[The seasonality of scabies morbidity and the fertility of the itch mite Sarcoptes scabiei de Geer as an index of the activity of a population of the causative agent].

The authors analyze the features of the epidemic process in scabies and review foreign and Soviet literature on the seasonal pattern of this condition. They have introduced the mite fertility index, that is determined by the number of eggs in the mite burrow, counted with the use of a new laboratory diagnostic technique with lactic acid. The studies have revealed that this index is high in September-December (11.5 +/- 1.0 - 12.6 +/- 1.3) and much lower in January-July (8.9 +/- 1.1 - 6.0 +/- 0.6). Another finding was that some females were in a latent state from December to July, when oogenesis was arrested and therefore the agent population activity dropped. The results have demonstrated regular seasonal changes in S. scabiei reproductivity, coinciding with the disease phenology; besides social and communal factors, these regularities also contribute to the epidemiology of scabies.