The Socio-Economic Impact of Brucellosis Outbreaks among Large and Small Ruminant under Extensive Nomadic Management System in Sierra Leone

Abstract

Livestock, particularly ruminants, are vital for resource-poor rural farmers in Sierra Leone, serving as a primary source of income and fulfilling socio-cultural roles. In addition to being a valuable protein source, livestock offer an opportunity to escape poverty. However, the transhumance nomadic extensive system, reliant on natural resources, poses challenges for ruminant production, including disease outbreaks like Brucellosis. A sero-prevalence study in Falaba and Koinadugu districts found a 33.3% infection rate, primarily affecting female small ruminants (90% of cases out of 135). Among the 150 confirmed cases, 66% were pregnant, and 25% experienced abortion. Implementing integrated prevention and control measures through the One Health strategy is crucial to combat the disease effectively. At present, the One Health approach is being used for the control of Brucellosis and hopefully, all stakeholders will appreciate the new dispensation in the control and prevention of many animal diseases in the country.

1. Introduction

Sierra Leone is a small country located along the west coast of Africa, with an estimated population of approximately 8,908,040 and an annual growth rate of 2.41% [1]. Agriculture is the mainstay of the economy, contributing between 45 and 50% of the Gross Domestic Product (GDP). However, livestock only contribute minimally to the GDP, estimated at 3.15%, compared to crops which contribute about 35.2%. This discrepancy is due to the fact that most agricultural development initiatives have been focused on the crop sector [2].

Livestock populations in Sierra Leone are estimated at 546,881 for cattle, 812,906 for goats, 427,667 for sheep, 1,956,650 for chickens, and 217,497 for pigs [3]. The herd size for small ruminants (goats and sheep) varies between 10 and 20 heads, tethered under a semi-free range system. However, the numbers can significantly increase from 50 to 100 when reared together with cattle. Livestock production, particularly large ruminants (cattle), is dominated by transhumance nomadic pastoralists from neighboring Guinea and other countries in the sub-region. Transhumance refers to the use of grassland grazing for livestock production [4]. These migrant pastoralists do not hold land title rights and depend on local landowners to lease them a place to rear their livestock. The traditional communal land ownership often creates social tension between nomadic livestock farmers and crop farmers, as strayed livestock can destroy crops and endanger the livelihoods of crop farmers.

Sierra Leone’s animal health delivery services face challenges due to poor diagnostic infrastructure, inadequately trained personnel, and inadequate logistics for rapid response to animal disease outbreaks (Figure 1). The country is a hotspot for the outbreaks of several transboundary zoonotic diseases. In 2018, an outbreak of Foot-and-Mouth Disease (FMD) was reported in Kambia and Port Loko districts. In 2020, a Brucellosis outbreak was reported in Falaba and Koinadugu districts, and in 2022, Anthrax outbreaks were reported in Port Loko and Kambia districts, followed by Bombali district in 2023. Endemic diseases in the country include Peste des petit ruminants (PPR), Newcastle disease (NCD), Fowl pox, and contagious pustular dermatitis.

Figure 1.

Map of Sierra Leone indicating four districts affected by animal diseases outbreaks. Source: Livestock and veterinary services division, epidemiological unit, Ministry of Agriculture and food security.

Livestock production in Sierra Leone is a key source of livelihood, especially for resource-poor rural farmers, and contributes 8.2% to the Agricultural Gross Domestic Product [2]. Livestock production is well integrated into the socio-cultural practices of many traditional societies in the country. Besides providing a readily available source of animal proteins, livestock play a critical role in the fulfillment of many socio-cultural traditions. For example, sheep are often slaughtered during the feast of Edul Ada to fulfill an important Muslim religious rite. Livestock such as cattle, goats, or sheep are also offered as part of matrimonial bride packages. Livestock are required for other social functions, including initiations and the practices of secret societies such as Wunde, Poro, and Bondo. Livestock also contribute significantly to poverty reduction among resource-poor rural farming communities. Small ruminants (goats and sheep), local poultry, and large ruminants (cattle) can be easily traded and converted into cash, which can be used to finance developmental initiatives such as school fees and medical bills. Traditionally, the number of herds owned by farmers determines their societal hierarchy and influence in making important decisions for their communities.

