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Another person has died in an outbreak of extensively drug-resistant bacteria linked to contaminated eye drops, the Centers for Disease Control and Prevention reported in an update on Thursday.

The outbreak now totals 81 cases across 18 states. In addition to the four deaths, health officials have tallied reports of 14 people with vision loss and an additional four people who have had their eyeballs surgically removed (enucleation) due to infection.

The bacteria behind the outbreak is a strain of Pseudomonas aeruginosa dubbed VIM-GES-CRPA. This unwieldy acronym stands for a carbapenem-resistant P. aeruginosa (CRPA) with Verona integron-mediated metallo-β-lactamase (VIM) and Guiana extended-spectrum-β-lactamase (GES). It is an extensively drug-resistant strain of bacteria that, until this outbreak, had never been seen in the US before.