Swine Health Impact on Carcass Contamination and Human Foodborne Risk

Abstract

This study showed a correlation between animal health and human health risk, as measured by carcass contamination. Therefore, animal management decisions on-farm, such as housing, antibiotic use, environment, and level of veterinary care, may directly impact public health.

Prevalence of Yersinia enterocolitica in Pigs Slaughtered in Chinese Abattoirs

“…Pigs (mainly their tonsils) are assumed to be the main reservoirs for pathogenic Y. enterocolitica because the pig is so far the only animal species from which pathogenic strains have frequently been isolated (16,19). In this study, Yersinia enterocolitica was isolated from 19.53% (878/ 4,495) of the tonsil samples, 7.51% (93/1,239) from intestinal contents, and 5.30% (161/3,039) from feces.…”

Assessing Potential Human Health Hazards and Benefits from Subtherapeutic Antibiotics in the United States: Tetracyclines as a Case Study

“…Potential human health benefits from continued use of tetracyclines and other antibiotics in food animals cannot easily be quantified. Although antibiotic‐free (ABF) and organic farms have been reported to have higher prevalence rates than conventional farms of bacteria such as Campylobacter in poultry (Luangtongkum et al , 2006) and Salmonella in pigs (Gebreyes, 2008) (but lower prevalence of Campylobacter in pigs, Hurd et al , 2008), it is not yet known to what extent, if any, these bacteria affect human health. Moreover, resistance rates for several antibiotics and bacteria are higher in bacteria isolated from conventional farms than in bacteria from ABF farms ( ibid ).…”

“…In Europe, growth promotion STA bans were initially estimated to have increased mortality rates in pig production, associated with scouring and proliferative enteritis, by 10%–15%, and these increases persisted for years (Hughes and Heritage, 2004; Cox and Ricci, 2008). If morbidity rates in pigs increased by a similar percentage due to withdrawal of tetracyclines and other STAs, then the initial results of Hurd et al (2008), showing a significant positive correlation between decreased animal health (indicated by subclinical lesions) and increased microbial loads of Campylobacter and Enterococcus on carcasses, might provide a causal mechanism by which reducing animal antibiotic use could account for some of the observed increases in campylobacteriosis (Lawley, 2007) and other zoonotic infections in Europe. To make this (or other) causal conjecture less speculative, it would be desirable to carry out more detailed time series analyses of changes in illness rates, microbial loads, and resistance fractions in isolates from animals, food, and people, as data become available.…”

“…On the one hand, conventional wisdom holds that healthy animals make for healthy people. STAs improve animal health and reduce microbial loads in meats, thereby presumably reducing the potential for food‐borne illnesses (Hurd et al , 2008; Arsenault et al , 2007; Singer et al , 2007). STAs can promote growth, particularly in poultry and hogs, by improving nutrient absorption and by depressing the growth of organisms that compete for nutrients, thereby increasing feed efficiency (MacDonald and McBride, 2009).…”

“…For example, it has been hypothesized that using tetracyclines in food animals might help to select for bacteria, such as MRSA, E. coli , or multidrug resistant (MDR) strains of Salmonella that also resist other antibiotics (e.g., Akwar et al , 2008) and this co‐selection might create risks larger than those from resistance to tetracyclines per se . Past risk analyses of animal‐use antibiotics have generally focused on ones with human‐use counterparts used to treat illness caused by food‐borne pathogens such as E. coli , Campylobacter , Salmonella , and Enterococci (FDA‐CVM, 2001; Cox and Popken, 2002, 2004; FDA‐CVM, 2004; Alban et al , 2008; Hurd et al , 2008; Cox et al , 2009). By contrast, tetracyclines, while heavily used in both animals and humans, are not typically used to treat food‐borne diseases.…”