James H. Steele

The human health implication of the use of antimicrobial agents in animal feeds.

Antimicrobials given in subtherapeutic levels in feed are credited with having contributed to lower cost of meat, milk and eggs. The practice often is associated with the acquisition of resistant enteric flora by the involved animals, and this may in turn contribute to the human reservoir of antimicrobial resistant coliforms and salmonellae. Associated farm workers may transiently acquire resistant flora and on rare occasions develop salmonellosis. Although irrefutable evidence of growth promotant properties of antibiotics in animal feed was provided 30 to 40 years ago, additional studies on mechanisms of the effect are presently needed. It may be possible to identify factors effective in promoting growth without deleterious effects on flora. A national surveillance programme of antimicrobial utilisation (both subtherapeutic and therapeutic) among food producing animals should be established. Molecular epidemiologic research efforts will need to be undertaken to establish whether genetic information of animal origin importantly contributes to the human environmental pool of antimicrobial resistance. In the meantime, it does not appear that the use of drugs as feed additives, while allowing their unrestricted use for therapy in both animals and persons, would favorably influence the problems of antimicrobial resistance of salmonellosis in human populations.

Veterinary public health: Past success, new opportunities

Abstract Animal diseases are known to be the origin of many human diseases, and there are many examples from ancient civilizations of plagues that arose from animals, domesticated and wild. Records of attempts to control zoonoses are almost as old. The early focus on food-borne illness evolved into veterinary medicines support of public health efforts. Key historical events, disease outbreaks, and individuals responsible for their control are reviewed and serve as a foundation for understanding the current and future efforts in veterinary public health. Animal medicine and veterinary public health have been intertwined since humans first began ministrations to their families and animals. In the United States, the veterinary medical profession has effectively eliminated those major problems of animal health that had serious public health ramifications. These lessons and experiences can serve as a model for other countries. Our past must also be a reminder that the battle for human and animal health is ongoing. New agents emerge to threaten human and animal populations. With knowledge of the past, coupled with new technologies and techniques, we must be vigilant and carry on.

Food irradiation : A public health challenge for the 21st century

Although the United States food supply is generally considered one of the safest in the world, foodborne illnesses remain a concern. Each year, millions of Americans become ill and as many as 5000 die from foodborne infections. The United States Department of Agriculture estimates that medical treatment and productivity losses associated with foodborne illnesses cost as much as

Age and sex differences in new and recurrent cases of guinea worm disease in Nigeria

37 billion annually. Irradiation, which involves exposing food briefly to radiant energy, can reduce or eliminate microorganisms that contaminate food or cause spoilage. So far, only limited quantities of irradiated foods--spices, herbs, dry vegetable seasonings, and some fresh fruits, vegetables, and poultry--have been available in the United States. Major purchasers are health care and food service establishments. The World Health Organization reviewed 500 studies and concluded that food irradiation poses no toxicological, microbiological, or nutritional problems. In more than 40 years, there have been no accidents in North America involving transport of the types of radioactive isotopes used for irradiation.

Food irradiation: A public health opportunity

In this population-based cross-sectional survey of the prevalence and incidence of guinea worm disease in Idere, a rural agricultural community of Oyo state in Nigeria, epidemiological data were collected by household interview of all 501 households (6527 persons, 3594 females and 2933 males). 86% of the households had at least one case. The prevalence was 32.4% in the overall population, but varied markedly by age and sex. About 10% of prevalent cases were first-time infections or new cases. Males over 19 years of age had a higher prevalence rate than adult females; however, females had a higher prevalence rate at younger ages. The prevalence in females peaked (47%) at 35 to 44 years; for males the proportion was highest (57%) at ages 45 to 54 years.

The Epidemiology of Zoonoses in the Philippines

Public health scientists have had an interest in food irradiation for a hundred years and more. The first investigations occurred within a few years of the discovery of x-ray and short wavelength by the German physicist Roentgen, in 1895. German and French scientists carried on studies on pasteurization of food by radiation until 1914 and the war years. The problem was an unacceptable taste following irradiation. In 1921, the x-ray was reported by the scientists of the United States Department of Agriculture (USDA) to be effective in killing Trichinella cysts in pork and that it could kill disease-causing organisms and halt food spoilage.

Use of antimicrobial agents in animal feeds: implications for human health.

The zoonoses are major infectious diseases so tooth man and lower animals in the Philippines, Of at least 181 diseases known to be zoonotic, 63% have been reported in the Philippines. In this article, the epidemiology and approaches toward control of 73 of these diseases are discussed. Epidemiologicaliy, the zoonoses may be classified on the characteristics of the etiological agents, human hosts, lower animal hosts, and vectors interacting in the environment to maintain the occurrence of these diseases. Prevention and control of the zoonoses must he made an their epidemiological cycles. Plague is the only zoonotic disease that has been eradicated from the Philippines; trichinosis has never been established; the eradication of rabies, Newcastle disease, brucellosis, and taeniasis is presently both feasible and necessary.