Cyclical changes in seroprevalence of leptospirosis in California sea lions: endemic and epidemic disease in one host species?

BackgroundLeptospirosis is a zoonotic disease infecting a broad range of mammalian hosts, and is re-emerging globally. California sea lions (Zalophus californianus) have experienced recurrent outbreaks of leptospirosis since 1970, but it is unknown whether the pathogen persists in the sea lion population or is introduced repeatedly from external reservoirs.MethodsWe analyzed serum samples collected over an 11-year period from 1344 California sea lions that stranded alive on the California coast, using the microscopic agglutination test (MAT) for antibodies to Leptospira interrogans serovar Pomona. We evaluated seroprevalence among yearlings as a measure of incidence in the population, and characterized antibody persistence times based on temporal changes in the distribution of titer scores. We conducted multinomial logistic regression to determine individual risk factors for seropositivity with high and low titers.ResultsThe serosurvey revealed cyclical patterns in seroprevalence to L. interrogans serovar Pomona, with 4-5 year periodicity and peak seroprevalence above 50%. Seroprevalence in yearling sea lions was an accurate index of exposure among all age classses, and indicated on-going exposure to leptospires in non-outbreak years. Analysis of titer decay rates showed that some individuals probably maintain high titers for more than a year following exposure.ConclusionThis study presents results of an unprecedented long-term serosurveillance program in marine mammals. Our results suggest that leptospirosis is endemic in California sea lions, but also causes periodic epidemics of acute disease. The findings call into question the classical dichotomy between maintenance hosts of leptospirosis, which experience chronic but largely asymptomatic infections, and accidental hosts, which suffer acute illness or death as a result of disease spillover from reservoir species

Supplementary Data 3 - Study sites: location, population wing length, monitoring method, tide

------------------------------------------------------------------------------------------------------ Description of the dataset "Supplementary Data 3 - Study sites.csv" -------------------------------------------------------------------------------------------------------- The dataset - is used in the paper "Unexpected diversity in socially synchronized rhythms of shorebirds" Nature 2016 by M. Bulla et al - contains estimates of mean female and male wing length for each population of biparental shorebirds from a specific study site, plus the locations of the study site, whether the locations had tide, and whether the tide was used by the population for foraging, and how the incubation was monitored. -------------------------------------------------------------------------------------------------------- Questions can be directed to: Martin Bulla ([email protected]) -------------------------------------------------------------------------------------------------------- Values are separated by comma. -------------------------------------------------------------------------------------------------------- 1. scinam : scientific name of the species 2. sp : four letter abbreviation of the species's English name 3. study_site : name of the study site 4. site_abbreviation : four letter abbreviation of the study site 5. type : was the study site at the breeding ground (breeding) or not (wintering) 6. lat : latitude of the study site (decimal) 7. lon : longitude of the study site (decimal) 8. tidal_habitat : is the study site at primarily tidal habitat (y=yes, n=no) 9. tidal_used : if the study site is at primarily tidal habitat, do the birds use it for foraging (y=yes, n=no) 10. incubation_monitoring : method used to monitor incubation (for details see the paper's Extended Data Table 4) 11. sexing_method : identifies the method used to sex individuals to estimate the mean female and male wing length 12. pop_wing_f : mean female wing length for the population 13. f_wing_N : sample size used for the female mean estimate 14. pop_wing_m : mean male wing length for the population 15. m_wing_N : sample size used for the male mean estimate 16. data_source : is the mean wing estimate based on the primary data ("our primary data") or literature (citation)) -------------------------------------------------------------------------------------------------------- WHEN USING THIS DATA, PLEASE CITE: Bulla et al (2016). Supplementary Data 3 - Study sites: location, population wing length, monitoring method, tide. figshare. https://doi.org/10.6084/m9.figshare.1536260. Retrieved ADD DATETIME. -------------------------------------------------------------------------------------------------------

Additional file 4 of Mapping age- and sex-specific HIV prevalence in adults in sub-Saharan Africa, 2000–2018

Additional file 4: Supplemental results.1. README. 2. Prevalence range across districts. 3. Prevalence range between sexes. 4. Prevalence range between ages. 5. Age-specific district ranges