Brucellosis is a disease caused by such a gram negative bacterium brucella and is considered one of the most widespread infections transmitted from animals to humans (zoonotic infections) worldwide.
In Europe, there has been a steady decrease in human cases of brucellosis in recent years, although due to under-reporting, the actual number of new cases (incidence) may be higher.
In addition to generating very significant problems, brucellosis causes significant economic losses linked both to the consequent decrease in the production and marketing of animals, and to the impact on public health costs.
In order to reduce the incidence of the disease, the European Commission has financed numerous health control programs in humans and farm animals, in particular, in the countries of the Mediterranean area.
In Italy, brucellosis, a disease that must be compulsorily reported since 1934, reached its highest incidence values in humans at the end of the 1940s (20 cases per 100,000 inhabitants). Only in the second half of the 1950s, afterwards upon the adoption of national and regional control plans, a decrease in new cases of disease (incidence) in humans and animals was highlighted.Symptoms
Brucellosis does not always cause ailments (symptoms). The infection can be present for many months without the person noticing and evolve into a very slow developing generalized infection (systemic infection), usually after a long incubation period. Brucella, penetrating the submucosa through cells of the skin, conjunctiva, pharynx or lung induce an active inflammatory reaction.
If the body's defense capabilities are exceeded by the microorganism, bacteria enter the blood (bacteremia) and the spread of infection to the spleen, liver and marrow with the formation of granulomas.
If the infection progresses without causing obvious disturbances (symptoms), it can only be detected by carrying out blood tests.
Acute and subacute disease, on the other hand, causes ailments (symptoms) that include:
- profuse sweating
- weight decrease
The fever is often of the "undulating" type, with alternating high fever (fever peaks) and times when the body temperature is normal (remissions).
The "classic" brucellosis is a papular and pustular form due to the onset of an allergy to brucella. It is more easily found in categories of professional risk operators.
The "acute" form, although rarely, can be fatal by causing the presence of toxic substances in the blood (toxemia); the reduction in the number of platelets (thrombocytopenia), corpuscles present in the blood that intervene in the coagulation processes; inflammation of the tissue that lines the inner walls of the heart (endocarditis) and other complications.
Generally, the evolution of the disease is good but some forms can develop in a severe way.Causes
Humans contract the infection above all through the consumption of certain foods:
- fresh milk from infected animals and not subjected to sterilization or pasteurization
- cheeses matured for less than three months, prepared with unpasteurized infected milk
- meat from infected animals, especially if undercooked or raw, although the latter eventuality is quite rare
Furthermore, brucellosis is also considered an occupational disease (occupational disease) which affects, above all, those who work in contact with infected animals (farmers, veterinarians, slaughterhouse workers). In fact, as well as via food, transmission can also occur through contact with tissues, blood, urine, vaginal secretions, aborted fetuses and placentas, and / or via air in stables, laboratories and slaughterhouses. .Diagnosis and therapy
Diagnosis and therapy
The assessment (diagnosis) of brucellosis in humans is based on the state of health and on the disorders (symptoms) that the patient reports to the doctor as well as on the tests performed on the blood serum (serological tests). If the results of the analyzes were doubtful, so-called enzyme immunoassays could be used. Definitive confirmation of the presence of the disease is obtained with blood cultures, bone marrow or other tissue cultures.
Treatment generally involves the use of antibiotics such as doxycline and rifampicin. The antibiotics of first choice are tetracyclines, which are usually associated with streptomycin in severe forms.Prevention
To date, there is no vaccine for humans. The best prevention is to avoid the consumption of milk, or milk products such as, for example, cheeses, if not pasteurized and to eat only well-cooked meat.
For those who carry out work at risk, it is advisable to wear suitable protective clothing (gloves, goggles, mask) and, in the presence of wounds, protect the skin with bandages.Bibliography
Mancini FR, Bella A, Graziani C, Marianelli C, Mughini Gras L, Pasquali P, Pompa MG, Rizzo C, Rizzuto E, Busani L. Trends of human brucellosis in Italy, 1998-2010. Epidemiology and infection. 2014; 142: 1188-1195
Salmaso S, Bella A, D'Ancona F, De Mei B, Mandolini D, Rota C, et al. Epidemiology of brucellosis in Italy. Newsletter of the Higher Health Institute. 2000; 3 (Suppl.): 4-8In-depth link
European Center for Disease Prevention and Control (ECDC). Disease data from ECDC Surveillance Atlas - brucellosis (English)
EpiCentro (ISS). Brucellosis
Experimental Zooprophylactic Institute of "Abruzzo and Molise" G. Corporal "(IZSAM). OIE Reference Laboratory for Brucellosis
World Health Organization (WHO). Brucellosis (English)