If a person had measles as a child, which of the following best describes their immunity to measles?

A. Naturally acquired active immunity

This results from infection and the body’s own immune response—not applicable to newborns.

B. Artificially acquired passive immunity

This comes from injection of antibodies (e.g., immunoglobulins)—not from the mother.

C. Naturally acquired passive immunity

This is passed from mother to child through the placenta (IgG antibodies) and via breast milk (IgA).

D. Artificially acquired active immunity

This comes from vaccines that stimulate the body to produce its own antibodies.

A. Digestive system through contaminated feces:

This is the port of exit for diseases spread by the fecal-oral route (e.g., cholera, hepatitis A).

B. Respiratory system by coughing or sneezing:

Droplet infections (e.g., flu, COVID-19, common cold) are primarily spread through respiratory secretions expelled via coughing or sneezing.

C. Central nervous system by contaminated cerebral spinal fluid:

While CSF can carry infections (e.g., meningitis), it is not a common port of exit.

D. Urinary system by contaminated urine:

Urinary tract infections may be transmitted this way, but not typically through droplets.