Introduction
Etiologic agent
Brucellosis is a common infection that affects man, swine, goats, and cattle, although it rarely infects wild mammals such as deer in the United States. The disease is responsible for the occurrence of abortion in cattle (Ingebrigtsen, Ludwig, Arlin, & McClurkin, 1986).
Brucellosis is caused by bacteria of the Brucella species. This disease infects mammals both wild and domestic. The various Brucella species that infect domestic mammals include B. melitensis and B. ovis, which infects sheep and goats respectively; B. suis,- pigs; B. abortus -cattle, and B. canis –dogs (center for disease control and prevention [CDC], 2005).
Country/state of origin
Brucellosis is speculated to have first manifested at around 1600 BC in the fifth plague of Egypt. Current laboratory examination of the ancient Egyptian bones, dating back to about 750 BC, indicated proof of osteoarticular lesions, including sacroiliitis that are common attributes of the infection (Pappas & Papadimitriou, 2007).
In 1887 David Bruce isolated B. melitensis (then known as Micrococcus melitensis) from a British soldier’s spleen who had been killed by Malta fever (febrile disease) widespread within the military personnel based on Malta. 20 decades after the isolation of B. mellitensis, the knowledge of Malta fever eluded scientists and they presumed it to be a vector-borne disease. However, in 1905 Themistocles Zammit by chance established the zoonotic attribute of the infection by detecting B. melitensis from goat’s milk (Seleem, Boyle, & Sriranganathan, 2010).
In 1987, Bang associated Bang’s bacillus (B. abortus) to be the etiologic agent of Bang’s disease. His proposition was further supported by Alice Evans’ work on infectious bacteria in dairy commodities, who verified the connection of Bang’s disease with Malta fever (Seleem, Boyle, & Sriranganathan, 2010).
In 1976 Brucellosis was observed in farmland in Minnesota, following a survey motivated by a decrease of white-tailed deer (Odocoileus virginianus) which was suspected to be due to drought, disease, and associated stress. A serological study was performed to establish the incidence of antibodies in these mammals to the etiologic agents of brucellosis, parainfluenza 3, leptospirosis, and Infectious bovine rhinotracheitis. The result of the survey indicated a positive outcome (Ingebrigtsen, Ludwig, & McClurkin, 1986).
Method of transmission
Zoonotic is often transmitted via abrasion on the skin surface from holding sick animals. In the US it often occurs from the consumption of unpasteurized milk and other daily commodities. Also, the organism is highly infectious in the lab through aerosolization and thus preparing cultures prerequisites the implementation of biosafety level-3 measures.
Symptoms
During the acute stage, that is between infection and eight weeks after infection, the disease manifest with uncertain and flu-like symptoms such as back pain, fever, myalgia, sweats, headache, malaise, and anorexia (CDC, 2005).
During the undulant staged, that is one year after the onset of infection, the disease manifest as arthritis, undulant fevers, and epididymal-orchitis in men. Also, neurological indications can present acutely in a maximum of 5 percent of clinical incidents (CDC, 2005).
During the chronic stage, which is more than a year after infection, the disease may manifest as chronic fatigue syndrome, arthritis, and depression.
Treatment
According to Saleem et al., (2008) Brucella has the potential for intracellular localization and the ability to adjust to the surrounding expressed in its replicative advantage. This confers to it the ability to resist drugs leading to increased treatment failure and relapse rates and requires drug combination as well as patient compliance to achieve effectiveness. Therefore, the optimal therapy for brucellosis is a combination prescription of two antibiotics to avoid relapse associated with monotherapies (Seleem et al., 2009).
A drug combination of doxycycline and streptomycin (DS) is the latest best therapeutic alternative with minimal adverse effects and less relapse, particularly in incidents of acute and localized types of brucellosis (Seleem et al., 2009). Noteworthy, neither doxycycline nor streptomycin can block the intracellular growth of brucellae on their own. The DS combination is regarded as the gold-standard therapy.
