Imported infectious diseases in migrants from Latin America: A retrospective study from a referral centre for tropical diseases in Spain, 2017-2022

INTRODUCTION

Detecting imported diseases by migrants and individuals visiting friends and relatives (VFR) is key in the prevention and management of emergent infectious diseases acquired abroad.

METHODS

Retrospective descriptive study on migrants and VFR from Central and South America between 2017 and 2022 attended at a National Referral Centre for Tropical Diseases in Madrid, Spain. Demographic characteristics, syndromes and confirmed travel-related diagnoses were obtained from hospital patient medical records.

RESULTS

1654 cases were registered, median age of 42 years, 69.1% were female, and 55.2% were migrants. Most cases came from Bolivia (49.6%), followed by Ecuador (12.9%). Health screening while asymptomatic (31.6%) was the main reason for consultation, followed by Chagas disease follow-up (31%). Of those asymptomatic at screening, 47,2% were finally diagnosed of any disease, mainly Chagas disease (19,7%) and strongyloidiasis (10,2%) CONCLUSION: Our study emphasizes the importance of proactive health screening to detect asymptomatic conditions in migrants and VFR, enabling timely intervention and improved health outcomes. By understanding the unique health profiles of immigrant populations, targeted public health interventions can be devised to safeguard the well-being of these vulnerable groups.

Advances in new target molecules against schistosomiasis: A comprehensive discussion of physiological structure and nutrient intake

Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is the only recommended drug for human schistosome infection. However, the lack of efficacy of praziquantel against juvenile worms and concerns about the emergence of drug resistance are driving forces behind the research for an alternative medication. Schistosomes are obligatory parasites that survive on nutrients obtained from their host. The ability of nutrient uptake depends on their physiological structure. In short, the formation and maintenance of the structure and nutrient supply are mutually reinforcing and interdependent. In this review, we focus on the structural features of the tegument, esophagus, and intestine of schistosomes and their roles in nutrient acquisition. Moreover, we introduce the significance and modes of glucose, lipids, proteins, and amino acids intake in schistosomes. We linked the schistosome structure and nutrient supply, introduced the currently emerging targets, and analyzed the current bottlenecks in the research and development of drugs and vaccines, in the hope of providing new strategies for the prevention and control of schistosomiasis.

Geographical Influence on Morphometric Variability of Genetically “Pure” Schistosoma haematobium Eggs from Sub-Saharan Migrants in Spain

Schistosome eggs play a key role in schistosomiasis diagnosis and research. The aim of this work is to morphogenetically study the eggs of Schistosoma haematobium found in sub-Saharan migrants present in Spain, analyzing their morphometric variation in relation to the geographical origin of the parasite (Mali, Mauritania and Senegal). Only eggs considered “pure” S. haematobium by genetic characterization (rDNA ITS-2 and mtDNA cox1) have been used. A total of 162 eggs obtained from 20 migrants from Mali, Mauritania and Senegal were included in the study. Analyses were made by the Computer Image Analysis System (CIAS). Following a previously standardized methodology, seventeen measurements were carried out on each egg. The morphometric analysis of the three morphotypes detected (round, elongated and spindle) and the biometric variations in relation to the country of origin of the parasite on the egg phenotype were carried out by canonical variate analysis. Mahalanobis distances, when all egg measurements were analyzed, showed differences between: (i) Mali-Mauritania, Mali-Senegal and Mauritania-Senegal in the round morphotype; (ii) Mali-Mauritania and Mauritania-Senegal in the elongated morphotype; and (iii) Mauritania-Senegal in the spindle morphotype. Mahalanobis distances, when spine variables were analyzed, showed differences between Mali-Senegal in the round morphotype. In conclusion, this is the first phenotypic study performed on individually genotyped “pure” S. haematobium eggs, allowing the assessment of the intraspecific morphological variations associated with the geographical origin of the schistosome eggs.

Clinical Spectrum of Schistosomiasis: An Update

Schistosomiasis is a helminthic infection and one of the neglected tropical diseases (NTDs). It is caused by blood flukes of the genus Schistosoma. It is an important public health problem, particularly in poverty-stricken areas, especially those within the tropics and subtropics. It is estimated that at least 236 million people worldwide are infected, 90% of them in sub-Saharan Africa, and that this disease causes approximately 300,000 deaths annually. The clinical manifestations are varied and affect practically all organs. There are substantial differences in the clinical presentation, depending on the phase and clinical form of schistosomiasis in which it occurs. Schistosomiasis can remain undiagnosed for a long period of time, with secondary clinical lesion. Here, we review the clinical profile of schistosomiasis. This information may aid in the development of more efficacious treatments and improved disease prognosis.

Commercial Simplex and Multiplex PCR Assays for the Detection of Intestinal Parasites Giardia intestinalis, Entamoeba spp., and Cryptosporidium spp.: Comparative Evaluation of Seven Commercial PCR Kits with Routine In-House Simplex PCR Assays

Nowadays, many commercial kits allowing the detection of digestive parasites by DNA amplification methods have been developed, including simplex PCR assays (SimpPCRa) allowing the identification of a single parasite, and multiplex PCR assays (MultPCRa) allowing the identification of several parasites at once. Thus, aimed at improving the diagnosis of intestinal protozoal infections, it is essential to evaluate the performances of these new tools. A total of 174 DNA samples collected between 2007 and 2017 were retrospectively included in this study. Performances of four commercial SimpPCRa (i.e., CerTest-VIASURE^TM) and three MultPCRa (i.e., CerTest-VIASURE^TM, FAST-TRACK-Diagnostics-FTD-Stool-Parasite^TM and DIAGENODE-Gastroenteritis/Parasite-panel-I^TM) were evaluated for the detection of Cryptosporidium spp., Entamoeba spp., and Giardia intestinalis in stool samples compared to our routinely used in-house SimpPCRa. Globally, the SimpPCRa showed better sensitivity/specificity for the detection of G. intestinalis, E. histolytica, E. dispar, and Cryptosporidium spp. (i.e., 96.9/93.6%; 100/100%; 95.5/100%; and 100/99.3%, respectively), compared to the three commercial MultPCRa tested. All in all, we showed that MultPCRa offer an interesting alternative for the detection of protozoans in stool samples depending on the clinical context.

