Abstract/Text: BACKGROUND: Existing travel health guidelines are based on a variety of data with underpinning evidence ranging from high-quality randomized controlled trials to best estimates from expert opinion. For strategic guidance and to set overall priorities, data about average risk are useful. The World Health Organization (WHO) plans to base future editions of "International Travel and Health" on its new "Handbook for Guideline Development."
METHODS: Based on a systematic search in PubMed, the existing evidence and quality of data on vaccine-preventable disease (VPD) risks in travelers was examined and essentials of vaccine efficacy were briefly reviewed. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework was used to evaluate the quality of the data.
RESULTS: Moderate-quality data to determine the risk of VPD exist on those that are frequently imported, whereas in most others the level of confidence with existing data is low or very low.
CONCLUSIONS: In order for the WHO to produce graded risk statements in the updated version of "International Travel and Health," major investment of time plus additional high-quality, generalizable risk data are needed.

© 2014 International Society of Travel Medicine.

Abstract/Text: BACKGROUND: No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk.
METHODS: We estimated the typhoid disease burden from studies done in LMICs based on blood-culture-confirmed incidence rates applied to the 2010 population, after correcting for operational issues related to surveillance, limitations of diagnostic tests, and water-related risk. We derived incidence estimates, correction factors, and mortality estimates from systematic literature reviews. We did scenario analyses for risk factors, diagnostic sensitivity, and case fatality rates, accounting for the uncertainty in these estimates and we compared them with previous disease burden estimates.
FINDINGS: The estimated number of typhoid fever cases in LMICs in 2010 after adjusting for water-related risk was 11·9 million (95% CI 9·9-14·7) cases with 129 000 (75 000-208 000) deaths. By comparison, the estimated risk-unadjusted burden was 20·6 million (17·5-24·2) cases and 223 000 (131 000-344 000) deaths. Scenario analyses indicated that the risk-factor adjustment and updated diagnostic test correction factor derived from systematic literature reviews were the drivers of differences between the current estimate and past estimates.
INTERPRETATION: The risk-adjusted typhoid fever burden estimate was more conservative than previous estimates. However, by distinguishing the risk differences, it will allow assessment of the effect at the population level and will facilitate cost-effectiveness calculations for risk-based vaccination strategies for future typhoid conjugate vaccine.

Copyright © 2014 Mogasale et al. Open Access article distributed under the terms of CC BY-NC-SA. Published by .. All rights reserved.

Abstract/Text: We review the epidemiological and clinical characteristics of tick-borne encephalitis, and summarise biological and virological aspects that are important for understanding the life-cycle and transmission of the virus. Tick-borne encephalitis virus is a flavivirus that is transmitted by Ixodes spp ticks in a vast area from western Europe to the eastern coast of Japan. Tick-borne encephalitis causes acute meningoencephalitis with or without myelitis. Morbidity is age dependent, and is highest in adults of whom half develop encephalitis. A third of patients have longlasting sequelae, frequently with cognitive dysfunction and substantial impairment in quality of life. The disease arises in patchy endemic foci in Europe, with climatic and ecological conditions suitable for circulation of the virus. Climate change and leisure habits expose more people to tick-bites and have contributed to the increase in number of cases despite availability of effective vaccines. The serological diagnosis is usually straightforward. No specific treatment for the disease exists, and immunisation is the main preventive measure.

Abstract/Text: Malaria is a leading cause of morbidity and mortality in endemic areas, leading to an estimated 438,000 deaths in 2015. Malaria is also an important health threat to travelers to endemic countries and should be considered in evaluation of any traveler returning from a malaria-endemic area who develops fever. Considering the diagnosis of malaria in patients with potential exposure is critical. Prompt provision of effective treatment limits the complications of malaria and can be life-saving. Understanding Plasmodium species variation, epidemiology, and drug-resistance patterns in the geographic area where infection was acquired is important for determining treatment choices.

Copyright © 2017 Elsevier Inc. All rights reserved.

Abstract/Text: Rabies is one of the most deadly infectious diseases, with a case-fatality rate approaching 100%. The disease is established on all continents apart from Antarctica; most cases are reported in Africa and Asia, with thousands of deaths recorded annually. However, the estimated annual figure of almost 60,000 human rabies fatalities is probably an underestimate. Almost all cases of human rabies result from bites from infected dogs. Therefore, the most cost-effective approach to elimination of the global burden of human rabies is to control canine rabies rather than expansion of the availability of human prophylaxis. Mass vaccination campaigns with parenteral vaccines, and advances in oral vaccines for wildlife, have allowed the elimination of rabies in terrestrial carnivores in several countries worldwide. The subsequent reduction in cases of human rabies in such regions advocates the multidisciplinary One Health approach to rabies control through the mass vaccination of dogs and control of canine populations.

