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Background: A survey was designed to assess travelers' willingness to take antibiotic chemoprophylaxis against travelers' diarrhea (TD) or to intervene with antibiotic or symptomatic treatments. Methods: A brief written questionnaire was administered to clients in North American (United States and Canadian) and European (UK and German) travel clinic waiting rooms to assess length, purpose, and destination of their upcoming trips; their perceived risk of developing TD at their destination; and their preferences for hypothetical treatment or chemoprophylaxis options, which included descriptions, but no mention of brand names, of a systemically absorbed antibiotic based on a fluoroquinolone, a nonabsorbed antibiotic based on rifaximin, and an over-the-counter antidiarrheal similar to loperamide. Results: The 209 UK and German travelers planned significantly longer travel than the 277 US and Canadian travelers (25 vs 15 d, p < 0.001) and correctly recognized high risk of TD more often than the North Americans (81% vs 61%, p < 0.001). More of the North Americans preferred any therapy options compared with the Europeans; only 14% of the North Americans preferred no treatment compared with 29% of the Europeans (p < 0.001). More of the North Americans and the Europeans preferred the nonabsorbed antibiotic than the systemically absorbed antibiotic, regardless of if combined with the antidiarrheal agent. Significantly more of the Europeans preferred not to take antibiotic chemoprophylaxis than North Americans (66% vs 37%, p < 0.001). Among the North Americans, significantly more travelers preferred chemoprophylaxis with the nonabsorbed than the systemic antibiotic (45% vs 33%, p= 0.003). Conclusions: Among the relatively small groups of travelers studied, the UK and German travelers were more cognizant of TD risk than US and Canadian travelers. The Europeans were less inclined to take chemoprophylaxis or treatment. Both groups preferred treatment or prophylaxis with the nonabsorbed antibiotic over the systemically absorbed antibiotic or the antidiarrheal agent. [ABSTRACT FROM AUTHOR]

Background: Epidemiologic features of tick typhus among German travelers has not been surveyed recently.Methods: Clinical features, travel and medical histories in 78 patients with tick typhus who presented to a German outpatient clinic for Infectious and Tropical Diseases were investigated, in order to identify common epidemiological factors and potential strategies of prevention. Diagnosis was confirmed by serological detection of IgG- and IgM-antibodies to Rickettsia conorii by indirect immunofluorescence.Results: The majority of patients (71.8%) had visited southern Africa prior to presentation. All patients presented with fever as the main symptom. An eschar was still present in 68 patients (87.2%) with regional lymphadenitis in 19.2%. However, only a minority of patients (17.9%) remembered a tick bite at the location of the eschar.Conclusion: Efforts to reduce the incidence of tick typhus in travelers should focus on preventive measures targeting behavioral changes. Avoiding tick bites during travel to endemic areas appears to be the single most important prophylactic action. Taking this into consideration, it should be possible to decrease the number of travelers returning with tick typhus significantly by adequate pretravel counseling. [ABSTRACT FROM AUTHOR]

Background: Traveling to tropical regions is related to increased health risks. Travelers' diarrhea is the most frequent health problem, but the range of travel-related diseases also includes potential life-threatening diseases such as malaria. The actual risk of European travelers acquiring specific infectious diseases and other hazards in the tropics is to a large extent unknown and is therefore often adopted from that of the indigenous population. The objective of this study was to elucidate the risk for travel-related diseases, symptoms, and accidents in a population of Europeans who travel to popular tourist destinations.Methods: From July 2003 to June 2004, 794 travelers consulting the travel clinic of the Berlin Institute of Tropical Medicine were recruited for a questionnaire-based observational study before traveling to Kenya, Tanzania, Senegal, the Gambia, India, Nepal, Thailand, or Brazil.Results: Overall, illness was reported by 42.9% of travelers, with 10.2% reporting more than one adverse health event. Most frequently gastrointestinal symptoms were noted (34.6%), followed by respiratory symptoms (13.7%). More than 5% experienced an accident. Travel to the Indian subcontinent nearly doubled the risk of becoming ill; travel to Thailand significantly decreased the risk. Additional risk factors were a long duration of staying abroad, young age, and traveling under basic conditions. Of all travelers, 80% did not follow the traditionally recommended dietary restrictions. Among travelers visiting malaria-endemic areas, 20% did not carry any antimalarial drugs with them, not continuous chemoprophylaxis or standby medication.Conclusions: Because of the rising travel activity, especially to tropical countries, the importance of qualified pretravel advice consultation is increasing. To improve the travelers' health, attention needs to be paid to individual risk factors, the prevention and therapy of travelers' diarrhea, malaria prophylaxis, management of respiratory illness, and personal safety. [ABSTRACT FROM AUTHOR]

The article presents data from the first 3 years of sentinel surveillance for imported schistosomiasis in Europe from the European Network on Imported Infectious Diseases Surveillance (TropNetEurop). An analysis of reports for epidemiologic and clinical features to generate valid data on imported infectious diseases is tackled. It reveals the difference of the pattern of regions where immigrants contracted schistosomiasis from the spatial distribution of schistosomiasis foci in endemic areas.

