The first confirmed case in Sierra Leone was a young woman who was admitted to a government hospital in Kenema (*) following a miscarriage on 24 May, 2014. A health worker suspected Ebola, given the outbreak in neighbouring Guinea. She was tested for Ebola on 24 May and placed in isolation on 25 May; the results were positive. WHO was notified about the Ebola outbreak in Sierra Leone by the Ministry of Health and Sanitation almost immediately.
Swift action
All the right precautions were taken. No one else at the hospital, neither patients nor medical staff, contracted Ebola virus disease. Fortunately, the young woman made a full recovery.
Tracking of her source of infection pointed to an earlier event and told a very different story. The vicinity around Kenema was home to a well-known and widely-respected traditional healer. Her famous healing powers were also known across the border in Guinea. As the outbreak in Guinea continued to swell, desperate patients sought her care.
Predictably, the healer became infected with the Ebola virus and died. Mourners came by the hundreds, also from other nearby towns, to honour her memory by participating in the traditional funeral and burial ceremony. Quick investigations by local health authorities suggested that participation in that funeral could be linked to as many as 365 Ebola deaths. Meanwhile in Guinea, 60% of all cases had been linked to traditional burial practices.
By mid-June, an explosive outbreak was clearly under way in Kenema, and the government hospital could no longer cope. Several nurses working there were quickly infected, and 12 of them died.
Nearby Kailahun district became the country’s second major hotspot. Kenema Government Hospital already had a well-equipped isolation ward – in fact, the only Lassa fever isolation ward anywhere in the world. Initially, the country’s Lassa Fever Programme used its contact-tracing staff and skills to try to contain the outbreak, but that capacity was rapidly overwhelmed.
The outbreak takes hold
As in Guinea, the virus spread quickly and widely, with a large proportion of doctors and nurses among the dead – severely depleting response capacity. As in Guinea, the virus marched into the capital city, Freetown, where it took advantage of overcrowded living conditions and fluid population movements to grow in explosive numbers.
On 29 July, another heart-breaking tragedy struck: the head of the country’s Lassa Fever Programme, Dr Sheik Humarr Khan, a virologist and world-renowned expert on viral haemorrhagic fevers, died of Ebola virus disease at the age of only 39. Sierra Leone – and the international public health community – lost one of its most respected and influential medical giants.
A breakthrough in the scientific understanding of Sierra Leone’s outbreak came on 28 August, when the journal Science published the results of a major surveillance study of Ebola virus genomes, involving 99 complete virus sequences, that traced the start of the outbreak and its further spread. No such massive study had ever been undertaken before.
Understanding the outbreak
The study confirmed the healer’s funeral as a seminal event at the outbreak’s explosive start, demonstrated that the virus’s genome is changing fairly quickly and pinpointed 2004 as the year when the virus changed. The study also demonstrated a pattern of adaptive mutation; the authors called for an urgent scaling up of control measures – lest the virus adapt to establish permanent residence in the affected areas.
The study was not, however, designed to determine whether changes in the virus were linked to either the epidemiology or the severity of this outbreak. Nonetheless, understanding of the outbreak now has cutting-edge science on its side; this can only contribute to response efforts in affected countries.
In yet another human tragedy in this heart-breaking outbreak, five co-authors of the study, who contributed greatly to public health and research in Sierra Leone, contracted Ebola virus disease and died before the paper was published.
The needs today
Today, Sierra Leone’s most urgent needs include opening up more Ebola care facilities – which means more trained staff to meet a severe shortage. Controlling the spread of the disease will also require stronger district surveillance and epidemiology, contact tracing and burial teams.
* Corrected the name of the city from Kailahun to Kenema.