zoonoses and communicable diseases common to ... - PAHO/WHO

244 BACTERIOSESThe results of many tests conducted to date indicate that immunization with vaccinesand some bacterins can prevent the disease (particularly in its severe form), butnot the infection or carrier status.A control measure known as Nurmi’s method originated in Finland. Salmonellafreecultures of fecal organisms from the cecum of adult birds are administeredorally to newly hatched chickens and turkey chicks. The cecal flora (some 60species of bacteria) from the adult birds compete with the salmonellae and thus protectthe chicks against salmonellosis at their most susceptible age. Treated chicksresist high doses of salmonellae. It is believed to work by competitive exclusion.Various countries have had success combating pullorum disease (S. pullorum) andfowl typhoid (S. gallinarum), reducing the rate of infection to a minimum. Severalcountries have undertaken control programs for S. enteritidis in fowl. Control isimportant to reduce both public health risk and economic losses. In general terms,the first step is to ensure that establishments that provide eggs for incubation and 1-day-old chicks are free of infection. Each group of egg layers must be examinedserologically and bacteriologically to certify those that are disease-free and destroythose that are infected. After the surroundings and the installations are disinfected,they should be repopulated from a safe source. Once a reliable source of eggs andchicks is assured, clean-up of commercial farms should begin.Some countries limit the control program to S. enteritidis, others to all invasiveserotypes, including S. typhimurium and S. hadar. In Sweden, during the first yearof control (1991–1992), infection was found in 6% of the layer establishments. Thisfell to 2% in the second year. An organization of broiler breeders in Northern Irelandhad a successful program that eradicated infection by S. enteritidis in the establishmentsof their associates (McIlroy et al., 1989).BibliographyAger, E.A., F.H. Top, Sr. Salmonellosis. In:Top, F.H., Sr., P.F. Wehrle, eds. Communicableand Infectious Diseases. 7th ed. Saint Louis: Mosby; 1972.Aserkoff, B., S.A. Schroeder, P.S. Brachman. Salmonellosis in the United States—a fiveyearreview. Am J Epidemiol 92:13–24, 1970.Barker, R., D.C. Old, J.C. Sharp. Phage type/biotype groups of Salmonella typhimurium inScotland 1974–6: Variation during spread of epidemic clones. J Hyg 84:115–125, 1980.Bauerfeind, R., L.H. Wieler, R. Weiss, G. Baljer. [Comparative plasmid profile analysis ofSalmonella typhimurium var. Copenhagen strains from a Salmonella outbreak in hospitalizedhorses.] Berl Münch Tierärztl Wochenschr 105:38–42, 1992.Benenson, A.S., ed. Control of Communicable Diseases in Man. 15th ed. An official reportof the American Public Health Association. Washington, D.C.: American Public HealthAssociation; 1990.Binsztein, N., T. Eiguer, M. D’Empaire. [An epidemic of salmonellosis in Buenos Aires andits suburbs.] Medicina 42:161–167, 1982.Bryan, F.L. Current trends in food-borne salmonellosis in the United States and Canada. JFood Protect 44:394–402, 1981.Butterfield, J., J.C. Coulson, S.V. Kearsey, P. Monaghan, J.H. McCoy, G.E. Spain. The herringgull Larus argentatus as a carrier of Salmonella. J Hyg 91:429–436, 1983.Buxton, A., H.I. Field. Salmonellosis. In: Stableforth, A.W., I.A. Galloway, eds. InfectiousDiseases of Animals. London: Butterworth; 1959.