Brazilian scientists recently identified a parasite that has infected more than a hundred people in the Northeast, causing severe liver, spleen and skin damage and killing at least one of these patients.
The characteristics of the disease resemble visceral Leishmaniasis, an endemic disease in the region, usually caused by the protozoan Leishmania infantum. But analysis of the microorganism's DNA has revealed that it is a new parasite whose close relatives usually infect only insects.
Researchers from UFSCar (Federal University of São Carlos), Federal University of Sergipe and USP Ribeirão Preto published the data in the journal Emerging Infectious Diseases.
The genomic data concludes a story that began in 2010, when Roque Pacheco Almeida of the Department of Medicine of the Federal University of Sergipe had the first contact with the patient who, after three attempts at treatment, eventually died.
The team still does not know how the microbe eventually infected the 141 patients they have been able to track so far (the actual number of those affected may, of course, be much higher). In research published now, they detail results about the patient who died as a result of the new disease.
So-called straw mosquito or sandfly transmit Leishmaniasis. However, the closest cousins of the new parasite, which belong to the genus Crithidia, are usually present in the organism of anophelines (the malaria transmitters) and Culex mosquitoes, such as the common mosquito.
"What we know is that, in this group of protozoa, the transition from being a parasite that only affects insects to infect vertebrates happens when the insect feeds on blood," explains the UFSCar biologist Sandra Maruyama, one of the authors of the study. "Studying this protozoan can be an important tool in understanding how the jump happens.”
Translated by Kiratiana Freelon