CAFPA SPRING MEETING ON UNPASTEURIZED MILK
On March 31, 2011, the Capital Area Food Protection Association (CAFPA) held its spring meeting at the Grocery Manufacturers Association in Washington, DC. The meeting focused on the safety of unpasteurized milk.
Dr. Isabel Walls, National Program Leader, Epidemiology of Food Safety at USDA-NIFA gave a quick presentation about the International Association for Food Protection (IAFP), its objectives and benefits of membership. Dr. Walls is the President-Elect of IAFP. To open our discussion, Walls provided background on foodborne disease, its continued importance and related economic issues. Current surveillance data is not adequate to determine the true global burden of foodborne illness. Estimates of annual foodborne illness cases in the US are over 48 million cases, with approximately 3,000 deaths. Norovirus causes the largest number of cases and Salmonella spp. cause the most deaths. PulseNet is increasing the identification of multi-state outbreaks that may have not been linked before or deemed sporadic. Pathogens associated with dairy include Salmonella, Campylobacter, Listeria monocytogenes, and Escherichia coli O157:H7. Several cases of foodborne illness have been linked to unpasteurized dairy products. Foodborne disease has economic implications, not only due to associated health care costs at the time of initial illness, but continued costs related to chronic illnesses that develop after infection. Other economic impacts include loss of paid work time, regional travel bans, and industry impacts on specific commodities after outbreaks.
Dr. Jo Ann Van Kessel of USDA-ARS presented slides on “Zoonotic Bacteria and Dairy Farming.” The main concerns of USDA-ARS related to dairy farms are worker safety, post-pasteurization contamination, the raw milk trend, petting zoo associated illnesses, and dairy cattle entering the meat supply. In the US there are over 90,000 dairy farms, 9 million cows, and 192 pounds of milk produced annually. Sources of bacteria in raw milk include feces (number one source), teat colonization or mastitis infection, bedding, and cross contamination from the milking staff and auto-milkers. Dr. Van Kessel summarized a 2002 bulk raw milk tank survey which included 861 samples in 21 states, which represented 86% of dairy herds in the US. Raw milk samples were tested for Salmonella, L. monocytogenes, and E. coli O157. Results included: Salmonella were 11.8% PCR positive and 2.6% culture positive, 10.4% were positive for Listeria spp. And 6.5% were positive for L. monocytogenes. Generic E. coli was found in 92% of raw milk samples with only 1 single sample being presumptive positive for E. coli 0157. A similar US survey in 2007 tested raw milk and filters used in the holding system. Results are summarized in the table below:
| Microorganism (method) | Raw milk (%) | Filters (%) |
| Salmonella spp. (culture) | 6.7 | 19.9 |
| Salmonella spp. (PCR) | 15.2 | 34.4 |
| L. monocytogenes | 4.3 | 6.3 |
Dr. Van Kessel discussed USDA’s involvement in a long term Regional Dairy Quality Management Alliance study. Three farms representative of three states are being evaluated during the study. There is a great variation between the farms in milking techniques, feeding practices, and manure control. The study entails intense sampling of individual cows over time, raw milk, milking equipment, etc. This study is ongoing, but some interesting observations have been made. For example, on one of the farms, high numbers of Salmonella spp. were recovered from cows that never displayed any symptoms of illnesses. On a different farm, a much lower incidence of Salmonella spp. was found than the referenced farm, yet these cows were sporadically ill. The presence or absence of pathogens can’t be predicted by animal health.
Dr. Beth Briczinski of the National Milk Producers Federation (NMPF) gave an industry perspective on raw milk comsumption. NMPF has over 30 members that represent 40,000 dairy farmers accounting for two thirds of the nation’s milk supply. FDA data attributes the following to consumption of raw milk and raw cheese products; 133 outbreaks, 2659 illnesses, 269 hospitalizations, 3 deaths, 6 still births, and 2 miscarriages. Approximately 70% of all dairy related outbreaks can be attributed to raw milk products including cheese. CDC data from between 1993-2006 was presented, see the table below:
| Associated | Raw Dairy Products | Pasteurized Dairy Products |
| Outbreaks | 73 | 48 |
| Illnesses | 1571 | 1223 |
| Hospitalizations | 202 | 30 |
| Deathes | 2 | 1 |
The significance of these numbers associated with raw dairy products is that only 1-3% of the US population is estimated to consume raw dairy products, yet the numbers are higher than those for pasteurized products. Dr. Briczinski dispelled several raw milk myths. One myth discussed was the belief that raw milk prevents, alleviates or cures any specific health ailment. Another myth is the belief that existing pathogens in raw milk would be eliminated by natural antimicrobials that are otherwise destroyed by pasteurization. The levels of natural antimicrobials present in raw milk (lactoferrin, lysozyme, etc.) are too low to have a adequately destructive or even significant effect on pathogens that may be present and many antimicrobials are only minimally affected by pasteurization. Raw milk advocates also site probiotics in raw milk deliver health benefits, but in reality significant numbers are not present in milk. NMPF’s opposes the direct consumption of raw milk even though the likelihood of illness is low, the consequences could be severe. Outbreaks and illness associated with raw dairy products also negatively impact the entire dairy industry.
Following the presentations, a panel discussion was moderated by George Wilson. It was also announced during the meeting that CAFPA launched a new website, www.cafpa.com.
For further information on CAFPA, contact Emily Mathusa at cafpadc@gmail.com.