Neglected Diseases
Leptospirosis is an infection caused by bacteria of the genus Leptospira, which affects both humans and animals.
The infection is transmitted to humans through contact with the urine or blood of infected animals, either directly or via contaminated water, food or soil. People who live in tropical climates, who work in flooded areas such as rice paddies and sugar cane plantations, or who work with animals are most at risk. The bacteria can survive for several weeks in water or soil, and outbreaks often occur after flooding.
Leptospirosis can be effectively treated with antibiotics if diagnosed accurately and timely. Gold standard leptospirosis diagnosis during the acute phase of infection currently involves polymerase chain reaction (PCR) techniques, which require sophisticated laboratory equipment and technical expertise, making it inappropriate for resource-limited settings. There are several leptospirosis diagnostic test kits commercially available. However, the marketed tests have questionable sensitivity and specificity. The recently published Thai-Lepto AKI study revealed that the five Leptospirosis RDTs commercially available in Thailand had overall sensitivity ranging from 1.8% to 75% and specificity ranging from 52.3% to 97.7%. This highlights the need for novel, easy-to-use, rapid diagnostic tests to accurately detect leptospirosis infection in LMIC settings.
There are nine diagnostics in the pipeline for leptospirosis, of which three are undergoing late stage validation or launch readiness testing. Results from a recently published study show that a combination test using commercially available Leptospira IgM RDT and a CRISPR-based molecular diagnostic currently under development (RPA-CRISPR/Cas12a FBDA), achieved significantly higher sensitivity and specificity than the conventional, single test, approach. These findings should have a positive impact in aiding early detection of leptospirosis in resource-limited settings.