Referencing the Past to Predict Ebola's Future: Marburg Virus in Europe
When examining the future of the Ebola virus, it is important to understand the epidemic in the context of similar outbreaks that occurred in the relatively recent past.
When examining the future of the Ebola virus, it is important to understand the epidemic in the context of similar outbreaks that occurred in the relatively recent past.
For instance, an outbreak of a hemorrhagic fever virus comparable to Ebola occurred in 1967 in Europe. The 1967 Marburg virus outbreak began in the city of Belgrade in the former Yugoslavia and soon spread to Frankfurt, Germany.
During that outbreak, 31 patients developed the infection, and 7 of them died. The outbreak occurred due to improper research technique. Laboratory workers in Belgrade had been working on tissue research in samples from imported African green monkeys when the infection spread to them, and then to the medical personnel caring for them.
Like Ebola, the Marburg virus has been traced to a natural reservoir in African fruit bats. Although the bats are unaffected by the virus outwardly, they can infect primates, including humans and monkeys.1
Marburg virus has been spread among animals and humans through unprotected exposure to bat feces or, possibly, through aerosolized bat feces. Unlike other viruses that only spread from animals to humans, including certain avian forms of influenza virus, the Marburg virus can move between people through direct contact with body fluids or cell cultures. Like Ebola, however, transmission between humans requires close or direct contact.2
Investigation into future vaccines for Marburg virus includes an attenuated vaccine derived from a similar infection called recombinant vesicular stomatitis virus (rVSV). In the early 2000s, this vaccine demonstrated efficacy in Marburg virus infection both preventively and therapeutically.3
The rVSV virus is currently undergoing trials through a partnership between NewLink Genetics and the Public Health Agency of Canada. The fact that the vaccine is effective in Marburg virus makes it a very strong candidate for future development, due to safety data collected over the past 40 years and its manufacturing through recombinant DNA technology.4,5
Researchers are learning more about how to control infections from Ebola and other highly contagious, dangerous viruses. For instance, during the 2003 sudden acute respiratory syndrome (SARS) epidemic, researchers pinpointed several problems with existing infection control procedures.6,7
In the 2003 SARS outbreak, infection control protocol violations were very common. Use of eye protection, gowns, powered air purifying respirators, N95 masks, and gloves was insufficient. Ultimately, simple research using fluorescent dyes identified important vulnerabilities even in the most protective gear, including the neck and the wrists (see image here).6,7
Researchers continue to learn more about controlling the spread of Ebola. At the CHEST 2014 conference held in Austin, Texas, health care professionals noted the importance of taping full-body suits longitudinally along the wrists to enable removal of protective gear in a single, fluid motion. Through this method, exposure of the wrists, which can become contaminated even through careful glove removal, is avoided.
Fear mongering has led to panic and calls to close borders and terminate aid to the countries that need it most: Liberia, Guinea, and other regions of West Africa. It is important to remember that, prior to the outbreak, Liberia has fewer than 100 physicians serving 4.3 million patients.4
With the development of an effective vaccine, adequate control measures, and proper control of the virus, perhaps the scourge of Ebola will be relegated to the past.
References:
1. Centers for Disease Control and Prevention. http://www.cdc.gov/vhf/marburg/. Accessed October 2014.
2. Centers for Disease Control and Prevention. http://www.cdc.gov/vhf/marburg/transmission/index.html. Accessed October 2014.
3. Bausch DG, Geisbert TW. Development of vaccines for Marburg hemorrhagic fever. Expert Rev Vaccines. 2007;6(1):57-74.
4. Pharmacy Times. Page MR. http://www.pharmacytimes.com/news/The-Ebola-Epidemic-What-Pharmacists-Need-to-Know. Accessed October 2014.
5. Kanapathipillai R, Restrepo AM, Fast P, et al. Ebola Vaccine - An Urgent International Priority. N Engl J Med. 2014.
6. The American Journal of Managed Care. http://www.ajmc.com/conferences/chest-2014/Managing-Ebola-How-ICUs-Can-Prepare-for-an-Outbreak-in-the-United-States. Accessed October 2014.
7. Zamora JE, Murdoch J, Simchison B, Day AG. Contamination: a comparison of 2 personal protective systems. CMAJ. 2006;175(3):249-254.
