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

BACKGROUND: Prolonged diarrhoea is common amongst returning travellers and is often caused by intestinal protozoa. However, the epidemiology of travel-associated illness caused by protozoal pathogens is not well described. METHODS: We analysed records of returning international travellers with illness caused by Giardia duodenalis, Cryptosporidium spp., Cyclospora cayetanensis or Cystoisospora belli, reported to the GeoSentinel Network during January 2007-December 2019. We excluded records of travellers migrating, with an unascertainable exposure country, or from GeoSentinel sites that were not located in high-income countries. RESULTS: There were 2517 cases, 82.3% giardiasis (n = 2072), 11.4% cryptosporidiosis (n = 287), 6.0% cyclosporiasis (n = 150) and 0.3% cystoisosporiasis (n = 8). Overall, most travellers were tourists (64.4%) on long trips (median durations: 18-30 days). Cryptosporidiosis more frequently affected people < 18 years (13.9%) and cyclosporiasis affected people ≥ 40 years (59.4%). Giardiasis was most frequently acquired in South Central Asia (45.8%) and sub-Saharan Africa (22.6%), cryptosporidiosis in sub-Saharan Africa (24.7%) and South-Central Asia (19.5%), cyclosporiasis in South East Asia (31.3%) and Central America (27.3%), and cystoisosporiasis in sub-Saharan Africa (62.5%). Cyclosporiasis cases were reported from countries of uncertain endemicity (e.g. Cambodia) or in countries with no previous evidence of this parasite (e.g. French Guiana). The time from symptom onset to presentation at a GeoSentinel site was the longest amongst travellers with giardiasis (median: 30 days). Over 14% of travellers with cryptosporidiosis were hospitalized. CONCLUSIONS: This analysis provides new insights into the epidemiology and clinical significance of four intestinal protozoa that can cause morbidity in international travellers. These data might help optimize pretravel advice and post-travel management of patients with travel-associated prolonged gastrointestinal illnesses. This analysis reinforces the importance of international travel-related surveillance to identify sentinel cases and areas where protozoal infections might be undetected or underreported.

A country classification system to inform rabies prevention guidelines and regulations.

BACKGROUND: Assessing the global risk of rabies exposure is a complicated task requiring individual risk assessments, knowledge of rabies epidemiology, surveillance capacity and accessibility of rabies biologics on a national and regional scale. In many parts of the world, availability of this information is limited and when available is often dispersed across multiple sources. This hinders the process of making evidence-based health and policy recommendations to prevent the introduction and spread of rabies. METHODS: CDC conducted a country-by-country qualitative assessment of risk and protective factors for rabies to develop an open-access database of core metrics consisting of the presence of lyssaviruses (specifically canine or wildlife rabies virus variants or other bat lyssaviruses), access to rabies immunoglobulins and vaccines, rabies surveillance capacity and canine rabies control capacity. Using these metrics, we developed separate risk scoring systems to inform rabies prevention guidance for travelers and regulations for the importation of dogs. Both scoring systems assigned higher risk to countries with enzootic rabies (particularly canine rabies), and the risk scoring system for travelers also considered protective factors such as the accessibility of rabies biologics for post-exposure prophylaxis. Cumulative scores were calculated across the assessed metrics to assign a risk value of low, moderate or high. RESULTS: A total of 240 countries, territories and dependencies were assessed, for travelers, 116 were identified as moderate to high risk and 124 were low or no risk; for canine rabies virus variant importation, 111 were identified as high-risk and 129 were low or no risk. CONCLUSIONS: We developed a comprehensive and easily accessible source of information for assessing the rabies risk for individual countries that included a database of rabies risk and protective factors based on enzootic status and availability of biologics, provided a resource that categorizes risk by country and provided guidance based on these risk categories for travelers and importers of dogs into the United States.