Emergence and dissemination of multi-drug resistant (MDR) and extensive drug-resistant (XDR) bacteria are an increasing public health problem, notably for extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) [1]. International travels in particular play an important part in the worldwide spread of MDR bacteria [2]. According to the United Nations Migration Agency, we are facing a dramatic increase in the number of displaced people across various regions of the world. Since 2015, more than 2 million migrants have entered Europe during the recent refugee crisis [3].

Migrants are exposed to an increased risk of carriage of MDR bacteria and various other infectious diseases due to supposed higher prevalence rates in countries of origin [4], adverse migratory conditions (such as compromised hygiene and sanitation arrangements, overcrowding in containment areas) [5, 6], limited access to healthcare systems [7], and poor living conditions after resettlement [8]. Exposure to violence and trauma during migration, as well as difficult post-migratory living conditions, have been linked to serious psychological disorders in settled migrants [9, 10].

Few studies, summarised in a recent review [11], are available concerning the rate of anti-microbial resistance (AMR) carriage in newly-arrived migrants in Europe. Rates of MDR bacteria (ESBL-E and methicillin-resistant Staphylococcus aureus (MRSA)) carriage range between 20% [12, 13] and 60% [14] in Germany, and between 25% and 30% in Italy [15] and the Netherlands [16], respectively. No such data are available in France. Concerning infectious diseases, high rates of latent tuberculosis and hepatitis B infections have been reported in refugee and asylum seekers in various countries around Europe [17, 18]. In a recent French study performed by Médecins du Monde, rates of positive testing for HIV, HBV and HCV were respectively of 3.6%, 10.9%, and 8.6% in newly-arrived migrants. Syphilis testing was positive for 1.6% of patients and rates of Chlamydiae trachomatis (CT), and Neisseria gonorrhoeae infections were of 6.4% and 1.6%, respectively [19]. The European Centre for Disease Prevention and Control (ECDC) recommends the screening of latent tuberculosis, HIV, HCV, HBV, schistosomiasis, and strongyloidiasis for newly-arrived migrants depending on their country of origin [20]. However, there is likely significant heterogeneity in screening practices across France and in Europe, which emphasises the need for additional data.

Lastly, literature is scarce concerning the mental health of migrants arriving in France. Studies suggest that exposure to traumatic experiences before and during migration and post-migration stress are associated with psychiatric disorders such as depression, anxiety, and post-traumatic stress disorder (PTSD) [9, 21]. In a systematic review performed in 2005, symptoms of PTSD and depression were reported in 9% and 5% of refugees, respectively [10], and more recent data are lacking.

The objectives of this study were 1) to estimate the rate of carriage of MDR and XDR bacteria, 2) to identify factors associated with AMR carriage, 3) to evaluate rates of HIV, HBV, HCV, syphilis, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and schistosomiasis infections, 4) and to screen for history of physical or sexual abuse and symptoms evocative of depression or PTSD in hospitalised migrants in and out settings.

Over the one-year period, 1023 records were screened, and 101 patients were included in the present analysis after identification of 148 eligible patients and exclusion of 47 (Figure 1). Among these, 71 were male (70.3%), with a median age (IQR [Q1, Q3]) of 30 years (12 [24, 36]). Seventy-nine (78.2%) originated from Sub-Saharan Africa and 30 (30.9%) were asylum seekers. The principal routes of migration were by direct flight (n = 31, 32%), through Libya and Italy (n = 32, 33%), and through Morocco and Spain (n = 24, 24.7%). The median duration of migration (IQR [Q1, Q3]) was 21.7 weeks (70.4 [0.14, 70.5]), and 30.1% of patients had been in at least one refugee camp. In France, 65% lived in poor conditions (homelessness or living in temporary accommodations, including shelters, refugee camps or hostels) (Table 1).

In this cross-sectional study of migrant individuals coming to France mainly from Sub-Saharan Africa, MDR bacteria carriage was estimated at 20.7% [95% CI: 12.4; 28.9%]. To our knowledge, this is the first such study to be carried out in France and reporting the prevalence of AMR in migrants. AMR carriage in the general French population has been estimated around 6% in 2011 [22]. Recently-arrived migrants therefore seem to have higher AMR carriage rates than the French population. This higher rate has already been described in other European countries, and mostly ranged between 20 and 30% [12, 15, 16].

E-ESBL were the most frequent MDR bacteria isolated (16.3%), as previously reported [11]. To our knowledge, our study is the first to identify ESBL with all but one enzyme being CTX-M-15, confirming the spread and globalization of CTX-M enzymes and especially CTX-M-15 [23].