Medical Advice for Travelers

BACKGROUND

In 2019, 1.5 billion international tourist trips were counted worldwide. Germany, with 70.8 million vacations lasting ≥ 5 days, was one of the populations most willing to travel. These days, even elderly and multimorbid persons regularly travel long-distance, which can be associated with significant health risks. By advising travelers and implementing preventive measures, the risk of illness can be reduced significantly.

METHODS

A selective survey of PubMed was performed to identify publications on medical advice for travelers between 2000 and 2020. We included guidelines, studies, and recommendations that mainly deal with the preventive aspects of travel medicine and have a high level of practical relevance and the highest possible level of evidence. Previously published guidelines (based on the GRADE criteria) were adopted, and recommendations not based on the results of scientific studies were characterized as Good Clinical Practice (GCP).

RESULTS

Many medical recommendations for travelers still rely on individualized, experience-based, or consensus-based assessments. Apart from a review of medical history and vaccination status, a risk analysis is performed, travel fitness is evaluated individually, and a prevention plan is designed. Particular attention is devoted to malaria prophylaxis, vector protection, and traveler's diarrhea. Medical advice before travel is especially important for the elderly, children, pregnant women, the chronically ill, long-term and adventure travelers as well as migrants from malaria-endemic areas who are returning home.

CONCLUSION

The health risks associated with travel can be minimized by specialist medical advice. Many recommendations are empirical in nature and require further research.

Mayaro Virus Pathogenesis and Transmission Mechanisms

Mayaro virus (MAYV), isolated for the first time in Trinidad and Tobago, has captured the attention of public health authorities worldwide following recent outbreaks in the Americas. It has a propensity to be exported outside its original geographical range, because of the vast distribution of its vectors. Moreover, most of the world population is immunologically naïve with respect to infection with MAYV which makes this virus a true threat. The recent invasion of several countries by Aedesalbopictus underscores the risk of potential urban transmission of MAYV in both tropical and temperate regions. In humans, the clinical manifestations of MAYV disease range from mild fever, rash, and joint pain to arthralgia. In the absence of a licensed vaccine and clinically proven therapeutics against Mayaro fever, prevention focuses mainly on household mosquito control. However, as demonstrated for other arboviruses, mosquito control is rather inefficient for outbreak management and alternative approaches to contain the spread of MAYV are therefore necessary. Despite its strong epidemic potential, little is currently known about MAYV. This review addresses various aspects of MAYV, including its epidemiology, vector biology, mode of transmission, and clinical complications, as well as the latest developments in MAYV diagnosis.

Malaria in Eritrean migrants newly arrived in seven European countries, 2011 to 2016

Global migration has resulted in a large number of asylum applications in Europe. In 2014, clusters of Plasmodium vivax cases were reported among newly arrived Eritreans. This study aimed to assess malaria among Eritrean migrants in Europe from 2011 to 2016. We reviewed European migration numbers and malaria surveillance data for seven countries (Denmark, Germany, Netherlands, Norway, Sweden, Switzerland and the United Kingdom) which received 44,050 (94.3%) of 46,730 Eritreans seeking asylum in Europe in 2014. The overall number of malaria cases, predominantly P. vivax, increased significantly in 2014 compared to previous years, with the largest increases in Germany (44 P. vivax cases in 2013 vs 294 in 2014, p < 0.001) and Sweden (18 in 2013 vs 205 in 2014, p < 0.001). Overall, malaria incidence in Eritreans increased from 1-5 to 25 cases per 1,000, and was highest in male teenagers (50 cases/1,000). In conclusion, an exceptional increase of malaria cases occurred in Europe in 2014 and 2015, due to rising numbers of Eritreans with high incidence of P. vivax arriving in Europe. Our results demonstrate potential for rapid changes in imported malaria patterns, highlighting the need for improved awareness, surveillance efforts and timely healthcare in migrants.

Imported human Schistosoma japonicum: A report on two cases in Filipino migrants present in Italy and a systematic review of literature

BACKGROUND

Schistosoma japonicum is endemic in the Philippines, China, and Indonesia, and is the third-most common schistosoma species. The infection can be asymptomatic for years but, if left untreated, can lead to irreversible complications.

METHOD

We report the results of a systematic review of the literature on imported S. japonicum infection and describe two previously unpublished cases diagnosed in Filipino migrants in Italy.

RESULTS

Twenty-five imported cases of S. japonicum schistosomiasis were retrieved. All patients but one were migrants. Most subjects acquired the infection in Philippines (n = 18, 72%). Median age at diagnosis was 46 years. Median period of residence in non-endemic countries before diagnosis was 14.5 years. Cases of prevalent hepatosplenic involvement were 10 (40%), those with prevalent intestinal involvement were 10 (40%), whereas five (20%) had overlapping manifestations. Ten patients suffered from cirrhosis; two underwent liver transplantation. Three patients presented with acute abdomen due to intestinal complications, leading to explorative laparotomy. In all cases, but one, the diagnosis was based on a histological examination of biopsy specimen, revealing S. japonicum ova. Seventeen patients were treated with praziquantel, and in three of them, possible treatment failures occurred.

CONCLUSIONS

S. japonicum infection is uncommonly reported in non-endemic areas, but is probably underestimated because of a low threshold awareness of clinicians and unavailability of specific diagnostic tools. Viable S. japonicum adults may persist for decades, indicating that migrants or travellers previously exposed in areas with high-risk areas can harbour viable worms and deserve treatment.

Low adherence with national travel medicine recommendations in Belgian expatriate children: A retrospective analysis

BACKGROUND

Expatriates (expats) from European countries regularly migrate to low-income countries where infectious diseases are more prevalent. Little evidence exists however on pediatric expatriates' compliance with preventive measures related to infectious diseases. This study aims to evaluate compliance in Belgian expat-children.

METHODS

Data of 135 Belgian expat-children, visiting the Institute of Tropical Medicine (Antwerp, Belgium), were collected from clinical notes, laboratory results and from a web-based immunization-register. Information on routine vaccinations, yellow fever, hepatitis A, rabies, typhoid fever, meningococcal ACW₁₃₅Y, Japanese encephalitis, BCG vaccine and anti-malaria chemoprophylaxis was collected.

RESULTS

Overall, 87% of expat-children were up-to-date with their routine vaccinations. Although all children were eligible for hepatitis A, typhoid and rabies vaccination, only 8-21% were fully vaccinated. Only 29 and 61% of eligible children were vaccinated against meningococcal (ACW₁₃₅Y) or yellow fever respectively. Finally, only 10% of children who lived in malaria-endemic-areas, reported chemoprophylaxis-use.

