Although it was largely eradicated from the United States 15 years ago, measles is making a comeback. From Jan. 1 through Feb. 13, according to the Centers for Disease Control, 141 people in 17 states, including at least two in New York City, were reported to have measles, a serious and sometimes deadly upper-respiratory disease.

In 2014, the CDC documented over 600 cases of measles. New York City itself experienced a measles outbreak that year, with 26 confirmed cases between February and April.

Measles is highly contagious. It is imperative that you take the proper precautions to protect yourself, your colleagues and your students. Symptoms of measles generally appear between seven and 14 days after initial infection. Early symptoms include fever, cough, runny nose and red, watery eyes. Two to three days after the start of symptoms, some people infected with measles develop small white spots that appear on the gums and inside of the cheeks. Within three to five days, infected people will develop a telltale rash on their face, which will then spread over the entire body.

Immediately inform your school nurse and principal if any of your students develop the symptoms of measles. Seek medical attention yourself right away if you develop any of these symptoms.

Schools are instructed to remove a student suspected of measles infection from the classroom and place him or her in quarantine until medical personnel from the Department of Health are able to arrive on the scene and determine whether the student in question is in fact infected.

You can help prevent the spread of measles. Measles is spread when an infected person coughs or sneezes. The virus can transmit directly from person to person; it can also survive on surfaces for up to two hours. Help fight its spread by following these simple, common-sense precautions and encouraging your students to do the same:

• Wash your hands often with soap and water for 20 seconds.
• Avoid touching your eyes, nose or mouth with unwashed hands.
• Avoid close contact such as kissing, hugging, and sharing cups or eating utensils.
• Cover your coughs and sneezes with a tissue or shirt sleeve, not your hands.
• Clean and disinfect frequently touched surfaces, such as doorknobs.
• Stay home when you are sick.

All children attending New York City public schools are supposed to be vaccinated against measles, but there are certain exceptions. For example, students may be exempted from the vaccination requirement if a parent holds “genuine and sincere” religious beliefs that are contrary to the requirement. Parents seeking such an exemption must provide a written explanation of the foundations of their religious belief opposing immunization to the Department of Education’s Office of School Health, which will determine whether to issue an exemption. Children may also be exempted for medical reasons with a letter from their physician indicating that the vaccination would be detrimental to their health. The Department of Health and Mental Hygiene will decide whether to issue a medical exemption. Students with a religious or medical exemption must be admitted to school. Finally, children transferring from out of state or from another country who can show a good-faith effort to acquire the vaccination may attend school for up to 30 days without proof of vaccination, after which time they will not be admitted. All other children may attend school for 14 days without proof of vaccination, after which time they will not be admitted.