High Leptospira Diversity in Animals and Humans Complicates the Search for Common Reservoirs of Human Disease in Rural Ecuador.
Leptospirosis is a zoonotic disease responsible for high morbidity around the world, especially in tropical and low income countries. Rats are thought to be the main vector of human leptospirosis in urban settings. However, differences between urban and low-income rural communities provide additional insights into the epidemiology of the disease.



Our study was conducted in two low-income rural communities near the coast of Ecuador. We detected and characterized infectious leptospira DNA in a wide variety of samples using new real time quantitative PCR assays and amplicon sequencing. We detected infectious leptospira in a high percentage of febrile patients (14.7%). In contrast to previous studies on leptospirosis risk factors, higher positivity was not found in rats (3.0%) but rather in cows (35.8%) and pigs (21.1%). Six leptospira species were identified (L. borgpetersenii, L kirschnerii, L santarosai, L. interrogans, L noguchii, and an intermediate species within the L. licerasiae and L. wolffii clade) and no significant differences in the species of leptospira present in each animal species was detected (χ2 = 9.89, adj.p-value = 0.27).



A large portion of the world's human population lives in low-income, rural communities, however, there is limited information about leptospirosis transmission dynamics in these settings. In these areas, exposure to peridomestic livestock is particularly common and high prevalence of infectious leptospira in cows and pigs suggest that they may be the most important reservoir for human transmission. Genotyping clinical samples show that multiple species of leptospira are involved in human disease. As these genotypes were also detected in samples from a variety of animals, genotype data must be used in conjunction with epidemiological data to provide evidence of transmission and the importance of different potential leptospirosis reservoirs.
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.|Instituto de Microbiologia, Colegio de Ciencias Biologicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador.
Veronica
0000-0002-2205-3010
V
Barragan
Instituto de Microbiologia, Colegio de Ciencias Biologicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador.
Jorge
J
Chiriboga
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.
Erin
E
Miller
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.
Sonora
S
Olivas
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.
Dawn
D
Birdsell
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.|Informatics and Computing Program, Northern Arizona University, Flagstaff, Arizona, United States of America.
Crystal
C
Hepp
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.
Heidie
H
Hornstra
Ministerio de Salud Pública, Quito, Ecuador.
James M
JM
Schupp
Ministerio de Salud Pública, Quito, Ecuador.
Melba
M
Morales
Instituto Nacional de Salud Pública e Investigación, Guayaquil, Ecuador.
Manuel
M
Gonzalez
Ministerio de Salud Pública, Quito, Ecuador.
Soraya
S
Reyes
Instituto Nacional de Salud Pública e Investigación, Guayaquil, Ecuador.
Carmen
C
de la Cruz
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.|Translational Genomics Research Institute, Flagstaff, Arizona, United States of America.
Paul
P
Keim
Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands.
Rudy
R
Hartskeerl
Instituto de Microbiologia, Colegio de Ciencias Biologicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador.
Gabriel
G
Trueba
The Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona, United States of America.
Talima
T
Pearson
D000818:Animals; D002417:Cattle; D004197:Disease Reservoirs / Q000382:microbiology; D004484:Ecuador / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D007919:Leptospira / Q000145:classification* / Q000235:genetics*; D007922:Leptospirosis / Q000453:epidemiology* / Q000635:transmission*; D058751:Livestock / Q000382:microbiology; D010802:Phylogeny; D011203:Poverty; D051381:Rats; D012044:Regression Analysis; D012424:Rural Population; D017422:Sequence Analysis, DNA; D013552:Swine; D015047:Zoonoses / Q000453:epidemiology* / Q000382:microbiology