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

250 BACTERIOSESA live streptomycin-dependent vaccine, administered orally in three or four doses,provided good protection against the clinical disease for 6 to 12 months. However,it is currently not in use due to side effects such as vomiting in a small number ofthose who have been given the vaccine. Another undesirable and more serious effectof this vaccine is the instability of the strain and reversion to its original virulence(WHO, 1991). Different types of vaccines have been developed, including hybridsof Shigella and E. coli, and of Shigella and Salmonella; vaccines obtained throughdeletions and mutations; and oral vaccines of dead shigellae. All these vaccines areawaiting evaluation (WHO, 1991).In two military camps in Israel, intensive measures (primarily bait and strategicallylocated traps) were taken in the early summer of 1988 to control flies for 11weeks. The test was repeated in the summer of 1989. The number of flies wasreduced by 64% and clinic visits for diarrhea caused by shigellosis fell by 42% inthe first year and 85% in the second. These results indicate that flies, acting asmechanical vectors, are an important factor in the transmission of shigellosis (Cohenet al., 1991).Indiscriminate use of antibiotics must be avoided in order to prevent the emergenceof multiresistant strains and to ensure that these medications remain availablefor use in severe cases.In animals, control consists of: (a) isolation and treatment of sick or carrier monkeys;(b) careful cleaning and sterilization of cages; (c) prevention of crowding incages; and (d) prompt disposal of wastes and control of insects.At the National Zoo in Washington, DC, carrier status for multiresistant S. flexneriwas eliminated through intramuscular administration of enrofloxacine (5 mg/kg ofbodyweight every 24 hours for 10 days). The large primates received the same medicineorally. In this way, it was possible to eradicate S. flexneri from a colony of 85primates, although after 10 to 12 months S. sonnei was isolated from the feces ofthree animals (Banish et al., 1993b).BibliographyBanish, L.D., R. Sims, D. Sack, et al. Prevalence of shigellosis and other enteric pathogensin a zoologic collection of primates. J Am Vet Med Assoc 203:126–132, 1993a.Banish, L.D., R. Sims, M. Bush, et al. Clearance of Shigella flexneri carriers in a zoologiccollection of primates. J Am Vet Med Assoc 203:133–136, 1993b.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.Bennett, J.V. Cited in: Wachsmuth, K., G.K. Morris. Shigella. In: Doyle, M.P. FoodborneBacterial Pathogens. New York: Marcel Dekker; 1989.Cohen, D., M. Green, M. Block, et al. Reduction of transmission of shigellosis by controlof houseflies (Musca domestica). Lancet 337:993–997, 1991.Edwards, P.R., W.H. Ewing. Identification of Enterobacteriaceae. 3rd ed. Minneapolis:Burgess; 1972.Fiennes, R. Zoonoses of Primates. Ithaca: Cornell University Press; 1967.Keusch, G.T., M.L. Bennish. Shigellosis. In: Evans, A.S., P.S. Brachman, eds. BacterialInfections of Humans. 2nd ed. New York: Plenum Medical Book Co.; 1991.Keusch, G.T., S.B. Formal. Shigellosis. In: Warren, K.S., A.A.F. Mahmoud, eds. Tropicaland Geographical Medicine. New Jersey: McGraw-Hill; 1984.