In rural Sierra Leone, livestock production is predominantly under traditional management systems and is characterized by transhumance and nomadic practices. These nomadic pastoralists are mainly migrants from neighboring Guinea and other countries in the sub-region, such as Mali and Burkina Faso. The transhumance production system involves nomads or pastoralists crossing the border from neighboring countries during specific times, usually during the dry season, in search of pastures and to market their livestock at the International Livestock Trading Center in Gbindi, Koinadugu district. This migration pattern faces several challenges, including conflicts with crop farmers and other indigenous livestock farmers, leading to heightened conflicts between livestock grazers and crop farmers. There is also a risk of introducing transboundary zoonotic diseases. Nomadic pastoralists are constantly seeking production resources, such as land, water, and pastures, which are also of interest to crop farmers. This conflict of interest is now a major source of tension between the major agricultural players in the country. The escalation of grazers-farmer conflicts is a subject of concern as it may have a direct effect on food and nutrition security, threatening the national security of the country.

2. Status of animal health delivery services and brucellosis in Sierra Leone

2.1 Animal health delivery services and status of brucellosis

Sierra Leone is a hotspot for many transboundary zoonotic diseases (Table 1). As recently as 2014, an Ebola outbreak was reported in the sub-region of West Africa, including Guinea, Liberia, and Sierra Leone. In 2018, there was an outbreak of FMD in the northwestern part of the country, and in 2020, Brucellosis was reported in Koinadugu and Falaba districts, while Anthrax was reported again in 2021 in Port Loko and Kambia districts. The West African region is highly active in the circulation of various transboundary and priority zoonotic diseases (PZDs) such as PPR, NCD, FMD, viral hemorrhagic fevers (VHFs) like Lassa fever, Ebola, and Marburg, as well as rabies [2].

No	Disease	Category
1	PPR	TAD
2	Rinderpest	TAD
3	Foot-and-mouth disease	TAD
4	African swine fever	TAD
5	Trypanosomiasis	TAD
6	Hemorrhagic septicemia	TAD
7	Contagious bovine pleuro-pneumonia	TAD
8	Black quarter	TAD
9	Bovine tuberculosis	Zoonosis
10	Brucellosis	Zoonosis
11	Anthrax	Zoonosis
12	Rabies	Zoonosis
13	Highly pathogenic avian influenza	Zoonosis
14	Viral hemorrhagic fevers (Ebola, Marburg, Lassa fever, Rift Valley fever, Crimean Congo fever)	Zoonosis
15	Salmonellosis	Zoonosis
16	Plague	Zoonosis

Table 1.

List of priority transboundary and zoonotic diseases in Sierra Leone.

Source: Livestock and Veterinary Services Division of the Ministry of Agriculture and Food Security Of Sierra Leone. TAD = Transboundary Animal Diseases.

The animal health delivery services, under the Livestock and Veterinary Services Division of the Ministry of Agriculture and Food Security, are severely limited in terms of diagnostic facilities and trained and qualified human resources. In rural areas, animal health services are provided by the staff of the Ministry of Agriculture and Food Security. However, due to a lack of trained and qualified personnel, trained Community Animal Health Workers (CAHWs) are also complementing the efforts of the Ministry. In extreme and desperate situations in remote and inaccessible rural areas, traditional livestock farmers reportedly resort to self-administration of animal health services.

2.2 Status of brucellosis under nomadic and transhumance production systems in Sierra Leone

Brucellosis is one of the neglected reportable zoonotic diseases of public health concern, causing significant economic losses in traditional livestock production systems in Africa. The disease primarily affects livestock, including cattle, goats, sheep, and pigs, but it can also infect other animals and wildlife. The etiology of Brucellosis is a gram-negative, non-motile, non-sporing, rod-shaped, facultative, and aerobic intracellular cocobacilli. Infection with Brucellosis leads to serious economic losses due to abortion, reproductive failure, sterility, and reduced milk production in affected animals [5]. The etiology is shed in large numbers in the animal’s urine, milk, placental fluid, and other fluids.

