Table 3.
Risk factors associated with the presence of zoonotic enteric pathogens in different endpoints (livestock, environment, human at all age range, and children under-five) through the animal contact pathway in smallholders in low- and middle- income countries (LMIC).
| Pathway | Risk factors | Endpoints (pathogen reservoir)&* | References |
|---|---|---|---|
| Animal contact | Random access to farm by visitors | Environment: Contamination of Salmonella spp. (A/Z) on farm's pen floors | (202) |
| Living in close proximity to livestock | Environment: fecal contamination in household, indicated by E. coli (A/Z); contamination of Salmonella spp. (A/Z) on farm | (202, 219) | |
| CU5: Giardia lamblia infection (A/Z) | (170) | ||
| Livestock ownership | Human: Enteric protozoa (A/Z) infection; Cryptosporidium spp. infection (A/Z) | (203, 206, 207) | |
| CU5: Campylobacter spp. infection (Z) | (200) | ||
| Increasing livestock density/quantity | Environment: visual presence of livestock feces in household | (220) | |
| inside household/at farm | Human: Intestinal parasite infection (A/Z) | (210) | |
| Presence of (pathogen-positive) livestock feces in/around households | CU5: Campylobacter spp. infection (Z) | (200) | |
| Direct contact with (diarrheal) livestock | Human: (symptomatic) Cryptosporidium spp. infection (A/Z); symptomatic Campylobacter spp. infection (Z) | (204, 221, 222) | |
| Home/informal slaughtering of livestock | Human: Campylobacter jejuni infection (Z), Intestinal parasite infection (A/Z) | (211, 223) | |
| Cohabiting with/Keeping livestock | Environment: presence of livestock feces in household | (220) | |
| inside household | Human: intestinal parasite infection (A/Z) | (209) | |
| CU5: (symptomatic) Cryptosporidium spp. infection (A/Z); (symptomatic) Campylobacter spp. infection (Z); infection of zoonotic enteric pathogens (Z) | (200, 205, 212, 213) | ||
| Presence of pet feces in/around household | Human: symptomatic Cryptosporidium spp. infection (A/Z) | (221) | |
| Presence of rodent | Livestock: presence of non-typhoidal Salmonella (Z) | (224) | |
| Presence of scavengers | Human: Cryptosporidium spp. infection (A/Z) | (225) |
Endpoints related to zoonotic enteric pathogen infection driven by the risk factors are characterized at the following levels: (1) Livestock: presence of zoonotic enteric pathogens in livestock; (2) Environment: presence of zoonotic enteric pathogens in the environment in/around a household (e.g., soil, water, food, fomites); (3) Human: (a)symptomatic zoonotic enteric pathogen infection in humans of all ages; (4) CU5 (children under five): (a)symptomatic zoonotic enteric pathogen infection in CU5.
A, anthroponotic; Z, zoonotic; A/Z, anthroponotic/zoonotic.