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Appendix F
Raw Milk An Editorial
RAW MILK: A CONTINUING VEHICL~FOR THE TRANSMISSION
OF INFECTIOUS DISEASE AGENTS IN THE UNITED STATES*
To many infectious disease workers it appears incredible that in this
day and age there should be a controversy over whether raw milk can
serve as a vehicle of transmission for Salmonella and other human path-
ogens. However, the controversy is a very real one and has been present,
albeit with different degrees of intensity, in various parts of the United
States since the turn of the century.
Human milk is the most valuable single food for infants, and in its
absence cow's milk is a good substitute. However, the shockingly poor
level of sanitation in many commercial dairies during the latter part of
the 19th century resulted in devastating outbreaks of infectious diseases;
many infants and children died because of contaminated milk. An im-
portant initial response to these deplorable conditions in commercial dairies
was the formulation, in 1893, of Medical Milk Commissions which es-
tablished sanitary criteria for the maintenance of dairy herds and for the
collection and handling of market milk. These criteria included standards
for raw milk which was "certified" by the Commissions; such raw milk
exists today under the copyrighted trademark "Certified Milk."
The work of the Medical Milk Commissions was a positive step in
*
This editorial is reprinted with permission from the Journal of Infectious Diseases 146(3):440-
441, 1982. Published by The University of Chicago Press. Copyright ~ 1982 by The University
of Chicago.
395
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396
APPENDIX F
reducing contamination of commercial raw milk, but it was recognized
by medical authorities that milk certification could not eliminate contam-
ination. The underside of a cow is often caked with mud and manure so
that, even if it is washed and wiped with several towels, the udders can
hardly be considered clean enough (much less sterile) to collect milk for
direct human consumption.
Pasteurization provided a means to prevent milk from transmitting in-
fectious disease agents. In 1893, Nathan Straus, a layman who personally
led the fight to have all milk in the United States pasteurized, established
the first facility for the pasteurization of milk for infant feeding in New
York City.2 A battle between advocates of raw milk and pasteurized milk
has raged since then.
Infectious disease epidemiologists have amply documented the health
risks of raw milk (including certified raw milk); the raw milk industry
has stressed the benefits of raw milk and minimized or denied any infec-
tious disease hazards. Raw milk advocates perceive health benefits from
the alleged "essential" enzymes, vitamins, and other undefined beneficial
substances which they claim are destroyed by pasteurization. They also
claim that pasteurization of the proteins in milk, together with homoge-
nization, promote atherosclerosis. What has evolved is a virtual cult of
advocacy for raw milk in which some believers absolutely deny any pos-
sible transmission of infectious disease agents by this so-called life-giving
fluid. Other raw milk advocates concede possible "minuscule" contam-
ination of raw milk on occasions with enteric pathogens such as Salmonella
but cite older medical papers which state that huge doses of Salmonella
(~106 organisms) are necessary to cause human disease. Those who place
such confidence in the safety of milk contaminated with Salmonella ignore
the potential logarithmic growth of these bacteria in milk: an initially low
level of contamination may, under suitable conditions, become very high
in a few hours. Such misplaced confidence also ignores recent findings
that contamination as low as one Salmonella organism/lOOg of food has
resulted in human infection and diseased
The raw milk industry believes that the abundant laboratory and epi-
demiologic data which associate raw milk with disease are, at best, con-
trived. Its concept of a milkborne outbreak is one in which virtually 100%
of exposed persons develop severe illness. Raw milk advocates find in-
comprehensible those factors known to govern the transmission of infec-
tion by contaminated raw milk as well as those variables which significantly
reduce the number of disease cases which come to public health recog-
nition. These factors can be placed in several major groups.
