Positive Schick's test indicates that person is:
Immune to diphtheria
Hypersensitive to diptheria
Susceptible to diphtheria
Carrier of diptheria
Positive Schick's test indicates that person is Susceptible to diphtheria. Schick test: Toxin-antitoxin neutralization test. Done on the people before staing immunization to identify susceptible individuals. Susceptible individuals develop erythema and induration on test arm following intradermal inoculation (0.2ml I/D MLD) of toxin. Vaccine is administered only to those susceptible people. Since now safer toxoid preparations are available, it is obsolete.
Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli)