Comparison of knowledge, attitude, and practices of animal and human brucellosis between nomadic pastoralists and non-pastoralists in Kenya

Brucellosis is a globally widespread zoonotic disease that causes substantial morbidity in both livestock and human populations, particularly in Latin America, Middle East, and Africa where it is endemic [1]. Of the six species of the bacteria, Brucella abortus and Brucella melitensis are the predominant species associated with human disease. These Brucella species are transmitted from infected animals primarily through inhalation of the bacteria, consumption of contaminated unpasteurized dairy products, and direct contact with infected animal fluids and tissues [1, 2]. While the disease is rarely fatal, human brucellosis is a chronic debilitating and disabling disease that is often difficult to diagnose and requires long and expensive antibiotic treatment, which may not always be successful [3, 4]. Among livestock (cattle, sheep, goats and camels), B. abortus and B. melitensis are spread through contact with infected birthing tissues and fluids via ingestion or direct contact with mucous membranes and sexually [1, 2]. Brucellosis infection in livestock is often chronic, leads to abortions and infertility and is associated with major economic losses associated with reduced productivity in animals, and trade restrictions [5].

In endemic countries, the seroprevalence of brucellosis in livestock varies from < 1 to 30% [6‐10]. In these regions, human incidence of the disease ranges widely, with areas such as Africa and Middle East reporting between 50 and 250 cases per 100,000 [3]. Most data show human seroprevalence of brucellosis is positively correlated with livestock seroprevalence, emphasizing the role of livestock as the source of human infections [3]. Public education in combination with livestock vaccination has been shown to reduce disease incidence in humans and animal populations through adoption of risk reduction practices [11]. Interestingly, many studies show significant knowledge of brucellosis among rural and urban populations in developing countries; with between 40 and 100% of populations reporting awareness of the disease and its clinical presentations [8, 12‐14]. However, few studies have been carried out among nomadic pastoralist communities residing in underdeveloped remote and arid areas and deriving livelihood primarily from rearing livestock- where infection risk is likely elevated [13, 15].

In Africa, over 100 million nomadic pastoralists, living in the underserved arid and semi-arid lands of the continents own more than 30% of all livestock and 50% of small ruminants, supplying 60% of beef and 40% of sheep and goat meat in the countries where they inhabit (FAO, 2012). In 2013, a study in Kenya reported a 12-fold higher seroprevalence of brucellosis among nomadic pastoralist livestock herds in northern Kenya compared to mixed farmers (livestock and crops) in central Kenya, and 14-fold higher prevalence in pastoralist households (humans) when compared to mixed farmers [10]. Similarly, the livestock prevalence (cattle, sheep, goats and camels) was 11-fold higher and human prevalence 19-fold higher among pastoralists when compared to mixed farmers. A breakdown of the seroprevalence among livestock species gave a range of 11–16% prevalence in pastoral livestock, compared to 0.8–2.4% in livestock reared in small-scale production systems [10].

Here, we compared the knowledge of brucellosis and risky practices of infection among seropositive households in two communities; nomadic pastoralists living in the remote, underdeveloped and arid northern region, and mixed farmers living in a developed, high potential, agro-ecological region of Kenya.

An important finding in this study was that whereas over 70% of both nomadic pastoralists and mixed farmers had heard of brucellosis disease and had knowledge of common symptom (chills and loss of appetite), less than10% could identify key risky practices associated with brucellosis infection in humans including consuming raw dairy products and contact with aborted fetuses. Despite these comparable levels of knowledge of the disease among the two communities, over two-thirds of nomadic pastoralists engaged in risky practices including consumption of unboiled milk and raw blood, assisting with animal birth and handling raw hides. In contrast, less than 10% of mixed farmers engaged in these practices, including about 2% in consumption of unboiled milk or raw blood. Our findings show a strong link between these practices and Brucella spp. seropositivity, including a nearly 3-fold higher odds of seropositivity for people who consumed unboiled milk. These practices combined with the high brucellosis seroprevalence (13.5%) among their livestock, predisposes nomadic pastoralists to high Brucella spp. sero-positivity.

