Leptospira spp. Prevalence in Small Mammal Populations in Cotonou, Benin

The aim of this study was to assess the Leptospira prevalence in small animals in Cotonou, the capital of Benin. Rodents and shrews were captured in urban and periurban settings and determined as species of the genera Rattus, Mastomys, and Crocidura. Kidney specimens of 90 animals were examined using a real-time PCR assay specific for leptospires that belong to pathogenic species. Leptospiral DNA was amplified from kidney tissues ranging from 13.3% (8/60) in Rattus rattus to 100.0% (1/1) in Crocidura spp. with an average of 18.9% (17/90) of the animals caught at 15 locations. Clade-specific Taqman PCR on 10 samples placed six of these within clade 1 comprising the species L. kirschneri, L. interrogans, L. meyeri, and L. noguchii and four within clade 2 consisting of species L. weilii, L. alexanderi, L. borgpetersenii, and L. santarosai. Phylogenetic analysis of partial sequences of the amplicons of seven samples of these 10 samples revealed that four of the clade 1 samples could equally be assigned to L. interrogans and L. kirschneri and three samples from clade 2 belonged to L. borgpetersenii. Results presented in the paper indicate that small mammals present a major public health risk for acquiring leptospirosis in Cotonou, Benin and will contribute to a raised awareness amongst health care workers and decision makers and hence promote appropriate clinical management of cases. 1. Introduction Leptospirosis is one of the most common bacterial zoonoses worldwide [1]. In the past decade, leptospirosis has emerged as a globally important infectious disease. Although the disease has a worldwide distribution, it is particularly common in countries with humid tropical and subtropical climates [2]. Although rodents and insectivores are notorious reservoirs of leptospires, the vast majority of domestic and feral mammalian species can be natural hosts and transient carriers of Leptospira [3–7]. The serovar is the basic taxon of leptospires. To date, more than 250 serovars have been identified [4], each of these adapted to one or more hosts. Mus musculus (house mouse), Rattus norvegicus (brown rat), and Rattus rattus (black rat) are three species of rodents with a worldwide distribution that are commonly associated with leptospiral infection [8]. Leptospires live in the kidneys and urogenital tract of the hosts and are excreted with the urine into the environment where they can survive for several months depending on favorable humid and warm conditions. Humans are infected through direct contact with infected animals or, indirectly, by exposure to contaminated