Brucellosis

Brucellosis


Important disease for public health,
Economic losses and human transmission


Brucellosis is a contagious disease of great importance for public health, by the transmission to human and for having significant economic and health consequences. Is contained in the code for the terrestrial animals of the World Organization for Animal Health (OIE), being an official control disease.

Transmission


It is caused by various bacteria of the family Brucella, affecting different species, such as sheep, goats and camels (Brucella melitensis); cattle, buffalo, camels and yaks (Brucella abortus); pigs, rodents, hares, reindeer, caribou (Brucella suis); and dogs (Brucella canis), among others. All them are also transmitted to the human being, by which the Brucellosis is an occupational disease, especially in veterinarians, slaughterers, researchers, breeders and caregivers working with this type of species.

Brucella is able to survive in the environment for relatively long periods. In feces up to 100 days, in soil up to 80 days and in frozen environments their survival can be prolonged for months, which means that the disease is constantly replicated in herds.

Transmission of Brucellosis is by direct contact with infected animals, abortions, excretions, skin wounds, ocular conjunctiva and nasal mucosa; as well as oral transmission, by ingestion of unpasteurized milk or milk products, especially from cows, sheep and goats, being of great importance for food safety. The excretions pollute the soil, pens, beds of straw, water from streams and wells.

Signs and symptoms


In man, Brucellosis causes an acute febrile illness - undulating fever or malta fever - which can become chronic and lead to serious complications affecting the muscles, cardiovascular system and central nervous system.

In animals, the disease is mainly characterized by the existence of abortions or lack of reproduction. Although the animals usually recover, and after the first abortion when are able to procreate, they can continue to excrete bacteria. Brucella is able to survive in the environment for relatively long periods. In feces up to 100 days, in soil up to 80 days and in frozen environments their survival can be prolonged for months.

How does Brucella affect livestock production?


  • Low birth rate for infertility and progeny weakness.
  • Loss of 25% of the value per animal.
  • Reduction of estrus by 40-50% in infected animals, increasing in calving range up to 20 months.
  • Unproductive maintenance of animals.
  • Decrease in milk production by up to 20%
  • Costs for loss of the population, for the slaughter of animals.
  • Increases production costs in almost 8% and operational costs for milk production in almost 10 %.
  • The losses due to bovine brucellosis in a dairy herd of 100 belly means almost US 39% of the benefits compared with a herd free of brucellosis.
  • The profitability of the production of a herd with brucellosis is lower with 1.53% in relation to a free herd.

How does Brucella affect health and food security?


  • Cost for the restriction on the mobilization and closure of national and international markets.
  • Additional cost of veterinarians for disease surveillance.
  • Cost of labor for the slaughter of infected animals.
  • Associated costs with the maintenance of vaccination programs, control and eradication of the disease.
  • Increase of occupational sickness (20,000 per year), among which are veterinarians, producers, rural personnel and researchers.
  • Implications on health of consumers of unpasteurized products.

Prevention: The best solution


It is of great importance to use prevention measures (especially in endemic areas of brucellosis) to reduce the prevalence of the disease.

Adequate biosafety and health measures within herds play an important role for the reduction of transmission in healthy animals.

Performing diagnostic tests periodically allows to determine the progress or decrease of the disease, in order to establish eradication programs.

Vaccination is the tool of choice to reduce and prevent brucellosis and, therefore, to avoid economic and sanitary losses.

References


  • Benkirane, A. Ovine and caprine brucellosis: World distribution and control/eradication strategies in West Asia/North Africa region. Sm. Rumin. Res. 2006, 62 (1–2): 19-25
  • Claros, A. J.W.; Camacho, A.S.; González A.E. Pérdidas económicas por brucelosis bovina en un hato lechero (Provincia Andrés Ibañéz, departamento de Santa Cruz). Facultad de Ciencias Veterinarias Uagrm. Santa Cruz de la Sierra, Bolivia, 2005
  • Córdova, A. Iglesias, A; Espinosa, R. Guerra, J; Inzunza, J; Villa, E; Méndez, M; Huerta, R; Mosqueda, Ma. De Lourdes; Gómez, A; Cancino, G; Méndez, W. Olivares, J; Sánchez, P. Importancia de la Brucelosis bovina y consecuencias económicas para el ganadero. Rev. Ent. Gan. 2016, 78: 18-24
  • Gul, S; Khan, A. Epidemiology and Epizootology of Brucellosis: A Review. Pakistan Vet. J., 2007, 27(3): 145-151 - McDermott, J; Grace, D; Zinsstag, J. Economics of brucellosis impact and control in low-income countries. Rev. sci. tech. Off. int. Epiz., 2013, 32 (1): 249-261
  • OIE . Brucelosis. http://www.oie.int/doc/ged/D13939.PDF
  • OIE. Brucelosis Bovina. http://web.oie.int/esp/normes/mmanual/pdf_es_2008/2.04.03.%20Brucelosis%20bovina.pdf
  • Singha, B.B; Dhandb, N.K; Gilla, J.P.S. Economic losses occurring due to brucellosis in Indian livestock populations. 2015, 119 (3–4): 211-215
  • Sofiana, M; Aghakhani, A; Velayatic, A; Banifazld, M; Eslamifarb, A; Ramezani, A. Risk factors for human brucellosis in Iran: a case–control study. Int. J. Inf. Dis. 2008, 12 (2): 157-161