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New test for brucellosis

Eduardo Cesar Cheese and milk produced without sanitary inspection can cause brucellosisEduardo Cesar

Researchers at the Adolfo Lutz Institute (IAL) in São Paulo are developing a new molecular assay to diagnose human brucellosis, a type of zoonosis caused by the Brucella bacteria. The disease is currently detected indirectly via a serological exam that identifies the existence of antibodies produced by the infected organism. The new test detects the genetic material of the bacteria directly and reveals the infection more quickly. It is also more sensitive and specific than the current method. About 500,000 new cases of the disease are reported annually worldwide, primarily in developing countries. The real scale of the disease’s spread in Brazil is unknown, since notification of cases is not compulsory. According to infectologist Marcos Vinícius da Silva, coordinator of the Tropical Diseases and Zoonoses Clinic at the Emílio Ribas Institute of Infectology in São Paulo, the number of people contracting the disease has grown in recent years. One reason is the increased vaccination of cattle against the disease, which has been compulsory since 2001. “Mandatory immunization has increased the number of accidents involving animal health agents, who can become infected when handling the vaccine,” says Silva. Another mode of infection is through the consumption of milk and cheese from producers not following health regulations. The IAL’s new molecular test identifies the species and strain responsible for the infection, which helps to treat the disease and understand its epidemiology. “Our first option is to test the urine, then the blood serum. We have already determined the concentration of each reagent, the reaction temperature, and other important variables of the test,” says immunologist Suely Kashino, a member of the team working on the method at the IAL. “We are halfway through the standardization process.” The test will also need to go through a validation phase.