Haemorrhagic fevers in Africa
Authors: Sanjeet Bagcchi
Journal: The Lancet Microbe (2021)

In August 2021, WHO reported a confirmed case of Marburg virus disease in Guinea—the first known case of this disease in west Africa. On July 25, a man at a village in the Guéckédou Prefecture in south-western Guinea, near the borders with Sierra Leone and Liberia, had the onset of symptoms of Marburg virus disease and on Aug 1 went to a small health facility near his village reporting fever, fatigue, headache, abdominal pain, and gingival haemorrhage. Despite being given treatment for symptom management, antibiotics, and rehydration, on Aug 2, the patient died, prompting the issue of an alert. In an investigation carried out by a team of national authorities from Guinea and scientists from WHO, an oral swab sample collected from the patient was confirmed to be positive for Marburg virus and negative for Ebola virus by real-time PCR. The diseases caused by Marburg and Ebola viruses can be difficult to distinguish, as they have similar symptoms, including haemorrhagic fever, and high case fatality rate (around 50%), and both viruses are transmitted by contact with bodily fluids or tissues of infected animals (eg, fruit bats and monkeys) or humans. According to the US Centers for Disease Control and Prevention, Marburg virus was first identified in Marburg and Frankfurt (Germany) and Belgrade (Serbia) in 1967, with the suspected origin being Uganda, in east Africa. Since then, there have been several cases and outbreaks of Marburg virus disease, with Uganda reporting small outbreaks in 2012 (n=15 cases), 2014 (n=1), and 2017 (n=4), and large outbreaks occurring in central and southern Africa. In 1998–2000, DR Congo recorded 154 cases of Marburg virus and 128 deaths, and in 2004–05, Angola recorded 252 cases and 227 deaths. Although this year's case of Marburg virus disease was the first in west Africa, this region and southern Africa have also been afflicted by other viral haemorrhagic fevers over the course of the past decades, most notably Ebola virus disease. Thus far, in 2021, Ebola virus disease has killed 12 of 23 infected people in Guinea and six of 12 infected people in the DR Congo, although the largest outbreak by far was in 2014–16, which caused 11 323 deaths (n=28 646 cases) in Guinea, Sierra Leone, and Liberia. “The recent case of Marburg virus in Guéckédou in Guinea was detected in the same area where the 2021 and 2014 Ebola cases were detected”, said Ifeanyi Nsofor (EpiAFRIC, Abuja, Nigeria and Aspen Institute, Washington, DC, USA). “This is worrisome because it shows the impact of close interactions between humans and animals, leading to infections jumping from animals to humans. More investigations [are] needed to find out reasons why haemorrhagic fevers are common in this locality”, he told The Lancet Microbe. Ebola virus and Marburg virus diseases are not the only haemorrhagic disease affecting Africa. In 2020, in Mauritania, seven animal breeders (of eight infected individuals) died of Rift Valley Fever (RVF), caused by RVF virus. RVF virus was first identified in livestock in Kenya in the early 1910s, and to this day RVF is most prevalent in regions of southern and eastern Africa where sheep and cattle are commonly raised, although cases are occasionally reported in most of sub-Saharan Africa. Another viral hemorrhagic fever, Lassa fever, which is transmitted to humans by contact with rodent urine or faeces via contaminated food or household items, is predominantly present in west African countries. The disease has an observed case fatality rate of 15% in severe hospitalised cases, and according to WHO it is endemic in several countries, including Nigeria, Ghana, Guinea, Mali, Sierra Leone, and Benin. In a 2018 Lassa fever outbreak, 1081 suspected cases and 90 deaths were recorded across Nigeria, and this year, in Liberia, as of July 18, 13 confirmed cases and 9 deaths due to Lassa fever had been reported. “In the midst of [the] global COVID-19 pandemic, haemorrhagic fever outbreaks in West African countries is very disconcerting. […] What is needed is a swift public health response that is coordinated by international agencies, funding organisations, and most importantly, the national health institutions at the district, local government, state, and regional levels to curb the recent outbreaks.” Isaac Olufadewa (Slum and Rural Health Initiative, Ibadan, Nigeria) told The Lancet Microbe. Oyewale Tomori, retired professor of virology (Redeemer's University, Ede, Nigeria), told The Lancet Microbe, that “[our] poor surveillance systems, poor laboratory diagnostic techniques and abandonment of the age old field surveillance activities are responsible for our failure to detect the presence of these pathogens.” According to Amesh Adalja (Johns Hopkins Center for Health Security, Baltimore, MA, USA), “The recent outbreaks underscore the continual threat viral haemorrhagic fevers pose in certain geographic regions. […] This threat requires vigilance when it comes to surveillance and diagnosis of these infections underscoring the need for diagnostic capacity in viral haemorrhagic fever-prone areas.”