Brucellosis in animals can result in various reproductive problems, such as abortion, stillbirths, reduced fertility, and decreased milk production. These effects cause significant economic losses for livestock farmers and negatively impact the overall productivity of animal agriculture. Moreover, infected animals serve as reservoirs for the bacteria, perpetuating the disease within herds and posing a risk of transmission to humans.

In Sierra Leone, the nomadic production system takes the form of communal grazing, where healthy, sick, and susceptible animals converge, increasing the risk of infection for healthy ones. Infected animals or aborted fetuses and fluids can contaminate the pasture, and healthy animals that feed on such pastures can easily become infected. Furthermore, communal grazing also provides opportunities for communal mating. If a bull mates with an infected cow with Brucellosis, it can infect susceptible healthy cows or heifers during their next mating. As a result, Brucellosis has become endemic in most communal grazing herds, and the disease continues to persist, especially in areas with poor animal health delivery services and surveillance systems, along with unchecked cross-border livestock trade.

Brucellosis is a prioritized zoonotic disease in Sierra Leone. Its first detection in the country dates back to 1966 [6, 7], but official reports of outbreaks were not made until 2020, when cases were identified in the Koinadugu and Falaba districts. During the 2020 outbreaks, the estimated prevalence of Brucellosis among goats and sheep in these districts was 38.3% for goats and 33.3% for sheep. The laboratory-confirmed cases of Brucellosis between 2019 and 2020 were estimated at 36.8%. It is important to note that these figures do not indicate the absence of the disease in susceptible herds but rather highlight the lack of an animal disease surveillance system, limited diagnostic facilities, and insufficient staff to effectively diagnose and respond to animal diseases.

To enhance disease reporting, the FAO’s Emergency Center for Transboundary Animal Diseases (ECTAD) Project, with support from United States Agency for International Development (USAID) under the Global Health Security Agenda (GHSA), established the Integrated Animal Health Disease Surveillance and Reporting System (IADSR) and facilitated the creation of the Epidemiology Unit at the Livestock and Veterinary Services Division (LVSD).

A comprehensive report on the sero-prevalence of Brucellosis among cattle at the Njala and Newton production facilities concluded that the disease is enzootic in semi-intensive production systems, with a prevalence rate of 75% [8]. In the same year, a suspected outbreak of Brucellosis was investigated in the Koinadugu and Falaba districts, which are located in the northern part of the country bordering Guinea. The results revealed a high sero-prevalence (90%) among females (n = 135) aged 1–2 years, with a prevalence of 10% (n = 15) among heifers. Out of the 150 confirmed cases, 66% were pregnant, and 25% resulted in abortions [7]. Additionally, 50 cattle imported from neighboring Guinea succumbed to the disease before testing, indicating the potential for transboundary introduction of the disease in the sub-region.

3. Brucellosis and its impact on public health in Sierra Leone

3.1 Public health risk along the livestock value chain

Brucellosis poses risks at various stages of the livestock value chain, from production to consumption. It is crucial to address these risks at each stage by promoting awareness and implementing best practices to minimize disease transmission and protect both animal and human health. The different stages of the livestock value chain include:

1. Animal acquisition: When introducing new animals into a herd or farm, there is a risk of introducing Brucella-infected animals. Purchasing animals from unknown or untrusted sources increases the likelihood of bringing in infected animals that can spread the disease to the existing herd.

2. Animal movement: The movement of infected animals between farms, markets, or slaughterhouses can contribute to the spread of Brucellosis. Infected animals shedding the Brucella bacteria in their urine, milk, placental fluid, and other body fluids can contaminate the environment, feed, and water sources, making it easier for healthy animals to become infected.

