n conclusion, this study highlights the importance of understanding the inflammatory response and the Jarisch-Herxheimer reaction (JHR) in leptospirosis patients. The findings suggest that leptospires induce a potent anti-inflammatory response rather than inflammation, challenging the traditional view of leptospirosis as an inflammatory disease. The study also raises questions about the use of immunosuppressive drugs and the choice of antibiotics in treating leptospirosis. The high incidence of JHR in New Caledonia suggests that the systematic use of ß-lactams as a first-line treatment should be reevaluated.
The study enrolled 81 patients diagnosed with leptospirosis in four hospitals in New Caledonia between 2021 and 2024. The majority of the cohort were middle-aged men, most of them Melanesian farmers, exhibiting typical symptoms and biochemical markers of leptospirosis. Unexpectedly, pro-inflammatory cytokine levels were low upon admission, while high levels of the anti-inflammatory cytokine IL-10 were measured. After antibiotherapy, increased levels of pro-inflammatory cytokines TNF and IL-6, as well as IL-10, were observed. The study also identified a new clinical score for JHR, which occurred in 48% of patients and was associated with higher cytokine levels, confirming the occurrence of JHR in leptospirosis patients.
