Laboratory Services at the National Communicable Disease Center 
The laboratories of the National Communicable Disease Center (NCDC) serve as a national reference or 
consultative facility and accept specimens from only the State public health laboratories and Public Health 
Service facilities. Specimens which cannot be examined locally should be sent to the State laboratory where 
they may be processed or, if the requested service is not available at the State level, the State laboratory 
director may then forward either the original specimen or the pure culture to the NCDC. Certain services 
available at NCDC are of value in epidemic situations only, and submission of single cultures from isolated 
cases would serve no useful purpose. Requests for serotyping of Group A streptococci and phage typing of 
Salmonella, Shigella, or staphylococci from such cases serve to illustrate the point. Acceptance of diagnostic 
specimens from private physicians or institutions and local health departments is not authorized. 
The volume of specimens submitted for virological examination has increased to the point that it is impos- 
sible for NCDC to examine routine specimens and, at the same time, provide the support needed for de- 
velopment of virological facilities within the State laboratories and assist the States in the solution of their 
epidemiologic problems. Because assistance to the States in the above matters is of major importance and 
a basic responsibility of NCDC, the resources of NCDC virology laboratories must be directed to these 
ends. Therefore, the Laboratory Program limits its acceptance to specimens having epidemiologic im- 
plications. 
Since virology is still a rapidly developing science, diagnostic problems may occasionally arise which require 
assistance from the NCDC laboratories even though the case has no immediate clear-cut epidemiologic im- 
plication. In such instances, the State laboratory director should consult with the Chief of the Virus Reference 
Unit at the NCDC. 
From the viewpoint of the practicing physician, this policy should work no hardship since most virological 
diagnosis is retrospective and of little or no value in the treatment of the individual patient. 
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