3. Breeding and reproduction: Brucellosis can be transmitted through mating or artificial insemination. If a bull or ram carrying the Brucella bacteria mates with a susceptible female, the infection can be transmitted. Additionally, infected animals may experience reproductive issues such as abortions, stillbirths, or reduced fertility, which can lead to further spread of the disease.

4. Handling and milking: During the milking process, Brucellosis can be transmitted from infected animals to humans. Contaminated milk or milk products can pose a risk of infection if consumed without proper pasteurization. Direct contact with infected animals’ bodily fluids, such as through wounds or mucous membranes, also presents a risk of transmission.

5. Slaughter and meat processing: Infected animals can carry Brucella bacteria in their lymph nodes, organs, and reproductive tissues. Improper handling and slaughter practices, as well as inadequate meat inspection and processing, can lead to the contamination of meat products with Brucella. Consuming undercooked or raw meat from infected animals can result in human infection [9].

6. Consumption: Consumption of unpasteurized milk, cheese, or other dairy products made from infected animals can pose a direct risk of Brucellosis transmission to humans. Additionally, consuming contaminated meat or meat products without proper cooking can also lead to human infection. Brucellosis is a well-documented zoonotic disease and a major public health concern worldwide. However, in Africa, particularly in Sierra Leone, the disease has been long neglected, and associated risks and health factors are not routinely ascertained [6, 10].

A mapping and analysis of the livestock value chain, particularly for ruminants (cattle, goats, and sheep), in Sierra Leone, as shown in Figure 2, provides a better understanding of the stakeholders at risk.

Figure 2.

Schematic representation of stakeholders at risk of contracting brucellosis along the ruminant value chain in Sierra Leone.

Stage 1: At the production stage, farmers, including cowboys who care for the animals during grazing, women who milk the cows, and household family members who participate in animal production, are at risk of contracting the disease. They come into direct contact with infected animals or their products, such as feces, urine, or milk, which may carry a high concentration of the etiology.

Stage 2: This stage involves the transportation of live animals from remote production sites to the market. Animals are often trekked for miles to reach transportation centers where they are loaded onto trucks and vans for their final destinations. The key players involved are cowboys, middlemen, and farmers themselves. These individuals are also at high risk of contracting the disease because they come into direct contact with the animals and their waste products.

Stage 3: The processing stage encompasses several stakeholders, including caretakers at livestock holding facilities, butchers at abattoirs and slaughterhouses, and meat marketers and distributors. They are all at high risk of contracting Brucellosis. Their jobs require them to come into direct contact with live and slaughtered animals, as well as the meat and waste products. In Sierra Leone, these meat processors are rarely seen wearing any form of personal protective equipment (PPE) at all stages of processing. The fact remains that they are simply not aware of the associated risks of contracting zoonotic diseases from infected animals.

Stage 4: The consumer stage is the final stage of the ruminant value chain. Meat is processed in restaurants in various forms, and there is a possibility of serving undercooked meat. Meanwhile, chefs, cooks, and other individuals involved in meal preparation could also be at risk.

3.2 Public health risk from traditional consumption practices

Extended literature reviews have indicated that 4% of the global foodborne disease burden and 12% of the animal-source disease burden are attributed to dairy products [11, 12, 13]. The consumption of raw or unpasteurized milk is a subject of discussion and is influenced by people’s knowledge and the rules and regulations governing the consumption of such products. Some people consume raw milk because they believe it enhances the nutritive value of the product and preserves the original taste. However, raw milk may contain complex microbiological components that pose serious health risks. Pathogens such as Campylobacter, Cryptosporidium, E. coli, Listeria, Brucella, and Mycobacterium can be present in raw milk.

In Sierra Leone, the custom of consuming unpasteurized milk is prevalent. Pasteurization, a process that involves heating milk to a specific temperature to kill harmful bacteria, including Brucella, is not routinely carried out. Consequently, raw unpasteurized milk remains untreated and may contain pathogens, including Brucella. Therefore, consuming raw milk increases the risk of Brucellosis infection. Pasteurization is a crucial step in ensuring the safety of milk and dairy products. It effectively kills harmful bacteria, including Brucella, thereby reducing the risk of foodborne illnesses. Pasteurization is widely recommended as a preventive measure to eliminate or reduce the transmission of Brucellosis and other pathogens.