CONCLUSION

Although routine vaccination coverage in expat-children seems adequate, additional preventive measures are often needed. Whether this is due to lack of high-quality health care-access, fear of side-effects or insufficient knowledge about the risks/available preventive measures, remains elusive. Nevertheless, expats seem to constitute a separate risk-group for infectious diseases and destination-related health issues.

No chikungunya virus infections among Dutch long-term travellers to (sub)tropical countries: a prospective study 2008-2011

Background

Chikungunya is an arthropod-borne viral disease now identified in over 60 countries in Asia, Africa, Europe, and the Americas. Chikungunya virus (CHIKV) has spread in the last 15 years to many countries, causing large local outbreaks. CHIKV infection can be clinically misdiagnosed in areas where dengue and/or Zika infections occur. Prospective studies are necessary to calculate the true incidence rate of CHIKV infection in travellers. The aim of this study was to obtain the attack and incidence rates of CHIKV infection among long-term travellers and identify associated risk factors.

Methods

A previously collected prospective cohort of Dutch long-term travellers (12–52 weeks) to subtropical and tropical countries was tested. From December 2008 to September 2011, participants were recruited at the travel clinic of the Public Health Service Amsterdam. A weekly diary was kept during travel in which participants recorded their itinerary, symptoms, and physician visits. On return, their pre- and post-travel blood samples were tested for the presence of IgG antibodies to CHIKV antigen. Seroconversions were confirmed by an in-house CHIKV neutralisation test.

Results

The median age of 603 participants was 25 years (interquartile range [IQR]: 23–29); 35.7% were male; median travel duration was 20 weeks (IQR: 15–25), and purpose of travel was predominantly tourism (62%).

The presence of anti-CHIKV IgG in the pre-travel sample, suggestive of previous CHIKV infection, was found for 3/603 participants (0.5%); all three had been previously travelling in either Africa or Asia. In one traveler who visited Latin America, a seroconversion was found (0.2%) but the CHIKV neutralisation test was negative, making the incidence rate 0.

Conclusion

No chikungunya virus infections were found in this 2008–2011 prospective cohort of long-term travellers. We recommend the research be repeated, particularly as the sample size of our cohort might have been too small. Also, extensive spread of chikungunya virus has likely increased incidence rates among travellers since 2013.

Estimating the incidence of norovirus acute gastroenteritis among US and European international travelers to areas of moderate to high risk of traveler's diarrhea: a prospective cohort study protocol

Background

Acute gastroenteritis (AGE) is the leading cause of illness among returning travelers seeking medical care. Multiple types of enteric pathogens can cause travel-acquired AGE and, while bacterial pathogens have a predominant role, the importance of viruses, such as norovirus, is increasingly recognized. There is a lack of information on travel-acquired norovirus incidence among symptomatic and asymptomatic individuals irrespective of healthcare-seeking behavior. Our aim is to estimate the incidence of travel-acquired AGE due to norovirus and to characterize the burden of disease among international travelers from the United States and Europe.

Methods

We describe a prospective cohort study implemented in five US and European sites to estimate the role of AGE due to norovirus among adult international travelers. We enrolled individuals aged 18 years and older who are traveling to regions of moderate-high risk of AGE, or via cruise ship with an international port stop, with a trip duration of 3–15 days. The study will generate a wide range of health and travel-related data for pre-, during, and up to 6-months post-travel. We will identify laboratory-confirmed travel-acquired norovirus infections among both symptomatic and asymptomatic individuals from self-collected whole stool samples tested via quantitative RT-PCR. Coinfections will be identified in a subset of travelers with AGE using a multiplex molecular-based assay.

Discussion

This study is unique in design and breadth of data collected. The prospective collection of health and behavioral data, as well as biologic samples from travelers irrespective of symptoms, will provide useful data to better understand the importance of norovirus AGE among international travelers. This study will provide data to estimate the incidence of norovirus infections and AGE and the risk of post-infectious sequelae in the 6-month post-travel period serving as a baseline for future norovirus AGE vaccination studies. This study will contribute valuable information to better understand the role of norovirus in travel-acquired AGE risk and the impact of these infections on a broad set of outcomes.

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.

Imported malaria in Spain (2009-2016): results from the +REDIVI Collaborative Network

Background

Imported malaria is a frequent diagnosis in travellers and migrants. The objective of this study was to describe the epidemiological and clinical characteristics of patients diagnosed with imported malaria within a Spanish collaborative network registering imported diseases (+REDIVI). In addition, the possible association between malaria and type of case, gender, age or area of exposure was explored.

Methods

Cases of imported malaria were identified among all cases registered in the +REDIVI database during the period October 2009–October 2016. Demographic, epidemiological and clinical characteristics were analysed.

Results

In total, 11,816 cases of imported infectious diseases were registered in +REDIVI’s database between October 2009 and October 2016. Immigrants seen for the first time after migration accounted for 60.2% of cases, 21.0% of patients were travellers, and 18.8% were travellers/immigrants visiting friends and relatives (VFRs). There were 850 cases of malaria (850/11,816, 7.2%). Malaria was significantly more frequent in men than in women (56.8% vs 43.2%) and in VFR-immigrants (52.6%) as compared to travellers (21.3%), immigrants (20.7%) and VFR-travellers (5.4%) (p < 0.001). Although this data was not available for most patients with malaria, only a minority (29/217, 13.4%) mentioned correct anti-malarial prophylaxis. Sub-Saharan Africa was found to be the most common region of acquisition of malaria. Most common reason for consultation after travel was a febrile syndrome although an important proportion of immigrants were asymptomatic and presented only for health screening (27.3%). Around 5% of travellers presented with severe malaria. The most prevalent species of Plasmodium diagnosed was Plasmodium falciparum (81.5%). Malaria due to Plasmodium ovale/Plasmodium vivax was frequent among travellers (17%) and nearly 5% of all malaria cases in immigrants were caused by Plasmodium malariae.

Conclusions

Malaria was among the five most frequent diagnoses registered in +REDIVI’s database. Some significant differences were found in the distribution of malaria according to gender, type of case, species. Among all malaria cases, the most frequent diagnosis was P. falciparum infection in VFR-immigrant men.

