With the aid of the culture technique they were able to trace the routes, along which infection is transmitted, to detect carriers and other sources of infection thereby making a rational combat of epidemics feasible. They could produce therapeutic sera and prophylactic vaccines. Finally, the culture technique was instrumental in the discoveries of the modern wonder drugs, sulfa, penicillin, streptomycin, etc. The 75 year old fight against the bacterial diseases has been successful. Although not completely eradicated, plague, cholera, typhoid, diphteria, and sepsis have ceased to be a threat to mankind.
Tuberculosis seems to be under control.
The trends are clearly reflected in the vital statistics. Turning to the virus diseases we meet an entirely different picture. It is true that smallpox is brought under control thanks to the efficient vaccine that Nature itself has provided. Yellow fever was checked by means of mosquito control and with the aid of Theiler 's vaccine, an achievement awarded the 1951 Nobel Prize . In all the others, however, our art fails us.