The process of collecting and processing milk is often unhygienic. Women in traditional cattle production facilities are responsible for milking the cows. Ideally, before collection, the teats of the udder should be thoroughly cleaned to minimize the chances of contamination. However, in traditional cattle production systems, milk is directly harvested from cows with little consideration for hygiene. The fat is then extracted from the milk using crude methods and subjected to fermentation. The fermented unpasteurized milk is sold to the public for consumption. Personal conversations with people who consume raw milk indicate a lack of knowledge and understanding about the risks associated with consuming such products.

Health authorities, such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), strongly advise against consuming raw milk due to the associated health risks, including the transmission of Brucellosis. They recommend consuming only pasteurized milk and dairy products.

Public awareness campaigns play a crucial role in educating individuals about the risks of consuming raw milk and the importance of pasteurization. It is important to inform consumers about the potential health consequences and promote safe milk consumption practices.

3.3 Public health risk from antimicrobial resistant (AMR) Brucella parasites and one health interventions

Antimicrobial resistance (AMR) is a significant public health concern that leads to treatment failures, prolonged hospitalizations, and high mortality rates among humans. It is estimated that in 2019, 1.27 million deaths were directly attributed to drug resistance, and projections indicate that by 2050, annual deaths could reach 10 million [14]. A recent report highlighted that if substantive efforts are not made to contain this threat, 10 million deaths and a loss of 100 trillion USD in the world’s economic outputs could be attributed to AMR by 2050 [15].

Livestock play a crucial role in many impoverished countries, particularly in Africa, where they hold a unique socio-cultural niche. Resistant strains of bacteria in terrestrial and aquatic animals can worsen animal performance, which, in turn, affects the livelihoods of poor rural African communities. Approximately 1.3 billion people rely on livestock for their livelihood, and over 20 million people depend on aquaculture [16]. Livestock contribute significantly to the development and transmission of zoonotic antibacterial-resistant parasites, including Brucellosis. Infected animals can act as reservoirs for the transmission of resistant strains to humans through direct contact, consumption of contaminated animal products (such as unpasteurized milk and cheese), or inhalation of contaminated aerosols. This can lead to treatment challenges, more severe illness, and potentially higher mortality rates among affected individuals.

Antibiotics are commonly used in the treatment of Brucellosis in both animals and humans. However, the development of antibiotic resistance in Brucella parasites can render standard treatment protocols ineffective. This poses a challenge in managing and controlling Brucellosis infections, resulting in prolonged illness, increased treatment costs, and potential treatment failures. Moreover, with the emergence of antibiotic resistance, the range of effective antibiotics for treating Brucellosis becomes limited. This reduction in treatment options can make it more difficult to achieve successful outcomes in infected animals and individuals.

A situation analysis report on antimicrobial use and resistance in the food and agricultural sector in Sierra Leone was conducted in 2021. Key findings indicate that methods for quantifying antimicrobial use in animals have not been developed, and the use of antimicrobials is undocumented. An estimated 74.1% of farmers use antimicrobials as growth promoters. Antimicrobials are also used as chemoprophylactic or chemotherapeutic drugs. Tetracycline (51.3%, n = 421), amoxicillin (18.4%, n = 151), ampicillin (11.8%, n = 97), and penicillin (5.9%, n = 48) are among the most commonly used antibiotics by livestock farmers. Approximately 60% of livestock farmers lack knowledge about antibiotics, and 27% disclose using antibiotics for treating infections without providing details about the name and description of the infection they treated. This underscores the fact that antimicrobials are haphazardly used in livestock production without an adequate understanding of their impact on generating resistant zoonotic parasites [17]. People consuming meat with a high burden of AMR parasites are at a high risk of contracting these parasites.

