The practice of travel medicine in Europe

Epidemiological Investigations of Infectious Diseases among Mobile Populations at the University Hospital Institute Mediterranean Infection in Marseille, France

We review the most recent work conducted by our group on the circulation of infectious agents in mobile populations, including pilgrims participating in the Hajj (Mecca, Saudi Arabia) and the Grand Magal of Touba (Senegal) pilgrimages, homeless people, and medical students participating in an elective abroad. Using a similar epidemiological study design with standardized questionnaires and molecular assays allows comparison of different populations of travelers. The main infectious pathogens and antibiotic resistance genes linked to travel were identified in certain specific populations of travelers, as well as in a group of homeless migrant people in Marseille. The role of several risk factors has also been demonstrated, allowing identifying individuals at increased risk of disease or pathogen carriage on which to base targeted preventive measures. Such results, together with those obtained through international surveillance networks allow better description of the epidemiology of travel-associated infectious diseases.

Mobile apps for travel medicine and ethical considerations: A systematic review

BACKGROUND

The advent of mobile applications for health and medicine will revolutionize travel medicine. Despite their many benefits, such as access to real-time data, mobile apps for travel medicine are accompanied by many ethical issues, including questions about security and privacy.

METHODS

A systematic literature review as conducted following PRISMA guidelines. Database screening yielded 1795 results and seven papers satisfied the criteria for inclusion. Through a mix of inductive and deductive data extraction, this systematic review examined both the benefits and challenges, as well as ethical considerations, of mobile apps for travel medicine.

RESULTS

Ethical considerations were discussed with varying depth across the included articles, with privacy and data protection mentioned most frequently, highlighting concerns over sensitive information and a lack of guidelines in the digital sphere. Additionally, technical concerns about data quality and bias were predominant issues for researchers and developers alike. Some ethical issues were not discussed at all, including equity, and user involvement.

CONCLUSION

This paper highlights the scarcity of discussion around ethical issues. Both researchers and developers need to better integrate ethical reflection at each step of the development and use of health apps. More effective oversight mechanisms and clearer ethical guidance are needed to guide the stakeholders in this endeavour.

PCR Multiplexing Based on a Single Fluorescent Channel Using Dynamic Melting Curve Analysis

Since its invention in 1986, the polymerase chain reaction (PCR), has become a well-established method for the detection and amplification of deoxyribonucleic acid (DNA) with a specific sequence. Incorporating fluorescent probes, known as TaqMan probes, or DNA intercalating dyes, such as SYBR Green, into the PCR mixture allows real-time monitoring of the reaction progress and extraction of quantitative information. Previously reported real-time PCR product detection using intercalating dyes required melting curve analysis (MCA) to be performed following thermal cycling. Here, we propose a technique to perform dynamic MCA during each thermal cycle, based on a continuous fluorescence monitoring method, providing qualitative and quantitative sample information. We applied the proposed method in multiplexing detection of hepatitis B virus DNA and complementary DNA of human immunodeficiency virus as well as glyceraldehyde 3-phosphate dehydrogenase in different concentration ratios. We extracted the DNA melting curve and its derivative from each PCR cycle during the transition from the elongation to the denaturation temperature with a set heating rate of 0.8 K·s^-1and then used the data to construct individual PCR amplification curves for each gene to determine the initial concentration of DNA in the sample. Our proposed method allows researchers to look inside the PCR in each thermal cycle, determining the PCR product specificity in real time instead of waiting until the end of the PCR. Additionally, the slow transition rate from elongation to denaturation provides a dynamic multiplexing assay, allowing the detection of at least three genes in real time.

Chikungunya resurgence in the Maldives and risk for importation via tourists to Europe in 2019-2020: A GeoSentinel case series

Background

Chikungunya virus (CHIKV) is an arthropod-borne virus mainly transmitted in tropical areas by Aedes spp. mosquitoes. It has been responsible for small-to-large outbreaks in temperate areas including southern Europe and North America. Past outbreaks in 2006 on the islands of Maldives, as well as on other islands in the Indian Ocean and in Southeast Asia, demonstrated for the first time the capacity of CHIKV to disseminate through travel and transcontinental commerce, and revealed the major socio-economic impact of CHIKV epidemics. Recently, CHIKV has been circulating in highly touristic areas including the Maldives, where 1736 cases were notified by the Health Protection Agency during 2019.

Case series

Among EuroTravNet/GeoSentinel patient records, eight CHIKV-confirmed cases imported the Maldives to France, Germany, Denmark, Italy and Spain were identified between February 2019 and February 2020; exceeding the total number of CHIKV infections travel-acquired in Maldives reported to this surveillance network during the previous 10 years.