Background: Due to time constraints imposed by pending departure dates of travelers, the application of multiple vaccinations is commonly practiced in pretravel counseling. However, data regarding the tolerability of schedules with simultaneous vaccinations with different products are sparse.Method: In order to investigate effects of this practice, a prospective study was conducted with 1,183 healthy travelers who presented prior to their departure. Standardized questionnaires covering possible side effects were collected during and after vaccination.Results: Results showed an increase of the overall frequency of side effects with an increasing number of simultaneously applied vaccines. In travelers with two or more vaccinations, side effects occurred less frequently than previously published. In double vaccinations, side effects occurred in 36.7% of vaccinees, triple vaccinations in 40.3%, in more than three vaccinations in 50.0%. Subjective rating by the vaccinees showed an excellent tolerability of multiple vaccinations.Conclusion: Multiple vaccines can be given at the same time with limited subjective side effects. These findings may increase the acceptability of vaccinations given in combination to travelers. [ABSTRACT FROM AUTHOR]

Rationale for Review: Chikungunya outbreaks continue to occur, with changing epidemiology. Awareness about chikungunya is low both among the at-risk travellers and healthcare professionals, which can result in underdiagnosis and underreporting. This review aims to improve awareness among healthcare professionals regarding the risks of chikungunya for travellers., Key Findings: Chikungunya virus transmission to humans occurs mainly via daytime-active mosquitoes, Aedes aegypti and Aedes albopictus. The areas where these mosquitoes live is continuously expanding, partly due to climate changes. Chikungunya is characterized by an acute onset of fever with joint pain. These symptoms generally resolve within 1-3 weeks, but at least one-third of the patients suffer from debilitating rheumatologic symptoms for months to years. Large outbreaks in changing regions of the world since the turn of the 21st century (e.g. Caribbean, La Réunion; currently Brazil, India) have resulted in growing numbers of travellers importing chikungunya, mainly to Europe and North America. Viremic travellers with chikungunya infection have seeded chikungunya clusters (France, United States of America) and outbreaks (Italy in 2007 and 2017) in non-endemic countries where Ae. albopictus mosquitoes are present. Community preventive measures are important to prevent disease transmission by mosquitoes. Individual preventive options are limited to personal protection measures against mosquito bites, particularly the daytime-active mosquitos that transmit the chikungunya virus. Candidate vaccines are on the horizon and regulatory authorities will need to assess environmental and host risk factors for persistent sequelae, such as obesity, age (over 40 years) and history of arthritis or inflammatory rheumatologic disease to determine which populations should be targeted for these chikungunya vaccines., Conclusions/recommendations: Travellers planning to visit destinations with active CHIKV circulation should be advised about the risk for chikungunya, prevention strategies, the disease manifestations, possible chronic rheumatologic sequelae and, if symptomatic, seek medical evaluation and report potential exposures., (© International Society of Travel Medicine 2023. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Background: Conventional rabies pre-exposure prophylaxis (PrEP) and Japanese encephalitis (JE) primary series vaccination regimens each require up to 4 weeks to complete and, thus, may not be feasible for individuals who need these immunizations on short notice. This Phase 3b, randomized, controlled, observer-blind study evaluated the immunogenicity and safety of concomitant administration of a purified chick embryo cell culture rabies vaccine and an inactivated, adsorbed JE vaccine according to an accelerated (1 week) regimen when compared with the conventional regimens (4 weeks). This report describes the kinetics of immune responses up to 1 year after vaccination., Methods: A total of 661 healthy adults (18 to ≤65 years) were randomized into the following accelerated or conventional vaccine regimens: Rabies + JE-Conventional, Rabies + JE-Accelerated, Rabies-Conventional and JE-Conventional. Immunogenicity was assessed by virus neutralization tests. Safety and tolerability were also evaluated., Results: Irrespective of rabies vaccination regimen, ≥97% of subjects had adequate levels of rabies virus neutralizing antibody (RVNA) concentrations (≥0.5 IU/ml) up to Day 57, with percentages of subjects with RVNA concentrations ≥0.5 IU/ml at Day 366 ranging between 68% in the Rabies + JE-Accelerated group and 80% of subjects in the Rabies-Conventional group. The Rabies + JE-Accelerated group revealed high JE neutralizing antibody titers at all-time points. At Day 366, the percentage of subjects with antibody titers indicative