There’s never been a worse time to have a headache. Or fever, nausea, sore throat, stomach pain, rash, bleeding, or red eyes: All symptoms of the violently lethal Ebola virus, which continues its spread through West Africa. The latest episode of the epidemic that began in Guinea this July has killed nearly a thousand people in the country as well as in neighbouring Liberia, Sierra Leone, and Nigeria. The virus spreads through body fluids like urine and blood of infected persons. It causes haemorrhagic fever, which makes the blood unable to clot wherever the germ’s minute infectious agents — or virons — tear through tissue. In extreme cases, blood gushes from all orifices, which is why Ebola’s very mention conjures up nightmarish images of people suddenly falling down dead in pools of blood.
The World Health Organization has declared the epidemic an international health emergency and Ebola is now on every doctor’s watchlist as health authorities across the world scramble to batten down the hatches before the microbe gets a chance to sneak in, piggybacking on some air passenger. Since the virus has a three-week incubation period between infection and the symptoms showing up, infected passengers could slip in past thermoscanners. Airports across India are on alert for travellers from the affected countries who show symptoms of the disease. Suspect passengers have to explain through health cards their movement in the recent past and undergo tests.
The fact that there is no vaccine or specific treatment for the disease adds to public fear of Ebola. “Stringent isolation precautions must be observed along with the use of gloves and masks, and disposal of material according to standard protocol,” says Dr Dinesh Kaul, consultant, Paediatrics Infectious Diseases at Delhi’s Sir Ganga Ram Hospital. “Currently test kits are available only at the National Institute of Virology, Pune and the Centre for Disease Control in Delhi; there are no private or commercial labs with facilities to test for the disease.”
Ebola outbreaks originate in wild animals and reach humans who eat them or come into contact with their faeces, urine or saliva. The microbe lies dormant in ‘reservoir species’ of animals for years before infecting human populations. Experts believe bats — or even chimpanzees that eat fruit bitten by bats — could be the most likely ‘reservoir species’ for the virus. And bats are eaten in those parts of West Africa where the microbe is now wreaking havoc.
The US government is expected to begin testing an Ebola vaccine on humans as early as September, after seeing positive results during tests on primates. But it is early days yet, says Dr Kartik Chandran, associate professor of Immunology & Microbiology at the Albert Einstein College of Medicine in New York, whose lab has done pioneering work on viruses like Ebola. “The Ebola must cross a cellular membrane to enter the host’s cytoplasm, where the raw materials and machinery required for multiplication are present. So we focus on developing antiviral therapies that block cell entry and interdict viral replication before the virus can commandeer the host cell,” he said. But a successful strategy for this type of emerging viral pathogens still eludes scientists, “in part because details of the entry-related virus-host interactions and viral protein transformations remain obscure for these agents.”
Ironically, the real problem in tackling the epidemic has more to do with economics than technology. Pharma majors have little incentive to put money into R&D for a disease that pops up once in a while in Africa where there is no lucrative market.
Prakash Chandra is a science writer
The views expressed by the author are personal