India has asked the United States’ public health agency, the Centers for Disease Control and Prevention, to “withdraw or modify” an advisory it issued on December 13 warning people against travelling to Rajasthan due to an outbreak of the Zika virus, The Indian Express reported on Saturday.

“We have sent a rebuttal to CDC along with all research done on the Zika strain in India, the cases reported, measures taken, etc,” said Secretary of Health Research Balram Bhargava. “We have told them to withdraw or modify the alert.” Bhargava is also the director general of the Indian Council of Medical Research.

The CDC had said the virus was endemic to India and pointed out “there is an unusual increase in the number of Zika cases in Rajasthan and surrounding states”. It cautioned pregnant women against travelling to such areas. “This is because Zika infection during pregnancy can cause serious birth defects,” the advisory said. The health agency classified its alert under Level 2, which requires “enhanced protection”. Level 1 advises “usual precautions” and Level 3 advises against “non-essential travel”.

Unidentified officials said the government took exception to the use of “endemic” in the advisory as Zika outbreaks in India have been contained within small areas.

Bharagava said the Indian government has sent a dossier on “all the research we have on Zika in India”. Research by scientists at the Indian Council of Medical Research have reportedly shown that Zika strains in the country are less virulent than in Brazil and are not associated with microcephaly.

The National Institute of Virology in Pune has said that the gene responsible for causing microcephaly in Brazil is absent in the Indian strain after genome sequencing of the Zika virus spreading in India. The research findings of the virology institute have also been sent to CDC.

The Zika virus is transmitted mainly by Aedes mosquitoes, including Aedes aegypti, which also carries dengue. Most infected people either show no symptoms or only mild symptoms such as fever, rash, joint pain, conjunctivitis and, possibly, muscle pain and headaches that may last a week.