Hi, I'm Crystal Donnelly. In this lecture, I'm going to talk you through the large Ebola epidemic that occurred in West Africa between 2013 and 2016. In 2014, an Ebola outbreak in West Africa was detected and went on to cause thousands of cases in the region over the subsequent two years. It had probably been spreading undetected since late 2013. The West African Ebola epidemic was the first Ebola outbreak to reach such a large size with the most significant loss of life from Ebola to date. Unlike earlier smaller outbreaks which were confined within countries or small geographical areas, there was considerable cross border spread in the West African outbreak with several countries primarily Guinea, Liberia, and Sierra Leone ultimately affected. In terms of the virus itself, there was nothing particularly special about the West African epidemic. Every outbreak has the capacity to be big, but the West African epidemic was large because transmission reached major cities with high population densities and greater opportunities for spread. When Ebola was detected in 2014, several control measures were implemented. On the ground, strict hygiene procedures were instituted to reduce the transmission of Ebola. Surveillance procedures and contact tracing also began. This means that teams tried to track down individuals who'd been in contact with those already known to be cases. These procedures tried to find those who may be ill, but not yet under the supervision of health officials. This is important as they may be transmitting Ebola to other people. Contact tracing is also used to identify a potential transmission source. Through such efforts, public health officials were eventually able to trace the outbreak back to its original source, which was a case that occurred in late 2013 in a young boy in Guinea. Aside from the disease control procedures described above, community awareness and education campaigns also began. Promoting public health messaging to reduce disease transmission. For example by encouraging safer practices for handling of the ill and deceased. Other international efforts were instigated with varying degrees of success, such as travel restrictions and international quarantine measures. You may have seen for example, the screening procedures undertaken in airports. They're looking for signs of fever. Although given that fever is quite non-specific, it's not clear how well this works. At the same time, there was a huge push for vaccine development. As this was the first widespread Ebola epidemic with significant international transmission, the threat of further international spread was felt by many. This helped to spur global efforts to develop and test a vaccine. Although this was ultimately successful, it came too late to have an impact on this epidemic. In total, during the West African epidemic, more than 28,000 people were infected, that's including confirmed, probable, and suspect cases. With more than 11,000 deaths attributed to the outbreak. That also means there were more than 10,000 Ebola survivors in West Africa. The WHO, ministries of health, and partners have been helping survivors overcome their medical and psychosocial challenges. Taking a step back, what does this epidemic tell us about emerging infection outbreaks more generally? We still face serious challenges in identification of illnesses and outbreaks. It took a long time between the first case occurring and sufficient disease control efforts being mounted. There are issues of capacity. Ebola was spreading in some populations with the least access to health services. In some cases, health centers were full and had to turn away additional cases. This meant that the health system could not get on top of transmission, by effectively treating all the people who were probably infectious. In terms of data, a lot were collected. But there were also gaps in data collection. There were significant challenges on the ground with accurate record keeping, trying to collect accurate data at the same time as fighting an active outbreak can be very difficult. There were also concerns that complex regulation meant that new and potentially helpful vaccines could not be used quickly enough. This catalyzed a rethink in the way that new vaccine candidates are tested and approved. Led to a new process called the WHO blueprint, whereby new vaccine candidates can be fast-tracked for testing and approval in the context of an outbreak situation. However, the responses to this epidemic also demonstrated some areas of good practice for future outbreaks. We will discuss lessons learned from Ebola and Zika outbreaks later on.