Initially, there are varying levels of infection at the source. Cows suffer
from enteric and mammary infections, and contamination of milk is a
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APPENDIX F
397
possibility at all times. After milking, variations in holding conditions and
holding temperatures up to the time of consumption can lead to rapid
growth of organisms. Equally important in determining whether disease
may occur is the response of persons who consume contaminated raw
milk. There are differences in the number of organisms ingested; host
defenses, such as gastric acidity; transit time; and immune status. Finally,
signs and symptoms of disease may vary widely as do patients in seeking
medical care of physicians in determining medical diagnoses. Laboratory
tests may or may not have been obtained for a given patient, and labo-
ratories differ in their isolation and identification of pathogens. Ultimately,
great variation exists in reporting and investigation of disease. Public
health epidemiologists are convinced that many thousands of enteric in-
fections due to raw milk contaminated with Salmonella, Campylobacter,
and other enteric pathogens occur annually in the United States, but few
of these infections are recognized or associated with raw milk.
The consistency of the findings of the Centers for Disease Control
reported in this issue of the Journal4 with previously published results in
Californias will likely be viewed by the unbelieving raw milk industry as
further evidence of what is alleged to be a conspiracy among public health
agencies to deny raw milk to those who want and need the "elixir of life"
the industry sells. The report by Taylor et al.4 does not present any new
or startling findings and may be considered to be essentially preaching to
the already converted. Infectious disease professionals consider the sci-
entific case against raw milk to be irrefutable. Several national health
organizations including the American Academy of Pediatrics, the Con-
ference of State and Territorial Epidemiologists, the American Veterinary
Medical Association, the U.S. Animal Health Association, and the Na-
tional Association of State Public Health Veterinarians have adopted policy
statements which recommend that milk and milk products for human
consumption be pasteurized. In some 20 states where the sale of raw milk
is legal, the American Veterinary Medical Association has recommended
that raw milk carry a warning label: "Not pasteurized and may contain
organisms that cause human disease." Even with such a label, any batch
of raw milk confirmed to be contaminated with Salmonella or other human
pathogens must be promptly removed from commercial distribution and
home refrigerators. To do any less would be to condone continuation of
human exposure to known pathogens.
The raw milk industry has lost its suit in the scientific and medical
courts, so it has now carried its case to the political and legal arenas,
where it is a formidable opponent in what amounts to a court of last
resort.6 In these forums, the industry and its advocates cannot be lightly
dismissed, especially in the current climate of heightened concern for
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APPENDIX F
personal liberties, freedom of choice, and frequent rejection of science.
Infectious disease workers cannot rest on the accumulated scientific evi-
dence alone since in the words of a modern epidemiologic sage "public
policy is established by the public, not by scientists."7 It is the respon-
sibility of all health professionals to see that the public-and the policy
makers are adequately informed about the scientific findings so that
public policy on raw milk may be compatible with scientific knowledge
and protective of the public's health.
James Chin
Infectious Disease Section
California Department of Health Services
Berkeley, California
REFERENCES
1. Methods and standards for the production of certified milk. American Association of
Medical Milk Commissions. Alpharetta, Georgia, 1976, 46 pp.
2. Straus, L. G. Disease in milk: the remedy pasteurization. The life work of Nathan Straus,
2nd ed. (Reprint ed. Arno Press, New York, 1977). E. P. Dutton, New York, 1917, 383 pp.
3. Fontaine, R. E. Cohen, M. L., Martin, W. T., Vernon, T. M. Epidemic salmonellosis
from cheddar cheese: surveillance and prevention. Am. J. Epidemiol. 111 :247-253, 1980.
4. Taylor, D. N., Bled, J. M., Munro, J. S. Feldman, R. A. Salmonella dublin infections
in the United States, 1979-1980. J. Infect. Dis. 146:322-327, 1982.
5. Werner, S. B., Humphrey, G. L., Kamei, I. Association between raw milk and human
Salmonella dublin infector. Br. Med. J. 2:238-241, 1979.
6. Currier, R. W. Raw milk and human gastrointestinal disease: problems resulting from
legalized sale of "certified raw milk." Journal of Public Health Policy 2:226-234, 1981.
7. Stallones, R. A. Epidemiology and public policy: pro- and anti-biotic. Am. J. Epidemiol.
115:485-491, 1982.
Representative terms from entire chapter:
infectious disease
