Thursday, October 30, 2014

Change of plans: Sierra Leone

I learned this week that Partners In Health (PIH) would like to send me to Sierra Leone rather than Liberia. During a conference call today I learned that we will be the first group that PIH sends to Sierra Leone and that we will be working in villages where there are no Ebola Treatment Units (ETU) but in which the communities have set up isolation units. We will be providing technical assistance while the ETUs are being built.

I'm excited about this opportunity. They told us that they were looking for people who could be flexible. I guess they figured from my background and my interviews that I fit that bill.

I will be in Anniston, Alabama on Monday to start CDC safety training and will travel from there to Freetown, the capital of Sierra Leone, where I will have further training before we go to Port Loko.

I should have good Internet access in Freetown, but I don't know what to expect in Port Loko. Posting my blog entry from Tanzania was challenging. I suspect that posting from Sierra Leone will be more difficult. I was able to Skype Holly and Andrew almost every day that I was in Tanzania. I'm not sure if or how often I'll be able to Skype them from Sierra Leone. That will be the hardest part of this trip.

I appreciate all of the positive feedback from family and friends and through social media. I appreciate the offers to help Holly and Andrew while I'm away. I am especially grateful for all of your prayers.

Next stop: Atlanta.





Friday, October 24, 2014

Why I am going to Liberia

10/28/2014 Update: I will be going to Sierra Leone instead of Liberia.

I suspect that many people who know me know some of the reasons I have chosen to work in the Ebola response in Liberia; I fell in love with Africa and its people during my first trip to the continent in the late 1980s, I became a nurse because I wanted to work in Africa, I have a passion for public health and tropical medicine, I'm Catholic, and I want to set an example for my son.

There is another reason that requires some explaining.

Basic reproduction number (R0)

The basic reproduction number, or R0 (pronounced "R-naught"), is the number of people who can be expected to be infected by a single person with a disease in a susceptible population (a population in which there is no immunity to the disease). For example, Fraser and colleagues (2009) estimated the R0 for 2009 H1N1 pandemic influenza to be 1.4 to 1.6, meaning that at the beginning of the pandemic, each person infected with 2009 H1N1 could be expected to infect 1.5 other people. In the pre-vaccine era, the R0 for measles was 12.5 to 18; each person with measles could be expected to infect up to 18 other people.

The reproduction number does not remain the same during an epidemic; it becomes R(t), where t is time. The reproduction number decreases as the number of susceptible individuals in a population decreases through death, outmigration, or immunity. Changes in behavior can also influence the reproduction number. An important point is that epidemics end when the R(t) is less than 1; that is, each infected person infects fewer than one person. We do not have sustained measles transmission in the U.S. because of high levels of immunity from immunization; the R0 for measles in the U.S. is less than 1.

The World Health Organization Ebola Response Team (2014) estimated the current reproductive number for Liberia to be 1.51. The authors estimated that the number of people infected will double every 23.6 days. Meltzer et al. (CDC, 2014) estimated the doubling time for Liberia to be between 15 to 20 days.

Interrupting Ebola transmission

Ebola is transmitted through contact with the body fluids of a person who has Ebola virus disease (EVD). There are few health care facilities and few health care workers available in the affected countries to provide care for people with Ebola, so people who are sick with the disease have been cared for at home where their families are exposed and become infected. Health care facilities frequently lack supplies of personal protective equipment (PPE), so health care workers have been getting infected and some have fled out of fear of being infected. Ebola is also transmitted during traditional funeral ceremonies.

Getting a person with EVD isolated and into treatment prevents transmission to other people, which reduces the R(t). People who survive EVD develop high levels of antibodies to the virus and are presumed to be immune to the species of the virus with which the individual was infected, reducing the R(t). Finding people with EVD though contact tracing and getting them into isolation and treatment reduces the R(t). Safe burial practices reduce the R(t).

These interventions, isolating and treating people with EVD, contact tracing, and facilitating safe burial practices require personnel who are able to care for people with the disease and work with communities to change behaviors that place people at risk for infection.

That is why I'm going to Liberia.

This epidemic began as a relatively small outbreak in Guinea in December, 2013. The WHO Ebola ResponseTeam found that the reproduction number in Guinea fluctuated between March and July 2014, a time when control efforts could have quickly brought an end to this epidemic. Both the WHO Ebola Response Team and the CDC authors concluded that delays in responding to this epidemic cost lives. Soon, there could be thousands of new cases every week instead of hundreds.

Supporting health care workers

Holly has been very supportive of my decision to work in Liberia. I would not have accepted the position without her approval. I am fortunate that my colleagues at the health department have also been supportive of my decision.

