other tropical regions.

Ocular infections in international travelers

INTRODUCTION

Ophthalmological conditions in international travelers may be associated with low mortality but high morbidity. Eye involvement in travelers is less frequently reported than febrile, gastrointestinal and respiratory infections, but data probably represent a degree of under-notification.

METHODS

an extensive narrative review of the main viral, bacterial, fungal and parasitic infections affecting the eye in travelers was performed.

MAIN FINDINGS

Common respiratory tract viral infections may cause ocular complications in travelers, human influenza viruses have been associated with conjunctivitis and emerging avian influenza subtypes may also affect the eye. Vector-borne viral infections may affect travelers, usually with systemic symptoms, but eye disease may be the first presenting feature. A spectrum of manifestations have been described with dengue, chikungunya and Zika infections, including conjunctivitis, anterior uveitis, posterior uveitis with chorioretinitis and macular involvement. Staphylococcus spp, Streptococcus spp, and Pseudomonas spp (especially associated with use of contact lenses) are common causes of keratitis, however, resistance patterns to antimicrobials might vary depending on area of travel. Less frequent infections, such as Burkholderia pseudomallei, associated with environmental exposure, and Bartonella spp. may rarely present with ophthalmological involvement in travelers. Fungal ocular infections, especially after ocular trauma caused by plants and contact lens use, should be considered in patients with stromal keratitis not improving with antibiotic eye drops. Parasitic eye infections tend to occur in tropical areas, but some, such as acanthamoebic keratitis or Toxoplasma spp retinitis, are found worldwide. Increasing exposure to animals, undercooked food consumption or poor hygiene during international travels might be leading to the emergence of certain parasitic eye diseases.

CONCLUSIONS

Clinical features, with identification of risk factors and geographical region of exposure, can assist in the definitive diagnosis of imported ophthalmological infections. Management of imported eye infections requires a multi-disciplinary approach involving ophthalmologists, travel medicine/infectious diseases physicians and other specialists.

Approach to skin problems in travellers: clinical and epidemiological clues

RATIONALE FOR REVIEW

Travel-related skin problems are a common reason for healthcare consultations. We present a clinical approach to diagnosing skin diseases in travellers, emphasizing clinical examination and epidemiological clues such as travel history, incubation time and at-risk behaviours.

KEY FINDINGS

Skin problems or manifestations of systemic infections are the third most common health issue encountered by travellers, though their causes and frequency may vary based on the season and destination. The four most frequent skin conditions affecting travellers include arthropod bites, sunburns, hookworm-related cutaneous larva migrans (CLM) and bacterial skin and soft tissue infections. Dengue fever is the leading cause of febrile exanthema in travellers returning from Asia, Latin America and the Caribbean, while hookworm-related CLM is the most common cause of creeping dermatitis. Notable travel-related infections associated with pruritus include cercarial dermatitis, scabies, creeping dermatitis and urticaria. Acute schistosomiasis is the most common parasitic cause of acute urticaria in travellers. African tick-bite fever is the most frequently encountered rickettsiosis, typically presenting with single or multiple eschars.

CONCLUSIONS

Diagnostic approaches emphasize the importance of travel history, at-risk activities during travel and lesion distribution. At-risk activities include sun exposure, walking barefoot, exposure to sea and fresh water, hiking in forested or jungle areas, exposure frequency to mosquitoes and sandflies, poor hygiene and food intake, drug history and sexual behaviour. Morphological characteristics (vesicula, bullae, pustule, papule, nodule, plaque, oedema and ulcer), distinguishing between single and multiple skin lesions, localized or generalized, and whether mucosa, scalp, palmar or plantar surfaces are affected, provide further clinical clues. Systemic signs and symptoms such as fever and pruritus will aid in the differential diagnosis algorithms. With a thorough clinical assessment and knowledge of geographic and exposure-related risk factors, the differential diagnosis of travel-associated skin conditions can be narrowed down allowing for timely clinical management.

How to manage adult patients with malaria in the non-endemic setting

BACKGROUND

The diagnosis and management of malaria in non-endemic countries presents a continuing challenge. Plasmodium falciparum, which is capable of rapidly inducing severe and life-threatening multiorgan disease, is the species most frequently diagnosed in Europe and North America.

OBJECTIVES

To summarise the more relevant diagnostic findings and clinical features of malaria observed in non-endemic settings and to provide an update of the key management decision points using three illustrative clinical scenarios of uncomplicated and severe malaria.

SOURCES

The discussion is based on a relevant literature search spanning the last 20 years. Recommendations are based on available clinical guidelines including those of the WHO, observational studies conducted in non-endemic settings, and, when available, extrapolation from randomised studies from malaria-endemic settings.

CONTENT

The following topics are covered: diagnosis, including the use of molecular biology; clinical characteristics; management with a specific focus on complicated (severe) and uncomplicated malaria; and areas of resistance to available antimalarial drugs.

IMPLICATIONS

Malaria imported to non-endemic settings, especially P. falciparum malaria, is sometimes initially overlooked and the delayed diagnosis is responsible for every year of preventable deaths. This review aims to raise awareness of malaria outside endemic countries and to provide clinicians with a practical guide for efficient diagnosis and targeted therapy for the different species involved.

Improving Quality of Care for Vacation-Related Emergency Department Visits: A Narrative Review of Patient Satisfaction and Contributing Factors

Emergency departments (EDs) encounter substantial challenges during peak vacation periods, including increased patient volumes, limited access to medical histories, language and cultural barriers, insurance complexities, and disruptions in continuity of care. These factors strain emergency department operations, resulting in prolonged wait times, diagnostic errors, and compromised care quality. This study reviews the literature to identify patient satisfaction indicators and common challenges and evaluate strategies to improve patient outcomes during vacation-related emergency department visits. Findings highlight critical issues in staffing and resource allocation, leading to delayed care. Limited interoperability of electronic health records (EHRs) often prevents access to essential patient information, increasing diagnostic errors and unnecessary repeat testing. Language and cultural barriers contribute to higher rates of misdiagnosis and lower patient satisfaction, while insurance and payment issues create delays, particularly for out-of-network or international patients. Effective strategies to address these challenges include the use of predictive analytics for better forecasting of patient volumes, specialized triage protocols, public health education campaigns, and telemedicine for remote management of non-critical conditions. These interventions help reduce wait times, optimize resource allocation, and improve patient satisfaction. By implementing adaptive approaches, such as flexible staffing models and enhanced electronic health record use, healthcare systems can significantly improve care delivery and patient outcomes during vacation seasons.

Epidemiology and Expected Cost of International Medical Repatriation Into South Korea: 2019 to 2021

OBJECTIVE

Overseas Koreans face challenges in accessing adequate medical care abroad. Understanding the epidemiology and costs of international medical repatriation is important.

METHODS

A retrospective analysis of overseas Korean patients who were repatriated to South Korea between 2019 and 2021 was conducted. The data collected from 121 countries included demographics, medical conditions, and costs. Variables from 9 continents (Southeast Asia, Northeast Asia, Southwest Asia-Pacific, Russia-Central Asia, North America, Central and South America, Europe, Middle East‒North Africa, and Sub-Saharan Africa) and the era of coronavirus disease 2019 (February 2020 and after) were analyzed and compared. Based on the available total cost data, stepwise extrapolation was conducted for the total cohort.

