Travel-associated pneumonias

Abstract

Respiratory infections are responsible for up to 11% of febrile infections in travellers or immigrants from tropical and subtropical regions. The main pathogens are the same as in temperate climate zones: Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, influenza viruses, Legionella pneumophila. However, some pulmonary diseases can be attributed to bacterial, parasitic, viral or fungal pathogens that are endemic in tropical and subtropical regions. The most commonly imported infections are malaria, dengue, and tuberculosis. Pulmonary symptoms and eosinophilia in returning travellers and migrants may be caused by several parasitic infections such as Katayama syndrome, Loeffler syndrome, tropical pulmonary eosinophilia, amebiasis, paragonimiasis, echinococcosis, and toxocariasis. In Asia, Tsutsugamushi fever is transmitted by chiggers, spotted fever rickettsiae are transmitted by ticks. Transmission of zoonotic diseases occurs mainly via contact with infected animals or their excretions, human-to-human transmission is generally rare: MERS-CoA (dromedary camels), pulmonary hantavirus infection (rodents), tularemia (rabbits and hares), leptospirosis (rats), Q-fever (sheep and goats), very rarely anthrax (hides of ruminants) and pest (infected rats and wildlife). Inhalation of contaminated dust can cause infections with dimorphic fungi: histoplasmosis (bat guano) and coccidioidomycosis in America and parts of Africa, blastomycosis in America. Some infections can cause symptoms years after a stay in tropical or subtropical regions (melioidosis, tuberculosis, histoplasmosis, schistosomiasis-associated pulmonary hypertension). Noninfectious respiratory diseases caused by inhalation of high amounts of air pollution or toxic dusts may also be considered.