Review of infectious diseases in refugees and asylum seekers-current status and going forward

An unprecedented rise in the number of asylum seekers and refugees was seen in Europe in 2015, and it seems that numbers are not going to be reduced considerably in 2016. Several studies have tried to estimate risk of infectious diseases associated with migration but only very rarely these studies make a distinction on reason for migration. In these studies, workers, students, and refugees who have moved to a foreign country are all taken to have the same disease epidemiology. A common disease epidemiology across very different migrant groups is unlikely, so in this review of infectious diseases in asylum seekers and refugees, we describe infectious disease prevalence in various types of migrants. We identified 51 studies eligible for inclusion. The highest infectious disease prevalence in refugee and asylum seeker populations have been reported for latent tuberculosis (9-45%), active tuberculosis (up to 11%), and hepatitis B (up to 12%). The same population had low prevalence of malaria (7%) and hepatitis C (up to 5%). There have been recent case reports from European countries of cutaneous diphtheria, louse-born relapsing fever, and shigella in the asylum-seeking and refugee population. The increased risk that refugees and asylum seekers have for infection with specific diseases can largely be attributed to poor living conditions during and after migration. Even though we see high transmission in the refugee populations, there is very little risk of spread to the autochthonous population. These findings support the efforts towards creating a common European standard for the health reception and reporting of asylum seekers and refugees.

Schistosomiasis in European Travelers and Migrants: Analysis of 14 Years TropNet Surveillance Data

Schistosomiasis remains one of the most prevalent parasitic diseases worldwide and the infection is frequently found in travelers and migrants. The European Network for Tropical Medicine and Travel Health conducted a sentinel surveillance study on imported schistosomiasis between 1997 and 2010. This report summarizes epidemiological and clinical data from 1,465 cases of imported schistosomiasis. Direct pathogen detection and serology were the main diagnostic tools applied. Of these, 486 (33%) cases were identified among European travelers, 231 (16%) among long-term expatriates, and 748 (51%) among non-European immigrants. Overall, only 18.6% of travelers had received pretravel advice; 95% of infections were acquired in the African region. On species level, Schistosoma mansoni was identified in 570 (39%) and Schistosoma haematobium in 318 (22%) cases; 57.5% of patients were symptomatic. Acute symptoms were reported in 27% of patients leading to earlier presentation within 3 months. Praziquantel was used in all patients to treat schistosomiasis. Many infections were detected in asymptomatic patients. In 47.4% of asymptomatic patients infection was detected by microscopy and in 39% by serology or antigen testing. Schistosomiasis remains a frequent infection in travelers and migrants to Europe. Travelers should be made aware of the risk of schistosomiasis infection when traveling to sub-Saharan Africa. Posttravel consultations particularly for returning expatriates are useful given the high potential for detecting asymptomatic infections.

Infectious Diseases in Immigrant Population Related to the Time of Residence in Spain

The aim of this study was to evaluate the data on the main imported infectious diseases and public health issues arising from the risk of transmission of tropical and common diseases in the immigrant population. During the period of study, 2,426 immigrants were attended in the Tropical Medicine Unit of the Hospital of Poniente. For each patient, a complete screening for common and tropical diseases was performed. The prevalence and main features of intestinal and urinary parasites, microfilarias, Chagas disease, malaria, hepatitis B (HBV) and C (HCV) viruses, extrapulmonary tuberculosis and syphilis was investigated taking into account the length of stay in Spain. Sub-Saharan Africa patients who had lived for <3 years in Spain had a high significantly number of infections produced by hookworms, Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni, Giardia lamblia, Entamoeba histolytica/dispar and Plasmodium spp. In patients who had lived for more than 3 years, there were significantly high rates of HBV infections, although HBV rates in sub-Saharan African patients are high even if the patients have been in Spain for <3 years. However, patients with large stays in Spain had also an important number of parasitological diseases. The main objective of the diagnosis is to avoid important public health problems and further complications in patients. It is advisable to carry out a screening of the main transmissible infections in all immigrant population regardless of the time outside their country. This screening should be individualized according to the geographical area of origin.

Diagnosis and Treatment of Leishmaniasis: Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH)

It is important to realize that leishmaniasis guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The IDSA and ASTMH consider adherence to these guidelines to be voluntary, with the ultimate determinations regarding their application to be made by the physician in the light of each patient's individual circumstances.

Morphological Characteristics of Schistosoma mansoni PZQ-Resistant and -Susceptible Strains Are Different in Presence of Praziquantel

Schistosomiasis is one of the most common human parasitic diseases whose socioeconomic impact is only surpassed by malaria. Praziquantel (PZQ) is the only drug commercially available for the treatment of all schistosome species causing disease in humans. However, there has been stronger evidences of PZQ-resistance on Schistosoma mansoni and thus it is very important to study the phenotypic characteristics associated with it. The aim of this study was to evaluate morphological alterations in S. mansoni PZQ-resistant adult worms and eggs, by comparing a PZQ- resistant strain obtained under PZQ drug pressure with a PZQ-susceptible strain. For this, scanning electronic microscopy was used to assess tegumental responsiveness of both strains under PZQ exposure, and optical microscopy allowed the monitoring of worms and eggs in the presence of the drug. Those assays showed that PZQ-susceptible worms exposed to the drug had more severe tegumental damages than the resistant one, which had only minor alterations. Moreover, contrary to what occurred in the susceptible strain, resistant worms were viable after PZQ exposure and gradually regaining full motility after removal of the drug. Eggs from resistant strain parasites are considerably smaller than those from susceptible strain. Our results suggest that there might be a difference in the tegument composition of the resistant strain and that worms are less responsive to PZQ. Changes observed in egg morphology might imply alterations in the biology of schistosomes associated to PZQ-resistance, which could impact on transmission and pathology of the disease. Moreover, we propose a hypothetical scenario where there is a different egg tropism of the S. mansoni resistant strain. This study is the first comparing two strains that only differ in their resistance characteristics, which makes it a relevant step in the search for resistance determinants.

