Potential risk factors for zoonotic disease transmission among Mongolian herder households caring for horses and camels

Abstract

Mongolia has more than ten times as many livestock as people. Herders are dependent on their livestock for their livelihood, and seasonal movement is driven by the livestock's grazing needs. The daily, seasonal interactions between Mongolian herders and their livestock put herders at risk for several zoonotic diseases. The goals of this pilot study were to describe potential risk factors for zoonotic disease transmission and note how they differed for herder families between provinces (aimags). As part of a larger study, a household survey was administered to 131 households in Arkhangai, Uvurkhangai, and Umnugobi provinces aimags during 2016 and 2017. The study was limited due to its self-reported survey data and its convenience sample design. We did not capture specific disease data. All households cared for either or both horses (Equus ferus caballus) and Bactrian camels (Camelus bactrianus). All households had a cell phone and access to a power source, primarily solar panels (93.1%). Families reported spending on average 3.9 h a day with their horses or camels. As all five of the most prevalent zoonotic pathogens in Mongolia have horses as reservoirs, and three of the five may also reservoir in Bactrian camels, herder families with horses or camels potentially experience daily risks from zoonotic diseases. Our pilot study data demonstrated that zoonotic disease transmission could occur through a number of ways, such as directly from contact with livestock or manure or from contaminated food, milk, or water. Sixty-four percent of herder households reported using dried manure for fuel. Unprocessed river water was often the primary source (52.7%) of drinking water, which is potentially contaminated with manure-borne pathogens. Fuel and water sources varied by herder household location. A unifying finding was the ubiquity of cellphones in all surveyed herder households, providing a potentially efficient method for public health communication.

Knowledge and practices surrounding zoonotic disease among Mongolian herding households

“…Collection and drying of animal manure for household fuel is common for rural Mongolian herding families (Swiss Agency for Development and Cooperation 2015; Sack et al 2018; Ahearn 2018b). Animal waste is a known vehicle for multiple zoonotic pathogens, and the extreme Mongolian winter weather makes it hard to achieve the sustained temperature periods necessary to inactivate pathogens for safe handling (Zambrano et al 2014;Sack et al 2018). For example, the average temperature from November to February in the winter of 2009-2010 was − 22.05°C (− 7.69°F) (Rao et al 2015).…”

“…Other hygiene-associated concerns for zoonotic disease exposures among nomadic and pastoral communities involve cultural food preparation techniques and dietary items (Tsend et al 2014;Barnes et al 2017). For example, in Mongolia, milk and milk products are produced and consumed daily within herding households such as milk tea, fermented mare's milk (airag), and dried milk curd (aaruul) (Foggin et al 1997;Foggin et al 2000;Bamana 2015;Sack et al 2018). The milking of lactating animals is largely done in the spring/summer, corresponding to the birthing season (Addison and Brown 2014).…”

“…For example, messages related to Brucella prevention could be best focused on female herding household members responsible for milking livestock while education on safe slaughter and butchering techniques to prevent echinococcosis may be aimed at male members. In herding households, all members experience contact with livestock, companion animals, and even wildlife, which can lead to zoonotic and reverse zoonotic disease transmission (Ebright et al 2003;Odontsetseg et al 2005;Barnes et al 2017;Sack et al 2018). Harsh climates, resource scarcity, and herd competition can also promote malnutrition and lowered immune competence among animals, exposing them to infection, outbreaks, and high mortality rates (Batsukh et al 2012;Ahearn 2018a).…”

“…In fact, historical records suggest that the early domestication of wild animals and the subsequent spread of livestock first began in this country more than 10,000 years ago (Badarch and Zilinskas 2015;Zinsstag et al 2016a). Agriculture, in particular herding, drives the Mongolian economy and provides the biggest employment sector for the working population (Odontsetseg et al 2007;Altangerel et al 2011;Ruhlmann 2018;Sack et al 2018; National Statistical Office of Mongolia 2019). Approximately 26% of the country's residents are herders (Boldbaatar et al 2017).…”

“…Intensive herding practices over the last several decades coupled with climate change drivers has led to desertification, land degradation, and an increase in natural disasters such as drought, windstorms, heavy snowfall as well as extreme temperature fluctuations (Batzukh et al 2012;Bedunah and Schmidt 2004;Reid et al 2014). The increasing necessity of moving livestock to better grazing pastures and water sources throughout the seasons and across larger areas means that herding households of Mongolia are often located far from city centres and other development infrastructure such as running water, municipal power grids, sewage systems, supermarkets, schools, veterinarians and health care facilities (Bold 1996;Benwell 2006;Mocellin and Foggin 2008;Schelling et al 2016;Sack et al 2018). The hardships faced by herders has led to a slow and steady rural-to-urban migration of youth in search of more opportunities in education, training, and employment (Batzukh et al 2012).…”