Robert Steffen

Traveler’s Diarrhea: A Clinical Review

IMPORTANCE Acute diarrhea is the most common illness that affects travelers to low-income regions of the world. Although improved hygiene has reduced the risk of travelers diarrhea in many destinations, the risk remains high in others. OBJECTIVE To review the current state of knowledge on the etiology, risk factors, prevention, and management of travelers diarrhea. EVIDENCE REVIEW A search of the PubMed, Google Scholar, and Cochrane Library databases for the period 2012-April 2014 was performed for articles on travelers diarrhea. The database search yielded 2976 articles, of which 37 were included in this review. These were added to 85 articles previously identified by the authors. FINDINGS Improved hygiene has reduced the risk of travelers diarrhea from 20% or more (for a 2-week stay) to between 8% and 20% in some parts of the world. Acquiring travelers diarrhea causes 12% to 46% of travelers to change their travel plans. Returning travelers seeking medical care have a diagnosis of gastrointestinal disturbance in approximately one-third of all cases. Postinfectious irritable bowel syndrome may occur in 3% to 17% of patients who have had travelers diarrhea. Prevention of travelers diarrhea by dietary avoidance measures is often not successful. Chemoprophylaxis should be restricted to travelers who are at risk of severe complications of diarrhea. Ciprofloxacin is the standard treatment in self-therapy of travelers diarrhea except when patients are in South or Southeast Asia, where azithromycin is preferred. CONCLUSIONS AND RELEVANCE Diarrhea remains a common problem for international travelers. Persons intending to travel to at-risk countries should be counseled regarding prevention measures and may be given a travel pack that includes medications for self-treatment should they become ill.

Emergence of medicine for mass gatherings: lessons from the Hajj

Summary Although definitions of mass gatherings (MG) vary greatly, they consist of large numbers of people attending an event at a specific site for a finite time. Examples of MGs include World Youth Day, the summer and winter Olympics, rock concerts, and political rallies. Some of the largest MGs are spiritual in nature. Among all MGs, the public health issues, associated with the Hajj (an annual pilgrimage to Mecca, Saudi Arabia) is clearly the best reported—probably because of its international or even intercontinental implications in terms of the spread of infectious disease. Hajj routinely attracts 2·5 million Muslims for worship. WHOs global health initiatives have converged with Saudi Arabias efforts to ensure the wellbeing of pilgrims, contain infectious diseases, and reinforce global health security through the management of the Hajj. Both initiatives emphasise the importance of MG health policies guided by sound evidence and based on experience and the timeliness of calls for a new academic science-based specialty of MG medicine.

Non-communicable health risks during mass gatherings

Mass gatherings (MGs) have been associated with high rates of morbidity and mortality from non-communicable diseases, accidents, and terrorist attacks, thus posing complex public health challenges. We assessed the health risks and public health responses to MGs to identify an evidence-based framework for public health interventions. Human stampedes and heat-related illnesses are the leading causes of mortality. Minor traumatic injuries and medical complaints are the main contributors to morbidity and, particularly, the need for on-site medical care. Infrastructure, crowd density and mood, weather, age, and sex determine the risks to health. Many predictive models for deployment of medical resources are proposed, but none have been validated. We identified the risks for mortality and morbidity during MGs, most efficient public health interventions, and need for robust research into health risks for non-communicable diseases during MGs.

The Risk of Meningococcal Disease in Travelers and Current Recommendations for Prevention

