Intestinal protozoa in returning travellers: a GeoSentinel analysis from 2007 to 2019

Area of Science:

• Infectious Diseases
• Parasitology
• Epidemiology

Background:

• Prolonged diarrhea is a common ailment among international travelers.
• Intestinal protozoa are frequent causes of travel-associated gastrointestinal illness.
• The epidemiology of protozoal infections in travelers is not well-documented.

Purpose of the Study:

• To describe the epidemiology and clinical significance of four intestinal protozoa in returning international travelers.
• To identify geographical hotspots and demographic risk factors for these infections.
• To inform pre-travel health recommendations and post-travel patient management.

Main Methods:

• Analysis of illness records from the GeoSentinel Network (January 2007-December 2019).
• Inclusion of cases caused by Giardia duodenalis, Cryptosporidium spp., Cyclospora cayetanensis, or Cystoisospora belli.
• Exclusion of migrants, travelers with unknown exposure countries, and data from non-high-income countries.

Main Results:

• 2517 cases identified: 82.3% giardiasis, 11.4% cryptosporidiosis, 6.0% cyclosporiasis, 0.3% cystoisosporiasis.
• Tourists on long trips (median 18-30 days) were the primary affected group.
• Specific protozoa showed distinct geographical acquisition patterns (e.g., Giardiasis in South Central Asia, Cyclosporiasis in Southeast Asia).
• Cryptosporidiosis frequently affected younger individuals (<18 years), while cyclosporiasis affected older adults (≥40 years).
• Cryptosporidiosis led to hospitalization in over 14% of cases.

Conclusions:

• This study provides crucial epidemiological insights into protozoal infections in international travelers.
• Findings can help optimize pre-travel advice and post-travel management for prolonged gastrointestinal illnesses.
• Reinforces the importance of international travel surveillance for detecting underreported protozoal infections.