Copyright © 2014 Elsevier Ltd. All rights reserved.

Abstract/Text: In order to have a rational approach to necessary preventive measures it is essential to know the health risks. The 80 million travellers each year with destinations in Africa, Asia, Latin America, Pacific Islands and remote areas in Eastern Europe are exposed to a broad range of pathogens that are rarely encountered at home. The risk depends on the degree of endemicity in the area visited, the duration of stay, the individual behaviour and the preventive measures taken. Travellers' diarrhoea (TD) is the most frequent ailment of visitors to countries with poor hygiene. The incidence rate is 25-90% in the first 2 weeks abroad. The risk of TD is far less in travellers originating in a high risk country, as some immunity develops. Malaria is an important risk for travellers going to endemic areas. Without chemoprophylaxis, the monthly incidence is high in some destinations, among them frequently visited tropical Africa where 80-95% of the infections are due to Plasmodium falciparum. The incidence rates are lower in most endemic areas of Asia and Latin America where Plasmodium vivax predominates. The risk is nil in all capital cities of South America and SE Asia, as well as in many frequently visited tourist destinations. The diseases preventable by immunization will be discussed in a separate paper (Vaccination priorities; page 175). Sexually transmitted diseases occur frequently, as some travellers (5% of Europeans) engage in casual sex, approximately half of them without being protected by a condom. The prevalence for HIV-infection, syphilis, gonorrhoea, etc. often exceeds 50% in prostitutes. In some European countries, a major proportion of heterosexuals with newly acquired HIV-infection have acquired it while abroad.

Abstract/Text: BACKGROUND: Data on relative rates of acquisition of gastrointestinal infections by travelers are incomplete. The objective of this study was to analyze infections associated with oral ingestion of pathogens in international travelers in relation to place of exposure.
METHODS: We performed a multicenter, retrospective observational analysis of 6,086 travelers ill enough with any gastrointestinal infection to seek medical care at a GeoSentinel clinic after completion of travel during 2000 to 2005. We determined regional and country-specific reporting rate ratios (RRRs) in comparison to risk in northern and western Europe.
RESULTS: Travel to sub-Saharan Africa (RRR = 282), South America (RRR = 203), and South Asia (RRR = 890) was associated with the greatest rate of gastrointestinal infections. RRRs were moderate (25-142) for travel to Oceania, the Middle East, North Africa, Central America, the Caribbean, and Southeast Asia. RRRs were least (<28) following travel to southern, central, and eastern Europe; North America; Northeast Asia; and Australasia. Income level of the country visited was inversely proportional to the RRR for gastrointestinal infection. For bacterial and parasitic infections examined separately, the regions group in the same way. RRRs could be estimated for 28 individual countries and together with regional data were used to derive a global RRR map for travel-related gastrointestinal infection.
CONCLUSIONS: This analysis of morbidity associated with oral ingestion of pathogens abroad determines which parts of the world currently are high-risk destinations.

Abstract/Text: BACKGROUND: More than 30,000 malaria cases are reported annually among international travellers. Despite improvements in malaria control, malaria continues to threaten travellers due to inaccurate perception of risk and sub-optimal pre-travel preparation.
METHODS: Records with a confirmed malaria diagnosis after travel from January 2003 to July 2016 were obtained from GeoSentinel, a global surveillance network of travel and tropical medicine providers that monitors travel-related morbidity. Records were excluded if exposure country was missing or unascertainable or if there was a concomitant acute diagnosis unrelated to malaria. Records were analyzed to describe the demographic and clinical characteristics of international travellers with malaria.
RESULTS: There were 5689 travellers included; 325 were children <18 years. More than half (53%) were visiting friends and relatives (VFRs). Most (83%) were exposed in sub-Saharan Africa. The median trip duration was 32 days (interquartile range 20-75); 53% did not have a pre-travel visit. More than half (62%) were hospitalized; children were hospitalized more frequently than adults (73 and 62%, respectively). Ninety-two per cent had a single Plasmodium species diagnosis, most frequently Plasmodium falciparum (4011; 76%). Travellers with P. falciparum were most frequently VFRs (60%). More than 40% of travellers with a trip duration ≤7 days had Plasmodium vivax. There were 444 (8%) travellers with severe malaria; 31 children had severe malaria. Twelve travellers died.
CONCLUSION: Malaria remains a serious threat to international travellers. Efforts must focus on preventive strategies aimed on children and VFRs, and chemoprophylaxis access and preventive measure adherence should be emphasized.