What is Ebola and how does it spread? For scientists tracking the deadly Ebola virus in West Africa, it is not about complex virology and genotyping, but about how contagious microbes - like humans - use planes, bikes and taxis to spread. The risk of the virus moving to other continents is low, disease specialists say. But tracing every person who may have had contact with an infected case is vital to getting on top of the outbreak within West Africa, and doing so often means teasing out seemingly routine information about victims lives. So far, the disease has claimed over 700 lives, making it the deadliest outbreak in history. What is Ebola? Ebola virus disease (also known as Ebola hemorrhagic fever), along with being one of mankinds deadliest diseases, is also one of its most brutal. It causes extreme body aches, high fever, heavy internal and external bleeding, profuse vomiting and diarrhea - all of which contain high concentrations of infectious virus. Symptoms can manifest themselves between two and 21 days after exposure and usually begin with headaches and fever. There is no cure for the disease, which has been fatal in up to 90 percent of patients during some outbreaks, though the current outbreak has killed about 60 percent of those so far infected. Treatments include managing the patients fluids and electrolytes, as well as blood pressure, all of which are in jeopardy as the infected bleed out of organs and even blood vessels. Transmission of the virus occurs when a person comes into contact with the bodily fluids - blood, vomit, feces - of an infected person. This puts health workers tending to Ebola patients in an extremely dangerous position as patients can throw off huge amounts of their fluids during painful, uncontrollable fits of pain and vomiting. Walls, sheets and medical equipment often become soaked in the highly contagious fluids. Patients are kept in isolation wards to avoid infecting others in a clinical setting. Even with the full body suits health workers wear - the iconic image of the disease - transmissions occur. Several American missionaries working to disinfect doctors and nurses operating in suits have contracted Ebola and the chief doctor fighting the outbreak in Sierra Leone, Dr. Sheik Umar Khan, caught the virus and died. The first diagnosed case of the Ebola Zaire strain was a nurse who perished after treating a nun who broke with the disease after helping treat the sick in then Zaire. There are five known strains of Ebola, which first manifested itself in humans in the 1970s in Zaire and Sudan. Four of the five have caused disease in humans, while the fifth, Ebola Reston, caused disease only in primates. The Reston strain is named for Reston, Virginia where the strain was discovered in a commercial monkey house in 1989. It killed hundreds of monkeys, and many more were euthanized, but never made the jump to human beings. How it spreads In Nigeria, which had an imported case of the virus in a Liberian-American who flew to Lagos this week, authorities will have to trace all passengers and anyone else he may have crossed paths with to avoid the kind of spread other countries in the region have suffered. The West Africa outbreak, which began in Guinea in February, has already spread to Liberia and Sierra Leone. With more than 1,300 cases and over 729 deaths, it is the largest since the Ebola virus was discovered almost 40 years ago. Sierra Leone has declared a state of public emergency to tackle the outbreak, while Liberia is closing schools and considering quarantining some communities. Some in the nations effected by Ebola are distrustful of of authorities battling the disease, thinking it might be caused by those treating it, or that traditional medicinal methods will be better than jam-packed isolation wards - quite literally - dripping with the virus. Protests broke out in Sierra Leone outside one hospital with an isolation ward last week. Assistant Inspector General Alfred Karrow-Kamara said the protest was sparked by a former nurse who had told a crowd at a nearby fish market that, Ebola was unreal and a gimmick aimed at carrying out cannibalistic rituals. The first case Epidemiologists and virus experts believe the original case in that instance to have been a woman who went to a market in Guinea and then returned, unwell, to her home village in neighbouring northern Liberia. The womans sister cared for her, and in doing so contracted the Ebola virus herself before her sibling died of the hemorrhagic fever it causes. Feeling unwell and fearing a similar fate, the sister wanted to see her husband - an internal migrant worker then employed on the other side of Liberia at the Firestone rubber plantation. She took a communal taxi via Liberias capital Monrovia, exposing five other people to the virus who later contracted and died of Ebola. In Monrovia, she switched to a motorcycle, riding pillion with a young man who agreed to take her to the plantation and whom health authorities were subsequently desperate to trace. Gatherer noted that while Ebola does not spread through the air and is not considered super infectious, cross-border human travel can easily help it on its way. Its one of the reasons why we get this churn of infections, he said. The risk of the Ebola virus making its way out of Africa into Europe, Asia or the Americas is extremely low, according to infectious disease specialists, partly due to the severity of the disease and its deadly nature. Patients are at the most dangerous when Ebola is in its terminal stages when bleeding and vomiting are at their heaviest. Anyone at this stage of the illness is close to death, and probably also too ill to travel, said Bruce Hirsch, an infectious diseases expert at North Shore University Hospital in New York. It is possible, of course, for a person to think he might just be coming down with the flu, and to get onto transport and then develop more critical illness. Thats one of the things we are concerned about, he said in a telephone interview. He added, however: The risk (of Ebola spreading to Europe or the United States) is not zero, but it is very small. touch.baltimoresun/#section/-1/article/p2p-80965383/
Posted on: Sat, 02 Aug 2014 09:45:58 +0000
Trending Topics
Recently Viewed Topics
© 2015