Cryptosporidiosis in animals and man: 3. prevention and control

Abstract

The control of cryptosporidiosis relies mainly on hygienic measures and good management. Preventive hygienic measures are by far the most effective approach to control this parasite in animals, the objective being to destroy the external forms of the parasite (infective mature oocysts) and to prevent their transmission among animals. The destruction of oocysts on surfaces of housing facilities, pens and parturition buildings is possible using effective disinfectants such as 50% ammonia, 3% hydrogen peroxide or 10% formalin. Measures to reduce transmission between animals should be encouraged. Limiting the number of animals enclosed in the same facilities and avoidance of high stocking rates in the parturition area, maintaining a short calving period, administration of appropriated supplies of colostrum especially hyper immune colostrum from immunized dams, isolation and treatment of diarrheic infected animals; all help to prevent outbreaks of cryptosporidiosis, reduce the spread of infection within a herd and minimize mortality and morbidity in infected herds. Chemotherapeutic agents such as paromomycin, decoquinate, lasalocid, halofuginone lactate, nitazoxanide, dinitrooryzalin, β-cyclodextrin and probioties have proved a potential therapeutic effect against cryptosporidiosis in the form of reduction the duration and numbers of oocysts shedding and the incidence and severity of the diarrhea. Immunization of ruminants during pregnancy with either recombinant C. parvum sporozoites surface antigens or plasmid DNA encoding the CP15 or CP23 antigens appear to be a valuable approach for producing colostrum for the passive immunotherapy of cryptosporidiosis. Hyper immune colostrum prevented diarrhea and reduced oocysts shedding in newly born calves, lambs and goat kids exposed to Cryptosporidium infections.