In this post I’m going to take a stab at addressing the clinical picture that a person with Ebola shows over the course of their illness. I’m basing this solely on what I’ve seen and learnt here. Disclaimer: it’s my impression of the disease rather than an evidence-based text.
It is actually quite tricky to describe Ebola, as the symptoms vary, are unpredictable, and, because we have no tests available, can be explained only through uncertain clinical deduction. Still, there are certainly common themes and some associations that we’ve noticed, so, with apologies for the lack of scientific rigour, and with fair warning about its vagueness, I think it’s worth a go….
Perhaps the best place to start is at the official case definition. In order to be classified as ‘suspect’ for Ebola (ie to need a blood test and isolation until a further blood test taken at least 72 hours after the onset of symptoms), you need to have had recent (within the previous 3 weeks) contact with someone who had Ebola or who died suddenly (this includes attending a funeral of someone who had Ebola or died without explanation), and you need to have a fever over 38 degrees C. Alternatively, you meet the case definition if you have one of the above features plus at least 3 of the common symptoms of Ebola, which include vomiting, diarrhoea, weakness, lethargy, headache, muscle or joint pain, bleeding, etc.
The reality of Ebola, however, seems rather less clear-cut. Certainly there is very often significant gastrointestinal symptoms such as abdominal pain, vomiting and diarrhoea, although not necessarily at the same time or throughout the illness. Things often start very subtly and vaguely. A person will feel weak and tired, will lose their appetite, then might experience some vomiting and muscle pain. The fever may or may not happen early in the illness. At this stage the only abnormal findings when examining someone would be a fever and maybe fast pulse and respiratory rate. Or not.
As the disease progresses more symptoms emerge. The weakness worsens to the extent that a person who is capable (with encouragement) of sitting up and taking a drink, is satisfied simply to lie still, not drinking and hardly moving at all. Pain in the abdomen, joints and muscles worsens and often requires strong pain relief to combat it. The vomiting and diarrhoea can become profuse (often vomiting precedes diarrhoea). People sometimes develop a conjunctivitis (red eyes) and also become confused and distant, resulting in a disturbing glazed stare that indicates established disease. Some people get hiccups: we don’t really know why.
The classic ‘bleeding’ of the viral haemorrhagic fevers (of which Ebola is one) only seems to occur about 10% of the time. It can manifest as bleeding from the bowel or mouth or anywhere, and of course, irrespective of the severity of the bleeding, indicates severe illness. Ebola infection during pregnancy is always fatal for the fetus and often also for the mother. Some people experience odd and seemingly random neurological issues such as various patterns of paralysis that last a few days then gradually recede, and there are reports of long term vision issues (iritis) emerging in survivors.
In my very limited experience, Ebola seems to worsen and become fully established over about 3 or 4 days from first symptoms. It stays severe for about another week, then, if the person survives, the symptoms abate relatively quickly, but the virus stays present in the blood for a further 5 days or so. Only once there is no virus in the blood can a person be deemed no longer infectious and be discharged, and even at that point virus remains present in some body fluids (such as breast milk and semen) for longer periods.
Infectious disease specialists in our team agree that the clinical appearance of someone with severe Ebola is not simply that of generalized severe infection (sepsis). There are things that set it apart: the red eyes; the hiccups; the confusion; the bleeding. A lack of fever does not mean that the disease is necessarily resolving, and I have also noticed that people’s heart rates are significantly slower than I’d expect in relatively dehydrated people (this is a sign sometimes seen in typhoid also). It is unpredictable and protracted; someone with seemingly hopeless symptoms can suddenly turn a corner and recover, and someone who seems to be doing well can suddenly deteriorate.
But for all the nastiness of its presentation, there is certainly some good news. There is no question that early treatment with relatively simple interventions such as adequate fluids improves survival, and survival is happening with gradually increasing frequency.