There is limited information available regarding people diagnosed with Brucellosis parasites, but this does not imply that such cases do not exist. The Livestock and Veterinary Services Delivery Unit of the Ministry of Agriculture and Food Security faces significant resource and capacity constraints in terms of human resources, diagnostic capabilities, and surveillance systems. In remote and inaccessible livestock production systems, local farmers often administer animal health services as a last resort to address desperate situations. Under such conditions, the proliferation of resistant Brucella parasites is extensive and can be easily transmitted to vulnerable and susceptible populations.

The emergence of antibiotic-resistant Brucellosis highlights the importance of a One Health approach that recognizes the interconnectedness of animal, human, and environmental health. Collaboration between veterinary and human healthcare professionals, as well as agricultural and environmental stakeholders, is essential in monitoring and managing the spread of antibiotic-resistant strains and implementing effective control measures. To mitigate the impact of antibiotic-resistant Brucella parasites, responsible and judicious use of antibiotics is crucial. This includes proper diagnosis, appropriate prescription, adherence to treatment protocols, and the promotion of alternative disease control strategies, such as vaccination and improved biosecurity measures. Lastly, regular surveillance of Brucellosis cases, including monitoring for antibiotic resistance, is vital for detecting and tracking the emergence and spread of resistant strains. This information can guide treatment protocols, inform public health interventions, and support the development of targeted control strategies.

3.4 The One Health approach

The One Health strategy plays a crucial role in the control and prevention of Brucellosis in both animals and public health. The One Health approach recognizes the interconnectedness of human, animal, and environmental health and promotes collaboration between multiple sectors to address health issues comprehensively [18]. The One Health strategy contributes to the control and prevention of Brucellosis through several key measures:

• Early detection and surveillance: One Health emphasizes the importance of active surveillance systems to promptly detect Brucellosis cases in animals and humans. This involves regular monitoring of livestock, wildlife, and humans in high-risk areas to identify infected individuals and trace the sources of infection.

• Integrated control measures: The One Health approach promotes integrated control measures that encompass both animal and human health [18]. This includes implementing vaccination programs for livestock, wildlife, and pets to prevent the spread of Brucellosis. Additionally, coordinated efforts are made to improve animal health management practices, such as hygiene, biosecurity, and proper waste disposal, which can help to reduce the transmission of Brucella bacteria.

• Collaboration and information sharing: One Health encourages collaboration among various stakeholders, including veterinarians, physicians, epidemiologists, public health officials, and policymakers. Sharing information and expertise across disciplines facilitates a better understanding of Brucellosis transmission dynamics, risk factors, and control strategies. This collaboration enhances surveillance, diagnostics, and treatment protocols for both animals and humans.

• Public awareness and education: The One Health approach recognizes the importance of public awareness and education in preventing Brucellosis. Raising awareness about the disease, its transmission routes, and preventive measures can help to reduce the risk of infection in both animal handlers and the general public. Education programs target livestock owners, hunters, farmers, and other individuals at higher risk of exposure to Brucellosis.

• Research and innovation: The One Health strategy emphasizes the need for continued research and innovation in the field of Brucellosis prevention and control. This includes developing improved diagnostic tools, vaccines, and treatment options for animals and humans. Research efforts focus on understanding the epidemiology of the disease, identifying risk factors, and evaluating the effectiveness of control strategies [18].

Sierra Leone has adopted the One Health (OH) approach with a vision of creating a healthy Sierra Leone where people and animals coexist in a safe environment, achieved through effective One Health collaboration. The One Health approach in Sierra Leone is guided by the concept of effective collaboration and integration through multidisciplinary and multisectoral engagement for the health of people, animals, and the environment. The country has established a One Health coordination structure, which is currently being tested. This approach has helped to overcome weak and ill-capacitated health delivery systems by enabling the prevention, prediction, detection, and response to health emergencies. The organizational structure ensures that decisions are made at higher political levels, thereby ensuring political will that is then cascaded to units responsible for coordinating the entire process.

