Leptospirosis: one million affected per year and insufficient control policies

While rich countries register a disease incidence of 1 person per every 100,000, in tropical countries this number can be up to 100 times greater

Leptospirosis is a disease of extremes and an example of how economic power is related to health differences among several regions of the planet. While in temperate climate countries – most of them, rich – the incidence is of one person for every 100,000 persons, in tropical climate countries, especially in urban slums, this rate is 10 times greater, and can be up to 100 times greater especially in settings where affected by extreme weather events, according to the World Health Organization (WHO). A recent research showed that the diseases global load is far greater than previously thought, reaching over a million new cases and killing over 59,000 people every year.

The work was conducted by doctors Federico Costa, Professor of Epidemiology at the Collective Health Institute at Bahia Federal University (UFBA), Albert Ko, Chair of the Department of Microbial Diseases at the Yale School of Public Health and other collaborators. Initially, they gathered data from previous published studies on leptospiriosis. From the 12 thousand available researches, they identified 80 high quality reports to inform estimates on the global burden. In some regions, especially in Africa, very few quality-ensured studies were found.

According to the results, published on the PLoS Tropical and Neglected Diseases website, the higher leptospirosis morbidity and mortality rates were registered in South and Southeast Asia, Oceania, Caribbean, Andean regions, Central and Tropical Latin America, Africa and Sub-Saharan East. Leptospirosis cases were mainly adult males, from 20 to 49 years-old, representing 48% of the total cases and 42% of the deaths.

According to Dr. Federico, studies different approaches have been performed during the past years, especially regarding the development of molecular techniques for the diseases diagnostic. However, we still need a fast and cheap method able to evaluate leptospirosis in health posts, when the patients have not yet presented the disease severe symptoms. This is fundamental to reduce lethality, explained the researcher.

Control measures

For Dr. Albert Ko, the countries where leptospirosis is a major public health problem need to implement control and prevention strategies to fight the disease. [These countries] must prioritize this neglected disease and develop the needed infrastructure to have an effective surveillance, clinical management orientations and preventive measures, he stressed.

Large part of the control measures include adequate sanitation, what is one of the most critical needs in affected countries. Control and possibly elimination of urban leptospirosis will be possible if public health authorities and governments prioritize actions to address poor environments in urban slums, as open sewage and rainwater drainage systems, which promote the diseases transmission, explained doctor Ko.

For the researcher, other problems include lack of appropriate diagnostic tests and vaccines against the disease, directly connected to its neglected disease status. These barriers begin in the large pharmaceutical companies, that have not invested in solutions for a disease that strikes mainly the poorest people.…