RESULTS

A total of 428 overseas Korean patients who had undergone international medical repatriation via air transport were included in this study. The greatest number of repatriated patients were from Southeast Asia (108 patients), and 279 patients were transported within the coronavirus disease 2019 era. The average cost per patient exceeded $7,000, and the total cost estimated by extrapolation was over $8 million.

CONCLUSION

International medical repatriation is significant for overseas Koreans. Standardized guidelines and system development are essential for effective air medical services.

Skin dermatoses in the returning traveller: a practical guide

Skin problems are common in returning travellers, despite the fact that vaccination, insect repellent techniques, adequate clothing and footwear are all ways to prevent skin disease. When travelling to unusual areas, the traveller can still expect to pick up diseases that are common across the world, such as lice, scabies, and staphylococcal or streptococcal infections. What can differ are the different arthropods and the diseases they can spread. Given the plethora of dermatoses in returning travellers, a methodological approach is necessary. We attempted such an approach by creating a practical guide that includes a diagnostic flowchart alongside a world map presenting common skin problems by continent. Additional information regarding possible investigations, along with tables presenting common infectious skin diseases and their corresponding presentations, is also included in our study. Our aim is to help clinicians approach skin dermatosis in patients returning from holidays, acknowledging the diagnostic difficulties that this might entail.

Unusual Unsatisfactory Treatment in Two Patients with Imported Cutaneous Leishmaniasis

Cutaneous leishmaniasis is one of the most commonly diagnosed dermatological condition in travel medicine after diarrhoeal diseases and febrile status. The disease is transmitted by Phlebotomus and Lutzomyia sandflies. It appears in various clinical forms, the most common of which is a painless ulcer with raised edges, usually present on exposed parts of the body on the side where the insect bite occurred. Annually, over a million new cutaneous leishmaniasis (CL) cases are reported globally. We present two cases of affliction, the first occurring in Patient 1, who attempted treatment through the Kambo cleanse in South America, which is considered a toxic, even life-threatening, procedure. It involves the subcutaneous application of a substance dangerous to humans derived from the surface mucus of a frog. Patient 2 applied caustic ointments, a fruitarian diet, and hyperbaric oxygen therapy in a private setting. After initial therapeutic failures caused by the patients' unconventional treatment ideas, the causal treatment effect was satisfactory, demonstrating the efficacy of these treatments in resolving the infection when applied appropriately. Despite the typical CL presentation in both patients, their self-treatment course was unusual. It is worth noting that alternative, sometimes harmful, self-treatment initiatives by patients may be surprising and ineffective. Promoting knowledge about tropical diseases among travellers and medical staff is crucial to improving treatment outcomes.

Travel-associated sexually transmitted infections in Japan: An observational study using imported infectious disease registry data

International travel is a risk factor for acquiring sexually transmitted infections (STIs) owing to factors such as increased sexual opportunities, a sense of freedom, and the allure of the sex industry. We investigated the incidence of travel-associated STIs in Japan using data from the Japan Registry for Infectious Diseases from Abroad (J-RIDA) reported by 17 participating medical institutions between October 2017 and December 2022. Data were collected on the patients' age, sex, nationality, chief complaint, whether they had visited a travel clinic before travel, travel history, and final diagnosis. Of 4545 cases of travel-associated illness reported, 52 (1.1%) were STIs. Most patients with STIs were male (81%) with a median age of 31 years. HIV (17%), genital herpes (13%), syphilis (13%), and gonorrhea (12%) were the most frequently reported STIs. Only one patient had visited a travel clinic before travel. Promoting awareness and vaccination is crucial for preventing travel-associated STIs.

Trends in imported infections among migrants and travellers to Spain: a decade of analysis through the +Redivi network (2012-2022)

BACKGROUND

High-speed global travel, increased trade, world population growth, migration, urbanization and climate change have favoured the emergence and spread of pathogens. We aimed to analyse the evolution of imported infections in Spain during 2012-2022 and the potential impact of some of the abovementioned factors on differential morbidity patterns.

METHODS

In this retrospective study (January 2012 to December 2022), we analysed data collected by the +Redivi network across 25 health centres. The network's standardised database records new cases of imported infections, including patient demographics, travel history, pre-travel advice and diagnostic information. To assess outcome rates over time and potential interactions, we constructed penalized weighted models to reduce the bias related to a low event rate and used weighted logistic regression for morbidity outcomes.

RESULTS

We recorded 25 632 episodes, comprising 13 913 migrants, 4047 visiting friends and relatives (VFR) immigrants, 392 VFR travellers and 7280 travellers. Most immigrants came from South America (48.3%), Sub-Saharan Africa (28.5%), North Africa (6.6%), South Central Asia (5.4%) and Central America/Caribbean (5.3%). The most common regions visited by travellers were Sub-Saharan Africa (33.5%), South America (24.5%), Central America/Caribbean (13.5%), Southeast Asia (12%) and South Central Asia (10%). The proportion of diagnoses of malaria, strongyloidiasis and unspecified self-limiting febrile syndrome < 3 weeks remained unchanged during the study period. An increased frequency of diagnosis was reported for schistosomiasis, blastocystosis, giardiasis, dengue, diarrhoea, new cases of HIV, latent and pulmonary tuberculosis, whereas a decrease was reported for syphilis, chikungunya fever, Chagas disease and eosinophilia. We detected interactions between time and sex or type of participant across the different diagnoses.

CONCLUSIONS

Our study underscores the importance of epidemiological data in understanding infectious diseases dynamics among travellers and migrants, emphasizing how demographic shifts, migration trends and healthcare policies affect disease profiles. Comprehensive data play an essential role in enhancing public health policies and travel advice.

Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Chorioretinitis among Immigrant and Travellers. Comment on Mansour et al. Presumed Onchocerciasis Chorioretinitis Spilling over into North America, Europe and Middle East. Diagnostics 2023, 13, 3626

We read, with interest, the paper by Mansour et al [...].

Beach volleyball and Cutaneous Larva Migrans

Cutaneous larva migrans can affect even athletes who travelled to play beach volleyball in Zanzibar. We describe a cluster of CLM infections in travellers who contracted the disease during their trip to Africa, rather than bringing a volleyball trophy. Despite presenting typical changes, all of them were misdiagnosed.

Injuries and medical emergencies among international travellers

BACKGROUND

Tropical infectious diseases and vaccine-preventable emergencies are the mainstay of pre-travel consultations. However, non-communicable diseases, injuries and accidents that occur during travel are not emphasized enough in these settings.

METHODS

We performed a narrative review based on a literature search of PubMed, Google Scholar, UpToDate, DynaMed and LiSSa and on reference textbooks and medical journals dedicated to travel, emergency and wilderness medicine. Relevant secondary references were extracted. We also aimed to discuss newer or neglected issues, such as medical tourism, Coronavirus Disease 2019, exacerbations of co-morbidities associated with international travel, insurance coverage, health care seeking abroad, medical evacuation or repatriation and tips for different types of travellers' emergency medical kits (personal, group, physician handled).