Spectrum of Imported Infectious Diseases: A Comparative Prevalence Study of 16,817 German Travelers and 977 Immigrants from the Tropics and Subtropics

The aim of this study was to assess the spectrum of imported infectious diseases (IDs) among patients consulting the University of Munich, Germany, between 1999 and 2014 after being in the sub-/tropics. The analysis investigated complete data sets of 16,817 diseased German travelers (2,318 business travelers, 4,029 all-inclusive travelers, and 10,470 backpackers) returning from Latin America (3,225), Africa (4,865), or Asia (8,727), and 977 diseased immigrants, originating from the same regions (112, 654 and 211 respectively). The most frequent symptoms assessed were diarrhea (38%), fever (29%), and skin disorder (22%). The most frequent IDs detected were intestinal infections with species of Blastocystis(900),Giardia(730),Campylobacter(556),Shigella(209), and Salmonella(183). Also frequently observed were cutaneous larva migrans (379), dengue (257), and malaria (160). The number of IDs with significantly elevated proportions was higher among backpackers (18) and immigrants (17), especially among those from Africa (18) and Asia (17), whereas it was lower for business travelers (5), all-inclusive travelers (1), and those from Latin America (5). This study demonstrates a large spectrum of imported IDs among returning German travelers and immigrants, which varies greatly based not only on travel destination and origin of immigrants, but also on type of travel.

Effectiveness of pre-travel consultation in the prevention of travel-related diseases: a retrospective cohort study

BACKGROUND

This study aims to evaluate the effectiveness of pre-travel counselling carried out in Travel Clinics.

METHODS

This is a retrospective cohort. Three hundred international travellers were enrolled; 150 people were from users of Bari Travel Clinic, 150 were users of a travel agency. Enrolled subjects were interviewed using a questionnaire.

RESULTS

The average age of the enrolled subjects was 37.5 ± 13.9, without statistically significant differences between the two groups. 86% of cases and 19.3% of the controls reported the use of anti-malaria prophylaxis (p < 0.0001). Vaccination against cholera was given to 62% of cases and 7.3% of the controls (p < 0.001). Travel Clinic users, 6% reported diarrhoea and these figures were 27% in the control group (p < 0.0001). The proportion of those interviewed who reported fever (3.7) or insomnia (1.3) did not differ between the two groups. Mosquito bites were reported by 8% of cases and 20% of the controls (p = 0.003). Three cases of malaria were reported among the controls but no cases were detected among the cases (chi-square = 3.03; p = 0.08).

CONCLUSIONS

Our study demonstrated the effectiveness of pre-travel counselling; in the future, new studies must investigate the cost-effectiveness of pre-travel prevention measures.

Global Epidemiology of Campylobacter Infection

Campylobacter jejuni infection is one of the most widespread infectious diseases of the last century. The incidence and prevalence of campylobacteriosis have increased in both developed and developing countries over the last 10 years. The dramatic increase in North America, Europe, and Australia is alarming, and data from parts of Africa, Asia, and the Middle East indicate that campylobacteriosis is endemic in these areas, especially in children. In addition to C. jejuni, there is increasing recognition of the clinical importance of emerging Campylobacter species, including Campylobacter concisus and Campylobacter ureolyticus. Poultry is a major reservoir and source of transmission of campylobacteriosis to humans. Other risk factors include consumption of animal products and water, contact with animals, and international travel. Strategic implementation of multifaceted biocontrol measures to reduce the transmission of this group of pathogens is paramount for public health. Overall, campylobacteriosis is still one of the most important infectious diseases that is likely to challenge global health in the years to come. This review provides a comprehensive overview of the global epidemiology, transmission, and clinical relevance of Campylobacter infection.

Arboviral infections diagnosed in a European area colonized by Aedes albopictus (2009-2013, Catalonia, Spain)

BACKGROUND

The invasive mosquito Aedes albopictus, with proven vectorial ability to transmit European autochthonous cycles of dengue and chikungunya virus, has currently colonized every coastal department of Eastern Spain. The main objective of the study was to define the epidemiological and clinical characteristics as well as the trends of these two arboviral diseases in a European area heavily colonized by Ae. albopictus.

METHOD

A voluntarily-based, prospective and multicenter surveillance study was performed in all medical units of the North Metropolitan area of Barcelona (406,000 inhabitants, Catalonia; Spain) with diagnostic capability from 2009 to 2013. Since any possible increase in arboviral cases could be justified by changes in traveling behaviors along the study period (especially longer trips) the trend showed by these two arboviral diseases was compared with that displayed by malaria cases during the same period.

RESULTS

38 out of 52 (73.1%) suspected cases could be serologically confirmed (IgM+): dengue 34/38 (89.5%) and chikungunya 4/38 (11.5%). No autochthonous cases were identified. The overall incidence of both arboviruses was 0.19 cases/10,000 inhabitants-year (95% CI: 0.07-0.3); dengue = 0.17 cases/10,000 inhabitants-year (95% CI: 0.05-0.3), and chikungunya = 0.02 cases/10,000 inhabitants-year (95% CI: 0.001-0.03). The Incidence Relative Risk of arboviral disease between 2009 and 2013 shown a significant trend (IRR = 1.27. IC 95%: 1.01-1.59; p = 0.043) when compared with that displayed by malaria (IRR = 1.04. IC 95%: 0.924-1.192). If no unexpected circumstances concur, the arboviral disease incidence tax would equal that of malaria about 2021-2022.

CONCLUSIONS

The incidence of dengue and chikungunya is steadily increasing in the North Metropolitan area of Barcelona, a region densely colonized by Ae. albopictus, at the entire expense of imported cases (especially Visiting Friends and Relatives travelers). To date, no secondary autochthonous cases have been identified and, thus, they have not taken part in this rise.

Dengue fever in Czech travellers: A 10-year retrospective study in a tertiary care centre

BACKGROUND

Dengue fever is a frequent cause of morbidity in travellers. The objective was to describe the epidemiological and clinical characteristics of dengue fever in Czech travellers.

METHOD

This descriptive study includes patients with acute dengue fever diagnosed at Hospital Na Bulovce during 2004-2013. Data were collected and analysed retrospectively.

RESULTS

A total of 132 patients (83 males and 49 females) of median age 33 years (IQR 29-40) were included. Diagnosis was established by NS1 antigen detection in 87/107 cases (81.3%) and/or RT-PCR in 50/72 (69.4%) and by serology in 25 cases (18.9%). Dengue was acquired in South-East Asia in 69 cases (52.3%), followed by South Asia (48 cases; 36.3%), Latin America (14; 10.6%) and Sub-Saharan Africa (1; 0.8%). The most frequent symptoms included fever, rash and headache. Initial leukocyte and lymphocyte counts were lower in patients who presented in the early phase (0-4 days), however, platelet count was lower and AST, ALT and LDH activity higher in patients with a longer symptoms duration (≥5 days). The clinical course was mostly uncomplicated.