Conclusions

The prevention and control of CHIKV introduction into naïve areas colonised by competent vectors is crucial. CHIKV outbreaks must be detected and reported in a timely manner. This must lead to adapted health information for international travellers and to prompt management of suspected imported cases. Conversely, travellers make for excellent sentinels and increased reports of imported cases might reflect a change in the level of endemicity or even herald an outbreak. Feedback to the local health authorities and matching this with local epidemiological surveillance data may lead to health benefits for the local population.

Mobile populations across the Mediterranean Sea and beyond: travel medicine, mass gathering medicine and homeless health

The Méditerranée Infection institute is internationally recognized for its expertise in infectious diseases and tropical medicine, and is one of the most active research centres for infectious diseases in Europe. Surveillance and research addressing infectious diseases in globally mobile populations is one of the strong components of the research conducted at the institute. A significant amount of clinical, microbiologic and epidemiologic works have been conducted in international travellers, pilgrims participating in large international religious gatherings, economic migrants and homeless migrant people over the last decades by our group. Our strong anchoring in several countries around the Mediterranean Sea and beyond, as well as the pivotal role of Marseille in the EuroTravNet and GeoSentinel international networks that monitor travel-associated diseases, reinforce our leading position in the fields of travel and tropical medicine, mass gathering medicine and homeless health.

A meta-analysis and systematic literature review of factors associated with sexual risk-taking during international travel

BACKGROUND

International travel facilitates global spread of sexually transmitted infections (STI). Travellers could contribute to onward transmission of pathogens rarely encountered at home and export new strains to the destination. The aim was to systematically examine evidence regarding determinants of travel-related sexual risk-taking and identify knowledge gaps and areas for targeted interventions.

METHOD

Articles published in peer-reviewed journals from 2000 to 2017 were screened in 6 databases and assessed for relevance against criteria. Data was extracted for factors associated with travel-related STI or proxies. Meta-analyses estimated pooled prevalence of casual sex and non-condom use. Adjusted odds ratios of predictors were pooled to generate a combined estimate.

RESULT

Forty-nine articles qualified for inclusion. A heterogeneity test indicated variation across studies. The pooled prevalence of casual travel sex was 35% and prevalence of non-condom use 17%. Expectations of casual sex strongly predicted sex with a new partner when travelling abroad. Planning to have sex indicated condom use.

CONCLUSION

The studies largely represented sub-groups of risk-taking populations from a European context, indicating substantial knowledge gaps. Studies investigating migrants travelling to visit friends and relatives, older travellers, and female travelers are needed. Post-travel harm reduction activities may serve as a focus for future interventions.

Travel-related infection in European travelers, EuroTravNet 2011

BACKGROUND

Limited data exist on infectious diseases imported to various locations in Europe, particularly after travel within the continent.

METHODS

To investigate travel-related disease relevant to Europe that is potentially preventable through pre-travel intervention, we analyzed the EuroTravNet database of 5,965 ill travelers reported by 16 centers in "Western" Europe in 2011.

RESULTS

There were 54 cases of vaccine-preventable disease, mostly hepatitis A (n = 16), typhoid fever (n = 11), and measles (n = 8); 6 cases (including 3 measles cases) were associated with travel within "Western" Europe. Malaria was the most commonly diagnosed infection (n = 482, 8.1% of all travel-related morbidity). Among patients with malaria, the military most commonly received pre-travel advice (95%), followed by travelers for missionary, volunteer, research, or aid work (81%) but travelers visiting friends and relatives (VFRs) were least likely to receive pre-travel advice (21%). The vast majority (96%) of malaria patients were resident in "Western" Europe, but over half (56%) were born elsewhere. Other significant causes of morbidity, which could be reduced through advice and behavioral change, include Giardia (n = 221, 3.7%), dengue (n = 146, 2.4%), and schistosomiasis (n = 131, 2.2%). Of 206 (3.5%) travelers with exposure in "Western" Europe, 75% were tourists; the highest burden of disease was acute gastrointestinal infection (35% cases). Travel from "Eastern" Europe (n = 132, 2.2%) was largely associated with migration-related travel (53%); among chronic infectious diseases, tuberculosis was frequently diagnosed (n = 20). Travelers VFRs contributed the largest group of malaria patients (46%), but also had the lowest documented rate of pre-travel health advice in this subset (20%). Overall, 44% of nonimmigrant ill travelers did not receive pre-travel advice.