The countries in the Mano River Union sub-region (Guinea, Liberia, Sierra Leone, and Ivory Coast) continue to face growing threats from zoonotic diseases. Weak health delivery systems, poor coordination of efforts, and mistrust among key stakeholders have exacerbated this problem, leading to inadequate response initiatives during disease outbreaks. In 2014, the sub-region experienced the devastating Ebola pandemic, followed by the COVID-19 outbreak in 2020. The experiences gained from these outbreaks, particularly the Ebola outbreak, laid the foundation for the establishment of the One Health platform.

This shift in the approach to disease outbreak response brought together other key players and institutions, such as the Ministry of Health and Sanitation, Ministry of Agriculture and Food Security, and Ministry of the Environment and Climate Change, to collaborate and pool resources for effective surveillance and response to disease outbreaks. Brucellosis is among the PZDs in Sierra Leone, and outbreaks of alarming proportions will receive the attention and response of the One Health platform for appropriate action.

4. Control and prevention strategies

4.1 Prevention and control of brucellosis in animals

Prevention and control of Brucellosis among ruminants in extensive free-range systems pose significant challenges. This is exacerbated by the constant influx of sick livestock from across the border, increasing the likelihood of infecting local herds. Furthermore, the movement of herds in communal grazing lands allows for direct contact and transmission through mating and natural instincts. However, concerted efforts and strategies must be implemented to establish effective prevention and control measures. The best approach is to adopt an integrated strategy for controlling and preventing the disease, which includes the following measures:

1. Mass vaccination of susceptible herds: Vaccinating enzootic areas can help to reduce the infection burden. For small ruminants, a vaccination schedule of at least every 6 months for three consecutive periods should be followed, including the vaccination of kids and lambs. It’s important to note that vaccination, when combined with proper husbandry practices, is more likely to achieve successful prevention and control of Brucella infections [19].

2. Laboratory-based surveillance: Both active and passive surveillance are essential for effective prevention and control measures. Passive surveillance is usually carried out by CAHWs who closely collaborate with local livestock farmers. They act as frontline personnel, identifying disease outbreaks and reporting them to the relevant authorities. During the 2020 Brucellosis outbreak, CAHWs were in the field to assess the nature and magnitude of the outbreak. Subsequently, active surveillance was initiated, and veterinarians were dispatched to collect samples, which were then sent to the Central Veterinary Laboratory at Teko in Makeni. Confirmed cases were identified, and prevalence and disease incidence were determined. Necessary prevention and control measures, such as herd movement restrictions, quarantine, selective testing, and slaughter, were implemented.

3. Community-based actions: Nomadic pastoralist farmers, known for their constant movements in search of pasture and water, contribute to the rapid spread of Brucellosis among vulnerable herds. Local authorities, including chiefs, village heads, and heads of livestock associations, play a crucial role in Brucellosis control. In Sierra Leone, Livestock bye-laws were developed and enforced in several communities where livestock are reared. These bye-laws prohibit livestock farmers from moving animals without prior approval from local authorities, and all livestock farmers are obligated to vaccinate their herds. Such bye-laws significantly reduce the spread of Brucellosis, as observed in the Falaba and Koinadugu districts.

4. Training and sensitization of stakeholders: Knowledge is essential in combating Brucellosis, as lack of knowledge can lead to misinformation and rumors. Training frontline Animal Health Workers is crucial, particularly in safe sample collection, community engagement, and proper transportation of samples. It is important to sensitize farmers and other stakeholders to understand the risks associated with handling Brucella-infected animals. Raising awareness among livestock farmers will foster cooperation in managing the outbreak.

5. Strengthening point of entry border posts: The ruminant livestock industry in Sierra Leone is largely influenced by migrants from Guinea and neighboring countries like Mali, Ivory Coast, and Burkina Faso. These transhumance nomadic migrants constantly move with their livestock in search of pasture and markets, following specific routes to cross international borders. Strengthening point of entry (PoE) posts by equipping them with basic testing equipment and establishing adequate quarantine facilities can help to prevent the introduction of sick animals into the country.

