Bacteria, Pathogen of the Month

Brucella: Newest Research on This Bioterror Zoonotic Disease

Author Chandana Balasubramanian , 06-May-2013

Table of contents

PATHOGEN OF THE MONTH

Brucella bacteria, 3D illustration. Gram-negative bacteria that cause brucellosis in cattle and humans and are transmitted to humans by direct contact with ill animal or by contaminated milk

Image: Brucella spp, a gram-negative bacteria that cause Brucellosis in cattle and humans

 

The Brucella species of gram-negative bacteria has an interesting past. The infection caused by Brucella – Brucellosis – is one of the most widespread zoonotic diseases and has been around for centuries. Brucella was even found in a 700-year-old skeleton from Italy [1]! The discovery that Brucella can be carried and transmitted through healthy goats is considered one of the “greatest advancements ever made in the study of epidemiology.” This medical milestone revolutionized the way the world understood diseases transmitted through animals and helped save British troops from getting infected [2]. 

The disease has many names, including Malta Fever, Gibraltar Fever, Rock Fever (after the Rock of Gibraltar), Cyprus Fever, Neapolitan Fever, Crimean Fever, and Goat Fever [3]. It is also often called ‘Bang’s Disease’ after the Danish veterinarian who isolated it – Bernhard Lauritz Frederik Bang. Another nickname for Brucellosis is Corp’s Disease since the British Royal Army Medical Corps played a significant role in discovering how it spreads. The Brucella pathogen itself is named after Sir David Bruce, the British military physician who first described it [4]. 

Unfortunately, Brucellosis is among the top “neglected zoonotic diseases” by the World Health Organization (WHO). Diseases in this category often affect poor and marginalized communities and populations without adequate resources. It is found predominantly in the Mediterranean region, but Brucella outbreaks in China have also been reported. Brucellosis has been largely eliminated from the developed world, which may be why it has not gotten the research and attention it needs. 

The good news is that there has been a greater focus and much-needed research on the Brucella bacteria in recent years. This includes epidemiology, diagnostic methods, treatment, preventive control measures, and much more. Many of these researchers continue to leverage the comprehensive GIDEON infectious disease database for data on worldwide and country-specific prevalence, incidence, and mortality rates over time.  

 

It is Important to Monitor and Curb Brucella Outbreaks

The most common way to get Brucellosis from animals is by eating raw or unpasteurized dairy products. It can also be spread through the air. Touching the body fluids of an infected animal can also transmit the infection to humans. 

Brucellosis cannot be transmitted from person to person like a cold virus. However, it can spread easily in the air, and many people can get infected at the same time [5]. When aerosolized, it can also cause widespread harm as a bioterror agent. 

The Brucella species of bacteria are, in fact, a perfect storm of a bioterror threat because they are easy to grow, store, transfer, and circulate. When Brucella is aerosolized and released, it can cause serious health issues, even though the human mortality rate is low [6].

Man and woman veterinarians at large goat farm checking goats's health.

Image: Veterinarians at large goat farm checking goat’s health

 

Symptoms of Brucellosis in Humans

Brucellosis, the infection caused by the Brucella bacteria, causes fever, chills, fatigue, sweats, joint pain, and headaches. The mortality rate is low. The incubation period is, on average, 2 – 4 weeks. 

It is essential to keep an eye out for recurrence because Brucellosis symptoms can even vanish and return after a few weeks or months. Some people end up with Chronic Brucellosis that can last years. 

In animals, Brucella can cause reproductive issues leading to abortions. As a result, there is an economic loss for farmers and cattle herds who may have to cull many infected animals. They are also at risk of getting infected if proper safety protocols for handling animals are not followed [7]. 

Because Brucella infections can cause widespread problems for humans and livestock and is a potential biothreat, the worlds of epidemiology and public health welcome the latest studies on this issue. 

 

A GIDEON map displaying Brucellosis outbreaks 1938 - 2021 and endemicity worldwide

Image: Brucellosis outbreaks 1938 – 2021 and endemicity worldwide. Copyright © GIDEON Informatics, Inc.