RESULTS

All sources reviewed led to the selection of >170 references. Among epidemiological data on morbidity and deaths while abroad, only retrospective data are available. Deaths are estimated to occur in 1 in 100 000 travellers, with 40% caused by trauma and 60% by diseases, and <3% linked to infectious diseases. Trauma and other injuries acquired during travel, such as traffic accidents and drowning, can be reduced by up to 85% with simple preventive recommendations such as avoiding simultaneous alcohol intake. In-flight emergencies occur on 1 in 604 flights on average. Thrombosis risk is two to three times greater for travellers than for non-travellers. Fever during or after travel can occur in 2-4% of travellers, but in up to 25-30% in tertiary centres. Traveller's diarrhoea, although rarely severe, is the most common disease associated with travel. Autochthonous emergencies (acute appendicitis, ectopic pregnancy, dental abscess) can also occur.

CONCLUSIONS

Pre-travel medicine encounters must include the topic of injuries and medical emergencies, such as the risk-taking behaviours and foster better planning in a comprehensive approach along with vaccines and infectious diseases advices.

Travel surveillance uncovers dengue virus dynamics and introductions in the Caribbean

Dengue is the most prevalent mosquito-borne viral disease in humans, and cases are continuing to rise globally. In particular, islands in the Caribbean have experienced more frequent outbreaks, and all four dengue virus (DENV) serotypes have been reported in the region, leading to hyperendemicity and increased rates of severe disease. However, there is significant variability regarding virus surveillance and reporting between islands, making it difficult to obtain an accurate understanding of the epidemiological patterns in the Caribbean. To investigate this, we used travel surveillance and genomic epidemiology to reconstruct outbreak dynamics, DENV serotype turnover, and patterns of spread within the region from 2009-2022. We uncovered two recent DENV-3 introductions from Asia, one of which resulted in a large outbreak in Cuba, which was previously under-reported. We also show that while outbreaks can be synchronized between islands, they are often caused by different serotypes. Our study highlights the importance of surveillance of infected travelers to provide a snapshot of local introductions and transmission in areas with limited local surveillance and suggests that the recent DENV-3 introductions may pose a major public health threat in the region.

Travel Medicine

International travel can cause new illness or exacerbate existing conditions. Because primary care providers are frequent sources of health advice to travelers, they should be familiar with destination-specific disease risks, be knowledgeable about travel and routine vaccines, be prepared to prescribe chemoprophylaxis and self-treatment regimens, and be aware of travel medicine resources. Primary care providers should recognize travelers who would benefit from referral to a specialized travel clinic for evaluation. Those requiring yellow fever vaccination, immunocompromised hosts, pregnant persons, persons with multiple comorbid conditions, or travelers with complex itineraries may warrant specialty referral.

Profiles of travelers to intermediate-high health risk areas following the reopening of borders in the COVID-19 crisis: A clustering approach

BACKGROUND

The reactivation of international travel in 2021 has created a new scenario in which the profile of the traveler to medium-high health risk areas may well have changed. However, few studies have analyzed this new profile since the reopening of borders in that year.

METHODS

We designed an ad hoc questionnaire that was administered face-to-face by our medical team during appointments with 330 travelers in the second half of 2021. Information was collected on the following topics: sociodemographic and socioeconomic status; type of travel and previous travel experience; health status and risk perception (of COVID-19 and tropical infectious diseases). Using all features simultaneously, an unsupervised machine learning approach (k-means) is implemented to characterize groups of travelers. Pairwise chi-squared tests were performed to identify key features that showed statistically significant differences between clusters.

RESULTS

The travelers were clustered into seven groups. We associated the clusters with different intensities of perceived risk of acquiring COVID-19 and tropical infectious diseases on the trip. The perceived risk of both diseases was low in the group "middle or lower middle class young inexperienced male tourist" but high in the group "middle or lower middle-class young with children inexperienced business traveler".

CONCLUSIONS

Broadening our knowledge of the profiles of travelers to intermediate-high health risk areas would help to tailor the health advice provided by practitioners to their characteristics and type of travel. In a changing health context, the k-means approach supposes a flexible statistical method that calculates travelers' profiles and can be easily adapted to process new information.

Travel-Related Diagnoses Among U.S. Nonmigrant Travelers or Migrants Presenting to U.S. GeoSentinel Sites - GeoSentinel Network, 2012-2021

Problem/Condition

During 2012-2021, the volume of international travel reached record highs and lows. This period also was marked by the emergence or large outbreaks of multiple infectious diseases (e.g., Zika virus, yellow fever, and COVID-19). Over time, the growing ease and increased frequency of travel has resulted in the unprecedented global spread of infectious diseases. Detecting infectious diseases and other diagnoses among travelers can serve as sentinel surveillance for new or emerging pathogens and provide information to improve case identification, clinical management, and public health prevention and response.

Reporting Period

2012-2021.

Description of System

Established in 1995, the GeoSentinel Network (GeoSentinel), a collaboration between CDC and the International Society of Travel Medicine, is a global, clinical-care-based surveillance and research network of travel and tropical medicine sites that monitors infectious diseases and other adverse health events that affect international travelers. GeoSentinel comprises 71 sites in 29 countries where clinicians diagnose illnesses and collect demographic, clinical, and travel-related information about diseases and illnesses acquired during travel using a standardized report form. Data are collected electronically via a secure CDC database, and daily reports are generated for assistance in detecting sentinel events (i.e., unusual patterns or clusters of disease). GeoSentinel sites collaborate to report disease or population-specific findings through retrospective database analyses and the collection of supplemental data to fill specific knowledge gaps. GeoSentinel also serves as a communications network by using internal notifications, ProMed alerts, and peer-reviewed publications to alert clinicians and public health professionals about global outbreaks and events that might affect travelers. This report summarizes data from 20 U.S. GeoSentinel sites and reports on the detection of three worldwide events that demonstrate GeoSentinel's notification capability.

