The Emergence of New Diseases

At the time, his optimism seemed justi? fied. Smallpox had nearly been eradicatr ed; tuberculosis and polio were on the decline and, with the exception of malar? ia, so were all of the other major infec? tious health threats of the 20th century. Scientists believed that, thanks to im? proved hygiene and sanitation, immu? nizations and antibiotics, all remaining infections of human beings and domes? tic animals would soon be eradicated.