Exposure and Carriage of Pathogenic Leptospira in Livestock in St. Croix, U.S. Virgin Islands.

Hannah M Cranford,Bethany Bradford,Karen Lecount,Andrew Springer Browne,Marissa Taylor,Linda Schlater,Esther M Ellis,Richard L Hornsby,Camila Hamond,David P Alt,Tod Stuber,Tammy Anderson,Valicia J Burke-France,Jarlath E Nally,Leah De Wilde

doi:10.3390/tropicalmed6020085

Abstract

From 2019–2020, the Virgin Islands Department of Health (VIDOH) investigated potential animal reservoirs of Leptospira spp., the pathogenic bacteria that cause leptospirosis. We examined Leptospira exposure and carriage in livestock on the island of St. Croix, United States Virgin Islands (USVI). We utilized the microscopic agglutination test (MAT) to evaluate the sera, and the fluorescent antibody test (FAT), real time polymerase chain reaction (rt-PCR), and bacterial culture to evaluate urine specimens from livestock (n = 126): 28 cattle, 19 goats, 46 pigs, and 33 sheep. Seropositivity was 37.6% (47/125) with agglutinating antibodies to the following serogroups identified: Australis, Djasiman, Icterohaemorrhagiae, Ballum, Sejroe, Cynopteri, Autumnalis, Hebdomadis, Pomona, Canicola, Grippotyphosa, and Pyrogenes. Urine from 4 animals (4.0%, 4/101) was positive by rt-PCR for lipL32: 2 sheep, 1 goat, and 1 bull. Sequencing of secY amplicons identified L. interrogans in 1 sheep and 1 bull. Livestock in USVI harbor pathogenic Leptospira bacteria and could play a role in the zoonotic cycle of leptospirosis.

Highlights

Pathogenic Leptospira species are diderm bacteria that cause the emerging infectious disease leptospirosis, a leading cause of global zoonotic disease with an estimated 1.03 million cases and 58,900 deaths annually worldwide [1]
There is no expectation of vaccination for leptospirosis for livestock in St
For the detection of anti-Leptospira antibodies in the sera, we performed microscopic agglutination test (MAT) according to World Organisation for Animal Health guidelines, using a panel of 18 antigens, Trop

Summary

Introduction

Pathogenic Leptospira species are diderm bacteria that cause the emerging infectious disease leptospirosis, a leading cause of global zoonotic disease with an estimated 1.03 million cases and 58,900 deaths annually worldwide [1]. Hurricanes Irma and Maria, the Virgin Islands Department of Health (VIDOH) identified the first three cases of human leptospirosis in the USVI [4]. In 1985, a similar survey in Grenada determined seropositivity to Leptospira spp. of 25% in 324 cattle, 35% in 130 pigs, 35% in 146 sheep, and 25% in 44 goats [7]. In August 2019, the VIDOH implemented an active public health surveillance system to identify sources of potential exposures and the possible reservoirs of leptospirosis in animals including rodents, mongooses, bats, dogs, and livestock. We describe one part of the surveillance program: exposure and carriage of Leptospira spp. in livestock on St. Croix, USVI, using serology [microscopic agglutination test (MAT)], excretion of bacteria in urine [fluorescent antibody test (FAT) and lipL32 rt-PCR testing], and bacterial culture of Leptospira

Materials and Methods

Results

Discussion