CD40LG and infection: After clinical and epidemiological assessment, a group of asymptomatic participants was identified (n = 102, 32.5% of enrolled individuals) that had no evidence of recent infection (without febrile episodes in the previous year before enrollment and without anti-Leptospira IgM antibodies detected); we call them “long-term asymptomatic individuals.” Within this group, six (5.9%) excreted pathogenic and intermediate-pathogenic Leptospira (75–229 bacteria/mL of urine, Table 3).