Results

During 2012-2021, data were collected by all GeoSentinel sites on approximately 200,000 patients who had approximately 244,000 confirmed or probable travel-related diagnoses. Twenty GeoSentinel sites from the United States contributed records during the 10-year surveillance period, submitting data on 18,336 patients, of which 17,389 lived in the United States and were evaluated by a clinician at a U.S. site after travel. Of those patients, 7,530 (43.3%) were recent migrants to the United States, and 9,859 (56.7%) were returning nonmigrant travelers.Among the recent migrants to the United States, the median age was 28.5 years (range = <19 years to 93 years); 47.3% were female, and 6.0% were U.S. citizens. A majority (89.8%) were seen as outpatients, and among 4,672 migrants with information available, 4,148 (88.8%) did not receive pretravel health information. Of 13,986 diagnoses among migrants, the most frequent were vitamin D deficiency (20.2%), Blastocystis (10.9%), and latent tuberculosis (10.3%). Malaria was diagnosed in 54 (<1%) migrants. Of the 26 migrants diagnosed with malaria for whom pretravel information was known, 88.5% did not receive pretravel health information. Before November 16, 2018, patients' reasons for travel, exposure country, and exposure region were not linked to an individual diagnosis. Thus, results of these data from January 1, 2012, to November 15, 2018 (early period), and from November 16, 2018, to December 31, 2021 (later period), are reported separately. During the early and later periods, the most frequent regions of exposure were Sub-Saharan Africa (22.7% and 26.2%, respectively), the Caribbean (21.3% and 8.4%, respectively), Central America (13.4% and 27.6%, respectively), and South East Asia (13.1% and 16.9%, respectively). Migrants with diagnosed malaria were most frequently exposed in Sub-Saharan Africa (89.3% and 100%, respectively).Among nonmigrant travelers returning to the United States, the median age was 37 years (range = <19 years to 96 years); 55.7% were female, 75.3% were born in the United States, and 89.4% were U.S. citizens. A majority (90.6%) were seen as outpatients, and of 8,967 nonmigrant travelers with available information, 5,878 (65.6%) did not receive pretravel health information. Of 11,987 diagnoses, the most frequent were related to the gastrointestinal system (5,173; 43.2%). The most frequent diagnoses among nonmigrant travelers were acute diarrhea (16.9%), viral syndrome (4.9%), and irritable bowel syndrome (4.1%).Malaria was diagnosed in 421 (3.5%) nonmigrant travelers. During the early (January 1, 2012, to November 15, 2018) and later (November 16, 2018, to December 31, 2021) periods, the most frequent reasons for travel among nonmigrant travelers were tourism (44.8% and 53.6%, respectively), travelers visiting friends and relatives (VFRs) (22.0% and 21.4%, respectively), business (13.4% and 12.3%, respectively), and missionary or humanitarian aid (13.1% and 6.2%, respectively). The most frequent regions of exposure for any diagnosis among nonmigrant travelers during the early and later period were Central America (19.2% and 17.3%, respectively), Sub-Saharan Africa (17.7% and 25.5%, respectively), the Caribbean (13.0% and 10.9%, respectively), and South East Asia (10.4% and 11.2%, respectively).Nonmigrant travelers who had malaria diagnosed were most frequently exposed in Sub-Saharan Africa (88.6% and 95.9% during the early and later period, respectively) and VFRs (70.3% and 57.9%, respectively). Among VFRs with malaria, a majority did not receive pretravel health information (70.2% and 83.3%, respectively) or take malaria chemoprophylaxis (88.3% and 100%, respectively).

Interpretation

Among ill U.S. travelers evaluated at U.S. GeoSentinel sites after travel, the majority were nonmigrant travelers who most frequently received a gastrointestinal disease diagnosis, implying that persons from the United States traveling internationally might be exposed to contaminated food and water. Migrants most frequently received diagnoses of conditions such as vitamin D deficiency and latent tuberculosis, which might result from adverse circumstances before and during migration (e.g., malnutrition and food insecurity, limited access to adequate sanitation and hygiene, and crowded housing,). Malaria was diagnosed in both migrants and nonmigrant travelers, and only a limited number reported taking malaria chemoprophylaxis, which might be attributed to both barriers to acquiring pretravel health care (especially for VFRs) and lack of prevention practices (e.g., insect repellant use) during travel. The number of ill travelers evaluated by U.S. GeoSentinel sites after travel decreased in 2020 and 2021 compared with previous years because of the COVID-19 pandemic and associated travel restrictions. GeoSentinel detected limited cases of COVID-19 and did not detect any sentinel cases early in the pandemic because of the lack of global diagnostic testing capacity.

Public Health Action

The findings in this report describe the scope of health-related conditions that migrants and returning nonmigrant travelers to the United States acquired, illustrating risk for acquiring illnesses during travel. In addition, certain travelers do not seek pretravel health care, even when traveling to areas in which high-risk, preventable diseases are endemic. Health care professionals can aid international travelers by providing evaluations and destination-specific advice.Health care professionals should both foster trust and enhance pretravel prevention messaging for VFRs, a group known to have a higher incidence of serious diseases after travel (e.g., malaria and enteric fever). Health care professionals should continue to advocate for medical care in underserved populations (e.g., VFRs and migrants) to prevent disease progression, reactivation, and potential spread to and within vulnerable populations. Because both travel and infectious diseases evolve, public health professionals should explore ways to enhance the detection of emerging diseases that might not be captured by current surveillance systems that are not site based.

Morbidity of Returning Travelers Seen in Community Urgent Care Centers throughout Israel

Information regarding post-travel morbidity is usually reported via dedicated post-travel clinics and mainly relates to travelers returning from low-middle-income countries (LMIC), however, the spectrum of morbidity seen within the community setting is scarcely reported. This prospective observational study among visitors to 17 community Urgent Care Centers (UCC) was designed to evaluate the reasons for post-travel community clinic visits and to compare travelers returning from LMIC to high-income countries (HIC). All visitors within one-month post-travel to all destinations were included. A total of 1580 post-travel visits were analyzed during 25 months. Travelers to LMICs were younger (mean 36.8 years old vs. 41.4 in the HIC group) and stayed longer periods abroad (30.1 ± 41.2 vs. 10.0 ± 10.6 in the HIC group) but more of them had pre-travel vaccines (35.5% vs. 6.6%). Travel-related morbidity was significantly more common in the LMIC group 58.3% (253/434) vs. 34.1% (391/1146) in the HIC group, (p < 0.001). Acute diarrhea was the leading cause of morbidity after visiting LMIC (28.8%) and was significantly more common than in the HIC (6.6%, p < 0.001). Other common morbidities in the LMIC cohort were respiratory (23.3%), cutaneous (15.8%), and injuries (9.9%). In the HIC group, the common morbidities were respiratory (37.3%), and diarrhea composed only 6.6% of the complaints. Our study group represents a less biased sample of travelers to LMIC as well as HIC, therefore, data from the UCC setting and at the specialized travel clinics complete each other in understanding the true extent of morbidity in travelers.

The Burden of Arboviral Infections in the Military Health System 2012-2019

Arboviral infections, including dengue (DNV), chikungunya (CHIKV), and Zika (ZIKV), impact both travelers and native populations of endemic regions. We sought to assess the disease burden of arboviral infections in the Military Health System, the validity of arboviral diagnostic codes, and the role of pretravel counseling on insect avoidance precautions. We searched for diagnostic codes consistent with arboviral infection and grouped them into DNV, CHIKV, ZIKV, Japanese encephalitis virus (JEV), and Other. Demographic data were evaluated. A subset of charts in each category were reviewed for diagnostic validity and travel characteristics. In all, 10,547 unique subjects carried 17,135 arboviral diagnostic codes, including 1,606 subjects (15.2%) coded for DNV, 230 (2.2%) for ZIKV, 65 (0.6%) for CHIKV, and 4,317 (40.9%) for JEV. A chart review was performed on 807 outpatient charts, yielding outpatient diagnostic code positive predictive values of 60.5% (DNV), 15.3% (ZIKV), and 64.5% (CHIKV); there were no valid cases of JEV. Dengue represented the greatest burden of arboviral infections with 2.2 cases per 100,000 military healthcare enrollees over the 2012-2019 fiscal years. More than 80% of subjects with arboviral infection did not have documented pretravel counseling. Arboviral infections represent a significant disease burden in young travelers to endemic regions. After adjustment for diagnostic validity, DNV represented the greatest burden. Diagnostic codes for ZIKV and JEV overestimate the burden of these diseases. Low rates of pretravel visits represent an opportunity for increased emphasis on insect exposure precautions.

