VIABILITY OF THE SPOROCYSTS OF SARCOCYSTIS-CRUZI AFTER EXPOSURE TO DIFFERENT TEMPERATURES AND RELATIVE HUMIDITIES

The effect of temperature and relative humidity (RH) on the survival o f sporocysts of S. cruzi were investigated in vitro. Under all experim ental conditions (temperature of 4 degrees C, 37 degrees C, or room te mperature; RH of 18%, 75%, or 100%) some sporozoites retained their vi ability to excyst for at least 90 days, The best conditions for surviv al were 4 degrees C at 100% RH (more than 240 days) and 37 degrees C a t 18% RH (more than 180 days), Sporocysts maintained at room temperatu re at all humidities had the lowest level of survival, It is concluded that sporocysts of S. cruzi are able to survive in most environments for several months and that the fluctuation of the daily ambient tempe rature is likely to influence the viability of the sporocysts.