According to the current CDC recommendations, health care workers who wore appropriate PPE while caring for patients with EVD are not considered to be at high risk for infection. The CDC recommends that people entering to the U.S. from countries affected by the Ebola epidemic self-monitor for fever and symptoms of EVD for 21 days (the incubation period). The CDC has not recommended isolating asymptomatic contacts of cases.

As I was writing this, the news media reported that New York Governor Andrew Cuomo and New Jersey Governor Chris Christie ordered 21 day mandatory quarantine of everyone entering those states from Guinea, Liberia, and Sierra Leone.

I have heard that doctors and nurses who return from working in West Africa are facing being furloughed for three weeks by their employers and that some health care professionals who had planned to go to West Africa to work in the Ebola response have cancelled those plans as a result.

These actions are, in my opinion, based on fear and not on objective evaluations of the risk that a health care worker will infect others in this country. Hundreds, if not thousands of expatriate health care professionals from around the world have responded to this epidemic, very few expatriate health care professionals have been infected, and none of those infected health care professionals has transmitted the virus to anyone in their home countries. I would not have decided to go to Liberia if I did not believe that my risk of being infected was negligible and the risk of me transmitting Ebola to Holly and Andrew was nonexistent.

While I understand the public's fear of this disease, I also realize that we live in a global community. The risk of Ebola importation to the U.S. and other countries outside of Africa increases with the duration of this epidemic and with the number of people infected with the virus. We have already seen the result of failure to recognize and respond to this threat; what began as a relatively small, isolated outbreak has become a multinational epidemic.

I encourage other health care professionals to consider working in West Africa to hasten the end of this epidemic. I encourage employers and politicians to provide incentives for health care professionals to work in West Africa for the sake of our global community rather than place unnecessary and poorly-considered burdens on their shoulders.

I thank my family and my colleagues at the health department for their support.

I have not yet seen my itinerary, but I am scheduled to be in Anniston, Alabama for CDC safety training November 3 – 5. I will be deployed to Liberia from there. I hope to be home for Christmas.


Centers for Disease Control and Prevention. (2014). Estimating the future number of cases in the Ebola epidemic – Liberia and Sierra Leone, 2014-2015. Morbidity and Mortality Weekly Report, 63(03), 1-14.

Centers for Disease Control and Prevention. (2014). Interim guidance for monitoring and movement of persons with Ebola virus disease exposure.

Fraser, C., Donnelly, C. A., Cauchemez, S., Hanage, W. P., Van Kerkhove, M. D., Déirdre, T. et al. (2000). Pandemic potential of a strain of influenza A (H1N1): early findings. Science, 324(5934), 1557-1561.

Strebel, P. M., Papania, M. J., Dayan, G. H., & Halsey, N. A. (2008). Measles vaccine. In S. A. Plotkin, W. A. Orenstein, & P. A. Offit (Eds.) Vaccines, 5th Ed. [Electronic version]. Elsevier.

White, P. J. & Enright, M. C. (2010). Mathematical models in infectious disease epidemiology. In J. Cohen, S. M. Opal, & W. G. Powderly (Eds). Infectious diseases, 3rd Ed. [Electronic version]. Elsevier.

World Health Organization Ebola Response Team. (2014). Ebola virus disease in West Africa – the first 9 months of the epidemic and forward projections. New England Journal of Medicine, 371(16), 1481-1495.



Wednesday, October 15, 2014

Isolation and quarantine

I started this blog nearly three years ago. Yesterday it broke 10,000 pageviews. That may not be much compared to more popular blogs, but I'm glad to know that someone is reading what I write.

I don't have the raw data, but this graph looks like a regression line would trend upward.

I don't expect this post to get a lot of hits.

Our office has received a lot of calls in the last few weeks from health care providers who are unsure of or confused about the recommendations for monitoring people who may have been exposed to Ebola virus, so I suspect that there is similar uncertainty and confusion among the general public.

For this discussion, I'm talking about people who have been in direct contact with a person with Ebola virus disease (EVD); that is, people who have potentially been exposed to and may have been infected with the virus but have no symptoms of the disease.

Also, I'm writing about the current recommendations for contacts of cases. These recommendations may change. Please refer to the Center for Disease Control and Prevention (CDC) website for changes in its recommendations.

The CDC does not recommend isolating people who have been in contact with a person with EVD but have no symptoms of the disease. A person who is infected with the virus but has no symptoms of the disease cannot infect other people. According to the current CDC guidelines, health care workers who have had contact with someone with EVD may return to work. Of course, that changes once a person develops a fever and symptoms of EVD.

The CDC recommends that contacts of cases take their temperature twice every day for 21 days (the longest incubation period for EVD) and notify their local health authority of fever or symptoms of EVD. Health care workers may be monitored by their employers.

