Leptospiral carriage by mice and mongooses on the island of Barbados.

Leptospirosis is a zoonotic disease, maintained by chronic infection of the kidneys of reservoir animals, usually small mammals. Infection in humans is acquired from direct or indirect exposure to the urine of infected animals. Leptospirosis has a high incidence in tropical regions, and has been studied extensively in several Caribbean countries. We studied the carriage of Leptospira serovars by two small mammals which are potential maintenance hosts of the disease in Barbados. A total of 136 mongooses (Herpestes auropunctatus) and 97 mice (Mus musculus) were caught in live traps. Leptospiral antibodies were detected by microscopic agglutination test (MAT) using antigens representing 12 serogroups, and kidney tissues were inoculated into polysorbate medium for isolation of leptospires. The seroprevalence (at a titre of > or = 100) in mice was 28.2% (24/85, 95% CI 19.0, 39.1) and in mongooses 40.7% (48/118, 95% CI 31.7, 50.1). In mice, antibodies were detected predominantly against serogroups Ballum and Autumnalis, while in mongooses the predominant serogroup was Autumnalis. Leptospires were isolated from 28 mice (28.9%, 95% CI 20.1, 39.0) and from 4 mongooses (2.9%, 95% CI 0.8, 7.4). Mouse isolates were identified as serovars arborea (17) and bim (7). As in other parts of the world, common house mice (Mus musculus) represent a significant reservoir of leptospirosis. Although carriage of the Ballum serovar, arborea, was not unexpected, this represents the first time that an animal reservoir of serovar bim has been identified. This is significant because bim causes about 63% of human leptospirosis in Barbados, and control efforts and education for prevention can now be targeted at a specific reservoir.

Leptospiral carriage by Mice and Mongooses on the island of Barbados

Leptospirosis is a zoonotic disease, maintained by chronic infection of the kidneys of reservoir animals, usually small mammals. Infection in humans is acquired from direct or indirect exposure to the urine of infected animals. Leptospirosis has a high incidence in tropical regions, and has been studied extensively in several Caribbean countries. We studied the carriage of Leptospira serovars by two small mammals which are potential maintenance host of the disease in Barbados. A total of 136 mongooses (Herpestes auropunctatus) and 97 mice (Mus musculus) were caught in live traps. Leptospiral antibodies were detected by microscopic aggutination test (MAT) using antigens representing 12 serogrouops, and kidney tissues were inoculated into polysorbate medium for isolation of leptospires. The seroprevalence (at a titre of o 100) in mice was 28.2 percent (24/85, 95 percent CI 19.0, 39.1) and in mongooses 40.7 percent (48/118, 95 percent CI 20.1, 39.0) and from 4 mongooses ( 2.9 percent, 95 percent, CI 0.8, 7.4). Mouse isolates were identified as serovars arborea (17) and bim (7). As in other parts of the world, common house mice (Mus musculus) represent a significant reservoir of leptospirosis. Although carriage of the Ballum serovar, arborea, was not unexpected, this represents the first time that an animal reservoir of serovar bim has been identified. This is significant because bim causes about 63 percent of human leptospirosis in Barbados, and control efforts and education for prevention can now be targeted at a specific reservoir. (AU)

Leptospiral carriage by mice and mongooses on the island of Barbados

Leptospirosis is a zoonotic disease, maintained by chronic infection of the kidneys of reservoir animals, usually small mammals. Infection in humans is acquired from direct or indirect exposure to the urine of infected animals. Leptospirosis has a high incidence in tropical regions, and has been studied extensively in several Caribbean countries. We studied the carriage of Leptospira serovars by two small mammals which are potential maintenance hosts of the disease in Barbados. A total of 136 mongooses (Herpestes auropunctatus) and 97 mice (Mus musculus) were caught in live traps. Leptospiral antibodies were detected by microscopic agglutination test (MAT) using antigens representing 12 serogroups, and kidney tissues were inoculated into polysorbate medium for isolation of leptospires. The seroprevalence (at a titre of > or = 100) in mice was 28.2 (24/85, 95 CI 19.0, 39.1) and in mongooses 40.7 (48/118, 95 CI 31.7, 50.1). In mice, antibodies were detected predominantly against serogroups Ballum and Autumnalis, while in mongooses the predominant serogroup was Autumnalis. Leptospires were isolated from 28 mice (28.9, 95 CI 20.1, 39.0) and from 4 mongooses (2.9, 95 CI 0.8, 7.4). Mouse isolates were identified as serovars arborea (17) and bim (7). As in other parts of the world, common house mice (Mus musculus) represent a significant reservoir of leptospirosis. Although carriage of the Ballum serovar, arborea, was not unexpected, this represents the first time that an animal reservoir of serovar bim has been identified. This is significant because bim causes about 63 of human leptospirosis in Barbados, and control efforts and education for prevention can now be targeted at a specific reservoir.

Identification of leptospira serovars by PCR-SSCP analysis

OBJECTIVE: To develop and evaluate a simple method for Leptospira serovar identification, based upon single-strand conformation polymorphism (SSCP) analysis of sequences amplified using diagnostic primers. DESIGN AND METHODS: PCR products of the G1/G2 and B64-I/B64-II diagnostic primer pairs were subjected to SSCP analysis of 15 percent polyacrylamide gels. Silver staining revealed polymorphisms which were used to standardise the method using reference strains. The method was then applied to the identification of clinical isolates of Leptospira. RESULTS: Closely related serovars, such as copenhageni and icterohaemorrhagiae, gave distinct but similar patterns. All other serovars could be discriminated by their SSCP profiles. The PCR-SSCP method was then applied to DNA extracted from tissue samples, allowing the identification of Leptospira serovars present in the tissues, in the absence of positive cultures. CONCLUSIONS: The method developed permits rapid and simple identification of Leptospira serovars in culture or in clinical material. Identification of serovars causing disease in many Caribbean populations will be possible for the first time.(AU)