At the time of sustained European contact in the 16th centuries and 17th centuries, the Lenape were a powerful Native American nation who inhabited a region on the mid-Atlantic coast spanning the latitudes of southern Massachusetts to the southern extent of Delaware in what anthropologists call the Northeastern Woodlands. Although never politically unified, the confederation of the Delaware roughly encompassed the area around and between the Delaware and lower Hudson rivers, and included the western part of Long Island in present-day New York. Some of their place names, such as Manhattan ("the island of many hills"), Raritan, and Tappan were adopted by Dutch and English colonists to identify the Lenape people that lived there. Based on the historical record of the mid-17th century, it has been estimated that most Lenape polities consisted of several hundred people but it is conceivable that some had been considerably larger prior to close contact, given the wars between the Susquehannocks and the Iroquois, both of whom were armed by the Dutch fur traders, while the Lenape were at odds with the Dutch and so lost that particular arms race.  During the Beaver Wars in the first half of the 17th century, European colonists were careful to keep firearms from the coastally located Delaware, while rival Iroquoian peoples such as the Susquehannocks and Confederation of the Iroquois became comparatively well armed. Subsequently, the Lenape became subjugated and made tributary to first the Susquehannocks, then the Iroquois, even needing their rivals' (superiors') agreement to initiate treaties such as land sales. Like most tribes, Lenape communities were weakened by newly introduced diseases originating in Europe, mainly smallpox but also cholera, influenza and dysentery, and recurrent violent racial conflict with Europeans. Iroquoian peoples occasionally fought the Lenape. As the 18th century progressed, many surviving Lenape moved west--into the (relatively empty) upper Ohio River basin.  Smallpox devastated Native American communities even located far from European settlements by the 1640s. The Lenape and Susquehannocks fought a war in the middle of the 17th century that left the Delaware a tributary state even as the Susquehannocks had defeated the Province of Maryland between 1642-50s.

Answer this question "Did other diseases affect them?" by extracting the answer from the text above.
mainly smallpox but also cholera, influenza and dysentery,