Biology Ebola is categorized as a member of the filoviridae family of viruses, one of three negative-stranded RNA viruses (Marburg, Ebola, and Reston) that often take on a “U” shape. Although it’s not yet known how it enters the cell, once inside, the RNA of the ebola virus is transcribed and replicated inside the cytoplasm, thereby infecting the cell. The Niemann-Pic C1 (NPC1) is a cholesterol transporter protein that is required for the ebola virus to permeate a cell, infect it, and replicate. The mutation of NPC1 is believed by many scientists to be key to finding a cure — perhaps through its mutation. As viruses are acellular, they do not replicate into other cells, but use the interior makeup of the host cell to multiply and assemble within the cell.
First cases and primary virus species
The name Ebola was given to the virus in 1976 after Zaire’s Ebola River, the region where the virus first broke out in what is now Democratic Republic of the Congo. The original species was called ebola-Zaire (considered the most lethal subtype), and the first outbreak occurred in the Yambuku region. With 318 reported cases, it resulted in an 88-percent death rate of 280 people. The second ebola subtype, ebola-Sudan, was introduced to the world that same year, spreading quickly around the Nzara and Maridi areas of the Sudan. There, 53 percent of the 284 reported cases resulted in death (151 people).
The Infamous Marburg Outbreak In 1967, the Filoviridae virus Marburg made its first appearance during outbreaks in three European cities: Marburg and Frankurt, Germany, and Belgade, former Yugoslavia. The source was said to be from labs where imported green monkeys from Uganda were being analyzed. A total of 31 cases of infections were documented when lab workers starting showing similar violent symptoms, and seven of these workers died.
Other species of the virus There are three other known types of the virus: ebola Côte d’Ivoire , ebola Bundibugyo (BDBV) and the Reston type. The former virus is also known as the Tai’ Forest virus and first surfaced in 1995 after a Swiss ethologist was infected from doing a necropsy on a chimpanzee in the Côte d’Ivoire forest. BDBV first surfaced in Uganda in 2007, and is as lethal as its cousin, the EBOV (classic ebola virus). The latter virus, Reston, is found in China and the Philippines, and while it can infect humans, has not killed one to date–instead causing the death of scores of monkeys and pigs.
Continued outbreaks throughout history
The worst outbreak after the late ’70s surge of the virus was in 1995, in the Democratic Republic of Congo, where the ebola-Zaire strain ravaged the areas surrounding the town of Kikwit, infecting 317 patients and killing 245. Lower-level outbreaks in the Gabon followed, but it was in Uganda in 2000 where the highest number of cases occurred; 415 people were infected with the Sudan subtype in the country’s Gulu district. It spread to other areas of the country. Task forces and the World Health Organization helped contain and eventually eliminate the breakout, but only after 224 deaths occurred. The last outbreak of high casualties was in 2007 in the D.R.C., where again ebola-Sudan’s hemorrhagic fever cut a swath through some very remote areas in the Kasai Occidental provinces. When the outbreak ended, 183 of the 247 infected had died.
Transmission Ebola can be transferred from animal to animal, from animal to human and from human to human. The infection travels via fluid secretions (blood, urine, semen, mucus), usually orally or through broken skin. In many cases, contaminated victims’ vomit has been a primary catalyst for the virus to travel, or burial ceremonies where improper handling methods infected community members. In Africa, contact with animals infected with the virus such as pigs, monkeys, bats, and porcupines inflicted humans. Many healthcare and hospital workers have died from the disease through lack of knowledge or environmental exposure.
The source Studies throughout the decades have led researchers to believe that one of the greatest sources for ebola is the fruit-eating bat. Three different bat species — hypsignathus monstrosus, epomops franqueti, and myonycteris torquata carry RNA sequences, proof that their bodies carry mutations from the ebola virus. This suggests that these bats may have lived with the virus for a long time, and that they could be the source. The often wide range of area a single outbreak can cover also implies that the source could be a mammal that can travel great distances very quickly. A proposed chain of events by many scientists is: bat droppings are eaten by terrestrial animals; the animals die, and then their carcasses are handled by a human. Keep in mind, not only the human race is at risk: approximately one third of gorillas in protected areas have perished from the virus in the last .
Symptoms Ebola and Marburg viruses start to show symptoms after approximately five days after infection. Chills, sore throat, a typical-feeling fever, sore joints — all common symptoms that would not necessarily send a victim to the doctor. Days later, vomiting, bloody diarrhea, body rashes and red eyes begin, and increase in severity. Many cases result in internal hemorrhaging or external bleeding from the mouth, nose, ears, and rectum.
