Food-safety hazards in pork chain

 

RECENT RESEARCH PAPER HIGHLIGHTS HEALTH IMPLICATIONS 

A recent research paper on laboratory testing of pigs and pork in Nagaland for a range of infectious and non-infectious hazards to consumers has revealed substantial microbial contamination (accidental introduction of infectious material like bacteria or virus) as well as antibiotic residues (potential threat to direct toxicity in human). The study has also identified several important pathogens for the first time in the state. 

The descriptive pilot study published last month (December 24, 2013) in International Journal of Environmental Research and Public Health (IJERPH) has also claimed it is the first risk-based assessment of food safety in Nagaland.

The paper was co-authored by nine experts and researchers - Anna Sophie Fahrion of Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Switzerland; Lanu Jamir and Simon Ao of Department of Veterinary and Animal Health, Nagaland; Kenivole Richa, Varijaksha P. Padmakumar, Ram Pratim Deka and Delia Grace of International Livestock Research Institute, Kenya; Sonuwara Begum of National Research Institute on Mithun, Jharnapani, Nagaland and Vilatuo Rutsa of NEPED, Kohima.

The study was carried out in November 2009 in Kohima district and the samples were taken at two important control points of the pork chain:

(a) Slaughterhouses from where faecal, blood samples were collected and lingual palpation performed on the fresh slaughtered pigs. 

(b) Butchers: 25 pork stalls were chosen by simple random sampling. Blood samples were taken from the vena cava during slaughtering process. 

Adopting a risk analysis framework, the study discussed some of the identified hazards and their proxies to characterize risks for pork borne disease.

The study said that based on questionnaire survey, pork consumers indicated that boiling of meat was the common method of preparing meat. 98% of the respondents cooked pork between 30 and 190 minutes. This meant that pork was well cooked and Enterobacteriaceae eliminated. 

However, there are chances for cross contamination. 57% of consumers reported white, rice grain like cysts in the meat they purchased.

Of the pork samples tested for this study, 4.5% contained traces of antibiotic residues. Heat treatment cannot eliminate the residues and the consumer is not able to mitigate the risk, said the study.

The study considered Enterobacteriaceae to be indicative of important hazards because this family includes Salmonella spp., toxigenic E. coli and other bacteria, which are known hazards. The two hazards chosen (T. solium and antibiotic residues) also have adverse effects on human health. 

The most common health effects of Enterobacteriaceae are gastro-intestinal illness. This is often most serious in young, old, pregnant and immune-compromised people. 

The study found that “levels of contamination with Enterobacteriaceae were unacceptably high at all steps along the value chain.” 

The paper also claimed that Nagaland had the highest density of pigs in India and highest pork consumption levels. 

The study found low microbiological quality. Only 25% of the samples had a satisfactory low level of total aerobic bacteria indicating poor handling and poor hygiene. 

However, the study also documented a number of practices that reduce risk including long cooking duration and typical consumption of pork within 12 hours of slaughter.

This study was the first to report Listeria spp., B. suis and Fasciola spp. eggs from swine and pork sampled in Nagaland. Infection with Listeria monocytogenes, an important food safety hazard and only pathogen in the genus Listeria spp., can lead to severe disease such as neurologic symptoms, meningitis, abortion and stillbirth. Listeria spp. are ubiquitous in the environment and are psychrotroph bacteria, said the research paper. 

The study found that slaughter places were an important source of contamination with faeces, lack of adequate water and waste disposal and poor practices by slaughterhouse workers. 

The research paper recommended training of slaughterhouse workers and butchers using peer-to-peer methods, in combination with improving consumer practices. 

The study was undertaken by International Livestock Research Institute and financially supported by Ratan Tata & Navajbai Ratan Tata Trust.