ABSTRACT
We examined under laboratory conditions the thermopreference of the migratory locust, Locusta migratoria migratorioides, following infection by the entomopathogenic fungus Metarhizium anisopliae var. acridum and its influence on mycosis. Infected locusts raised their body temperature more frequently than healthy conspecifics through selection of high temperatures in a heat gradient. Thermoregulation did not, however, alter the frequency of feeding events nor the amount of food eaten by infected L. migratoria. A thermoregulation regime of a minimum of 4 h/day substantially increased survival of inoculated insects (by 85%). However, the therapeutic effect decreased when thermoregulation was delayed following inoculation of the pathogen. Thermoregulation reduced locust mortality but did not completely eliminate the fungus from infected hosts; the fungus grew and killed the insects when thermoregulation was interrupted. We suggest that periodic, short bouts of thermoregulation, when performed from the onset of infection and for an extended period of time, are sufficient to provide a therapeutic effect to infected hosts. Such thermoregulatory capacity of locusts may limit the potential of fungal pathogens as biological control agents under certain ecological conditions.
Subject(s)
Body Temperature Regulation , Grasshoppers/microbiology , Grasshoppers/physiology , Mycoses/veterinary , Adaptation, Physiological , Animals , Behavior, Animal , Insect Control , Periodicity , Survival AnalysisABSTRACT
The objective of this study is to collect preliminary epidemiologic data about nosocomial infections (NI) in the National Hospital of Ouagadougou. A prevalence survey of NI was realized in surgical wards (116 patients). All hospitalized patients were included, excepted those stayed less than 48 hours. Using the definitions of the "Conseil Supérieur d'Hygiène Publique de France", the nosocomial infections studied were surgical wards, pneumonia and urinary tract infection. The result showed that 19 patients (16.4%) had 26 nosocomial infections (prévalence: 22.4%). Six patients had at least 2 nosocomial infections. The infection rate increases with operation, debilated preoperative physical statute, and invasive care. The average increasing of duration of hospital stay for infected patients was 10 days. This data confirm the importance of nosocomial infections and emphasize the need of surveillance and control of nosocomial infections. But deeper epidemiological studies must be undertaken before.