 

 

The Latest Research On Brucella

1. Brucella in Palestine

Aljanazreh et al. (July 2021) studied the resurgence of Brucellosis in Palestine from 2015 to 2017 after a decade without it. Even though Palestine had a Brucellosis Control Program since 1998, cases began to emerge after 2012. A similar pattern was found in their neighbor, Israel. DNA analysis found that all isolates were Brucella melitensis strains of a local origin. The authors used the GIDEON infectious diseases database to map the epidemiology of Brucella outbreaks within the country.

To prevent further recurrence of the disease, the researchers proposed that Palestinian and Israeli Brucellosis control programs be strengthened. Longer-term cooperation between key stakeholders is also crucial for long-term success in preventing Brucellosis in the region [8].

2. Brucella in Tunisia

Battikh et al. (March 2021) reported on the clinical and laboratory features of Brucellosis in Tunisia. The country saw a rise in the number of Brucellosis cases from 2014 to 2017. It prompted this study about patients hospitalized in the Rabta university hospital in the capital city of Tunis. The authors relied on the GIDEON infectious disease database for Brucellosis incidence and prevalence data as part of the study.  

They concluded that Brucellosis is still endemic in Tunisia. Most infected patients in the hospital seemed to have consumed raw milk or milk products. The surge in cases was due to less stringent vaccination efforts for cattle and livestock, lower border controls since 2011, illegally importing livestock, and insufficient health checks at key facilities [9].  

3. Brucella in Greece

Katsiolis et al. (preprint, 2021) published about the detection of Brucellosis in ruminant herds in Greece. The researchers emphasize the economic significance of their study apart from health concerns. Brucellosis can cause reproductive issues in animals and abortions in herds. Along with other European countries, Greece had also applied control and eradication programs for sheep, goats, and cows. Since current laboratory Brucella detection methods have several challenges, the study proposes a new diagnostic tool for greater reliability to detect Brucella from samples [10]. 

4. Brucella in Kazakhstan

Nicolaevna Gavrilova et al. from Kazakhstan (August 2021) studied the effect of a Lactobacillus-based probiotic to help prevent Brucella outbreaks. The researchers used information from GIDEON about how Brucella affects humans as part of their discussion on important it is to curtail the periodic epizootic outbreaks that occur in hot spots. The study concluded in favor of using probiotics for prophylactic and therapeutic reasons to reduce bacterial load in infected mice [11]. 

5. Brucella in Costa Rica

Rosales Galeano et al. (2020) addressed the issue of under-reporting of Brucellosis cases in Costa Rica. The authors studied cases between 2015-2017 in people who worked on dairy farms. They found seroprevalence for smooth Brucella spp. was 12.5%. Risky cultural practices were the main reasons for the prevalence.

These include preparing and consuming food with unpasteurized milk products, artificial insemination, and birthing calves without adequate protection. The study references data from GIDEON when discussing Brucellosis epidemiology and worldwide incidence and prevalence [12]. 

6. Brucella study from Ethiopia

Rosales Galeano et al. (2019) reviewed the epidemiology, diagnosis, control, and prevention of Brucellosis. The authors discuss how Brucella was first identified, isolated, and eliminated in developed countries. The article discusses how developing countries must implement similar stringent methods of animal immunization, farm sanitation, and more [13]. 

7. Brucella in Armenia

Sargsyan et al. (2019) published their observations of acute and chronic Brucellosis from an 11-year audit of a tertiary hospital in Armenia. Data from the GIDEON infectious diseases database helped them understand the epidemiology of Brucellosis outbreaks in Armenia. This research was significant because brucella incidence had been almost twice as high in Armenia than in other countries. Cases in Armenia had doubled over the last three decades.

The authors studied patients hospitalized between the years 2006 to 2016. They found that the majority of them were primarily males between the ages of 20-60 years. Many had not sought medical help until almost two months after they developed symptoms. The authors stressed the importance of targeted educational campaigns to help lower the prevalence of this disease [14]. 

Please note, while this list is a curated list of some significant research, it is not comprehensive. Here are more studies for further reading: 

Conclusion

Eliminating Brucellosis from the developing world requires collaboration, awareness-building, and education among communities that work closely with animals. Since Brucellosis often presents with flu-like symptoms, frontline clinicians in high and moderate risk regions must test for Brucellosis to account for potential cognitive biases. 