of seroprotection (PRNT50 titers ≥1:10) remained high across JE vaccine groups (86-94%)., Conclusions: The accelerated PrEP rabies and JE vaccination regimens, once licensed, could represent a valid alternative in the short-term to currently recommended conventional regimens. The concomitant administration of these two vaccines does not compromise immune responses to any of the vaccine antigens particularly when aiming for short-term protection. Further evidence will clarify the need for and timing to administration of rabies vaccine booster doses in subjects primed with an accelerated PrEP regimen. (NCT01662440)., (© International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The current Japanese encephalitis (JE) vaccination regimen requires two doses and 4 weeks to complete, which may not always be feasible for travelers on short notice. One of the primary endpoints of this phase III study was to demonstrate noninferiority of immune responses to a JE vaccine following an accelerated 1-week JE vaccination regimen administered concomitantly with a rabies vaccine as compared to a standard 4-week JE regimen alone. In addition, the immunogenicity of concomitant administration of JE and rabies vaccines following standard regimens was evaluated, as well as the tolerability and safety profile of each regimen under study., Methods: Healthy adults aged 18 to ≤65 years were randomized to regimens with an accelerated or standard schedule: JE+rabies-standard (n = 167), JE+rabies-accelerated (n = 217) or JE-standard (n = 56). Immunogenicity against JE antigen was assessed by a 50% plaque reduction neutralization test (PRNT50 ) titer of ≥1 : 10, measured 28 days after last active vaccine (LAV) administration. Solicited reactions were collected 7 days after each vaccination; spontaneously reported adverse events (AEs) and serious AEs were monitored up to day 57. This paper reports results until day 57., Results: Noninferiority of immune responses was established for JE+rabies-accelerated compared to the JE-standard regimen 28 days after LAV administration. Overall, 99% and 100% of subjects in the JE+rabies-accelerated and JE-standard groups, respectively, achieved PRNT50 titers of ≥1 : 10 at 28 days after LAV administration. No impact of concomitant rabies vaccination was observed either on immune responses or on the safety profile of the JE vaccine., Conclusions: This was the first randomized, controlled trial that demonstrated the strong short-term immunogenicity of a new, accelerated, 1-week JE-regimen, which was noninferior to that of the standard regimen, with a satisfactory tolerability and safety profile and no impact of concomitant rabies vaccination. This accelerated regimen, if licensed, could potentially be a valid alternative for individuals requiring a primary series of JE vaccination and rabies pre-exposure prophylaxis on short notice., (© 2015 International Society of Travel Medicine.)

Background: This phase 3b randomized, open-label study evaluated the immunogenicity and safety of coadministration of a hepatitis A and/or B vaccine with a quadrivalent oligosaccharide meningococcal CRM197 -conjugate vaccine (MenACWY-CRM), in the context of an accelerated hepatitis A and/or B immunization schedule., Methods: A total of 252 healthy adult subjects were randomized to three groups to receive hepatitis A/B only (HepA/B), hepatitis A/B coadministered with MenACWY-CRM (HepA/B+MenACWY-CRM), or MenACWY-CRM only (MenACWY-CRM). Hepatitis A and/or B vaccination was administered in the form of a single booster dose or a primary three-dose series, depending on the hepatitis A and/or B vaccination history of subjects. Antibody responses to hepatitis A/B vaccination were assessed 1 month following the last hepatitis A and/or B dose. Serum bactericidal activity with human complement (hSBA) against meningococcal serogroups A, C, W-135, and Y was assessed 1 month post-MenACWY-CRM vaccination. Safety was monitored throughout the study., Results: At 1 month following the final hepatitis A and/or B vaccination, concomitant administration of hepatitis A/B and MenACWY-CRM was non-inferior to administration of hepatitis A/B alone in terms of geometric mean concentrations of antibodies against the hepatitis A and B antigens. One month post-MenACWY-CRM vaccination, the percentages of subjects achieving hSBA titers ≥8 for serogroups A, C, W-135, and Y in the HepA/B+MenACWY-CRM group (76, 87, 99, and 94%, respectively) were comparable to those in the MenACWY-CRM group (67, 82, 96, and 88%, respectively). The percentages of subjects reporting adverse events (AEs) were similar across study groups and a majority of the reported AEs were mild to moderate in nature. There were no study vaccine-related serious AEs., Conclusions: MenACWY-CRM can be administered concomitantly with a hepatitis A and/or B vaccine in the context of an accelerated hepatitis A and/or B immunization schedule without increasing safety concerns or compromising the immune responses to any of the vaccine antigens. [NCT01453348]., (© 2014 International Society of Travel Medicine.)