With the economic recovery gaining momentum, travel experts predict that tourism in all regions will increase in 2010 by an estimated 3% to 4%. 1 This increase in travel is forecasted to exceed 5% in Africa, Asia, and the Middle East, where the risk of acquiring meningococcal disease or becoming a carrier is higher. 2 When evaluating the need for vaccination in travelers, particularly for those traveling to developing world countries, it is important to consider not only the incidence rate but also the impact of the respective infection (Figure 1). 3 As an example, meningococcal disease is rarely reported in travelers, but the impact of this infection can be as devastating for travelers as for any other individual. With its rapid clinical course and narrow window for diagnosis, the potential for negative outcomes from meningococcal disease may be increased particularly in travelers to remote locations where access to adequate health care facilities and antibiotics is limited. There is an additional public health concern with meningococcal infection, as travelers who are carriers may spread the infection in the society back home. Figure 1 Impact and incidence of vaccine‐preventable diseases in travelers to developing countries. 3 PPD = purified protein derivative, a tuberculin test. Outbreaks of meningococcal disease frequently occurred among Hajj pilgrims, their contacts, and thereafter even in persons without known contacts prior to 2002, when authorities of the Kingdom of Saudi Arabia issued a quadrivalent meningococcal vaccination requirement to obtain a Hajj visa. 4,5 Otherwise meningococcal disease usually has been considered to be rare among travelers (Figure 2). 6 A single retrospective survey has attempted to quantify the risk of meningococcal disease among international travelers originating in industrialized countries. 7Health authorities in 56 of 108 contacted countries (51.9%) completed questionnaires concerning reported cases of meningococcal disease, and tourism … Corresponding Author: Robert Steffen, MD, ZRM/ISPM, Hirschengraben 84/E29, CH‐8001 Zurich, Switzerland. E‐mail: roste{at}ifspm.uzh.ch

Fifty years of travel medicine epidemiology: what have we learnt?

Division of Infectious Diseases, Department of Public Health, Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Center for Traveller’s Health, University of Zurich, Zurich, Switzerland; Division of Epidemiology, Human Genetics & Environmental Sciences, The University of Texas School of Public Health, Houston, Texas, USA; Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA; Global Health Sciences, University of California San Francisco, California, USA

Redefining priorities towards graded travel-related infectious disease research

Our knowledge of the health problems and infections encountered by international travellers has evolved considerably in the past decades. The growth of global networks such as the GeoSentinel Surveillance network, TropNet Europe, EuroTravNet and networks based in North America have provided valuable information on the frequency of a wide array of travel-related diseases and accidents, including details on the destination of travel and trends over time. The information gained from these network studies has provided important data for the practice of travel medicine and in some instances for the development of practice guidelines. However, network data due to a lack of denominators usually cannot serve as a basis for a GRADE approach to guideline development. Although epidemiological network studies will continue to serve an important role in travel medicine we encourage an additional strong focus towards translational scientific research questions and towards the broader use of novel techniques to obtain more accurate epidemiological analyses to address the many unanswered questions in our field.

Filling Gaps on Influenza En Route and the Etiology of Influenza During a Pandemic Year

This is the first issue of Journal of Travel Medicine with the cross‐bar “Influenza” on the cover. In view of the fact that this infection is sometimes labeled the most frequent vaccine‐preventable disease in travelers, this is justified. But what missing pieces do the four submitted original articles fill in the epidemiological and etiological puzzle? The contribution by Vilella and colleagues confirms that influenza, particularly pandemic influenza A(H1N1) 2009, is intensely and probably rapidly transmitted among groups with close and prolonged interpersonal contact, such as during a 4‐hour bus ride.1 Among the 113 Spanish medical students who traveled for 1 week to the Dominican Republic, 6 (5.3%) developed mild influenza‐like illness abroad 1–3 days before return; 62 among 86 (72.1%) who could be interviewed developed illness within 4 days after landing back in Spain. Overall, pandemic influenza A(H1N1) 2009 was confirmed in 39 patients, 2 of them asymptomatic. Also, there is additional evidence that social distancing—far easier back home in the usual environment as compared to during travel—drastically reduces the risk of transmission: among 98 contacts of the 39 students with confirmed infection, only 5 developed probable or confirmed (1 patient) influenza (overall 5.1%). Among possible biases for such a significant difference is that viral shedding may have decreased after the trip, but this is unlikely to have played the decisive role, as viral detection was still demonstrated in a large proportion of students. Based on anecdotes from families and friends there is common belief that “flu” is frequently transmitted on flights. Vilella and colleagues describe that aboard the flight from Santo Domingo back to Madrid the “students who became ill (upon return) … Corresponding Author: Prof. Robert Steffen, MD, University of Zurich ISPM/ZRM, Hirschengraben 84/E29, CH‐8001 Zurich, Switzerland. E‐mail: roste{at}ifspm.uzh.ch