EN
The author summarizes the results hitherto obtained by Bulgarian authors due to investigations on diseases with foci in free nature, according to Z. N. Pavlovsky's theory. The following diseases were taken into consideration: Q fever, Marseilles faver, ornithosis, hemorrhagic fever, encephalitis and meningitis, choriomeningitis lymphocytica, leptospirosis, brucellosis, tularemia, toxoplasmosis and leishmaniasis.