Ebola is not Swine Flu
The increasing alarm surrounding the most recent outbreak of the Ebola virus disease (EVD) is a chilling reminder of the potential for the spread of viruses to rapidly reach epidemic proportions. The virus causes haemorrhagic fever marked by severe bleeding, organ failure and, often, death. The first recorded outbreak of EVD was in 1976 and since then at least 3000 cases have been identified, with 1600 deaths recorded in Sudan, Congo, Uganda and the Democratic Republic of Congo.
The scale and spread of the current emergency in Guinea, Sierra Leone and Liberia since March 2014 is of concern as it has claimed more lives than any previous outbreak. Usually EVD is transmitted in small communities and in healthcare settings, but it has now appeared in cities as well as rural and border areas. It is also striking that the outbreak has occurred almost simultaneously in three previously unaffected countries. There are fears modern logistics could facilitate spread to more countries within Africa or even internationally.
In June 2009, as the number of people with H1N1 (swine) influenza reached 42,000 in 80 countries, the World Health Organization (WHO) elevated its pandemic alert to “level 6” – the highest emergency state. In the end, that strain of flu proved far less deadly than was feared. The WHO has announced a $100 million response plan to tackle this new “unprecedented” Ebola outbreak, currently exhibiting a 56% mortality rate. Should underwriters also be at “level 6”? The evidence suggests not.
Outbreaks of EVD occur primarily in remote areas in Central and West Africa following close contact with the wild animals that host the virus. It spreads easily between humans through direct contact: broken skin, damaged mucous membranes, during sex, in infected blood and bodily fluids including sweat, or indirectly through contact with virus contaminated environments. People remain infectious as long as their blood and secretions contain the virus, typically up to seven weeks, and this risk persists even after death. Family members are often infected as they care for sick relatives or prepare the dead for burial.
A person infected with EVD complains of sudden-onset fever, intense weakness with muscle pain, headaches and a sore throat. These rather non-specific symptoms suggest a mild illness and raise the possibility of many diseases including hepatitis, typhoid fever and malaria – all of which must be ruled out before a diagnosis of EVD can be made. During this time symptoms worsen to include vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.
The incubation period – the time interval from infection to onset of symptoms – is 2 to 21 days so some people seek help sooner than others. People who are severely ill with EVD require intensive care. In a rural setting where the health infrastructure is weak or mistrusted and where cultural beliefs strongly influence how people interpret symptoms and seek treatment, diagnosis and intervention are likely to be delayed.
No specific treatment is available although new drug therapies are being evaluated. Following diagnosis patients need intensive care in total isolation. Supportive treatment includes intravenous fluid, to prevent dehydration, and maintenance of blood oxygen and blood pressure levels, as most sufferers die of low blood pressure and not bleeding. Transfusions may be needed to replace blood lost through haemorrhage, and subsequent infections need to be treated.
Identifying those at risk
EVD makes people very sick very quickly so it seems unlikely any person who has it would slip through the underwriting net. An applicant with unexplained or unusual illness and who has visited an affected area within the preceding month should be viewed with increased suspicion.
An EVD diagnosis is confirmed in a laboratory setting by isolating the virus in cell culture, antigen detection or enzyme-linked immunosorbent assay (ELISA). Other findings include low white blood cell and platelet counts and elevated liver enzymes.
People who survive EVD make a slow recovery, taking many months to regain their weight and strength as the virus remains in the body for weeks. Typically they suffer hair loss, sensory changes, eye and testicular inflammation, hepatitis and general malaise. Survivors often develop chronic inflammatory conditions affecting the eyes (uveitis) and joints.
Travel to Africa increases the risk of exposure to the virus. The Centres for Disease Control has recommended Americans avoid the area. WHO has stopped short of recommending travel restrictions or border closures but admits this position is fluid. The ease with which people travel worldwide implies infection could spread rapidly and without control, but there is no evidence of this yet. The International Air Transport Association has taken this as an opportunity to state that in the rare event a person infected with the virus is unknowingly transported by air, the risk to other passengers is low. It seems highly unlikely that a person with the advanced signs of EVD – the stage when onward transmission is most likely – would be physically well enough to undertake air travel.
Health and humanitarian workers who disclose imminent travel pose an increased risk. Medical personnel may be infected if they fail to take appropriate precautions to avoid infection by wearing protective clothing, masks and gloves when tending to the patients. In this new outbreak, several health workers have been infected whilst treating patients with suspected or confirmed EVD and not strictly practicing infection control techniques.
Anyone who requires treatment in poorly equipped medical centers in the affected area may be exposed to re-used needles and syringes or contaminated equipment that has been improperly sterilized. People involved in animal research or observation have an increased chance of contact. Anyone butchering or eating infected animals or coming into contact with their faeces or urine also increase their chance of infection. No vaccine is available for use in people or animals.
It seems unlikely that EVD poses a threat beyond its immediate geographical location or the indigenous population and visitors working closely with them. Isolation centres, arrivals screening and modern treatment facilities would use quarantine to limit international spread and ensure that the rapid incubation of EVD experienced during the current outbreak is not replicated in other countries. Deadly though it is, EVD is not airborne and so there is no credible risk of a swine flu-like epidemic.