A measles outbreak affecting mainly Orthodox Jewish neighbourhoods in New York is at an end, officials declared on Tuesday.

The city’s health commissioner Oxiris Barbot said two incubation periods had passed since the last reported cases without any new infections.

But she added that a threat remained from what she called “one of the most contagious diseases on the face of the earth”, and that children must be immunised before the start of the new academic term.

“Staying up to date on vaccines is the best way for people to protect the health and safety of their friends, family and neighbours,” Ms Barbot told AP.

There have been 654 cases of measles since an outbreak in Jewish neighbourhoods of Brooklyn that began in October 2018.

Officials said it was the highest number of cases in three decades, prompting state politicians in New York to revoke a religious exemption to mandatory school vaccinations.

In April New York City ordered all yeshivas in a Strictly Orthodox areas of Brooklyn to keep students out of class if they are not vaccinated against measles, or face a possible fine or closure.

Three other US states — California, Mississippi and West Virginia — have eliminated religious and personal-belief exemptions for vaccines.

Cases have been reported as far afield as Canada, where an outbreak in Montreal’s Chassidic community has prompted a vaccination programme for hundreds of children.