We are currently working with the Washington State Department of Health, other local health jurisdictions, and hospitals to develop policies and procedures to monitor health care workers who have potentially been exposed to Ebola. This will include those of us who return from working in West Africa.

One thing to remember is that the CDC is not a regulatory agency. In general, the CDC can make recommendations and serve in advisory capacity, but it has no authority to enforce its recommendations.

Isolation and quarantine

The words isolation and quarantine are sometimes used interchangeably but, in public health, they do not have the same meaning. The CDC defines isolation as separating sick people with a contagious disease from people who are not sick. Quarantine is separating and restricting the movement of people who were exposed to a contagious disease to see if they become sick.

For example, I am a tuberculosis case manager. We routinely ask people who have tuberculosis and are contagious to isolate themselves to avoid infecting other people. Because tuberculosis is not transmitted outdoors, we do not tell a person with pulmonary tuberculosis that she or he must remain indoors. That person may leave the home but may not enter another building where other people could be exposed to tuberculosis. This is called voluntary isolation.

Washington State law gives local (county) health officers the authority to order a person into isolation. If that person fails to comply with the health officer order, we may get a court order for involuntary isolation. Washington State health officers have the authority to restrict the movement of (quarantine) individuals who are a threat to public safety. Fortunately, I've never had to do more than explain that the health officer has that authority.

The CDC has the authority to detain individuals who are entering the U.S. or traveling across state lines, but it does not have the authority to quarantine individuals within the boundaries of states or local health jurisdictions. State and local health officers have that authority.

I know that a lot of people are worried about Ebola in the U.S. I am also concerned about the risk of this epidemic spreading beyond the borders of Guinea, Liberia, and Sierra Leone to neighboring countries and out of Africa. That is why I decided to work in West Africa to help get people with EVD into treatment and end this epidemic.


Centers for Disease Control and Prevention. (2014). Infection prevention and control recommendations for hospitalized patients with known or suspected Ebola virus disease in U.S. Hospitals.

Centers for Disease Control and Prevention. (2014). Interim guidance on monitoring and movement of persons with Ebola virus disease exposure.

Centers for Disease Control and Prevention. (2014). Legal authorities for isolation and quarantine.

Washington State Legislature. (n.d.) Conditions and principles for isolation and quarantine.

Washington State Legislature. (n.d.) Tuberculosis – prevention, treatment, and control.


Sunday, October 12, 2014

Is Ebola airborne?*

Regarding my upcoming trip to Liberia, I suspect that there are people who are concerned about not only my safety, but also the safety of my family and my community. I adore my wife and son and would not have chosen to work as an Ebola Response Clinician unless I believed that I could do so safely and without leaving Holly without a husband and Andrew without father or, unthinkably, exposing either of them to a highly lethal virus.

From hearing people's comments in the media and from some of the phone calls we have received at the health department, it seems to me that there is a lot of confusion about the means by which ebolaviruses are transmitted. Although I addressed Ebola transmission in the presentation I gave to the Pierce County Medical Reserve Corps, I'd like to go into more detail about the question of whether ebolaviruses are transmitted by the airborne route.

The Centers for Disease Control and Prevention, the World Health Organization, and every textbook chapter on Ebola virus disease (EVD) that I have read acknowledge that there is a risk of ebolavirus transmission through respiratory droplets, which are expelled when a person coughs or sneezes. At the same time, all of those sources state that there is no evidence that ebolaviruses are transmitted from person-to-person by the airborne route. That may seem like a contradiction, but the difference is in the size of the droplets.

Coughing and sneezing generates large respiratory droplets that fall out of the air within a few feet. Transmission through large droplets usually requires close contact. These droplets can come in contact with the eyes or be inhaled and trapped in the upper airway: the nose, mouth, pharynx, trachea, and bronchi.

NCI, 2012
Pertussis and influenza are examples of diseases that are transmitted by large respiratory droplets. These large droplets can be blocked by wearing a simple surgical mask – the type you can buy at your local drug store.

Airborne transmission refers to pathogens that are carried by droplet nuclei, particles that are 1 to 5 micrometers (μm) in diameter. These particles can remain suspended in the air for hours and can pass through the upper airway into the alveoli.

Droplet nuclei are not blocked by surgical masks and require high-efficiency particulate air filtration (HEPA) for protection. In a health care setting, these are usually N95 masks or a powered air-purifying respirator (PAPR). Mycobacterium tuberculosis, the bacteria that causes tuberculosis, is an example of a pathogen that is transmitted by the airborne route.
Powered air-purifying respirator (PAPR)
Measles is another example of a disease that is transmitted by the airborne route. This year in Pierce County we had two public measles exposures that required the health department to notify the public of where and when a person with measles had been.
Because the small particles that transmit measles can remain suspended in the air for hours, we recommend that people who were in a place at the time a person was measles was there and two hours after either ensure that they are either immune to measles or receive a dose of MMR.