CONCLUSION

There is a burden of infectious diseases in travelers attending European health centers that is potentially preventable through comprehensive pre-travel advice, chemoprophylaxis, and vaccination. Targeted interventions for high-risk groups such as travelers VFRs and migration-associated travelers are of particular importance.

Travel reported by pilgrims from Marseille, France before and after the 2010 Hajj

Sixty-seven percent of French pilgrims reported to have traveled out of France just before the 2010 Hajj (mainly in North Africa) and 26% planned to do so after leaving Saudi Arabia. Surveillance of Hajj-associated infectious diseases in returned French pilgrims should be coordinated between France and North African countries.

Knowledge and interests of Romanian medical students in parasitology, tropical and travel medicine

As travel has become easier and faster, the rate of tropical infections across the world is expected to increase; more students working abroad are going to encounter these diseases more often. Disorders of parasitic etiology play an important role in travel and tropical medicine. The aim of our study was to assess the preclinical students' knowledge regarding parasitic diseases, tropical and travel medicine in the broad context of their professional background. A total of 346 Romanian medical students completed a 13-item questionnaire on the above-mentioned topics. In order to allow for complex evaluation, the questionnaire also included items related to their extracurricular training as well as their future perspectives. The majority of the students (97.7%) declared they had prior knowledge (before studying parasitology) of malaria. Most of the responders (90.2%) knew that a journey in (sub)tropical regions requires adequate prophylactic measures. About a quarter of those interviewed (26.4%) would agree to practice tropical medicine after graduation. They were mainly interested in helping people from underdeveloped countries regardless of remuneration (52.7%). The majority of students (59.8%) wished to practice clinical medicine. It has been observed that fewer than 5% of the questioned students had ever read a scientific paper or book in the field of tropical medicine. English was the most commonly spoken foreign language (92.8%), and 99.1% of students had at least intermediate computer skills. Finally, 71.6% of students would choose to practice the specialty of travel medicine if it were available in Romania. The implementation of appropriate measures towards the globalization of medical teaching in Romanian universities should represent an important issue in this new millennium, in which borders between various nations are starting to fade; otherwise the next generations of physicians will lose the chance to gain wider experiences and share the international influences on health.

Travel and migration associated infectious diseases morbidity in Europe, 2008

BACKGROUND

Europeans represent the majority of international travellers and clinicians encountering returned patients have an essential role in recognizing, and communicating travel-associated public health risks.

METHODS

To investigate the morbidity of travel associated infectious diseases in European travellers, we analysed diagnoses with demographic, clinical and travel-related predictors of disease, in 6957 ill returned travellers who presented in 2008 to EuroTravNet centres with a presumed travel associated condition.

RESULTS

Gastro-intestinal (GI) diseases accounted for 33% of illnesses, followed by febrile systemic illnesses (20%), dermatological conditions (12%) and respiratory illnesses (8%). There were 3 deaths recorded; a sepsis caused by Escherichia coli pyelonephritis, a dengue shock syndrome and a Plasmodium falciparum malaria.GI conditions included bacterial acute diarrhea (6.9%), as well as giardiasis and amebasis (2.3%). Among febrile systemic illnesses with identified pathogens, malaria (5.4%) accounted for most cases followed by dengue (1.9%) and others including chikungunya, rickettsial diseases, leptospirosis, brucellosis, Epstein Barr virus infections, tick-borne encephalitis (TBE) and viral hepatitis. Dermatological conditions were dominated by bacterial infections, arthropod bites, cutaneous larva migrans and animal bites requiring rabies post-exposure prophylaxis and also leishmaniasis, myasis, tungiasis and one case of leprosy. Respiratory illness included 112 cases of tuberculosis including cases of multi-drug resistant or extensively drug resistant tuberculosis, 104 cases of influenza like illness, and 5 cases of Legionnaires disease. Sexually transmitted infections (STI) accounted for 0.6% of total diagnoses and included HIV infection and syphilis. A total of 165 cases of potentially vaccine preventable diseases were reported. Purpose of travel and destination specific risk factors was identified for several diagnoses such as Chagas disease in immigrant travellers from South America and P. falciparum malaria in immigrants from sub-Saharan Africa. Travel within Europe was also associated with health risks with distinctive profiles for Eastern and Western Europe.

CONCLUSIONS

In 2008, a broad spectrum of travel associated diseases were diagnosed at EuroTravNet core sites. Diagnoses varied according to regions visited by ill travellers. The spectrum of travel associated morbidity also shows that there is a need to dispel the misconception that travel, close to home, in Europe, is without significant health risk.