Additionally, public health officials worldwide must implement rigorous Brucella control programs and encourage more studies on Brucellosis to help identify and protect vulnerable populations. 

 

 

References

 

[1] G. L. Kay, J. M. Sergeant, V. Giuffra, P. Bandiera, M. Milanese, R. Bramanti and M. J. Pallen, “Recovery of a Medieval Brucella melitensis Genome Using Shotgun Metagenomics,” MBio, vol. 5, no. 4, pp. pp. e01337-14, 2014. 
[2] W. J. Tulloch, “Sir David Bruce; an appreciation,” J R Army Med Corps, vol. 101, no. 2, pp. 81-90, 1955. 
[3] GIDEON Informatics, “GIDEON Infectious Diseases Database”.
[4] N. C. Hull and B. A. Schumaker, “Comparisons of Brucellosis between human and veterinary medicine,” Infection Ecology & Epidemiology, vol. 8, no. 1, p. 1500846, 2018. 
[5] CDC (Centers for Disease Control and Prevention), “Brucellosis,” CDC, 20 02 2021. [Online][Accessed 28 10 2021].
[6] G. D. Doganay and M. Doganay, “Brucella as a potential agent of bioterrorism,” Recent Pat Antiinfect Drug Discov, vol. 8, no. 1, pp. 27-33, 2013. 
[7] O’Callaghan, “Human Brucellosis: recent advances and future challenges,” Infectious Diseases of Poverty, vol. 9, no. 1, p. 101, 2020. 
[8] B. Aljanazreh, K. Alzatari, A. Tamimi, M. H. Alsaafeen, W. Hassouneh, and Y. Ashhab, “Brucellosis re-emergence after a decade of quiescence in Palestine, 2015-2017: A seroprevalence and molecular characterization study,” Transboundary and Emerging Diseases, vol. Epub Ahead of print, p. 14270, 2021. 
[9] H. Battikh, A. Berriche, R. Zayoud, L. Ammari, R. Abdelmalek, B. Kilani, H. Tiouri Ben Aissa and M. Zribi, “Clinical and laboratory features of Brucellosis in a university hospital in Tunisia,” Infectious Diseases Now, vol. 51, no. 6, pp. 547-551, 2021. 
[10] A. Katsiolis, E. Papanikolaou, A. Stournara, P. Giakkoupi, E. Papadogiannakis, A. Zdragas, N. Giadinis, and E. Petridou, “Molecular Detection of Brucella spp. in Ruminant Herds in Greece,” preprint – Tropical Animal Health and Production, 2021. 
[11] N. N. Gavrilova, K. A. Sadanov and I. Alexandrovna, “Effect of Lactobacillus-Based Probiotic in the Prevention and Complex,” Advances in Animal and Veterinary Sciences, vol. 8, no. 3, 2020. 
[12] C. R. Galeano, P. C. Mojica, A. O. Rojas and J. J. R. Zúñiga, “Epidemiological aspects of Brucellosis in humans in the Health Areas of Aguas Zarcas and Los Chiles, Costa Rica 2015-2017 (Aspectos epidemiológicos de la brucelosis en humanos en las Areas Rectoras Aguas Zarcas e Los Chiles, Costa Rica, 2015-2017,” Rev. Ciencias Veterinarias, vol. 38, no. 1, pp. 2215-4507, 2020. 
[13] T. D. Dana, “Review on Epidemiology, Diagnosis Control and Prevention of Brucellosis,” International Journal of Research Studies in Biosciences (IJRSB), vol. 7, no. 6, pp. 1-8, 2019. 
[14] L. Sargsyan, K. Davtyan, K. Hann, S. Gasparyan, V. Davidyants, V. Shekoyan, G. Poghosyan, and D. Petrosyan, “Acute and chronic Brucellosis eleven-year audit from a tertiary hospital in Armenia,” JIDC (The Journal of Infection in Developing Countries), vol. 13, no. 5.1, pp. 42S-50S, 2019. 
Author
Chandana Balasubramanian

Chandana Balasubramanian is an experienced healthcare executive who writes on the intersection of healthcare and technology. She is the President of Global Insight Advisory Network, and has a Masters degree in Biomedical Engineering from the University of Wisconsin-Madison, USA.

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