Tropical infections as occupational diseases among young volunteers in social projects

PURPOSE

The trend of volunteering overseas has increased tremendously over the last decade. Volunteers often go to regions where they are exposed to the risk of tropical infections like malaria, dengue, typhoid fever and schistosomiasis. Health assessments have shown a high occurrence of tropical infections among young volunteers. Such tropical infections are notifiable in Germany, as they are covered by a separate branch of the social insurance system. However, there is still limited data on systematical improvement of medical prevention and health care for volunteers.

METHODS

This retrospective study included 457 cases with a diagnosis for a tropical infection or typhoid fever from January 2016 to December 2019. Data sets were anonymised and then analysed with descriptive statistics first. Cases of volunteers sent abroad by "Weltwärts" were compared to cases of aid workers sent to non-industrial countries.

RESULTS

A high occurrence of tropical infections as occupational diseases has been shown for volunteers compared to other (mostly older) aid workers being sent to tropical regions. The risk of acquiring a tropical infection was significantly higher in Africa compared to other tropical regions. Cases of malaria were reported significantly more often among the group of volunteers than among aid workers during the period under review. Medical check-ups after travel were rare among volunteers.

CONCLUSIONS

Data imply a disproportionate risk for malaria in Africa with a higher risk of acquiring malaria tropica in Sub-Saharan regions. Region-specific risks need to be addressed in training seminars in order to raise awareness among young volunteers before travel. Medical examinations after travel should be mandatory and specific to a particular region.

Chikungunya: risks for travellers

RATIONALE FOR REVIEW

Chikungunya outbreaks continue to occur, with changing epidemiology. Awareness about chikungunya is low both among the at-risk travellers and healthcare professionals, which can result in underdiagnosis and underreporting. This review aims to improve awareness among healthcare professionals regarding the risks of chikungunya for travellers.

KEY FINDINGS

Chikungunya virus transmission to humans occurs mainly via daytime-active mosquitoes, Aedes aegypti and Aedes albopictus. The areas where these mosquitoes live is continuously expanding, partly due to climate changes. Chikungunya is characterized by an acute onset of fever with joint pain. These symptoms generally resolve within 1-3 weeks, but at least one-third of the patients suffer from debilitating rheumatologic symptoms for months to years. Large outbreaks in changing regions of the world since the turn of the 21st century (e.g. Caribbean, La Réunion; currently Brazil, India) have resulted in growing numbers of travellers importing chikungunya, mainly to Europe and North America. Viremic travellers with chikungunya infection have seeded chikungunya clusters (France, United States of America) and outbreaks (Italy in 2007 and 2017) in non-endemic countries where Ae. albopictus mosquitoes are present. Community preventive measures are important to prevent disease transmission by mosquitoes. Individual preventive options are limited to personal protection measures against mosquito bites, particularly the daytime-active mosquitos that transmit the chikungunya virus. Candidate vaccines are on the horizon and regulatory authorities will need to assess environmental and host risk factors for persistent sequelae, such as obesity, age (over 40 years) and history of arthritis or inflammatory rheumatologic disease to determine which populations should be targeted for these chikungunya vaccines.

CONCLUSIONS/RECOMMENDATIONS

Travellers planning to visit destinations with active CHIKV circulation should be advised about the risk for chikungunya, prevention strategies, the disease manifestations, possible chronic rheumatologic sequelae and, if symptomatic, seek medical evaluation and report potential exposures.

Infectious diseases in German military personnel after predominantly tropical deployments: a retrospective assessment over 13 years

OBJECTIVES

Military deployments to the tropics are associated with specific infection risks. To add to the available epidemiological information, infectious disease risks in German military personnel returning from predominantly tropical deployments were assessed.

METHODS

Since 2006, German soldiers returning from predominantly tropical deployments have been offered the opportunity of returnee screenings at the Department of Tropical Medicine and Infectious Diseases of the Bundeswehr Hospital Hamburg. Case files and diagnostic results recorded between 2006 and 2018 were retrospectively assessed to identify deployment-associated infectious disease risks.

RESULTS

Along with high enteric colonisation rates with apathogenic protozoa and resistant Enterobacteriaceae, direct or indirect proof of infections among the 764 assessed cases comprised Plasmodium spp (n=37), Giardia duodenalis (n=21), Schistosoma spp (n=14), Yersinia enterocolitica (n=5), Strongyloides stercoralis (n=3), Campylobacter jejuni (n=1), Leishmania spp (n=1) and Salmonella enterica (n=1), as well as latent infections with Mycobacterium tuberculosis complex (n=8). The infections were mainly imported from the African region and Eastern Mediterranean region and high proportions of cases lacked typical symptoms. Reported side effect rates of antimalarial chemoprophylaxis for mefloquine (n=121), atovaquone/proguanil (n=49) and doxycycline (n=6) were 36.3%, 19.3% and 11.8%, respectively, while non-compliance rates were 12.9%, 13.0% and 5.9%, respectively.

CONCLUSIONS

Considerable rates of infections with sometimes atypical or absent symptoms confirm a need for returnee screenings after tropical deployments. High reported side effect rates for mefloquine support its replacement by atovaquone/proguanil or doxycycline for antimalarial chemoprophylaxis.

Imported diseases in travellers presenting to the emergency department after a stay in a malaria-endemic country: a retrospective observational study

BACKGROUND

We aimed to investigate the aetiology and outcomes of illnesses in patients presenting to an emergency department after travelling to a malaria-endemic country, in order to raise awareness of both tropical and cosmopolitan diseases.

METHODS

A retrospective chart review was performed for all patients who underwent blood smear testing for malaria at the Emergency Department of the University Hospitals Leuven from 2017 to 2020. Patient characteristics, results of laboratory and radiological examinations, diagnoses, disease course and outcome were collected and analysed.

RESULTS

A total of 253 patients were included in the study. The majority of ill travellers returned from Sub-Saharan Africa (68.4%) and Southeast Asia (19.4%). Their diagnoses fell into three major syndrome categories: systemic febrile illness (30.8%), inflammatory syndrome of unknown origin (23.3%) and acute diarrhoea (18.2%). Malaria (15.8%) was the most common specific diagnosis in patients with systemic febrile illness, followed by influenza (5.1%), rickettsiosis (3.2%), dengue (1.6%), enteric fever (0.8%), chikungunya (0.8%) and leptospirosis (0.8%). The presence of hyperbilirubinemia and thrombocytopenia increased the probability of malaria, with a likelihood ratio of 4.01 and 6.03, respectively. Seven patients (2.8%) were treated in the intensive care unit, and none died.

CONCLUSION

Systemic febrile illness, inflammatory syndrome of unknown origin and acute diarrhoea were the three major syndromic categories in returning travellers presenting to our emergency department after a stay in a malaria-endemic country. Malaria was the most common specific diagnosis in patients with systemic febrile illness. None of the patients died.