Our study found that two-thirds of the pastoralists had no formal education whereas almost all (92%) of the mixed farmers had at least primary school education, including almost half that had secondary school education or higher. The low level of formal education among pastoralists, who typically live in expansive and sparsely populated remote semi-arid and arid lands of sub-Saharan Africa, when compared to other communities living in more developed and agriculturally productive regions, is associated with underdevelopment and poor infrastructures, and the occupation and lifestyle of pastoralists [19‐21]. Despite this disparity in education, our study found the two livestock-owning communities with comparable knowledge levels of brucellosis disease, including a moderate to high knowledge of its existence and its effects on humans and low knowledge such as mechanisms of animal-to-human transmission and prevention and control measures. This finding is in agreement with other studies showing there is significant knowledge of common endemic zoonotic disease including brucellosis, echinococcosis, and rabies exists among nomadic pastoralists despite the lack of formal education [22].

The question is why pastoralists engage in risky practices given their knowledge level is similar to mixed farmers. One possibility is that nomadic pastoralists, perhaps because of low levels of formal education and representation in national leadership, distrust the government health services, resulting in low receptiveness to public health and animal health education on disease prevention and control [22]. This is unlikely because our experience during field studies and vaccination campaigns show comparable reception of among all communities. A more plausible explanation is that lack of other sources of livelihood and occupations, apart from rearing livestock in these arid lands, leaves pastoralists with no choice but to engage in risky practices in the course of their interactions with livestock - perhaps even when they know the associated risks. Our interactions with nomadic pastoralists including some with education and knowledge of risk factors of brucellosis revealed that they engage in risky practices because of culture. Social studies to understand why people engage in risky practices such as commercial sex workers engaging in unsafe sex, drug users, and youth engaging in texting while driving identified economic insecurity and culture as possible reasons [23‐26]. The studies among drug users involved in risky income generation showed that almost half of them would continue the risky practices even if they went off drugs but remained economically insecure [23]. The primary occupation of nomadic pastoralists is to herd livestock and use these and their products including milk, meat, fur, hides, leather and manure for their livelihood and socio-economic advancement. They routinely give extra care to pregnant livestock, which are typically kept near pasture areas to reduce the long treks that other animals undertake and including assisting them with birth and management of the newborn animals. In addition, they routinely drink raw blood and unboiled milk obtained for survival during their movement across the arid lands [9, 27, 28]. Nomadic pastoralists believe that unboiled camel milk has better taste and it possesses medicinal value including aphrodisiac properties [27‐31]. In addition, they engaged in skinning and therefore handling raw hides because of the high market value of camel leather and hair [32]. Since our study also found that lack of formal education was an important risk factor associated with increased risk of brucellosis infection, we envision that promoting formal education among the pastoralists would result in improved economic opportunities and reduction in risky practices as has been observed in other studies [33, 34].

Previous findings showed over 65% household prevalence of brucellosis among the nomadic pastoralist communities of Marsabit County, which was 12-fold higher than other regions of the country [10]. The findings of our current study suggest that health education should emphasize risky cultural practices and accompanied by increased formal education and economic renaissance. It is likely the recent introduction of a devolved government in Kenya, which increased public participation and resource allocation to such marginalized areas will begin to turn the tide of such endemic zoonotic diseases. However, a more effective approach should be to promote formal education and development and implement a prevention and control strategy targeting reduction of the disease in both livestock through routine vaccination, and public education among humans to curb the risky practices we identified.

This study had some limitations. First, the exclusion of children below 5 years of age limits the generalizability of our data to the entire population. Our determination of risky practices was based on interviews, which could likely introduce information bias with participants giving responses they consider favorable. We think that this possible bias was minimal based on findings of the key informant interviews on the prevalence of the practices in the communities.

The little knowledge of how brucellosis is transmitted to humans and among animals suggest that more public education on the disease would be useful, while at the same time developing behavior change communication strategies for different communities is critical. In addition, there is need for collaboration between the veterinary and public health professionals through the one health approach in the provision of health education and information including symptoms, transmission pathways and prevention of brucellosis at community level to reduce disease prevalence.

Our findings show that despite comparable levels of knowledge of brucellosis disease by both nomadic pastoralists and mixed farmers, over two-thirds of nomadic pastoralists engaged in at least one of four key risky practices including consumption of unboiled milk and raw blood, assisting with animal birth and handling raw hides. We also found a strong link between these practices and Brucella spp. seropositivity, including a nearly 3-fold higher odds of seropositivity for people who consumed unboiled milk. We argue that nomadic pastoralists are likely to engage in risky practices which promote Brucella spp. infection probably related to occupation and culture, despite having significant knowledge of the disease.