Containment Early symptoms of the virus do not look much different from the common flu, fever, or stomach viruses. Therefore, the disease usually is unreadable until there are multiple cases, which is why containment is difficult. In most outbreaks, isolation wards in hospitals or medical centers have been established. In many cases, isolating victims and tracking their contacts has helped prevent the disease from becoming more widespread. The World Health Organization (WHO), Red Cross, Doctors Without Borders, and many disease control prevention workers descend on areas as soon as an breakout has been reported. In light of the current West African outbreaks, Senegal has closed its borders with Guinea, and many airports are taking the temperatures of arriving travelers before allowing them to enter the country.
Safety
“Barrier nursing techniques” are crucial for the safety of medical personnel during an Ebola outbreak. Basically, they get suited up–goggles, gloves, face mask, gown, and protection for the shoes. In the common event of an Ebola patient hemorrhaging or projectile vomiting, this helps to ensure that transmission does not occur. Many cases of hospital workers becoming infected are from early incidents of an outbreak before the actual disease has been diagnosed.
Treatment While there is not a known cure, the ebola virus can be mollified and often eliminated if discovered in a timely fashion. In 2012, groundbreaking scientific findings were published in Science Translational Magazine, claiming that two leukemia drugs showed signs of halting ebola virus replication. Intensive care treatment is necessary, and many drug therapies are in the process of being validated. Further work on finding a definitive vaccine continues; in many cases, electrolyte and nutritional management have aided in rehabilitating infected patients.
But why no cure? There are many reasons why finding a cure for Ebola is quite an uphill battle. For starters, antiviral treatments are much harder to establish than antibacterial. The ebola virus develops rapidly and evolves at breakneck speed, which means that today’s vaccine could be obsolete tomorrow. At a research safety level categorized as “biosafety level 4″, the total-lockdown laboratory situation means that there are limited facilities for studying the virus and extremely delicate, time-consuming procedures.
Early 2014 Outbreaks
As of late February, 2014, West Africa has seen an alarming outbreak of the Ebola virus. In Guinea, the epidemic started with five confirmed cases in the capital of Conakry. By March, cases were proliferating, with 60 deaths by hemorrhagic fever reported in three other districts. On May 15, the number of cases in Guinea totaled to 248, with 171 dead. The borders between Guinea and Liberia were closed when Liberia reported 35 cases and 11 deaths. Sierra Leone reported its first-ever outbreak of the virus, with five deaths initially. This has grown. The W.H.O. confirmed that the cases were along the country’s border with Guinea.
The New Outbreak: 1,000 and More Infected Sierra Leone is now being called the epicenter of this continued, intensified outbreak, which cut a swath across three countries in West Africa–Liberia, Guinea, and Sierra Leone. More than 1,201 cases have been reported by the World Health Organization, with 672 deaths documented. A Liberian man held in quarantine in Lagos, Nigeria, died Friday after traveling from Monrovia on a business trip, illustrating how easily the virus can hop national borders. Hysteria is on the rise; many who feel symptoms of even a common cold will not admit to it, on account of becoming stigma. There are two infected U.S. citizens being treated in intensive care in Liberia.
The Fight to Contain this Outbreak The rush to quarantine all areas in West Africa where the virus may spread has been intense. In Liberia, all public gatherings are banned and nearly every border has been shut down. Police forces as well as medical personnel are in a state of emergency, and work to enforce quarantines. The hospital in Lagos–Africa’s most populated city– where the Liberian Patrick Sawyer died of ebola, has been entirely shut down. Officials are tracing his contacts over the last few days, including fellow airline passengers and airport personnel. Airports in Liberia are screening all international passengers for symptoms.
Bioterrorism In East Africa especially, where terrorist cells have been the culprits of serious acts of violence against the public, it may be a reasonable concern to fear a situation where the ebola virus surfaces as a deliberate outbreak. While security in containment sites is always very high and areas always heavily monitored with surveillance, there is an increased need for policymakers to take measures against bioterrorism ever becoming a possibility.
The future “Stop eating bats!” Guinea has already made this a legal order. Sanitary methods have been undertaken in West African countries, including the banning of ceremonially washing dead bodies by hand. Scientists have been working on mutations of the virus to create a safe strain, with the hopes of finding a vaccination. Sporadic ebola flare-ups over the decades leave a big question mark over the continent of Africa. Are better sanitation, better health care, and better education key to keeping this killer virus at bay? -
culled from: http://afkinsider.com/55110/history-ebola-virus/18/
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