Impact of Chemoprophylaxis on Plasmodium vivax and Plasmodium ovale Infection Among Civilian Travelers: A Nested Case-Control Study With a Counterfactual Approach on 862 Patients

BACKGROUND

The impact of chemoprophylaxis targeting Plasmodium falciparum on Plasmodium vivax and Plasmodium ovale, which may remain quiescent as hypnozoites in the liver, is debated.

METHODS

We conducted a nested case-control analysis of the outcomes of P. vivax and P. ovale infections in imported malaria cases in France among civilian travelers from 1 January 2006, to 31 December 2017. Using adjusted logistic regression, we assessed the effect of chemoprophylaxis on the incubation period, time from symptoms to diagnosis, management, blood results, symptoms, and hospitalization duration. We analyzed the effect of blood-stage drugs (doxycycline, mefloquine, chloroquine, chloroquine-proguanil) or atovaquone-proguanil on the incubation period. We used a counterfactual approach to ascertain the causal effect of chemoprophylaxis on postinfection characteristics.

RESULTS

Among 247 P. vivax- and 615 P. ovale-infected travelers, 30% and 47%, respectively, used chemoprophylaxis, and 7 (3%) and 8 (1%) were severe cases. Chemoprophylaxis users had a greater risk of presenting symptoms >2 months after returning for both species (P. vivax odds ratio [OR], 2.91 [95% confidence interval {CI}, 1.22-6.95], P = .02; P. ovale OR, 2.28 [95% CI, 1.47-3.53], P < .001). Using drugs only acting on the blood stage was associated with delayed symptom onset after 60 days, while using atovaquone-proguanil was not.

CONCLUSIONS

Civilian travelers infected with P. vivax or P. ovale reporting chemoprophylaxis use, especially of blood-stage agents, had a greater risk of delayed onset of illness. The impact of chemoprophylaxis on the outcomes of infection with relapse-causing species calls for new chemoprophylaxis acting against erythrocytic and liver stages.

Questionnaire-Based Analysis of Adverse Events and Compliance with Malaria Chemoprophylaxis in Taiwan

Malaria was eradicated in Taiwan in 1952; however, imported malaria cases are reported every year. The subtropical climate in Taiwan permits mosquito propagation and possible outbreaks of mosquito-borne diseases. The aim of this study was to investigate travelers' compliance and side effects of malaria prophylaxis to prevent a malaria outbreak in Taiwan. In this prospective study, we enrolled travelers who visited our travel clinic before going to malarious areas. A total of 161 questionnaires were collected and analyzed. Associations between the occurrence of side effects and compliance with antimalarial drugs were analyzed. Adjusted odds ratios were calculated after adjusting for potential risk factors in multiple logistic regression analysis. Of the 161 enrolled travelers, 58 (36.0%) reported side effects. Insomnia, somnolence, irritability, nausea, and anorexia were associated with poor compliance. Mefloquine was not associated with more neuropsychological side effects than doxycycline. Multiple logistic regression analysis showed that chemoprophylaxis compliance was affected by a younger age, visiting friends and relatives, visiting the travel clinic more than 1 week before the trip, and preferring to use the same antimalarial regimen on the next trip. Our findings could provide information to travelers besides labeled side effects to improve compliance with malaria prophylaxis and consequently help to prevent malaria outbreaks in Taiwan.

Present and future: infectious tropical travel rashes and the impact of climate change

In this article, we discuss pertinent cutaneous findings with which patients may present after travel to tropical destinations. We address arthropod-borne infectious diseases such as cutaneous leishmaniasis, Chagas disease, cutaneous larva migrans, and myiasis. We discuss other relevant diseases with cutaneous signs such as monkey pox and severe acute respiratory syndrome coronavirus 2. We provide clinicians with information regarding the background, diagnosis, treatment, and prevention of these tropical rashes. In addition, we address the impact that climate change will have on the temporal and geographic incidence of these rashes. Viral, fungal, and vector-borne diseases have seen a geographic expansion into more northern latitudes. Among these are tick-borne Lyme disease, aquatic snail-related seabather's eruption, and atopic dermatitis. As these diseases spread, we believe that the updated information within this article is significant to the practicing physician in today's warming world.

Effects of sanitation and hygiene perceptions on international travelers' health, travel plans and trip experiences in India

Background

International travelers often experience travelers' diarrhea. However, there is paucity of data on whether self-reported gastrointestinal symptoms influence travelers' perceptions of adequacy of sanitation and hygiene services encountered during travel, and to what degree their travel plans, and overall trip experience are impacted.

Methods

A cross-sectional face-to-face survey was conducted amongst international travelers in India. Data collected included socio-demographics, travel characteristics, self-reported occurrence and frequency/severity of gastrointestinal symptoms, perceptions of sanitation and hygiene encountered, and adverse effects of symptoms on travel plans and trip experiences. Chi-square tests and logistic regression were performed to describe differences and associations between categorical variables.

Results

Of the 300 international travelers surveyed, 46.3% experienced diarrhea. At least two thirds of travelers perceived the quality of sanitation (67.0%) and hygiene (70.0%) encountered to be inadequate. Perceptions of inadequate sanitation (adjusted OR = 3.0; 95% CI 1.7-5.5) and poor hygiene (adjusted OR = 7.7; 95% CI 4.1-15.5) were higher among travelers who experienced diarrhea. Additionally, both higher likelihood of travel plans being affected (adjusted OR = 10.7; 95% CI 5.1-23.6) and adverse impacts on overall trip experience (adjusted OR = 2.8; 95% CI 1.4-5.8) were reported among those who experienced diarrhea.

Conclusions

More than two thirds of travelers surveyed in India experienced inadequate sanitation and hygiene services, with perceptions influenced by occurrence and frequency of diarrhea. Self-reported diarrhea was also associated with adverse effects on travel plans and overall trip experience. While these results may seem intuitive, they have important implications and suggest that improving sanitation and hygiene standards in India could potentially enhance tourism.

Hepatitis A in the Eastern Mediterranean Region: a comprehensive review

INTRODUCTION

With 583 million inhabitants, the Eastern Mediterranean Region (EMR) is a worldwide hub for travel, migration, and food trade. However, there is a scarcity of data on the epidemiology of the hepatitis A virus (HAV).

METHODS

The MEDLINE and grey literature were systematically searched for HAV epidemiological data relevant to the EMR region published between 1980 and 2020 in English, French, or Arabic.

RESULTS

Overall, 123 publications were extracted. The proportion of HAV cases among acute viral hepatitis cases was high. HAV seroprevalence rate ranged from 5.7% to 100.0% and it was decreasing over time while the average age at infection increased.

CONCLUSION

In the EMR, HAV remains a significant cause of acute viral hepatitis. The observed endemicity shift will likely increase disease burden as the population ages. Vaccinating children and adopting sanitary measures are still essential to disease prevention; vaccinating at-risk groups might reduce disease burden even further.

