Assessment of the Increased Risk of Infection Following an Ultratrail (INFultra)

The increase in the practice of running has encouraged a proliferation of studies evaluating the impact of this sport on health. A number of these studies have looked at the influence of endurance events on the immune system. After prolonged exercise, a systemic inflammatory syndrome sets in, with repercussions for the functioning of the immune system. The number of lymphocytes in the blood is reduced, the function of natural killer (NK) cells is impaired and secretory immunity is impaired. During this period of immunosuppression, often referred to as the 'open window', the host may be more susceptible to micro-organisms that bypass the first line of defence.

The invetigators' hypothesis is therefore that ultratrailers are overexposed to the risk of infection due to immunodepression resulting from practising this sport. In order to support this hypothesis, the investigators would like to look at infectious complications in general and ear-nose and throat episodes (rhinitis, pharyngitis, laryngitis, etc.) in particular, which are the most common infections encountered in primary care, along with urinary tract infections.

Study Overview

• Status: Completed
• Conditions: Infections; Running; Immune Deficiency
• Intervention / Treatment: Other: Ultra-trail

• Study Type: Interventional
• Enrollment (Actual): 471
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Reunion
  • Saint-Denis, Reunion, 97400
    • Chu Reunion

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• > 18 years
• Participating in a Grand Raid de la Réunion 2023 race (Mascareignes, Trail de Bourbon, Diagonale des Fous)
• Have a companion living under the same roof during the week preceding the race and the 21 days following the race and who agrees to answer the questionnaires
• Do not object to the research

Exclusion Criteria:

• Do not understand French
• A protected adult (guardianship or curatorship) or under court protection

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exposed (Runners); Ultra-endurance runners taking part in an ultra-trail of 72 km, 109 km or 165 km	Other: Ultra-trail; Questionnaires sent to runners at various pre-race and post-race times (Day3, Day6, Day10, Day14 and Day21)
No Intervention: Non-exposed (companions); Runners' companions not running

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Increased risk of infection	Comparing the incidence of all infectious symptoms in runners taking part in one of the Grand Raid races (exposed subjects) with the incidence of infectious symptoms in those accompanying them on the race. fever, congestion, stuffy nose, sneezing, shortness of breath, vomiting, diarrhea, headache, sore throat, general fatigue, burning and urinary symptoms, other infectious symptoms; associated with major infections (respiratory, skin, gastrointestinal, urinary, other)	Day 21

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Kinetic of infections' appearance	Kinetics of the onset of infectious symptoms within 21 days following one of the Grand Raid de La Réunion races in runners (exposed subjects) and their companions (unexposed subjects). Survival curves over the 3 weeks post-race will be produced. An on-line questionnaire will be used to collect infectious data.	Day 21
Risk factors: running distance	Identify if the distance of the race in which the runner participates is a risk factor associated with the risk of infection in the 21 days following one of the Grand Raid de La Réunion races in runners (exposed subjects). An on-line questionnaire will be used to collect data related to the race distance.	Day 21
Risk factors: training volume	Identify if the runner's training volume is a risk factor associated with the risk of infection in the 21 days following one of the Grand Raid de La Réunion races in runners (exposed subjects).	Day 21
Risk factors: sex of the runner	Identify if sex of the runner is a risk factor associated with the risk of infection in the 21 days following one of the Grand Raid de La Réunion races in runners (exposed subjects).	Day 21
Risk factors: age category	Identify if the age of the runner is a risk factor associated with the risk of infection in the 21 days following one of the Grand Raid de La Réunion races in runners (exposed subjects).	Day 21

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de la Réunion
• Collaborators: Jean Monnet University; Hôpital Privé de la Loire- Saint Etienne
• Investigators: Principal Investigator: Nicolas BOUSCAREN, MD, CHU de la réunion

Study record dates

Study Major Dates

• Study Start (Actual): October 6, 2023
• Primary Completion (Actual): November 14, 2023
• Study Completion (Actual): November 14, 2023

Study Registration Dates

• First Submitted: August 11, 2023
• First Submitted That Met QC Criteria: October 16, 2023
• First Posted (Actual): October 18, 2023

Study Record Updates

• Last Update Posted (Actual): February 17, 2026
• Last Update Submitted That Met QC Criteria: February 16, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Infection; Immune deficiency; Ultra-running
• Additional Relevant MeSH Terms: Immune System Diseases; Infections; Immunologic Deficiency Syndromes
• Other Study ID Numbers: 2023/CHU/23

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No