Several rafters visiting the Grand Canyon between May and June have reported experiencing prolonged, mysterious illnesses following their trips. The National Park Service is currently investigating these reports to determine if the cases are linked to a specific cause. One affected individual, Matt Wappett, reported a severe knee infection followed by persistent fatigue, fever, joint pain, and pneumonia. While doctors investigate potential connections, Wappett is awaiting test results for valley fever, dengue fever, and hantavirus. Other rafters in private boating groups have reported similar ailments, leading to theories involving tickborne diseases like Lyme or waterborne illnesses like leptospirosis. The NPS is actively interviewing individuals and working with other agencies to identify the source. They have advised anyone experiencing similar symptoms after visiting the canyon to contact the NPS Office of Public Health immediately for further assistance.