First Report of Asymptomatic Carrier Transmission of Leptospirosis
- Leptospirosis
Abstract
Since 1970, periodic outbreaks of leptospirosis, caused by pathogenic spirochetes in the genus Leptospira, have caused morbidity and mortality of California sea lions (Zalophus californianus) along the Pacific coast of North America. Yearly seasonal epizootics of varying magnitude occur between the months of July and December, with major epizootics occurring every 3–5 years. Genetic and serological data suggest that Leptospira interrogans serovar Pomona is the infecting serovar and is enzootic in the California sea lion population, although the mechanism of persistence is unknown. We report asymptomatic carriage of Leptospira in 39% (33/85) of wild, free-ranging sea lions sampled during the epizootic season, and asymptomatic seroconversion with chronic asymptomatic carriage in a rehabilitated sea lion. This is the first report of asymptomatic carriage in wild, free-ranging California sea lions and the first example of seroconversion and asymptomatic chronic carriage in a sea lion. Detection of asymptomatic chronic carriage of Leptospira in California sea lions, a species known to suffer significant disease and mortality from the same Leptospira strain, goes against widely-held notions regarding leptospirosis in accidental versus maintenance host species. Further, chronic carriage could provide a mechanism for persistent circulation of Leptospira in the California sea lion population, particularly if these animals shed infectious leptospires for months to years.
Prager, K.C., Greig, D.J., Alt, D.P., Galloway, R.L., Hornsby, R.L., Palmer, L.J., Soper, J., Wu, Q., Zuerner, R.L., Gulland, F.M.D., Lloyd-Smith, J.O. 2013. Asymptomatic and chronic carriage of Leptospira interrogans serovar Pomona in California sea lions (Zalophus californianus). 164 (2013): 177-183.
Related Publications
{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/sea-lions-in-water-photo-c-bill-hunnewell-2140-212-1308-1022-1603918234.jpg","alt":"large group of California sea lions in the water","title":"Detecting the Spread of Leptospirosis Through Asymptomatic Carriers","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/detecting-the-spread-of-leptospirosis-through-asymptomatic-carriers","label":"Research Paper"}
{"image":"\/Animals\/Patients\/California sea lions\/cropped-images\/csl-by-bill-hunnewell-c-the-marine-mammal-center-7-0-1446-2827-2208-1603918668.jpg","alt":"California sea lion on pool ledge","title":"Effectiveness of Antibiotics in Treating Leptospirosis in California Sea Lions","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/effectiveness-of-antibiotics-in-treating-leptospirosis-in-california-sea-lions","label":"Research Paper"}
Effectiveness of Antibiotics in Treating Leptospirosis in California Sea Lions
Read More{"image":"\/Animals\/Wild\/California sea lion\/cropped-images\/sea-lions-underwater-baja-shutterstock-186-4-4173-3260-1603919420.jpg","alt":"California sea lions underwater","title":"Seasonal Migration Contributes to Spread of Leptospirosis","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/seasonal-migration-contributes-to-spread-of-leptospirosis","label":"Research Paper"}
{"image":"\/Animals\/Patients\/California sea lions\/cropped-images\/csl-eating-by-bill-hunnewell-c-the-marine-mammal-center-0-361-1799-1405-1617816863.jpg","alt":"California sea lion eating a fish","title":"Predicting Prognosis in Wildlife Rehabilitation: A Case Study of Leptospirosis in Sea Lions","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/predicting-prognosis-in-wildlife-rehabilitation-a-case-study-of-leptospirosis","label":"Research Paper"}
Predicting Prognosis in Wildlife Rehabilitation: A Case Study of Leptospirosis in Sea Lions
Read MoreRelated News
{"image":"\/Animals\/Wild\/Humpback whale\/cropped-images\/humpback-whale-sea-lions-photo-c-bill-hunnewell-102-0-1270-992-1743014972.jpg","alt":"A California sea lion jumps out of the ocean next to a humpback whale showing its tail and another whale showing its back.","title":"What is the Loudest Animal on Earth? And Other Animal Trivia","link_url":"https:\/\/www.marinemammalcenter.org\/news\/what-is-the-loudest-animal-on-earth-and-other-animal-trivia","label":"News Update","date":"2025-03-26 07:00:00"}
{"image":"\/Animals\/Patients\/California sea lions\/2024\/csl-autumn-photo-by-chris-deimler-c-the-marine-mammal-center.jpg","alt":"A California sea lion with a small satellite tag on its back walks on a rocky beach toward the ocean.","title":"From Treating Sick Sea Lions to Tracking Them in the Wild: Follow Autumn","link_url":"https:\/\/www.marinemammalcenter.org\/news\/from-treating-sick-sea-lions-to-tracking-them-in-the-wild-follow-autumn","label":"Patient Update","date":"2025-02-27 15:23:46"}
From Treating Sick Sea Lions to Tracking Them in the Wild: Follow Autumn
February 27, 2025
Read More{"image":"\/Misc\/cropped-images\/leashed-dog-on-beach-shutterstock-10-10-5572-4352-1696014237.jpg","alt":"a golden retriever lying on a sandy beach with a leash and harness","title":"How to Keep Your Dog Safe on Beaches","link_url":"https:\/\/www.marinemammalcenter.org\/news\/how-to-keep-your-dog-safe-on-beaches","label":"News Update","date":"2023-09-29 02:00:00"}
{"image":"\/Animals\/Patients\/Rescues\/cropped-images\/csl-grazer-pre-rescue-photo-c-the-marine-mammal-center-515-229-784-612-1694454282.jpg","alt":"California sea lion on a sandy beach with flippers tucked to abdomen","title":"San Francisco Chronicle: Why Sick Sea Lions are Washing Up on the California Coast","link_url":"https:\/\/www.marinemammalcenter.org\/news\/san-francisco-chronicle-why-sick-sea-lions-are-washing-up-on-the-california-coast","label":"In the News","date":"2023-09-09 02:00:00"}
San Francisco Chronicle: Why Sick Sea Lions are Washing Up on the California Coast
September 9, 2023
Read More