Background: Compact and short pre-travel immunization schedules, which include several vaccinations in a single visit, are desirable for many travelers. However, concomitant vaccination could potentially compromise immunogenicity and/or safety of the individual vaccines and, therefore, possible vaccine interferences should be carefully assessed. This article discusses the immunogenicity and safety of travel vaccines for typhoid fever (TF) and yellow fever (YF), when administered with or without a quadrivalent meningococcal glycoconjugate ACWY-CRM vaccine (MenACWY-CRM)., Methods: Healthy adults (18-≤60 years) were randomized to one of three vaccine regimens: TF + YF + MenACWY-CRM (group I; n = 100), TF + YF (group II; n = 101), or MenACWY-CRM (group III; n = 100). Immunogenicity at baseline and 4 weeks post-vaccination (day 29) was assessed by serum bactericidal assay using human complement (hSBA), enzyme-linked immunosorbent assay (ELISA), or a neutralization test. Adverse events (AEs) and serious adverse events (SAEs) were collected throughout the study period., Results: Non-inferiority of post-vaccination geometric mean concentrations (GMCs) and geometric mean titers (GMTs) was established for TF and YF vaccines, respectively, when given concomitantly with MenACWY-CRM vaccine versus when given alone. The percentages of subjects with seroprotective neutralizing titers against YF on day 29 were similar in groups I and II. The antibody responses to meningococcal serogroups A, C, W-135, and Y were within the same range when MenACWY-CRM was given separately or together with TF and YF vaccines. The percentage of subjects reporting AEs was the same for TF and YF vaccines with or without MenACWY-CRM vaccine. There were no reports of SAEs or AEs leading to study withdrawals., Conclusions: These data provide evidence that MenACWY-CRM can be administered with typhoid Vi polysaccharide vaccine and live attenuated YF vaccine without compromising antibody responses stimulated by the individual vaccines. MenACWY-CRM can, therefore, be incorporated into travelers' vaccination programs without necessitating an additional clinic visit (NCT01466387)., (© 2014 International Society of Travel Medicine.)

Background: A patch vaccine containing heat-labile toxin (LT) from enterotoxigenic Escherichia coli (ETEC) has demonstrated to be beneficial in reducing the rate and severity of travelers' diarrhea in Latin America. To evaluate the efficacy of this transdermal vaccine system in an area with a different diarrheal pathogen profile, an additional phase 2 study was conducted in European travelers to India., Methods: For this multicenter, randomized, double-blinded, placebo-controlled field study 723 subjects were recruited; 603 (299 LT vaccine, 304 placebo) were included in the per-protocol-population (PPP)., Results: Although the LT patch induced a measurable LT immune response in recipients, it failed to protect against LT ETEC or all-cause diarrhea. In the PPP the incidence rate of diarrhea as per primary endpoint was 6.0% (18 of 299) in the vaccine group and 5.9% (18 of 304) in the placebo group. Additionally, lower than expected rates of LT ETEC diarrheas were observed in India. The vaccine delivery system frequently produced rash and pruritus at the site of application, long term hyperpigmentation persisted in a minority of LT recipients, and also few site reactions were noted in the placebo group., Conclusions: The evaluated patch vaccine failed to satisfy mainly with respect to protective efficacy. Noninvasive prophylactic agents against travelers' diarrhea, particularly vaccines against the most frequent pathogens, thus continue to be badly needed., (© 2013 International Society of Travel Medicine.)

