Florida's invasive macaques harbor deadly herpes B virus, study finds

Twelve Asian rhesus macaques were released in Silver Springs State Park in the 1930s to boost tourism, eventually growing to hundreds before trapping ended in 2015. A University of Florida and University of Washington team examined blood from 317 macaques collected between 2000 and 2012, finding roughly 25 % seropositive for macacine herpesvirus 1. Non-invasive saliva swabs taken across three seasonal periods identified three positive samples, all during the fall breeding season, indicating active viral shedding in about 4-14 % of monkeys at that time.

Sequencing demonstrated the virus is nearly identical to strains linked to severe human disease in laboratory settings. No human infection from the wild population has been documented, but frequent feeding of the monkeys by boaters creates opportunities for bites or scratches, leading park officials to close areas on several occasions. The CDC now lists the free-ranging macaques as a public-health concern.