This study confirms that two-tiered serologic testing algorithms are insensitive in early Lyme disease, particularly within the first 2 weeks after symptom onset or when erythema migrans is not accompanied by constitutional symptoms. It also demonstrates that seroconversion is rare after antibiotic treatment. These results highlight the need for novel diagnostics for early Lyme disease that do not rely on serologic testing.
Horn et al. (2026) studied this question.