After the H1N1 influenza (swine flu) in 2009 and polio in May 2014, the WHO has now declared the Ebola (Ebola virus disease) outbreak in West Africa as an “extraordinary event” and a “public health risk to other countries.” It has also highlighted that the “consequences” of its spread across the world could be “particularly serious” considering the virulence of the virus. After the first outbreak in December 2013 in the Guéckédou region in Guinea’s remote southeastern forest region, the virus has spread to three other West African countries — Liberia, Nigeria and Sierra Leone. As on August 6, as many as 1,779 people (with 1,134 confirmed cases) were infected and the mortality figure was 961. The death toll this time is much more than the combined count of all previous Ebola epidemics. The biggest threat comes from the extremely high virulence of the Zaire Ebola virus species, the most lethal Ebola virus known, with fatality rates going up to 90 per cent; the Zaire virus species is usually restricted to Central Africa. Though the virulence has been lower at 55 per cent, it is still alarmingly high. The incubation period — the time interval from infection to onset of symptoms — of two to 21 days poses a real danger to public health. In this era of global travel, though infected people would not transmit the virus till they develop the disease, they could facilitate virus spread once symptoms show up.

Despite the deadly characteristics of the virus, transmission occurs only when people come into contact with the body fluids of affected people; there is no scientific confirmation of humans getting infected through airborne transmission. Yet, transmission has been rampant both in the community and in health-care settings. Poor handling practices in weak health-care systems are putting doctors and healthworkers at great risk. Currently, no approved drugs or vaccines are available to prevent infections or treat infected people. But an experimental drug tested only in animals has improved the condition of two Ebola-infected U.S. nationals who were flown back to America. It is highly unlikely that the drug would be used to treat those in the four countries. One way to prevent the spread is to stop symptomatic passengers from travelling in normal passenger aircraft, and to screen and follow up those arriving from or transiting through these countries as the infected people act as carriers of the virus. India has its task cut out as nearly 5,000 Indians who live in Guinea, Liberia and Sierra Leone and about 40,000 in Nigeria may return here. The Union Health Minister has held out the assurance that the Ministry has put into operation “the most advanced surveillance and tracking systems”. Utmost care is called for.

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