CONCLUSIONS

Dengue fever is becoming a frequent cause of fever in Czech travellers. Clinicians should be familiar with the typical clinical findings and novel diagnostic methods.

Schistosomiasis in a migrating population in the lake region of China and its potential impact on control operation

Coverage of migrating people in schistosomiasis control program is a growing concern in China. Schistosomiasis caused by Schistosoma japonicum is still one of the major infectious diseases of public health importance in China though tremendous efforts have been made to control the transmission over the past decades. Along with the rapid social-economic development, migrant population has been remarkably increasing across the country. The infected migrants may introduce a new souse of infection to endemic areas or the areas where the transmission had been controlled or interrupted but the intermediate host Oncomelania snail is still present. Preliminary studies for surveillance on schistosomiasis prevalence in migrants were reported, but there is little basic information provided. We carried out an investigation on the prevalence in immigrants, emigrants and permanent residents in three villages of Hunan province located in the main endemic area of lake region, and analyzed the potential impact of migration on control practice. In the study villages, the migrant population accounts for 53.6% of the total. Schistosoma infection was detected by modified Kato-Katz method and miracidium hatching test. Questionnaire survey was conducted comprising knowledge of disease and its transmission, water contact, personal protective measures, and whether examined and treated after water contact. The survey indicated that the migrants and permanent residents had similar life style, and the majority of them experienced water contact in agricultural work or routine life activities. However, the infection rate in immigrants was significantly higher than that in permanent residents. It was also found that the migrants had significantly less knowledge about the disease than the permanent residents, and took no personal protective measures. This is due to that the control program could not cover the migrants when they were absent at the time the program being implemented. The present study suggested that the surveillance and intervention for migrants, immigrants in particular, should be included and strengthened in schistosomiasis control program and a feasible scheme be developed.

Estimating air travel-associated importations of dengue virus into Italy

BACKGROUND

Southern Europe is increasingly at risk for dengue emergence, given the seasonal presence of relevant mosquito vectors and suitable climatic conditions. For example, Aedes mosquitoes, the main vector for both dengue and chikungunya, are abundant in Italy, and Italy experienced the first ever outbreak of chikungunya in Europe in 2007. We set out to estimate the extent of dengue virus importations into Italy via air travelers.

METHODS

We attempted to quantify the number of dengue virus importations based on modeling of published estimates on dengue incidence in the countries of disembarkation and analysis of data on comprehensive air travel from these countries into Italy's largest international airport in Rome.

RESULTS

From 2005 to 2012, more than 7.3 million air passengers departing from 100 dengue-endemic countries arrived in Rome. Our Importation Model, which included air traveler volume, estimated the incidence of dengue infections in the countries of disembarkation, and the probability of infection coinciding with travel accounted for an average of 2,320 (1,621-3,255) imported dengue virus infections per year, of which 572 (381-858) were "apparent" dengue infections and 1,747 (1,240-2,397) "inapparent."

CONCLUSIONS

Between 2005 and 2012, we found an increasing trend of dengue virus infections imported into Rome via air travel, which may pose a potential threat for future emergence of dengue in Italy, given that the reoccurring pattern of peak importations corresponds seasonally with periods of relevant mosquito vector activity. The observed increasing annual trends of dengue importation and the consistent peaks in late summer underpin the urgency in determining the threshold levels for the vector and infected human populations that could facilitate novel autochthonous transmission of dengue in Europe.

[Mosquitoes as vectors for exotic pathogens in Germany]

As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics.

Schistosomiasis in non-endemic countries

Schistosomiasis is one of the major parasitic diseases of the tropics, causing acute and long-term clinical syndromes. Almost all schistosomiasis is now imported from sub-Saharan Africa. This article summarises the aetiology, clinical presentation, diagnosis and management of schistosomiaisis for clinicians in non-endemic countries.

Parasitic infections in travelers and immigrants: part I protozoa

ABSTRACT 

The growth in international commerce, travel and migration contribute to the global emergence of certain parasitic infections. Importation of vectors and food products may contribute to the emergence of protozoan infections in nonendemic countries. Infections such as malaria are potentially fatal, especially in nonimmune patients, and outcome depends largely on timely diagnosis and treatment. Diagnosis/management of imported parasitic infections may be complex especially as some patients may have underlying immunosuppressive conditions such as HIV infection. Major challenges concern the development of improved diagnostic techniques, safer/more effective drug therapies and identification of biological markers of progression and response to treatment. Imported parasitic diseases which may be transmitted vertically or through blood transfusion/organ donation could become a public health priority in the near future. Climate change may affect arthropod distribution and facilitate the spread of protozoan vector-borne diseases. The first part of this review focuses on protozoan infections in travelers and immigrants.

Failure of atovaquone-proguanil malaria chemoprophylaxis in a traveler to Ghana

Clinical failure of Malarone™ chemoprophylaxis is extremely rare. We report a case of Plasmodium falciparum malaria in a returned traveler to Ghana who fully adhered to atovaquone-proguanil (Malarone™) chemoprophylaxis daily dosing, yet took the pills on an empty stomach. Screening of the P. falciparum isolate revealed triple codon mutation of Dhfr at positions 51, 59, and 108. Plasma drug levels of both atovaquone and proguanil revealed sub-therapeutic concentrations.

Travel-associated infection presenting in Europe (2008-12): an analysis of EuroTravNet longitudinal, surveillance data, and evaluation of the effect of the pre-travel consultation

BACKGROUND

Travel is important in the acquisition and dissemination of infection. We aimed to assess European surveillance data for travel-related illness to profile imported infections, track trends, identify risk groups, and assess the usefulness of pre-travel advice.

METHODS

We analysed travel-associated morbidity in ill travellers presenting at EuroTravNet sites during the 5-year period of 2008-12. We calculated proportionate morbidity per 1000 ill travellers and made comparisons over time and between subgroups. We did 5-year trend analyses (2008-12) by testing differences in proportions between subgroups using Pearson's χ(2) test. We assessed the effect of the pre-travel consultation on infection acquisition and outcome by use of proportionate morbidity ratios.

