A possible trachoma cluster unveiling the mist of Le Rôdeur: probes in favor and against an alternative cause of the crew blindness.

In 1819, a puzzling outbreak of infectious blindness afflicted nearly all crew members and African slaves aboard the French vessel Le Rôdeur during the transatlantic slave trade. This paper investigates the etiology of this unique event, comparing different pathogens that cause blindness: Chlamydia trachomatis, Neisseria gonorrhoeae, and Onchocerca volvulus; endemic in the African Continent. Reviewing naval medicine since the seventeenth century and eye infection knowledge in 1800, alongside historical records, we explore the singular case of Le Rôdeur's outbreak. While some clinical features favor trachoma, rapid onset, and progression align with gonococcal conjunctivitis. We suggest both as possible causes, underscoring the intricate intersection of infectious diseases and transatlantic trade.