The question of whether humans can contract parasitic worms from goats is complex because most parasites carried by ruminants are host-specific, meaning they do not successfully infect people. However, a potential for zoonotic transfer exists, particularly concerning certain intestinal parasites that are less species-specific. This risk involves microscopic organisms often grouped with “worms” by the general public, but it also includes some true helminths. Understanding the specific organisms and transmission pathways is important for minimizing health risks when working with goats.
Identifying Zoonotic Parasites
The organisms posing the most frequent risk of transfer from goats to humans are single-celled protozoa, not true worms. Cryptosporidium and Giardia are the two most common intestinal parasites in goats that can infect humans. The Cryptosporidium parvum genotype has a high potential for zoonotic transmission from livestock, including goats. These protozoa form environmentally robust cysts or oocysts that are shed in the feces of infected animals.
While protozoa are the primary concern, some true helminths, or worms, also have zoonotic potential. The eggs of Strongylid-type nematodes, a broad group of roundworms, are frequently found in goats, and some species can complete their lifecycle in humans. Fasciola species (liver flukes) are another helminth found in goats whose eggs can be passed to humans, causing fascioliasis. Additionally, some species within the Trichostrongylus genus are known to be zoonotic.
Understanding Transmission Pathways
Humans contract these parasites primarily through the fecal-oral route, which involves ingesting the infectious stages of the organism. Goats, even those appearing healthy, may shed millions of resilient parasite oocysts or cysts in their feces. These microscopic stages contaminate the local environment, including soil, feed, and water sources.
Contact with a contaminated environment is a significant pathway for human infection. Transfer occurs by touching surfaces, equipment, or clothing soiled with goat manure and then touching the mouth. Water contamination is another serious concern, as runoff can carry oocysts into drinking water supplies, leading to widespread infection. Close handling of young or sick animals, such as kids, is particularly risky because young ruminants often shed high numbers of parasites.
The consumption of contaminated food or products also presents a transmission risk. Unpasteurized goat milk can carry zoonotic bacteria like Campylobacter and Salmonella. The risk associated with parasites is often linked to contamination of food crops by manure or inadequate hygiene during the handling and processing of meat or dairy products.
Essential Safety and Prevention Practices
Implementing rigorous hygiene protocols is the most effective strategy for blocking the transfer of parasites from goats to humans. Strict hand hygiene is paramount, requiring thorough washing with soap and water after any contact with goats, their feed, or their living environment. This should be performed even after using gloves, as infectious stages can readily contaminate skin surfaces.
Proper management of the goat environment is also necessary to reduce the infectious load. Manure and soiled bedding should be promptly and safely disposed of, ideally composted away from human living areas and water sources. Regularly cleaning and disinfecting equipment and housing areas helps to minimize the concentration of environmental contaminants.
Biosecurity measures should be observed, especially concerning vulnerable populations who may experience more severe illness. Young children, pregnant women, and individuals with compromised immune systems should limit or avoid contact with goats, particularly those with diarrhea. People should also refrain from eating, drinking, or placing objects in their mouths while in areas where goats are housed or handled.
Reducing the risk through dietary choices involves avoiding unpasteurized goat milk and dairy products. Ensuring that all meat is cooked thoroughly and that produce grown in areas potentially exposed to livestock runoff is washed properly will reduce the likelihood of ingesting parasitic cysts or eggs.