Wednesday, August 6, 2014

Vomiting and Diarrhoea doesn't necessarily mean food poisoning.

If someone reported that they had vomiting and diarrhoea, I would normally suggest that they had contracted food poisoning.  Further questions about recent meals, travel history, etc. would help to clarify the situation.

However, with the current Ebola virus outbreak in West Africa - Sierra Leone, Guinea and Nigeria - and two Americans apparently infected, together with a reported potential case in Sydney, the possibility of a world wide epidemic is not far fetched.  


Ebola viral disease is not new - it first appeared in 1972, just after I qualified as a microbiologist, in the Sudan and Democratic Republic of Congo.  There was then and still is no licenced vaccine and the fatality rate can be as high as 90%.  



Ebola is not transmitted by food.  The reservoir appears to be wild animals and there are documented cases of transmission of the virus to humans through handling or contact with bodily fluids of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest (WHO, 2014).  Transmission is then human to human, again by contact with bodily fluids through broken skin or mucous membranes.  Contact with environments contaminated with fluids from infected individuals can also result in transmission.

According to staff at the Mayo Clinic, signs and symptoms typically begin abruptly within five to 10 days of infection with Ebola or Marburg virus. Early signs and symptoms include:
Fever
Severe headache
Joint and muscle aches
Chills
Weakness

Of course, some other diseases including influenza can produce similar symptoms. However, in the case of Ebola viral disease, symptoms become increasingly severe and may include:
Nausea and vomiting
Diarrhea (may be bloody)
Red eyes
Raised rash
Chest pain and cough
Stomach pain
Severe weight loss
Bleeding, usually from the eyes, and bruising (people near death may bleed from other orifices, such as ears, nose and rectum)
Internal bleeding


There is no need to panic if you or family members have vomiting and diarrhoea, but the application of sensible precautions can help to limit the spread of the virus or any other causative agent.  Air travel is a very rapid way for infections to spread around the world.  If you have been in Central or West Africa within the last few days and start to show the early symptoms listed above, you should immediately contact a doctor and, to be fair to your fellow man, avoid air travel.  If you have been on an aircraft where someone had vomiting and diarrhoea, it might also be a good idea to consult a doctor, even thought the cause is most likely food poisoning.

As with all cases of vomiting and diarrhoea, take great care with personal hygiene and ensure that those people looking after you do the same.  The chances are that you don't have Ebola, but this outbreak looks to be the most widespread so far. 

WHO (2014)  Fact sheet N°103. Updated April 2014.Retrieved from:  http://www.who.int/mediacentre/factsheets/fs103/en/

1 comment:

John Brooks said...

I received an e-mail today that refers, among many things, to Ebola. It is typical of many posts on various websites: it contains a lot of information and URLs for other websites. However, the links made between the various bits of information are spurious and in some cases downright misleading. For example, there is, as far as I am aware, no link between the discovery that genetic information could be transferred between bacteria in the laboratory, a technique that has become widely known as 'genetic engineering', and the first outbreak of Ebola two years later. The subtlety is that the author never claims directly that there is a link, but the relative placement of these two facts suggests to the reader that there is a direct causal relationship.

Similarly, E coli O157:H7 does in some cases cause haemolytic uraemia, but again, this is a completely different mechanism from the haemorrhagic Ebola viral disease.

Yes, viruses can infect bacteria and bacteria are central to sewage treatment processes. But the viruses that attack bacteria (bacteriophage) are very specialised. Again, as far as I am aware, Ebola and other haemorrhagic viruses cannot infect bacteria.

Be very careful when reading material on the Internet: some sites can be trusted, such as the FDA Bad Bug Book, but others have all the value of snake oil.

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