Sanitation workers from Portugal: is there evidence of Leptospira spp.?

Leptospires are spirochetes of Leptospira genus. Infection in humans occurs by penetration into the mucous membranes, or into the skin (small wounds or abrasions). Humans are infected when they contact with urine of rodents, the main reservoirs. We aimed to evaluate the presence of anti-Leptospira spp antibodies and leptospiral DNA in sanitation workers (occupational group with increased risk) from Lisbon and Tagus Valley Region (Portugal). Blood samples were collected from 347 sanitation workers, being applied a questionnaire to analyze exposure to rodents and preventive measures. The samples were screened by MACROLepto-test, for the presence of antibodies against pathogenic leptospires. “Positive” and “Non conclusive” samples were then tested with Microscopic Agglutination Test (MAT). Two nested-PCR protocols (primers LeptoA-LeptoB and lipL32) were applied for Leptospira spp DNA detection. It was not observed anti-Leptospira spp antibodies in the worker's samples. However, it was detected non-pathogenic leptospires in a serum sample. Furthermore, 77% had previously seen rodents in the workplace and 94% always used Personal Protective Equipment (PPE). Despite the regular presence of rodents in their workplace, the use of PPE and hygiene measures seemed to be able to prevent the workers contact with this infectious agent.