Should we be alarmed if a Singaporean is infected with Ebola?
Senior writer Andy Ho explains why there is no need to be unduly worried if a Singaporean is infected overseas. Just fly him back to be treated, he writes.
Published on Aug 11, 2014 1:26 PM
This piece was first published in the Think section of The Sunday Times on Aug 10, 2014
Two Americans who caught Ebola in an epidemic in West Africa have been flown back to the United States for treatment. A reader asked whether it would be wise to bring such persons back for treatment if they were hypothetically Singaporeans. Would doing so risk causing an Ebola outbreak on these shores?
The answer depends on how easily the virus spreads and how well such a patient would be isolated in hospital here.
The illness, which first emerged in 1976 in Zaire and Sudan, can have a kill rate of over 90 per cent with no treatment. With therapy, however, this rate can fall to about 57 per cent.
There is no anti-viral drug that can cure the infection, so doctors isolate the patient and support his condition with blood products. The latter serve to combat any bleeding tendency that may develop since Ebola is a viral haemorrhagic fever - like dengue.
As the Ebola virus multiplies, it interferes with blood clotting, which makes the patient very prone to bleeding. When this happens, the patient may bleed from the eyes, ears, gums, mouth and nose, or vomit or cough up blood, or pass blood in the stools. There can be internal bleeding with organ damage, ending in multiple organ failure and death.
The virus can be found in the blood, saliva, urine, stools, broken skin or mucous membranes, the linings of the bodily orifices. This is why people who handle the patient or the corpse of an infected person and may come into contact with these bodily fluids - health- care workers, family members and those involved in funerals - tend to be the ones infected in a hospital setting.
After death, the body's skin, connective tissue and organs begin to liquefy, so fluids suffused with the Ebola virus will leak from the corpse. In West Africa, funerary practices involve relatives handling the body, whose fluids - blood, saliva, semen, vomit, urine or faeces - can still spread the virus. Unlike most germs which do not survive on a corpse for very long, the Ebola virus can stay infectious for perhaps weeks after the patient dies.
Since Ebola is transmitted only through bodily fluids, infections within a hospital setting occur in the affected countries in Africa where there may not be enough resources for the proper sterilisation of syringes, needles, surgical instruments and so on.
It is such equipment - contaminated with bodily fluids, but inadequately sterilised and then reused anyway - that causes Ebola to spread within hospitals.
By the same token, treating an Ebola patient in a hospital in Singapore would not pose an inordinate degree of risk as we may take for granted that there is the proper sterilisation of medical devices, surgical instruments, supplies and equipment used in direct patient care and surgery here.
In addition, patient isolation practices and barrier nursing - where those who take care of the patient in an isolation room wear masks, goggles, gloves and gowns to protect themselves - would meet the highest standards here. This may not be so in the affected countries in Africa.
Obviously, for these stringent practices to work, they must be meticulously observed. During Sars, some health-care workers became infected when they did not observe some precautions.
Subsequently, many hospitals would station monitors outside isolation rooms to ensure that such precautions were followed. As long as these precautions are observed, hospital-acquired Ebola should be a rarity. There would not be completely no risk at all, but it should be nearly nil.
Given the high standards in local hospitals in all these areas - sterility, isolation and nursing - the risks in treating the hypothetical Singaporean infected with Ebola would be manageable and neither health-care workers nor the public would be placed at an unacceptable level of risk.
Suppose a health-care worker or family member did get infected in a hospital anyway. Could the disease then spread throughout Singapore like in West Africa?
Note that the infected person is not himself infectious during the incubation period, which can range from two to 21 days.
Ebola patients become contagious only when they start having symptoms such as fever, weakness, muscle pains, joint pains, headaches and a sore throat.
As the virus can be transmitted only by the bodily fluids of someone who is sick, very unhygienic conditions on a very wide scale would be needed for it to spread like wildfire. Thus, in a developed country, Ebola is highly unlikely to ever spread widely.
So let us not get hysterical about Ebola. Despite its horrendous reputation, an infection can lead to anything ranging from a relatively mild disease to the frighteningly deadly form if a bleeding tendency develops.
Moreover, like hepatitis C, say, Ebola is transmitted only through contact with body fluids, and not through the air like measles, say, which is thus more contagious.
So it should not be too surprising to learn that, from 1976 to last year, there have been only 2,387 reported cases of Ebola with 1,136 deaths. Its largest outbreak to date is the ongoing one in West Africa, with more than 1,700 reported cases and more than 900 reported deaths.
This means that, since 1976, Ebola has infected just over 4,000 people and killed just over 2,000. The context, it must be remembered, is Africa, with a total population of one billion.
By contrast, in 2012, measles killed 122,000 people globally, according to the World Health Organisation which also reports hepatitis C-related liver diseases as killing between 350,000 and 500,000 people each year.
Ebola is unlikely to reach such figures because it is not infectious enough - it cannot be transmitted by mere proximity or by an airborne route - and because it kills so fast when the illness turns haemorrhagic that the virus runs out of human hosts quickly and the outbreak burns itself out.
In sum, we need not be unduly alarmed if a Singaporean is unfortunate enough to catch Ebola in the affected countries in Africa. He or she should certainly be flown back here for treatment.
And Ebola continues to pose a low public health risk here as the latest health advisory from the Health Ministry rightly says.
Let us not get hysterical about Ebola. Despite its horrendous reputation, an infection can lead to anything ranging from a relatively mild disease to the frighteningly deadly form if a bleeding tendency develops.