The US Centers for Disease Control and Prevention says the number of cases in the state of Nagpur has reached 20,000.
The latest figures indicate the district is the epicenter of the outbreak.
It is one of the poorest districts in India and has seen a spike in cases since the end of September.
Nagpur district chief Ashok Goyal said a surge in the number and frequency of new cases in one district has been recorded since November 10.
“There is no doubt that the district has the highest number of new patients with Ebola, but the situation in other districts has been better,” Goyal told NDTV.
“The district has recorded only three cases, but that is because of the vigilance of our district health officials.”
Nagpuri, a small town in south-west India’s southern states of Gujarat and Odisha, has seen two cases of Ebola since November 12, and the district health department is working to identify other clusters of cases.
The state government is also looking at a potential outbreak of other infections like hepatitis and polio.
The health department has warned that the spread of Ebola virus could cause the death of people with compromised immune systems.
In Delhi, a group of people, including a woman, were rushed to a hospital in north Delhi after they were diagnosed with Ebola.
“We have identified six people who have been in contact with the patient,” said Dr Sanjay Mishra, an official of the National Institute of Allergy and Infectious Diseases (NIAID).
“Our team has been conducting a thorough examination of the patient and the case, and has been given all the necessary facilities,” Mishra said.
Officials say the patient, a resident of the western district of Kharagpur, is being treated at a private hospital in a critical condition.
He was taken to the district hospital to be tested.
The World Health Organization (WHO) has issued a travel advisory for India.
“Travel is advised between Delhi and all the affected countries.
All travelers should ensure they are up-to-date on all local and international travel advisories and travel documents and do not postpone or change travel plans,” WHO spokeswoman Mariam Ali said in a statement.
India’s Health Minister Dr Jitendra Singh has also said that the state has recorded 6,000 cases, while the country has recorded 1,716 deaths from the disease.
The country is on high alert after the first case was recorded in Delhi.
The Health Ministry is also keeping an eye on three other people who were tested positive for Ebola, the statement said.
India is on heightened alert because of recent cases in neighbouring Nepal, where an epidemic of Ebola has been reported in several districts.