With all of the media coverage of the Ebola outbreak in this country, it is easy to concentrate on all of the many mistakes that have been made, especially by Texas Health Presbyterian Hospital in Dallas. It cannot be denied that those mistakes may have contributed to the death of their patient, Thomas Duncan, and all most certainly contributed to the infections of two of their nurses, Nina Pham and Amber Vinson. Despite everything that went wrong in Dallas, what is going virtually unnoticed is that the outbreak will most likely be contained without spreading beyond those originally exposed to Thomas Duncan after he became ill. The two groups which fall into that category are those who were exposed to him after be became symptomatic, but before he was placed into isolation, and the hospital workers who came in contact with him after he was admitted to the hospital.
As anyone who has keep up with this story knows, the incubation period for the Ebola virus – the time period between when patients are first infected and when symptoms appear – is between two and twenty one days, with the average being 8 to 10 days. The chances of someone who might have been exposed to the virus coming down with the disease grows smaller every day from the 11th day on. It also well known that Ebola can only be transmitted from person to person after the infected person becomes symptomatic.
That first group exposed to Mr. Duncan includes his girl friend and her children who were famously quarantined in their apartment with linens and other items contaminated with Duncan’s bodily fluids before authorities moved them to another location. Duncan was admitted into the hospital and isolated on September 28th. Therefore it has been 17 or 18 days since the people in that group had any contact with him. While it is not impossible for someone to start showing Ebola symptoms up to 21 days after exposure, it is unusual for someone to come down with the disease 16 to 18 days later. Regardless, the people in that group are still being monitored and given the lessons learned from mistakes made in Dallas I think we can be fairly certain that if one of them starts to show symptoms, he or she will be put in isolation almost immediately to minimize the possible exposure to anyone else.
The second group who might have been exposed to Mr. Duncan was the 76 healthcare professionals who had varying degrees of contact with Mr. Duncan when he was being cared for at Health Presbyterian Hospital in Dallas. It is logical to assume that those with the highest risk of contracting the disease were those personnel caring for him directly during the first few days after he was admitted when confusion about how the health care workers should protect themselves was at its highest. In fact both Nina Pham and Amber Vinson, the nurses who were diagnosed with the virus, fit that description exactly. Duncan was admitted late in the evening of September 28th and died the morning of October 8th. Therefore Pham and Vinson started showing Ebola symptoms 11 days and 14 days respectively after Duncan was admitted and 3 and 6 days after he died.
Most of the other 74 health care workers did not have the close personal contact with Mr. Duncan which Nina and Amber experienced every day and none of the others have yet exhibited symptoms of Ebola. Now that this group has been subjected to travel restrictions and told to stay away from public places, they are also being monitored and will be isolated almost immediately should they start to show symptoms. It has now been 19 days since Mr. Duncan was admitted to the hospital and 9 days since he died. Hopefully by the time that the nurses were admitted to the same hospital the hard lessons learned in treating Mr. Duncan were put to good use and Nina and Amber did not present additional risks to the hospital staff. Regardless, with every passing day the chances that one of the other 74 hospital worker will be diagnosed with Ebola grow less and less.
Now given what we know about their situations, there is not much risk that Nina Pham and Amber Vinson could have infected others before they were put in isolation. In an abundance of caution, those in contact with them are similarly being monitored and will be isolated at the first sign of trouble.
Even if one of these people being monitored because of possible contacts with Duncan, Pham and Vinson start exhibiting symptoms of the Ebola and are in contact with a few others before being totally isolated, the procedure of monitoring and isolation will be followed again until there are no new cases of Ebola.
This tried and true protocol of locating the possible contacts of Ebola victims, monitoring them, and isolating and treating them when necessary has been used successful to halt Ebola outbreaks since the disease was first identified in 1976. Since that time there have been 27 Ebola outbreaks, most of which were in African countries with health care infrastructures which are exceedingly primitive compared to those in this country, Before the current major epidemic which begun in Guinea and then spread to Liberia and Sirra Leone and which got out of hand before it was suitably addressed, previous outbreaks were relatively isolated. In 27 recorded outbreaks, 19 involved less than 100 victims and many involved just a few. Based on what is known about the disease and the current situation of the Dallas outbreak, I think that there is a good chance that no more new cases will be identified. At worst I believe we might see one or two more and then it will be over.
After the current situation is handled, we just need to ensure that if yet another hospital in the United States faces a similar situation, the very public and difficult lessons of Dallas will have been put to good use and that the second hospital is well prepared to both treat the patient and protect its care givers.