One of the most interesting results of this study is the significantly higher risk of ESBL-E carriage in cases of direct migratory trajectory by flight (p = 0.033) and a trend towards a higher risk in cases of shorter duration of migration (p = 0.074). This suggests that the country of origin may be an important marker for AMR carriage in newly-arrived migrants. The importance of the country of origin was previously described in a study in Switzerland, where a higher risk of ESBL-E carriage for patients was reported in patients originating from the Middle East [24]. However, a recent meta-analysis of previous European studies highlighted higher AMR prevalence in high-migrant community settings (refugee centers or outpatient’s clinics), suggesting that AMR carriage was mostly acquired during transit or in migrant settings [11]. Indeed, in the literature, adverse migratory conditions such as compromised hygiene and overcrowding in containment areas have been linked to increasing infectious diseases transmission [6]. Thus, both countries of origin and migratory conditions may have a role in AMR carriage acquisition and transmission.

We also found that older age was significantly associated with ESBL carriage, which to our knowledge has not been previously reported. As the patterns of migration in Europe are likely to evolve over time, with an expected generalization of migration from populations of more diverse age groups, this aspect certainly warrants further consideration.

High rates of venereal diseases such CT infections were found in our study (7.8% [95% CI: 1.8–13.8%]). It should however be noted that this could be confounded by similarly high rates of HIV infection in our population, due to bias caused by reasons for hospital referral. It can also be mentioned that CT infections were screened in vaginal or urinal samples and not in pharyngeal or rectal ones that may have led to underestimate CT prevalence. However, similar rates (6.4%) were previously reported in a study of newly-arrived migrants tested on a voluntary basis [19]. These rates remain high compared to the 3.8% globally observed in 2016 [25]. Screening for venereal diseases is not recommended for newly-arrived migrants. Our data suggest that it should be considered for systematic screening.

Serological evidence for schistosomiasis was found in 15% of patients originating from Sub-Saharan Africa. This high prevalence is similar to the 17% already reported in Italy [26], and strongly suggests the need for systematic screening in these populations. A recent European review confirmed the safety, high effectiveness, and cost-effectiveness of systematic screening of schistosomiasis and praziquantel-based treatment for newly-arrived migrants from endemic countries [27].

Hemoglobin electrophoresis was systematically performed in patients originating from sub-Saharan Africa and showed abnormalities in almost a quarter (22.4%) of cases, including 10.3% of sickle cell disease trait. In France, high-risk population could benefit from early diagnosis in order to prevent complications. Testing for sickle cell disease trait in migrants originated from Sub-Saharan could also lead to information about prenatal diagnosis. No data seemed available on this topic in the literature.

The high rates of psychological symptoms are a significant concern. Indeed, symptoms of depression and anxiety (from excessive irritability to PTSD) were reported in 53.2% [95% CI: 43.1–63.3%] and 60.4% [95% CI: 50.4–70.5%] of patients, respectively. This is higher than was previously reported in the literature: from 5 to 30% for depression and from 10 to 30% for PTSD [10, 28]. Psychological symptoms may be explained by pre-displacement factors, including political persecution, gender, and sexual orientation, and by post-displacement factors, such as social isolation and difficulties in finding employment and housing [29]. Once diagnosed, providing access and continuity to appropriate mental health care for these patients remains a significant challenge, due in part to infrequent recourse to healthcare professionals, lack of social security coverage, and to cultural considerations. Psychiatric symptoms in this setting are however barriers to social integration [30], and are likely to have long-term repercussions on the overall health of migrants. This highlights the urgent need for increased medical awareness of these issues and improvements in the screening and care for mental health in migrants.

The main limitations of our study are the small sample size and the retrospective nature that implies some missing data. Due to the low sample size of our study and the number of missing data for some co-variables, our study may be underpowered and therefore, have underestimated the prevalence of studied conditions and the association between ESBL carriage and some exposure variables. All the screening tests are routinely performed and correspond to the usual practice of our department, which minimizes the risk for recruitment bias and limits the amount of missing data. It is important to notice that the patients included in our study were specifically referred to our department for medical care, and therefore are not representative of the general migrant population. However, reasons for hospitalization were not directly related to the studied conditions which minimizes the risk for recruitment bias. Furthermore, as recommended in France (High Council of Public Health 2019), AMR carriage research was performed as soon as the patients are hospitalized in order to reduce any over risk directly related to hospital settings. Screening patients in first referral medical centers would improve the sensitivity of these analyses.

The European Center for Disease Prevention and Control recently published guidelines on screening for infectious diseases in newly-arrived migrants [20]. This study adds necessary data concerning the health of recently-arrived migrants. As high rates of MDR carriage, of CT infections, and of psychological disorders were observed in our population, the results of this study should argue for the addition of these conditions to a comprehensive screening policy of all newly-arrived migrants.

Finally, more comprehensive data regarding the global prevalence of AMR carriage are required, particularly in low-income countries where increased use of antibiotics is likely to increase the prevalence the prevalence of MDR bacteria. This would allow for a better understanding of the dynamics of dissemination of AMR carriage on a global scale and mitigate the risk of the spreading of an AMR pandemic.