FINDINGS

The top diagnoses in 32 136 patients, ranked by proportionate morbidity, were malaria and acute diarrhoea, both with high proportionate morbidity (>60). Dengue, giardiasis, and insect bites had high proportionate morbidity (>30) as well. 5-year analyses showed increases in vector borne infections with significant peaks in 2010; examples were increased Plasmodium falciparum malaria (χ(2)=37·57, p<0·001); increased dengue fever (χ(2)=135·9, p<0·001); and a widening geographic range of acquisition of chikungunya fever. The proportionate morbidity of dengue increased from 22 in 2008 to 36 in 2012. Five dengue cases acquired in Europe contributed to this increase. Dermatological diagnoses increased from 851 in 2008 to 1102 in 2012, especially insect bites and animal-related injuries. Respiratory infection trends were dominated by the influenza H1N1 pandemic in 2009. Illness acquired in Europe accounted for 1794 (6%) of all 32 136 cases-mainly, gastrointestinal (634) and respiratory (357) infections. Migration within Europe was associated with more serious infection such as hepatitis C, tuberculosis, hepatitis B, and HIV/AIDS. Pre-travel consultation was associated with significantly lower proportionate morbidity ratios for P falciparum malaria and also for acute hepatitis and HIV/AIDS.

INTERPRETATION

The pattern of travel-related infections presenting in Europe is complex. Trend analyses can inform on emerging infection threats. Pre-travel consultation is associated with reduced malaria proportionate morbidity ratios and less severe illness. These findings support the importance and effectiveness of pre-travel advice on malaria prevention, but cast doubt on the effectiveness of current strategies to prevent travel-related diarrhoea.

FUNDING

European Centre for Disease Prevention and Control, University Hospital Institute Méditerranée Infection, US Centers for Disease Control and Prevention, and the International Society of Travel Medicine.

The current spectrum and prevalence of intestinal parasitosis in Campania (region of southern Italy) and their relationship with migration from endemic countries

BACKGROUND

In Italy, the current clinical-epidemiological features of intestinal parasitosis and the impact of recent massive migration flows from endemic areas on their distribution are not very well known.

METHODS

An analysis was carried out involving 1766 patients (720 natives and 1046 immigrants) observed during the period 2009-2010 (the 'current group') and 771 native patients observed during the period 1996-1997 (the 'historical group'), a time at which immigration in the area was minimal. Patients were analyzed for intestinal parasitosis at four healthcare centres in Campania.

RESULTS

A wide variety of intestinal parasites was detected in the study subjects. Immigrants had a significantly higher prevalence of parasitosis and multiple simultaneous infections than natives in both groups. In both study groups of natives, the detection of at least one parasite was significantly associated with a history of travel to endemic areas. Among immigrants, we found an inverse correlation between the frequency of parasite detection and the amount of time spent in Italy. No circulation of parasites was found among contacts of parasitized patients.

CONCLUSIONS

Intestinal parasites are still a cause of intestinal infection in Campania. Although immigrants have a significantly higher prevalence of parasitosis than natives, this does not increase the risk of infection for that population. This is likely due to the lack of suitable biological conditions in our area.

Trends in hospital admissions at a Department for Infectious Diseases in Italy from 1995 to 2011 and implications for health policies

BACKGROUND

Interactions among several environmental, behavioral, social, and biological variables contribute to the epidemiology of infectious diseases (IDs) and have an impact on the healthcare system and hospitalizations. We evaluated trends in ID hospitalizations at our Department for Infectious Diseases in the last two decades to aid decision-makers in defining appropriate healthcare strategies.

METHODS

The discharge diagnoses of all patients admitted to the ID Department of L Sacco University Hospital between 1995 and 2011 were classified by the International Classification of Diseases (ICD-9) grouped in Major Diagnostic Categories (MDC). Linear regression was used to determine the trends in hospitalizations for each MDC. Estimates of the average annual change were based on the slope of the regression line.

RESULTS

A sharp decline in HIV/AIDS cases (-22.5 +/-6.0 cases per calendar year), and an increase in admissions for respiratory, cardiovascular, renal and musculoskeletal infections were recorded. The mean age of the patients increased by 1.2 years (+/-0.049) for each calendar year of observation (linear trend, p < 0.0001), increasing from 37.02 +/-11.91 years in 1995 to 56.02 +/-19.62 years in 2011 (p < 0.0001). The mean number of comorbidities per patient increased significantly over time (Mann-Whitney U test, p = 0.0153). From 1998/1999 to 2010/2011 the hospital length of stay (LOS) increased for cardiovascular, digestive system, musculoskeletal, and skin/subcutaneous infections, and infectious and parasitic diseases (p < 0.01). The rate of hospital stay over threshold (HSOT) increased in the last 5 years by 1.12% for every 10-year age group.

CONCLUSIONS

Older age, a higher number of comorbidities, a longer hospital LOS for certain conditions, and a higher rate of HSOT characterize the patients admitted to this ID department in recent years. Despite progress in treatment and management, infectious diseases continue to be a major threat to human health. The current challenge for ID departments is the treatment of complex cases, often associated with chronic diseases in elderly patients. Continuous monitoring at a local and national level will allow early identification of changes in the epidemiological patterns of IDs and provide information for healthcare system planning.

Imported Plasmodium vivax malaria ex Pakistan

BACKGROUND

According to WHO, 1.5 million cases of malaria are reported annually in Pakistan. Malaria distribution in Pakistan is heterogeneous, and some areas, including Punjab, are considered at low risk for malaria. The aim of this study is to describe the trend of imported malaria cases from Pakistan reported to the international surveillance systems from 2005 to 2012.

METHODS

Clinics reporting malaria cases acquired after a stay in Pakistan between January 1, 2005, and December 31, 2012, were identified from the GeoSentinel (http://www.geosentinel.org) and EuroTravNet (http://www.Eurotravnet.eu) networks. Demographic and travel-related information was retrieved from the database and further information such as areas of destination within Pakistan was obtained directly from the reporting sites. Standard linear regression models were used to assess the statistical significance of the time trend.

RESULTS

From January 2005 to December 2012, a total of 63 cases of malaria acquired in Pakistan were retrieved in six countries over three continents. A statistically significant increasing trend in imported Plasmodium vivax malaria cases acquired in Pakistan, particularly for those exposed in Punjab, was observed over time (p = 0.006).

