Scientists have examined cattle in Uruguay for the presence of pathogens of leptospirosis and found that the strains of their infectious bacteria of the genus Leptospira were unexpectedly diverse. A total of 40 strains of six different serogroups were detected, three of which were not previously known. These new data will help improve the diagnosis of leptospirosis and contribute to the development of a vaccine against it. The article with the research is published in the journal PLOS Neglected Tropical Diseases .
Leptospirosis is found in animals all over the world, and humans can also become infected by humans, for example, after drinking water that is contaminated with the secretions of sick animals, including rats, pigs, dogs and cattle. Therefore, in the tropics and subtropics after strong rains and floods, outbreaks of this disease are often observed. In many countries of South America, exports of beef and dairy products are the leading source of national income, particularly in Uruguay, the number of cattle is four times higher than the number of people. Therefore, the spread of leptospirosis here threatens not only the health of people, but also the economy. In infected animals, in addition to deteriorating the body, often there are miscarriages, or they generally become sterile.
The authors of the article decided to find out which strains of bacteria that cause leptospirosis infect cattle in Uruguay, and how widespread the infection. They collected urine and blood samples from animals living on farms in Uruguay, as well as from slaughterhouses. Totally in their study, scientists used data from more than 1500 animals. It turned out that this bacterium was present in 20 percent of the samples. The bacteria found showed a great phenotypic and genetic diversity. In total, scientists found 40 strains, including representatives of three serogroups, which were not determined by standard tests.
Scientists believe that this study will help improve the diagnosis of leptospirosis, understand its epidemiology in South America, and it will also be useful in developing effective vaccines against this disease.
In the tropics and subtropics there is another mass disease – malaria. Recently, it was announced the creation of a highly effective vaccine, consisting of live malarial plasmodia.