In the last week, the export of Brazilian meat to China has been suspended due to confirmed infection of an animal with bovine spongiform encephalopathy, known as mad cow disease. The trade agreement between the countries follows a previously established health protocol. Although infection in humans is considered rare, it can occur if contaminated meat is consumed.
Mad cow disease is part of the transmissible spongiform encephalopathies, which are fatal neurodegenerative diseases that can affect animals and humans and have as their main characteristic the abnormal accumulation of proteins in the brain, which destroys nerve cells.
Veterinarian Guilherme Moura, manager of technical services at Vetoquinol Saúde Animal, explains that the disease is caused in animals by a prion, an infectious protein particle. The disease can be developed in two ways: the first, through the animals ingestion of infected carcasses. To avoid such contagion, Brazilian legislation prohibits the use of ingredients of animal origin in cattle feed. The second way occurs by atypical and spontaneous mutation of a normal protein — this is the most common means of occurrence.
If any sign of the disease is found, it is necessary that the local health inspection entity be notified. Confirmation must be made by tests in national and international laboratories, to verify whether the infection was atypical mad cow, which can be dealt with by destroying only the infected carcass, or whether it is a case of the classic disease, which results in the destruction of the entire herd, as well as any materials that may be linked to the infected cattle, in order to maintain animal and human health, as per the responsibility of Mapa (Ministry of Agriculture, Livestock and Supply).
According to infectologist José Branco Filho, executive director of IBSP (Brazilian Institute for Patient Safety), mad cow disease, or vCJD (variant Creutzfeldt-Jakob disease), the disease is rare among humans, but when it occurs , usually affects young people, who have rapid brain deterioration. He claims that the disease occurs from the consumption of infected meat, especially meat from the nervous system, such as the brain and spinal cord.
The Ministry of Health states that the symptoms are usually sensory, behavioral and psychiatric, but nothing specific. Identification only occurs through blood tests for the genetic analysis of the prion and the study of the cerebrospinal fluid for the detection of a neuronal protein; definitive confirmation only comes with neuropathological examination of brain fragments.
Branco claims that there is no treatment for the disease; only palliative care measures can be adopted for the symptoms, with patient support. vCJD is a deadly disease, with evolution to death within a year in most cases.
Moura concludes that there is no need to be afraid when consuming beef, always remembering to pay attention to the purchase of products with a sanitary inspection seal, such as the one issued by the SIF (Federal Inspection Service), as well as not eating beef unknown origin or infected areas.