CONCLUSIONS

Our observation may herald a variation in malaria incidence in the Punjab province of Pakistan. This is in contrast with the previously described decreasing incidence of malaria in travelers to the Indian subcontinent, and with reports that describe Punjab as a low risk area for malaria. Nevertheless, this event is considered plausible by international organizations. This has potential implications for changes in chemoprophylaxis options and reinforces the need for increased surveillance, also considering the risk of introduction of autochthonous P. vivax malaria in areas where competent vectors are present, such as Europe.

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.

Genotyping Plasmodium vivax isolates from the 2011 outbreak in Greece

BACKGROUND

Plasmodium vivax malaria was common in Greece until the 1950s with epidemics involving thousands of cases every year. Greece was declared free of malaria by the World Health Organization in 1974. From 1974 to 2010, an average of 39 cases per year were reported, which were mainly imported. However, in 2009 and 2010 six and one autochthonous cases were reported culminating with a total of 40 autochthonous cases reported in 2011, of which 34 originated from a single region: Laconia of Southern Peloponnese. In this study the genotypic complexity of the P. vivax infections from the outbreak in Greece during 2011 is described, to elucidate the possible origin and spread of the disease.

METHODS

Three polymorphic markers of P. vivax were used; Pvmsp-3α and the microsatellites m1501 and m3502 on P. vivax isolates sampled from individuals diagnosed in Greece. Thirty-nine isolates were available for this study (20 autochthonous and 19 imported), mostly from Evrotas municipality in Laconia region, in southern Greece, (n = 29), with the remaining representing sporadic cases originating from other areas of Greece.

RESULTS

Genotyping the Evrotas samples revealed seven different haplotypes where the majority of the P. vivax infections expressed two particular Pvmsp-3α-m1501-m3502 haplotypes, A10-128-151 (n = 14) and A10-121-142 (n = 7). These haplotypes appeared throughout the period in autochthonous and imported cases, indicating continuous transmission. In contrast, the P. vivax autochthonous cases from other parts of Greece were largely comprised of unique haplotypes, indicating limited transmission in these other areas.

CONCLUSIONS

The results indicate that several P. vivax strains were imported into various areas of Greece in 2011, thereby increasing the risk of re-introduction of malaria. In the region of Evrotas ongoing transmission occurred exemplifying that further control measures are urgently needed in this region of southern Europe. In circumstances where medical or travel history is scarce, methods of molecular epidemiology may prove highly useful for the correct classification of the cases.

Autochthonous case of dengue in France, October 2013

In October 2013, autochthonous dengue fever was diagnosed in a laboratory technician in Bouches-du-Rhone, southern France, a department colonised by Aedes albopictus since 2010. After ruling out occupational contamination, we identified the likely chain of local vector-borne transmission from which the autochthonous case arose. Though limited, this second occurrence of autochthonous dengue transmission in France highlights that efforts should be continued to rapidly detect dengue virus introduction and prevent its further dissemination in France.

Climate change effects on Chikungunya transmission in Europe: geospatial analysis of vector's climatic suitability and virus' temperature requirements

BACKGROUND

Chikungunya was, from the European perspective, considered to be a travel-related tropical mosquito-borne disease prior to the first European outbreak in Northern Italy in 2007. This was followed by cases of autochthonous transmission reported in South-eastern France in 2010. Both events occurred after the introduction, establishment and expansion of the Chikungunya-competent and highly invasive disease vector Aedes albopictus (Asian tiger mosquito) in Europe. In order to assess whether these outbreaks are indicative of the beginning of a trend or one-off events, there is a need to further examine the factors driving the potential transmission of Chikungunya in Europe. The climatic suitability, both now and in the future, is an essential starting point for such an analysis.

METHODS

The climatic suitability for Chikungunya outbreaks was determined by using bioclimatic factors that influence, both vector and, pathogen. Climatic suitability for the European distribution of the vector Aedes albopictus was based upon previous correlative environmental niche models. Climatic risk classes were derived by combining climatic suitability for the vector with known temperature requirements for pathogen transmission, obtained from outbreak regions. In addition, the longest potential intra-annual season for Chikungunya transmission was estimated for regions with expected vector occurrences.In order to analyse spatio-temporal trends for risk exposure and season of transmission in Europe, climate change impacts are projected for three time-frames (2011-2040, 2041-2070 and 2071-2100) and two climate scenarios (A1B and B1) from the Intergovernmental Panel on Climate Change (IPCC). These climatic projections are based on regional climate model COSMO-CLM, which builds on the global model ECHAM5.

RESULTS

European areas with current and future climatic suitability of Chikungunya transmission are identified. An increase in risk is projected for Western Europe (e.g. France and Benelux-States) in the first half of the 21st century and from mid-century onwards for central parts of Europe (e.g. Germany). Interestingly, the southernmost parts of Europe do not generally provide suitable conditions in these projections. Nevertheless, many Mediterranean regions will persist to be climatically suitable for transmission. Overall, the highest risk of transmission by the end of the 21st century was projected for France, Northern Italy and the Pannonian Basin (East-Central Europe). This general tendency is depicted in both, the A1B and B1 climate change scenarios.

CONCLUSION

In order to guide preparedness for further outbreaks, it is crucial to anticipate risk as to identify areas where specific public health measures, such as surveillance and vector control, can be implemented. However, public health practitioners need to be aware that climate is only one factor driving the transmission of vector-borne disease.

Prolonged polyarthralgia in a German traveller with Mayaro virus infection without inflammatory correlates

Background

Mayaro virus is endemic in South America and sporadic outbreaks have been described. It causes a dengue-like febrile illness accompanied by severe and long-lasting polyarthralgias. Outside endemic regions, however, the disease is not well known and can be misdiagnosed as dengue. International travellers are at risk to acquire Mayaro virus and due to increased worldwide travel infectious disease specialists need to be aware of such rare clinical entities.

Case presentation

We report the first Mayaro virus infection imported into Germany. A 20-year-old woman developed fever, myalgia, maculopapular rash, and polyarthralgias following a 10-day trip in the Rurrenabaque region of Bolivia. Severe polyarthralgias persisted for 5 months and were treated with non-steroidal anti-inflammatory drugs. Serological analysis demonstrated Mayaro virus-specific-IgM and -IgG antibodies two months after onset of symptoms. Except for CXCL8/IL-8 other proinflammatory chemokines and cytokines were unremarkable at this time.

Conclusions

Dissemination of knowledge on rare disease might improve patient management. Understanding the inherent features of Mayaro virus infection and how the virus interacts with its host are essential for optimal patient care and therapy.