A day after a doctor who had returned from Guinea about a week earlier became New York’s first Ebola case, the governors of New York and New Jersey announced that they would begin quarantining travelers who had been in contact with Ebola patients in West Africa.

The move, which went beyond federal policy, drew protests from medical aid groups and the Obama administration, who said it would penalize people who were trying to contain Ebola and discourage others from doing so.

But since Kaci Hickox, a nurse, flew into Newark’s airport on Oct. 24 and was kept at a hospital for three days, no one else has been caught up in the quarantine dragnet at the New York and New Jersey airports.

The absence of quarantines is striking, not only because both governors emphatically defended the policy as a necessary precaution, but also because most people returning from Ebola-stricken countries arrive in the United States through Kennedy and Newark Liberty International Airports. Several aid organizations have American health care workers in West Africa, a handful of whom return every week. But New York and New Jersey officials say no one coming through the two airports since Ms. Hickox has reported direct contact with Ebola patients.