Background: The indications for prescribing malaria chemoprophylaxis lack a solid evidence base that results in subjectivity and wide variation of practice across countries and among professionals., Methods: European experts in travel medicine, who are members of TropNetEurop, participated in a survey conducted using the Delphi method. This technique aims at evaluating and developing a consensus through iterations of questionnaires, controlled feedback, and statistical group responses., Results: A first questionnaire, including questions about controversial issues in prescribing malaria prophylaxis, required responses on a visual scale between 1 and 10. The questionnaire included issues on problematic prescribing, characteristics of drugs, relevance of geography, and importance of insect bite prevention. The repeat questionnaire with the group response from the first round revealed an increasing consensus on most issues. A second survey considered 14 practical scenarios (including two internal standards) and investigated preferred choice of prophylaxis. A significant consensus was noted in 8 of 14 scenarios, which did not increase after a second round. The analysis revealed a wide variation in prescribing choices with preferences grouped by region of practice, and a greater willingness to prescribe in northern and southern Europe than in central Europe. The second round showed a 9.5% change of opinion., Conclusions: The study shows that improving the evidence base on efficacy and tolerability and risk of malaria for prescribing chemoprophylaxis is needed as is further discussion across Europe to achieve harmonization of prescribing practice.

Background: Malaria poses a significant threat to military personnel stationed in endemic areas; therefore, it is important to examine the risks of military operations, particularly in areas where malaria-related data are scarce. The recent deployment of Japan Ground Self-Defense Force (JGSDF) for a peacekeeping operation in East Timor provided an opportunity to investigate these risks. The results of these studies may be translated into chemoprophylactic strategies for travelers., Methods: A total of 1,876 members were deployed between April 2002 and September 2003. They consisted of three battalions; each remained for 6 months and was put on mefloquine prophylaxis. Malaria infection was investigated, including exposure to Plasmodium falciparum sporozoites, assessed by seroconversion for anticircumsporozoite (anti-CS) protein antibodies. Adherence to and adverse events (AEs) of mefloquine were studied via questionnaires., Results: Four members were evacuated: one each with optic neuritis, lung cancer with brain metastasis, IgA nephropathy, and psychotic reactions that may have been precipitated by mefloquine. Six clinical episodes of Plasmodium vivax occurred, including one relapse, but there were no clinical cases of P falciparum, yielding a crude malaria attack rate of 0.32% for the 6-month period. Overall, 3.1% of the study population seroconverted for the anti-CS protein antibodies, with some regional differences noted. About 24% of questionnaire respondents, reported AEs; however, none of the AEs was severe. The AEs tended to emerge during the initial doses of chemoprophylaxis., Conclusions: The implementation of mefloquine prophylaxis among JGSDF personnel in East Timor, where P falciparum constitutes a moderate risk, appears to have been a success. Mefloquine prophylaxis was generally safe for Japanese unless predisposed to neuropsychiatric illness. However, given that mefloquine is the only chemoprophylactic agent available, a risk-benefit analysis tailored to the traveler is required for visits to countries such as East Timor.

Background: Migrants form 9% of Germany's population and 13% of its capital Berlin. Only limited data are available regarding general health status and prevalence of tropical diseases among migrants in Germany. This study was conducted to investigate the spectrum and frequency of tropical diseases among migrants in Berlin and to evaluate the quality of the medical care provided. The necessity of a routine screening for tropical diseases among migrants was assessed., Methods: Anonymized data of migrants presenting to the Berlin Institute of Tropical Medicine between 1999 and 2004 with a stay in Germany below 1 year (n= 153) were analyzed., Results: Of all examined migrants, 48% needed immediate medical treatment and 38% carried an infectious disease, mainly nematodes and intestinal protozoa. 19% suffered from a noninfectious disease, mainly anemia, and 12% were transferred to other specialists for further investigation. These figures were similar among asymptomatic and symptomatic patients. The median duration of stay in Germany until presentation was 42 days. While 40% of the migrants were examined within the first 4 weeks of their stay, 20% had not received a medical examination after 6 months. Of this population, 50% required treatment upon presentation., Conclusions: The high proportion of delayed diagnosis and treatment indicates a lack of medical service for migrants. While this clearly translates into increased health risks for the individual patient, it also indicates a potential risk for transmission of communicable diseases in the community. The lack of a correlation between symptoms and detected infectious disease indicates the need for a standardized routine screening examination in all migrants.

Dengue is an acute, mosquito-transmitted viral disease characterized by fever, arthralgia, myalgia, rash, nausea, and vomiting and caused by any of four different serotypes of the virus (DEN-1, DEN-2, DEN-3, and DEN-4).1 The disease is endemic in most tropical areas of the world and has been reported in international travelers returning from such areas.2 The incidence of epidemic and endemic dengue has increased substantially in the Americas since 1977, and various epidemics have occurred.1-4