Another important difference between measles and ebolaviruses is that people with measles are contagious up to 4 days before showing symptoms of the disease. A person with EVD cannot transmit the virus until she or he is symptomatic.

A number of people have raised concerns over the adequacy of surgical masks to prevent health care workers frombeing infected with Ebola. Adding to the confusion, it appears that there is airborne transmission of Reston ebolavirus (which does not cause disease in humans) between non-human primates and Zaïre ebolavirus has been transmitted between non-human primates under experimental conditions. Michael Osterholm raised the question of whether Zaïre ebolavirus, the species causing the current epidemic in West Africa, could mutate to become airborne.

It is very distressing that several health care providers working in the Ebola epidemic in West Africa have become infected and developed EVD. We don't know the circumstances under which they became infected. It's important to realize that there are hundreds of expatriate health workers in West Africa so, although it certainly gives us reason for concern, those providers are a small proportion of the total those who have worked and continue to work in clinical settings in West Africa.

As I mentioned in my last post, my first stop will be Atlanta to receive safety training at the CDC. Once I return to the U.S., I will monitor my temperature twice daily and report any symptoms suggestive of EVD to the local health authority; that is, the very office where I work!

I intend to take every precaution to protect myself, my family, and my community.

I appreciate the support and prayers from my family, friends, and colleagues.

I encourage other health care providers to consider volunteering your time to help end this epidemic.

Blumberg, L., Enria, D., & Bausch, D. G. (2014). Viral hemorrhagic fevers. In J. Farrar, P. J. Hotez, T. Junghanss, G. Kang, D. Lalloo, & N. J. White (Eds.) Manson's tropical diseases, 23rd Ed. [Electronic version]. Elsevier.

Brosseau, L. M. & Jones, R. (Sept. 17, 2014). Commentary: Health workers need optimal respiratory protection for Ebola.

Centers for Disease Control and Prevention. (2014). Infection prevention and control recommendations for hospitalized patients with known or suspected Ebola virus disease in U.S. hospitals.

Geisbert, T. W. (2014). Marburg and Ebola hemorrhagic fevers (Filoviruses). In J. E. Bennett, R. Dolin, & M. J. Blaser (Eds.). Mandell, Douglas, and Bennett's principles and practice of infectious diseases, 8th Ed. [Electronic version]. Elsevier.

Hartman, A. L. (2013). Ebola and Marburg virus infections. In, A. J. Magill, D. R. Hill, T. Solomon, & E. T. Ryan (Eds.) Hunter's tropical medicine, 9th Ed. [Electronic version]. Elsevier.

Osterholm, M. T. (Sept. 11, 2014). What we're afraid to say about Ebola.

World Health Organization. (2014). What we know about transmission of the Ebola virus among humans.

*Betteridge's law: Any headline which ends in a question mark can be answered by the word no.


Wednesday, October 8, 2014

Ebola virus disease

I never finished unpacking from my trip to Tanzania.

A couple of weeks ago I received an Email from the American Society of Tropical Medicine and Hygiene that included contact information for several organizations that are recruiting nurses and doctors to work in the Ebola epidemic response in West Africa. My first thought was that I couldn't do it, I couldn't leave Holly and Andrew again, I can't afford to leave work for an extended period of time. I jokingly forwarded the Email to Holly and my supervisor expecting a chorus of, "No!"

At some point that day, I couldn't think of anything else.

I sat down with Holly and told her what I had been thinking. This is what is needed to end this epidemic. This is why I became a nurse. This is why I got a degree in tropical medicine. I want to set an example for my son. I thought she would object. She didn't. Holly has been very supportive. She has prayed that this would work out.

It has. I'm going to Liberia Sierra Leone.

I've been offered a temporary position with Partners In Health. In a few weeks I'll go to Atlanta for training at the CDC, then I'll receive two weeks training in Liberia, and then I'll spend four weeks at my worksite.

The hardest thing about being in Tanzania for a month was being away from my little boy. The hardest part of making my decision  to go to Liberia is being away from Andrew for even longer than my trip to Tanzania. I'll be able to Skype Holly and Andrew while I'm in Liberia, which will make that a little easier. I plan to make spending time with Andrew my priority between now and the time I leave for Atlanta.

This is a presentation on Ebola virus disease that I gave to the Pierce County Medical Reserve Corps on Monday: