Epidemiology of leptospirosis: observations on serological data obtained by a “diagnostic laboratory for leptospirosis” from 1995 to 2001.

This research article discusses a study on the epidemiology of leptospirosis based on serological data analyzed from a range of domestic, wild animals and humans in Northern and Central Italy from 1995 to 2001. Using a macro-agglutination test (MAT), the study determined that 6.81% of the subjects were positive for leptospirosis.

Methodology

• The most common method for detecting leptospirosis antibodies in blood is through a macroagglutination test (MAT), which was used in this study.
• From 1995 to 2001, the researchers analyzed the blood serum samples of 9885 subjects (consisting of domestic and wild animals, along with humans), all based in Northern and Central Italy.
• The antigens employed in the MAT were bratislava, ballum, canicola, grippotyphosa, icterohaemorrhagiae, pomona, hardjo and tarassovi serovars; strains of bacteria which cause leptospirosis.
• Subjects with an antibody titer score of 1:400 or higher were perceived as positive for leptospirosis.

Findings

• Out of the total number of subjects tested, 674 (or 6.81%) were found to have positive results.
• The highest number of positive responses came from sheep, horses, pigs and dogs.
• The bratislava strain was the most common in sheep, horses, and pigs while dogs were more commonly infected with the icterohaemorrhagiae strain.
• As for the percentage of seropositivity (or presence of the disease) based on species, the research presented these findings:
  • Ovine: 12.13% (132 positive from 1088 tested)
  • Horses: 11.40% (107 positive from 938 tested)
  • Swine: 9.46% (123 positive from 1299 tested)
  • Dogs: 6.36% (278 positive from 4369 tested)
  • Wild Boars: 2.39% (11 positive from 459 tested)
  • Deer: 1.39% (2 positive from 143 tested)
  • Cattle: 0.48% (3 positive from 626 tested)
• It was also worthy to note that 5.60% of human subjects (or 14 out of 250) were found to be positive for leptospirosis.

Significance of the Study

• The research provides a valuable contribution to the current understanding of leptospirosis epidemiology in Italy, primarily in the regions of Northern and Central parts of the country.
• The findings underlined the importance of regular screening among domestic animals, which exhibited higher rates of positivity for leptospirosis compared to wild animals and humans.
• The study may serve as an impetus for the health department to put in place measures to combat the spread of leptospirosis, given its relatively high prevalence among both animal and human populations.