The Emergence of Travel-related Infections in Critical Care Units

Several tropical or geographically confined infectious diseases may lead to organ failure requiring management in an intensive care unit (ICU), both in endemic low- and middle-income countries where ICU facilities are increasingly being developed and in (nonendemic) high-income countries through an increase in international travel and migration. The ICU physician must know which of these diseases may be encountered and how to recognize, differentiate, and treat them. The four historically most prevalent "tropical" diseases (malaria, enteric fever, dengue, and rickettsiosis) can present with single or multiple organ failure in a very similar manner, which makes differentiation based solely on clinical signs very difficult. Specific but frequently subtle symptoms should be considered and related to the travel history of the patient, the geographic distribution of these diseases, and the incubation period. In the future, ICU physicians may also be more frequently confronted with rare but frequently lethal diseases, such as Ebola and other viral hemorrhagic fevers, leptospirosis, and yellow fever. No one could have foreseen the worldwide 2019-up to now coronavirus disease 2019 (COVID-19) crisis caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was initially spread by travel too. In addition, the actual pandemic due to SARS-CoV-2 reminds us of the actual and potential threat of (re)-emerging pathogens. If left untreated or when treated with a delay, many travel-related diseases remain an important cause of morbidity and even mortality, even when high-quality critical care is provided. Awareness and a high index of suspicion of these diseases is a key skill for the ICU physicians of today and tomorrow to develop.