Ebola in Guinea? What Have We Learned From Past Epidemics? 2021

New reports of Ebola in Guinea cause anxiety given the Epidemic history in Africa from West from 2014-2016. It was the largest Ebola outbreak reported to date – 28,000 cases were recorded, including 11,000 deaths. It is originally from Guinea and then spread to Sierra Leone and Liberia. This time, the confirmed cases have been reported in southeastern Guinea about 800 km by road from the capital, Conakry, but only about 100 km from various border points with Liberia and Côte d’Ivoire. The problem is that the virus could spread to other places in Guinea and neighboring countries if it is not quickly contained. Jacqueline Weyer answers questions about the latest outbreak.

What has been done to prevent new outbreaks from developing since 2016?

Ebola development, assessment, and registration vaccines and antivirals were major activities following the 2014-2016 epidemic since two vaccines have been pre-approved by the World Health Organization (WHO) and registered with various regulatory bodies.

During the Ebola outbreak 2018-2020 in the Democratic Republic of Congo (DRC), several countries in the region national registration of these products. Nearly 50,000 people have been vaccinated as part of containment efforts in the DRC. Ring vaccination – the vaccination of individuals in a circle around cases – with the Ebola vaccine is vital in preventing the spread of infection because it produces an immune barrier that disrupts the chain of transmission of the virus.

Why did the disease come back?

The natural transmission cycle of the virus affects certain species of forest fruit bats. These act as a reservoir for the virus in nature, and this cycle is continuous, ensuring that the virus is maintained in nature over time. However, the virus can spread from its natural reservoir to other forest animals or directly to humans to trigger an epidemic in the human population.

Animals infected with Ebola, such as non-human primates, monkeys, and antelopes, have already been reported and could present a source of exposure for humans. For example, hunters or people who kill these animals come into contact with infected blood and tissue. But, it is also believed that fallout can occur through direct contact from infected bats to humans. The exact mechanism remains to be defined, but contact with infected blood and tissue is likely an infection source.

The virus is always present in nature and, when circumstances permit, it can pass from one species to another.

What are lessons from previous outbreaks currently being applied?

There are many important lessons, but no doubt, quick and safe action will make the difference. In the aftermath of the 2014-2016 epidemic, the initial responses’ apparent delay was a major critical response effort.

Containing the outbreak early is critical before it spreads beyond zero points to other places in Guinea and neighboring countries. If this happens, longer and more complicated containment efforts will be required.

One feature that distinguishes this outbreak is that it occurs against the backdrop of the global pandemic of COVID-19 – which has health care and other resources around the world under severe pressure.

International support has been a pillar of containment efforts in West Africa and most of the Ebola outbreaks reported to date. Time will tell how to deal with the impact of the COVID-19 pandemic on Ebola containment efforts.

Does Guinea have the health infrastructure to manage the disease?

Access to health care in Guinea has improved slightly over the years. But the country struggles with one of the worst healthcare infrastructures in the world. Most deaths in Guinea remain associated with communicable diseases, maternal and neonatal, and nutritional disorders. The 2014-2016 Ebola outbreak galvanized intensified efforts to improve the country’s health systems, but progress is slow.

Given that the Ebola outbreak in West Africa ended only five years ago, it can be assumed that some of the infrastructures that were developed during the outbreak remain and could be quickly put back into service. The “muscle memory” for the public health response to Ebola acquired during the previous epidemic in Guinea will be put to the test in the coming weeks.

What is the relationship between the epidemic in West Africa and Central Africa?

Studies conducted during and after the 2014-2016 epidemic show that the Zaire Ebolavirus species circulated in local bat populations in West Africa before the epidemic. The genomic similarity of the Ebola viruses associated with the West African epidemic and the Ebola viruses that have caused outbreaks in Central Africa since 1976 supports the hypothesis that the virus spread from Central Africa to West Africa.

On the other hand, when analyzing the differences between these viruses, there is evidence of a distinct evolution in space and time. The exact mechanism of spread from Central Africa to West Africa remains uncertain. But the transfer is plausible given, for example, that many fruit bat species – some of which are implicated as natural reservoirs of the Ebola virus – are migratory and can migrate over great distances.

Efforts are underway to determine the genomic sequence virus associated with recently reported cases. This could point to the potential source of the outbreak and indicate the link between these viruses associated with recent cases and viruses circulated during the previous outbreak. Another consideration is that the currently available Ebola vaccines have not been tested against strains other than Zaire Ebolavirus. The efficacy of these vaccines against other species of the virus is therefore uncertain.

Jacqueline Weyer, Senior Medical Scientist, National Institute of Communicable Diseases

This article is republished from The Conversation under a Creative Commons license. Read the original article.