Animal Disease Surveillance System key to understanding disease dynamics

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The significant increase in demand for animal-sourced foods in sub-Saharan Africa (SSA) has resulted in the rise of animal diseases, which could pose severe economic and public health threats. These diseases have the potential to cross international boundaries, disrupt global trade, and pose severe threats to public health and livelihoods. After recent global public health emergencies, the importance of animal disease surveillance as an early warning system remains a major concern.

While no surveillance system is perfect, the ADSS in sub-Saharan Africa is weak, poorly funded, produces poor-quality sensitivity and specificity information on disease status and trends, and requires urgent improvement to detect the occurrence of silent epidemics and outbreaks. The system must be strengthened to improve its sensitivity, specificity, coverage, cost-benefit, timeliness, diagnostic accuracy, flexibility, and completeness.

An early alert system

A resilient ADSS demands baseline national animal health and disease indices, improving the sensitivity of the current reporting system, and increasing diagnostic accuracy and disease containment activities, using an integrated approach. The ADSS ought to be an early-alert surveillance system, which is essential to understand important disease dynamics, prioritize intervention plans to prevent epidemics (or pandemics), and prevent the spill-over of diseases from animals to humans.

A pilot field activity, in May 2022, evaluated farmers’ preparedness under the Risk Assessment for Animal Epidemic Prone Disease (RA-4-AEPD) project in Nigeria. Several farmers that had suffered recent mass pig mortalities had symptoms consistent with ASF. These cases were not reported to the relevant authorities due to the fear of ostracization and lack of compensation.

An effective ADSS could reduce the emergence of infectious diseases such as monkeypox across Africa, leptospirosis in Tanzania, Marburg virus in Ghana, anthrax in Sierra Leone, or hepatitis E in Southern Sudan, amongst other reported ongoing zoonotic outbreaks.

Approaches to monitoring

To effectively serve as an early warning system on the continent, the ADSS must develop epidemiological intelligence to predict the risk of incursion, provide risk estimates, evaluate the preparedness of states, target changes in disease dynamics in the source population, and model their impact. This requires training, improved funding, compensation, technological innovations in disease reporting, and investments in diagnostic capacity to generate sensitive, reliable, and valid reports of animal health events. This also requires the establishment of short, medium, and long-term financing framework to enable it to deliver on its mandates.

A short-term approach to counter under-reporting is syndromic surveillance, a proven effective tool to complement traditional surveillance systems for several human and animal diseases.

ADSS revitalization funds should be channelled to crucial packages such as the provision of biosecurity materials, training for surveillance officers, point-of-care rapid diagnostic kits, as well as surveillance materials and consumables. This would help strengthen the ADSS in most SSA countries.

Although compensating farmers after epidemics could increase voluntary disease reporting, inconsistencies in local animal disease control policies, the compensation rate, what diseases are to be compensated for, what baseline criteria to be used for pre-qualification for compensation, and lack of procedural transparency raises questions over their potential success of financial compensations and makes it unsustainable in on the continent. For instance, the UK government paid more than £1.1b in compensation for animals slaughtered during FMD control activities in 2001. In addition, feedback through reports, diagnostic test results, and control measures such as fumigation of affected farms may enhance the willingness to report disease outbreaks.