In her early years of research, Dr. Jane would allow the chimpanzees to touch her. Although she never regretted this, she later decided to implement a no-contact rule as more research students came to Gombe and as she learned more about chimpanzeesí susceptibility to disease. In 1966, an outbreak of polio, traced back to a nearby village, struck the Gombe chimpanzee community. Twelve of the chimpanzees were either killed or crippled by the disease, but the rest of the community was unaffected. In addition to polio, chimpanzees are able to contract many of the same diseases as humans including tuberculosis, hepatitis, Ebola, and even the flu and common cold. One exception to this similarity is that chimpanzees have shown a resistance to AIDS.