However, the DS prescription is less reasonable since the streptomycin has to be administered parenterally for 3 weeks. Thus, a combination of doxycycline therapy, for 6 weeks, in conjunction with a parenteral administration of gentamicin [5 mg per kg] for 7 days is regarded as the necessary optional regimen (Glynn and Lynn, 2008).
DS combination regimen had been regarded as the gold-standard treatment against Brucellosis for many years by the WHO. Nevertheless, in 1986 Joint FAO/WHO Expert Committee on Brucellosis amended their suggestion for therapy of adult acute brucellosis to rifampicin (600-900 mg per day orally) and doxycycline (200 mg per day orally) DR for 6 weeks as the best-sorted treatment. However, the superiority of the DS regimen over the DR regimen has been proven by research studies.
Epidemiology and economic impact
Brucellosis is a countrywide notifiable highly infectious disease as well as reportable to the local health authorities. In the past 15 years, the incidence of the disease had been estimated to be 100 per year in the US.
The incidence of brucellosis in the United States is below 0.5 cases for every 100,000 population, for mostly the B. melitensis. The disease is most prevalent in California, Virginia, Florida, and Texas. The groups of people who are at high risk of infection include animal laboratorians, Abattoir workers, veterinarians, meat inspectors, and animal inspectors.
The epidemiology of brucellosis is continually shifting, with new varieties emerging or re-emerging. The epidemiology of human brucellosis has rapidly shifted throughout the previous few years due to several sanitary, political, socioeconomic factors, as well as increased international movements. A novel variety of human brucellosis has developed, especially in central Asia, at the same time the condition in specific regions of the Middle East is increasingly deteriorating (Pappas et al., 2006b).
The disease occurrence is global, except in certain first-world countries in which the bovine brucellosis (B. abortus) has been eliminated. Eliminated in this sense implies that no case has been reported for a minimum of 5 years. Such countries include the UK, Sweden, Australia, Norway, Canada, New Zealand, Cyprus, Netherlands, Denmark, and Finland.
Those countries in which brucellosis is prevalent within its various population, include South America, Mexico, Central America, northern and eastern Africa, Central Asia, India, Near East countries, and Mediterranean Countries of Europe,
Conclusion
Reducing the incidence of brucellosis in third world countries necessitates substantial efforts to develop a framework that enlightens people concerning the risk factors of brucellosis; deliver appropriate lab facilities and instruct personnel to collect and analyze samples; rigorous surveillance programs and maintain records. In addition, when the occurrence of brucellosis is reduced or exterminated within the animal reservoir, this translates to a corresponding considerable decrease in the occurrence within the human population.
Reference list
Center for Disease Control and Prevention (CDC). (2005). Brucellosis: Brucella melitensis, abortus, suis, and canis. Clifton Rd, Atlanta, USA. Department of Health and human services CDC.
Glynn, M.K., Lynn, T.V., 2008. Brucellosis. J. Am. Vet. Med. Assoc. 233, pp. 900–908.
Ingebrigtsen, D. K., Ludwig, J. R., & McClurkin, A. W. (1986). Occurrence of antibodies to the Etiologic agents of infectious bovine rhinotracheitis, parainfluenza 3, leptospirosis, and brucellosis in white-tailed deer in Minnesota. Journal of Wildlife Diseases, 22(1), 1986, pp. 63-86.
Pappas, G., Papadimitriou, P., (2007). Challenges in Brucella bacteremia. Int. J. Antimicrob. Agents 30 (Suppl. 1), S29–31.
Pappas, G., Papadimitriou, P., Akritidis, N., Christou, L., Tsianos, E.V. (2006b). The new global map of human brucellosis. Lancet Infect. Dis. 6, 91–99.
Seleem, M.N., Jain, N., Pothayee, N., Ranjan, A., Riffle, J.S., Sriranganathan, N. (2009). Targeting Brucella melitensis with polymeric nanoparticles containing streptomycin and doxycycline. FEMS Microbiol. Lett. 294, 24–31.
Seleem, M. N., Boyle, S. M., & Sriranganathan, N. (2010). Brucellosis: A re-emerging zoonosis. Veterinary Microbiology 140. pp. 392–398.