An Ebola Turning Point: An Early Diagnosis?

Read my earlier Ebola primer and a look at what we know about how the virus behaves.

As the Ebola situation in West Africa progresses, we are dealing with increasingly complex medical and cultural challenges. I addressed some of the cultural issues in a Morning Consult column last month, and highlighted the importance of identifying infected patients:

The only solution is prevention, which relies on containment and isolation. The sick must be rapidly identified and contained. Their contacts must be followed for 21 days so they can be rapidly isolated, should they develop symptoms. Their care must be delivered in a hazmat suit. If the patient dies, and [50%] do, the body must be properly disposed of because a recently deceased Ebola victim is actively shedding the virus from his skin.

But thus far, identification has not been straightforward. In its earliest stages, Ebola looks like other diseases: malaria, typhoid fever, cholera. It’s clear that these patients are sick, but it’s not clear that they are infected with Ebola virus. During the incubation period, the infected individual may not show any symptoms at all.

Currently, public health workers try to work backwards from a very sick patient. Who lives with them? Who is in their community? Where have they traveled? Who may they have had contact with over the past month? Find those individuals. Follow their health for the next month. If anyone gets sick, the process starts over.

An early, precise diagnosis would be a game changer for this process.

  1. We could separate infected from uninfected patients immediately—before they are contagious. Even in locations without sophisticated quarantine facilities, physical separation of Ebola patients from others would cut down on cross contamination within clinics and communities, and better protect one of the hardest hit groups: health workers.
  2. We could dramatically decrease the virus’s geographic spread. Incubation takes 2 to 10 days, and usually that means the person is positive but not yet symptomatic. We believe that a patient isn’t contagious until the fever starts, but a rapid diagnostic test could identify a carrier before symptoms appear, and before they travel and risk spreading the virus.
  3. We could focus on post-exposure drug development. Identifying carriers before they feel ill would let us treat them early. Some drugs have already shown great efficacy if they are given immediately. Zmab is a drug designed as a prophylactic. It’s shown to be 100% effective in primates if given within 24 hrs of exposure and 50% in 48 hours. Other similar treatments could be extremely effective if we know who to give them to.
  4. Health care workers that have been exposed to Ebola can be quarantined for up to 21 days, and often they have not been infected. In an area with a severe shortage of trained medical personnel, the loss of any workers is disastrous. An early diagnostic test would let those medical professionals continue to safely treat their patients if they have not been infected.

The situation in West Africa is complex for so many reasons, and a rapid diagnostic test would not be an ultimate solution, but it could be the tipping point we need to stem the tide of new cases.