Uganda's silent threat: Underdiagnosed brucellosis risks long-term health catastrophe

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OPINION

By Esther Nabatta

In Uganda, a silent epidemic is unfolding: brucellosis, a zoonotic bacterial disease silently leaping from animals to humans, primarily through contact with infected livestock or consumption of infected animal products. Alarmingly, this debilitating illness remains significantly underdiagnosed and frequently misdiagnosed, leading to delays in correct treatment and a heightened risk of severe, long-term health complications.

There is an urgent need for increased awareness among communities, healthcare providers, and policymakers to improve early detection, accurate diagnosis, and effective control measures.

One of the major challenges in identifying brucellosis is its presentation. The disease manifests with non-specific symptoms such as persistent fever, fatigue, muscle aches, and joint pain. These symptoms closely resemble those of other common infections like malaria, typhoid, and tuberculosis, making it difficult for healthcare providers to distinguish brucellosis, especially in rural or resource-limited settings where advanced diagnostic tools may not be available. Consequently, countless Ugandans are likely receiving treatment for the wrong ailments while the true cause of their suffering remains unaddressed.

The consequences of this diagnostic failure are terrible. Untreated or improperly managed brucellosis can relentlessly progress, causing destruction on multiple organ systems. Chronic infections can trigger incapacitating conditions such as arthritis (swelling of joints), crippling neurological disorders (problems with the brain, nerves, and the spine) and even life-threatening endocarditis, an inflammation of the heart's inner lining. These severe complications not only condemn individuals to prolonged suffering but also dramatically escalate the cost and complexity of their care.

Uganda's diagnostic capabilities for brucellosis are critically limited. The gold standard for confirmation – bacterial culture, involving the growth of the Brucella organism – is currently beyond the reach of any laboratory within the country due to significant biosafety risks. This absence of definitive diagnostic capacity leaves a gaping hole in the national health system's ability to accurately identify the disease.

Faced with this limitation, healthcare facilities rely on serological tests for brucellosis screening. While useful, these tests have notable limitations.  Serological tests sometimes react to similar germs from other species and may not detect the disease in its early stages. Despite these drawbacks, they remain a practical first-line approach, particularly in resource-constrained settings, where access to more definitive diagnostics is limited.

The Rose Bengal Test (RBT), one of the serological tests, serves as a common initial screening tool due to its simplicity and speed. Rose Bengal test is commonly used in the animal health sector to screen for Brucellosis in herds.

On the other hand, in humans, screening for brucellosis is done using the Brucella Abortus reagent (Special chemicals or substances that health workers use to test for diseases in the laboratory), which is also equally fast but is not as good at correctly identifying those with or without the disease when compared with the Rose Bengal test.

To improve the diagnostic outcome, serological tests should ideally be used in combination with clinical history, epidemiological information, and, where possible, followed up with confirmatory testing.  

For confirmation, other more advanced tests like Enzyme-Linked Immunosorbent Assays (ELISA), Brucella Fluorescent Polarisation Assays (FPA), and molecular diagnostic tests such as Polymerase Chain Reaction (PCR) offer improved accuracy in detecting brucellosis. ELISA and FPA offer improved specificity, particularly in veterinary samples.

Molecular diagnostics tests, such as Polymerase Chain Reaction (PCR), offer highly sensitive detection of Brucella DNA in both humans and animals, but their accessibility remains severely restricted by the high cost of equipment and the need for specialised expertise.

To reduce the suffering caused by undiagnosed brucellosis, Uganda urgently needs to invest more in improving and expanding its testing services. This includes equipping laboratories with the necessary tools, providing comprehensive training for healthcare workers to increase the suspicion index for brucellosis, and ensuring widespread access to reliable and accurate tests for brucellosis diagnosis.

Importantly, a concerted effort to raise awareness among both clinicians and communities about the disease's often-subtle symptoms and key risk factors is essential to promote timely testing and treatment-seeking behaviour.

A robust intersectoral approach is equally vital. As a zoonotic disease, effective brucellosis control demands seamless collaboration between the human health, animal health, and environmental sectors.

Embracing a comprehensive One Health strategy will improve disease surveillance efforts, facilitate early detection of outbreaks, and pave the way for more coordinated and effective responses. Through these unified efforts, Uganda could alleviate the significant burden of brucellosis, safeguarding both the health and the livelihoods of its people.

Don’t let persistent fever go unchecked, act early, test smart, and think brucellosis!

The writer is a laboratory leadership fellow on the Uganda Public Health Fellowship Program, Ministry of Health. She is also a staff at National Animal Disease Diagnostic and Epidemiology Centre, Entebbe. The opinions therein are not for the institutions, partners nor stakeholders.