New research by the Yale School of Public Health and the Oswaldo Cruz Foundation/Brazilian Ministry of Health on leptospirosis, a bacterial infection largely spread by rats, sheds light on how the disease causes death and uncovered a potentially novel treatment.
While rare in the United States, leptospirosis remains an important health threat for impoverished populations in developing countries, causing more than one million illnesses and 60,000 deaths annually.
The reasons why leptospirosis causes life-threatening manifestations, such as pulmonary hemorrhage and acute kidney failure, have been poorly understood. School of Public Health researchers led by Janet Lindow, Ph.D., Elsio Wunder, D.V.M., Ph.D, and Professor Albert Ko, M.D., analyzed the transcriptome, or the spectrum of messenger RNA molecules expressed from patients with leptospirosis, to understand why some individuals die and others survive after infection.
Patients who died from leptospirosis had a defect in the expression of the gene encoding an antimicrobial peptide, cathelicidin, which is capable of killing bacteria, the researchers found. In contrast, survivors were able to mount a vigorous response to the infection as exemplified by the expression of genes that encode cathelicidin as well as those that play a role in adaptive immunity such as antigen presentation and immunoglobulin production.