A 60-year-old man who traveled to Haiti and took prophylactic chloroquine but stopped just as he left the region now has developed Plasmodium vivax malaria. What stage(s) was/ were not eliminated because he stopped taking the drug early?

Question

Quizplus · Accepted Answer

Chloroquine kills only the erythrocytic schizonts/merozoites, so you must take the chloroquine for 4 weeks after leaving the malarial area to allow all stages to continue past the liver stages into the sensitive forms.

A 60-Year-Old Man Who Traveled to Haiti and Took Prophylactic