6. Use of protective equipment: In the ruminant value chain analysis, it is important to identify stakeholders at risk of contracting the disease. Farmers, transporters, processors, marketers, and even cooks are at risk if proper preventive measures are not taken. The use of PPE will prevent direct contact between farmers and other stakeholders along the value chain and sick animals or their products (meat, feces, urine, aborted placentas, or fetuses).

4.2 Prevention and control of brucellosis in humans

Brucellosis is a well-documented zoonotic disease that can cause severe illness in humans. It has been noted that humans can contract the disease from infected animals or contaminated animal products. The most common ways of contracting Brucellosis include consuming raw dairy products contaminated with Brucella, inhaling air contaminated by Brucella, and coming into contact with the blood or body fluids of infected animals [20]. In Sierra Leone, many people have contracted the disease due to ignorance and traditional cultural practices. To prevent and control the occurrence and spread of Brucellosis, the following measures are essential:

1. Pasteurization of milk: The consumption of raw, unpasteurized milk is a common practice in Sierra Leone. The public and other stakeholders must be educated about the risks associated with consuming unpasteurized milk. Additionally, traders in fresh milk should be taught simple techniques of pasteurization and other value-addition methods to increase their income.

2. Strengthening and enforcing ante- and post-mortem inspection of meat and animal products: Conducting ante- and post-mortem inspections of meat animals and their products is crucial in safeguarding consumers from contracting Brucellosis. This can be achieved through the presence of adequate facilities and trained personnel who can effectively perform these inspections.

3. Use of personal protective equipment (PPE): Individuals who handle meat, fluids, and other animal products infected with Brucella are at risk of contracting the disease. Butchers in abattoirs and slaughterhouses are particularly exposed to the disease and should wear effective PPE to protect themselves.

4. Public sensitization and education: Many people are unaware of the risks involved in dealing with Brucella-infected animal products. Mass sensitization campaigns aimed at educating the public about basic prevention and control measures can help to curb human infections.

5. The One Health approach: The One Health approach is gaining recognition among health workers and policymakers. This approach is particularly suitable for low-income countries with limited facilities and infrastructure for effective and rapid response to outbreaks. In Sierra Leone, the Ministry of Health is closely collaborating with the Livestock and Veterinary Division of the Ministry of Agriculture and Food Security, allowing the Livestock Division to benefit from the facilities and experiences of the Ministry of Health [21].

5. Conclusions

Brucellosis, a priority animal disease with public health implications, has been a neglected issue in Sierra Leone, resulting in significant economic losses for farmers. Despite its detection in 1966, insufficient efforts have been made to control and prevent the disease among livestock. As a consequence, Sierra Leone continues to experience sporadic outbreaks of Brucellosis, leading to substantial economic losses and deepening poverty among rural livestock farmers. The persistence of Brucellosis poses a significant challenge to the development of the livestock sector, particularly within the nomadic extensive free-range system, primarily for ruminants. The complexity of the prevention and control measures is further compounded by this system.

However, the introduction of the One Health approach has revitalized efforts for the control and prevention of Brucellosis. This approach promotes collaboration across sectors and disciplines, facilitating prompt detection and response to Brucellosis outbreaks. Currently, all endeavors are concentrated on effectively controlling and preventing the disease in Sierra Leone. It is hoped that through the implementation of this new approach, Brucellosis outbreaks will be minimized, allowing farmers to reap the economic benefits associated with their livestock.

Acknowledgments

My profound appreciation to Dr. Sahr Raymond Gborie of the Epidemiological Unit at the Livestock and Veterinary Services Division of the Ministry of Agriculture and Food Security for drawing the map of Sierra Leone. Let me conclude by thanking my students at the Faculty of Agriculture and Food Security for improving my internet connectivity.

Conflict of interest

There is no conflict of interest in this piece of academic work. It has been written to improve the knowledge of my students and other users who may find it useful.