The invention relates to the use of at least one dialkyl thiosulfonate or thiosulfinate in order to reduce the number of apicomplexa, such as coccidioides and, in particular, Eimeria, in monogastric animals, such as poultry or pigs, or ruminants, such as cattle, sheep or goats. The invention relates to the use of at least one dialkyl thiosulfonate or thiosulfinate in order to reduce the number of apicomplexa, such as coccidioides and, in particular, Eimeria, in monogastric animals, such as poultry or pigs, or ruminants, such as cattle, sheep or goats. Bed bug infestations are combated by a disinfecting method comprising exposing the bed bugs to a disinfecting atmosphere which includes ozone and hydrogen peroxide, at a relative humidity of at least 30%. A portable system for destroying bed bugs, eggs and larvae in rooms and on surfaces is also disclosed. The system comprises an ozone generator, an ozone controller, a source of hydrogen peroxide, humidity adjusting means as well as an ozone remover adapted to destroy ozone down to a safe level in the room atmosphere.La invención es concerniente con el uso de por lo menos un tiosulfonato o tiosulfinato de dialquilo con el fin de reducir el número de apicomplejos, tales como coccidioides y en particular Eimera en animales monogástricos, tales como aves de corral o puercos o rumiantes tales como ganado, oveja o cabras.