Health authorities are keeping more than 260 people under observation for the Ebola virus in Texas and Ohio, after family and friends of Thomas Eric Duncan, the Liberian who contracted Ebola in his country and died in the US, concluded their quarantine period without developing symptoms.
In Dallas, Texas, 43 people were in contact with Duncan, among them his fiancee Louise Troh and their son, who have ended their 21-day isolation period recommended by the health authorities.
The Centres for Disease Control and Prevention (CDC) announced Monday new measures to avoid further infection among doctors who treat patients with Ebola.
The new recommendations have been suggested by doctors in US hospitals who have treated Ebola patients, staff of Doctors Without Borders and experts of other organisations who are working to combat the disease.
Among the guidelines are that under no circumstances should any part of the skin be exposed while donning protective gear and that there should be someone supervising while taking it off and on.
The CDC said it was looking for hospitals or medical centres that were equipped to treat Ebola patients because there are currently only four that have special isolation units to treat infected patients.
Dallas authorities Monday said that there were still 120 people under observation for having come in contact with Duncan or with nurses Nina Pham and Amber Joy Vinson, who treated Duncan in the hospital.
The Dallas mayor's office said in a statement Monday that the analysis of urine and excreta of Bentley, Pham's dog, has already begun.
Pham was admitted to the hospital Oct 10 and the authorities have kept Bentley in isolation.
The fear of a possible Ebola outbreak in the US occurred last week when it was revealed that before being diagnosed, Vinson traveled by a commercial airliner from Cleveland, Ohio, to Dallas with a slight fever and with the approval of a CDC officer.
As a precautionary measure, health authorities in Ohio continue to monitor 142 people, three of whom remain isolated due to their contact with Vinson.
Meanwhile, the Pentagon announced Sunday the formation of a military group of 30 people specialised in rapid response for fighting Ebola in the US should the need arise.
Training is expected to begin this week in Houston, Texas, and the team will be formed by 20 intensive care nurses, five doctors specialised in infectious diseases, and five protocol trainers.
US President Barack Obama has been reluctant to ban flights coming from Ebola-affected countries in West Africa (Guinea Conakry, Sierra Leone and Liberia), inviting criticism from several Republicans.
Faced with Republican criticism concerning lack of leadership and slow progress in controlling the virus, Obama designated Ron Klain Friday as the federal "czar" to deal with the Ebola response and to manage government performance.