The Emergence of Travel-related Infections in Critical Care Units

Several tropical or geographically confined infectious diseases may lead to organ failure requiring management in an intensive care unit (ICU), both in endemic low- and middle-income countries where ICU facilities are increasingly being developed and in (nonendemic) high-income countries through an increase in international travel and migration. The ICU physician must know which of these diseases may be encountered and how to recognize, differentiate, and treat them. The four historically most prevalent "tropical" diseases (malaria, enteric fever, dengue, and rickettsiosis) can present with single or multiple organ failure in a very similar manner, which makes differentiation based solely on clinical signs very difficult. Specific but frequently subtle symptoms should be considered and related to the travel history of the patient, the geographic distribution of these diseases, and the incubation period. In the future, ICU physicians may also be more frequently confronted with rare but frequently lethal diseases, such as Ebola and other viral hemorrhagic fevers, leptospirosis, and yellow fever. No one could have foreseen the worldwide 2019-up to now coronavirus disease 2019 (COVID-19) crisis caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was initially spread by travel too. In addition, the actual pandemic due to SARS-CoV-2 reminds us of the actual and potential threat of (re)-emerging pathogens. If left untreated or when treated with a delay, many travel-related diseases remain an important cause of morbidity and even mortality, even when high-quality critical care is provided. Awareness and a high index of suspicion of these diseases is a key skill for the ICU physicians of today and tomorrow to develop.

Management and Prevention of Traveler's Diarrhea: A Cross-Sectional Study on Knowledge, Attitudes, and Practices in Italian Occupational Physicians (2019 and 2022)

Even though Italian Occupational Physicians (OP) are increasingly involved in the managing of overseas workers, their knowledge, attitudes, and practices (KAP) in travel medicine are mostly undefined. We, therefore, permed a KAP study specifically targeting the management of travelers' diarrhea (TD) by OP. A total of 371 professionals (43.4% males; mean age 40.8 ± 10.9 years) completed in 2 rounds (2019 and 2022) a specifically designed web questionnaire that inquired participating OP on their knowledge status (KS), risk perception, and management of TD through pre- and post-travel advice and interventions. Multivariable odds ratios (aOR) for predictors of a better knowledge status were calculated through regression analysis. Eventually, the majority of participants (53.4%) had participated in the management of cases of TD in the previous months, but only 26.4% were reportedly involved in pre-travel consultations. The overall knowledge status was unsatisfying (potential range: 0-100%, actual average of the sample 59.6% ± 14.6), with substantial uncertainties in the management of antimicrobial treatment. Interestingly, only a small subset of participants had previously prescribed antimicrobial prophylaxis or treatment (3.5% and 1.9%, respectively). Main effectors of a better knowledge status were: having a background qualification in Hygiene and Public Health (aOR 14.769, 95%CI 5.582 to 39.073), having previously managed any case of (aOR 3.107, 95%CI 1.484 to 6.506), and having higher concern on TD, reported by acknowledging high frequency (aOR 8.579, 95%CI 3.383 to 21.756) and severity (aOR 3.386; 95%CI 1.741 to 6.585) of this disorder. As the adherence of participating OP to official recommendations for TD management was unsatisfying, continuous Education on Travel Medicine should be improved by sharing up-to-date official recommendations on appropriate treatment options for TD.

Unusual migration of cutaneous larva migrans

We report the case of a 62-year-old woman who presented with cutaneous larva migrans (CLM) of the breast after a trip to Long-Island, NY. The location of the rash is very unusual, and the region the patient was infected in NY is not known to be endemic forCLM.

Colitis caused by Entamoeba histolytica identified by real-time-PCR and fluorescence in situ hybridization from formalin-fixed, paraffin-embedded tissue

Intestinal amoebiasis in a 35-year-old German patient with a 3 weeks travel history in Indonesia was initially misidentified as non-steroidal anti-inflammatory-drug associated colitis in colonoscopy and histopathological analysis. Furthermore, initial stool examination by microscopy and Entamoeba faecal antigen ELISA did not reveal any protozoan infection. When cessation of non-steroidal anti-inflammatory drug (NSAID) use and mesalazine treatment did not lead to clinical improvement, the patient presented to a specialist for tropical diseases. An intensive reinvestigation including a workup of formalin-fixed, paraffin-embedded colonic biopsies by molecular analysis with real-time PCR and fluorescence in situ hybridization (FISH) proofed the diagnosis of Entamoeba histolytica colitis. Molecular methods including real-time PCR and FISH for the diagnosis of amoebiasis from histopathological samples are rarely used for the diagnosis of E. histolytica infections. Bloody diarrhoea vanished after the onset of metronidazole treatment. In conclusion, the here-presented case demonstrates how modern molecular diagnostics may help to diagnose E. histolytica-associated colitis, even from difficult specimens like paraffin-embedded, formalin-fixed tissue.

Metagenomic Sequencing for the Diagnosis of Plasmodium spp. with Different Levels of Parasitemia in EDTA Blood of Malaria Patients-A Proof-of-Principle Assessment

Molecular diagnostic approaches are increasingly included in the diagnostic workup and even in the primary diagnosis of malaria in non-endemic settings, where it is difficult to maintain skillful microscopic malaria detection due to the rarity of the disease. Pathogen-specific nucleic acid amplification, however, bears the risk of overlooking other pathogens associated with febrile illness in returnees from the tropics. Here, we assessed the discriminatory potential of metagenomic sequencing for the identification of different Plasmodium species with various parasitemia in EDTA blood of malaria patients. Overall, the proportion of Plasmodium spp.-specific sequence reads in the assessed samples showed a robust positive correlation with parasitemia (Spearman r = 0.7307, p = 0.0001) and a robust negative correlation with cycle threshold (Ct) values of genus-specific real-time PCR (Spearman r = -0.8626, p ≤ 0.0001). Depending on the applied bioinformatic algorithm, discrimination on species level was successful in 50% (11/22) to 63.6% (14/22) instances. Limiting factors for the discrimination on species level were very low parasitemia, species-depending lacking availability of reliable reference genomes, and mixed infections with high variance of the proportion of the infecting species. In summary, metagenomic sequencing as performed in this study is suitable for the detection of malaria in human blood samples, but the diagnostic detection limit for a reliable discrimination on species level remains higher than for competing diagnostic approaches like microscopy and PCR.

Imported Panton-valentine leucocidin (PVL)-positive Staphylococcus aureus skin infections: patients' perspective on quality of life and quality of medical care

PVL-positive S. aureus skin and soft tissue infections have a major impact on quality of life and mental health, often for months and beyond the period of infection. Pre-treating physicians were poorly informed about the PVL toxin. Increased awareness for early diagnosis and treatment of this yet neglected disease are required.

Persistent abdominal symptoms in returning travellers: clinical and molecular findings

BACKGROUND

Persistent abdominal symptoms (PAS) are the leading cause of post-travel morbidity although there is a paucity of evidence concerning the aetiology of this condition. Recently molecular methods for protozoa detection in stool have been introduced. Herein, we describe the clinical aspects and the prevalence of gastrointestinal protozoa in returning travellers with PAS.

