With information from Elaine Patricia Cruz, from Agência Brasil

A new disease, with symptoms similar to visceral leishmaniasis but more severe and resistant to treatment, was discovered in Sergipe. Two people died from the disease, which has already affected 150 people in Aracaju. The parasite is still unknown, but researchers have already identified that it is different from Leishmania, responsible for leishmaniasis.

The disease is being investigated by a group of Brazilian researchers who published an article in Emerging Infectious Diseases, the journal of the US Center for Infectious Disease Control (CDC). The research is conducted at the Center for Research on Inflammatory Diseases (CRID), with funding from the São Paulo State Research Support Foundation (Fapesp).

Led by Professor Sandra Regina Costa Maruyama, from the Federal University of São Carlos (UFSCar), the study is being developed in collaboration with colleagues from Professor João Santana Silva’s team, at Ribeirão Preto Medical School, University of São Paulo (FMRP). -USP).

Diagnosis, Symptom and Treatment

The diagnosis and treatment of the patients was made by physician Roque Pacheco de Almeida, professor of the Department of Medicine of the Federal University of Sergipe, researcher and physician at the University Hospital / EBSERH of Aracaju. In an interview with Agência Brasil, Almeida said that the disease has been infecting people since 2011 in the capital of Sergipe, when he diagnosed and treated the first case. This patient died in 2012 as a result of the disease.

The symptoms, he says, are very similar to those of kala-azar (the most popular name for visceral leishmaniasis), but develop more severely. “We treat a lot of kala-azar patients here. There are several a year. One of these patients did not respond to treatment. He relapsed [the disease reappeared], we treated again, relapsed again. And on the third relapse, skin lesions appeared. In patients without HIV we do not see this. He had no HIV and there were button-shaped skin lesions all over his body that we call papules, ”said the doctor.

“When we did the biopsy, they were cells full of parasites. Then the patient evolved severely to what we call severe visceral leishmaniasis with bleeding. His spleen was giant, and we tried treatment, but he didn’t survive, ”he said.

Almeida collected tissue samples from this patient and sent them to João Santana Silva, an immunology specialist at FMRP-USP, who could not identify the parasite by traditional methods, comparing it to known Leishmania species. In 2014, the parasite was identified by biologist and immunologist Sandra Regina Costa Maruyama, who began to suspect that it was, in fact, a new parasite that had not yet been described by science.

“We were facing a serious case. As we didn’t know other diseases, we thought it was a serious kala-azar. But when we went to see, the parasite isolated from the bone marrow, skin, and spleen [of this patient] also behaved differently in a [laboratory] mouse. The parasite [removed] from the skin damaged the skin of the mouse but did not damage the organs. And the parasite that came from the bone marrow gave a calazar-like lesion in the spleen and liver. So we have two different parasites in the same patient, ”said Almeida.

They then sequenced the parasite’s DNA, which was compared to that of other protozoa. The researchers then realized that this was not Leishmania. The new parasite resembles Crithidia fasciculata, which infects only insects and is unable to infect mammals. However, this new species of parasite was able to infect humans and mice – and severely.

According to Almeida, the 150 isolated patients are also being tested to assess if they have also been infected with this new parasite. “Most of these patients also belong to this new group. That is, the problem may be even bigger than we are imagining, ”he said.

Researchers hope soon to be able to describe the new parasite and name the new disease. “We identified a new parasite, a new disease, that causes a serious disease and a therapeutic response that is not entirely sufficient or effective. We want to understand the extent of this and where this parasite appeared, if it was a mutation. There’s a big line of research for us to investigate. We also want to see, geographically, where the parasite is expanding, ”said Almeida.