The Avella district is in the throes of a typhoid fever epidemic with more than 30 cases reported today. The source of the disease has not been ascertained. It was indicated that schools may be suspended. One death has so far resulted. The epidemic has also spread to West Middletown, four being stricken there. The waster supply for the district is tested regularly and has been pronounced pure. One report is that the germs of the disease have been discovered in one of the principal sources of milk supply. State authorities have been investigating but have made no definite statement as to the cause. Residents are taking every possible precaution to prevent a further spread, by boiling both water and milk.