METHODS

From 2017 to 2019, clinical information and stool specimens from returning travellers with PAS were analysed for the presence of parasites using the Allplex-GI-Parasite-assay. Stool findings from symptomatic patients without a travel history were used as a comparator.

RESULTS

During the 2-year study, 203 stool specimens from returning travellers were analysed. The median duration of symptoms before seeking care was 6 months, the most common symptoms were fatigue (79.2%), abdominal pain (75.7%) and loose stool (70.8%).Most of travellers had returned from Asia (57.6%), mainly from the Indian-subcontinent and only 52.6% were backpackers. Altogether, 36.9% samples were positive for protozoa, with Blastocystis hominis being the most common (26.6%) in samples, followed by Dientamoeba fragilis (18.7%), Giardia lamblia (3.0%) and Cryptosporidium spp (0.5%). The former two were dominant in all regions. In all cases but one, G. lamblia was acquired, but one were acquired in the Indian subcontinent (odds ratios 16.9; 95% confidence intervals: 1.9-148.3). Entamoeba histolytica was not detected. The demographic characterization of the 1359 non-travellers was comparable with the travellers. Among them D. fragilis was the most common followed by B. hominis, which was significantly less frequent compared among the travellers (16.7% vs 26.6%, P < 0.001). Average Cycle threshold values for each stool parasites were comparable between the two groups.

CONCLUSION

Among returning travellers with PAS, more than one-third were positive for gastrointestinal protozoa. A low rate of giardia was found and no E. histolytica while B. hominis followed by D. fragilis were the dominant findings. Further studies are required to better understand the role of these protozoa in PAS.

Multicentric Evaluation of SeeGene Allplex Real-Time PCR Assays Targeting 28 Bacterial, Microsporidal and Parasitic Nucleic Acid Sequences in Human Stool Samples

Prior to the implementation of new diagnostic techniques, a thorough evaluation is mandatory in order to ensure diagnostic reliability. If positive samples are scarcely available, however, such evaluations can be difficult to perform. Here, we evaluated four SeeGene Allplex real-time PCR assays amplifying a total of 28 bacteria, microsporidal and parasitic nucleic acid sequence targets in human stool samples in a multicentric approach. In the assessments with strongly positive samples, sensitivity values ranging between 13% and 100% were recorded for bacteria, between 0% and 100% for protozoa and between 7% and 100% for helminths and microsporidia; for the weakly positive samples, the recorded sensitivity values for bacteria ranged from 0% to 100%; for protozoa, from 0% to 40%; and for helminths and microsporidia, from 0% to 53%. For bacteria, the recorded specificity was in the range between 87% and 100%, while a specificity of 100% was recorded for all assessed PCRs targeting parasites and microsporidia. The intra- and inter-assay variations were generally low. Specifically for some helminth species, the sensitivity could be drastically increased by applying manual nucleic acid extraction instead of the manufacturer-recommended automatic procedure, while such effects were less obvious for the bacteria and protozoa. In summary, the testing with the chosen positive control samples showed varying degrees of discordance between the evaluated Allplex assays and the applied in-house reference assays associated with higher cycle threshold values in the Allplex assays, suggesting that samples with very low pathogen densities might be missed. As the targeted species can occur as harmless colonizers in the gut of individuals in high-endemicity settings as well, future studies should aim at assessing the clinical relevance of the latter hint.

Arthropod exposure accounts for about half of skin disorders in returning travellers

We report the spectrum of skin diseases in returning international travellers seen in our department, with the participation of a dermatologist for each consultation. Of 135 dermatoses (60% appearing abroad), 33.3% were considered as tropical, and 44–52% were related to arthropod exposure, highlighting the need and importance of anti-mosquito measures.

Epidemiological characteristics of imported respiratory infectious diseases in China, 2014‒2018

Background

With the progress of globalization, international mobility increases, greatly facilitating cross-border transmission of respiratory infectious diseases (RIDs). This study aimed to analyze the epidemiological characteristics and factors influencing imported RIDs, with the goal of providing evidence to support adoption of high-tech, intelligent methods to early find imported RIDs and prevent their spread in China.

Methods

We obtained data of imported RIDs cases from 2014 to 2018 from the Inbound Sentinel Network of Customs and the National Notifiable Diseases Reporting System in China. We analyzed spatial, temporal, and population distribution characteristics of the imported RIDs. We developed an index to describe seasonality. Pearson correlation coefficients were used to examine associations between independent variables and imported cases. Data analyses and visualizations were conducted with R software.

Results

From a total of 1 409 265 253 inbound travelers, 31 732 (2.25/100 000) imported RIDs cases were reported. RIDs cases were imported from 142 countries and five continents. The incidence of imported RIDs was nearly 5 times higher in 2018 (2.81/100 000) than in 2014 (0.58/100 000). Among foreigners, incidence rates were higher among males (5.32/100 000), 0–14-year-olds (15.15/100 000), and cases originating in Oceania (11.10/100 000). The vast majority (90.3%) of imported RIDs were influenza, with seasonality consistent with annual seasonality of influenza. The spatial distribution of imported RIDs was different between Chinese citizens and foreigners. Increases in inbound travel volume and the number of influenza cases in source countries were associated with the number of imported RIDs.

Conclusions

Our study documented importation of RIDs into China from 142 countries. Inbound travel poses a significant risks bringing important RIDs to China. It is urgent to strengthen surveillance at customs of inbound travelers and establish an intelligent surveillance and early warning system to prevent importation of RIDs to China for preventing further spread within China.

Graphical Abstract

Key informant perspectives on sexual health services for travelling young adults: a qualitative study

BACKGROUND

International travel has become increasingly popular among young adults. Young adults often engage in casual sexual relationships abroad, exhibit sexual risk behaviours and may thus be at risk of contracting sexually transmitted and blood-borne infections. Pre-travel interventions and consultations may mitigate this risk. At present, we know little about sexual health-related pre-travel interventions. The aim of this study was therefore to document key informants' experiences, perceptions and recommendations in the context of sexual health of young adult travellers.

METHODS

Key informants were professionals working in Ottawa, Canada travel clinics, travel organizations or sexual health clinics with a young adult clientele. This study used a qualitative approach and consisted of 13 in-person or Skype semi-structured interviews with key informants. Thematic content analysis was informed by a sexual health framework, with themes emerging both inductively and deductively.

RESULTS

Sexual health was not common in pre-travel interventions described by key informants. Risk-assessment, and practical or purpose-driven pre-travel interventions were identified, resulting in risk mitigation strategies tailored to the destination region and/or mission/culture of the travel organization. Dissemination (e.g. limited time, lack of training) and uptake (e.g. young adults' embarrassment, provider discomfort, financial constraints) barriers limited in-depth discussions of pre-travel interventions related to sexual health. Key informants acknowledged the importance of early sexual health education, and recommended ongoing, comprehensive sexual education for both youth and young adults.

CONCLUSION

The findings of this study suggest that more time and resources should be allocated to the topic of sexual health during pre-travel interventions with young adults. Professionals who guide and prepare young adults for travel must develop concomitant skills in sexual health promotion. Early, comprehensive sexual education is recommended to improve overall sexual health in young adults and mitigate risk behaviours during travel.