Positive Schick's test indicates that person is:: (A) Immune to diphtheria, (B) Hypersensitive to diptheria, (C) Susceptible to diphtheria, (D) Carrier of diptheria
Answer is C. 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 Since now safer toxoid preparations are available, it is obsolete.