A virus that infects your brain, makes you want to bite things and is almost always fatal after symptoms appear probably sounds like something from a zombie movie. However, this has been the modus operandi of rabies at least since 2300 BC, when it was described in the Eshuma Code of Babylon. The word’s Sanskrit etymology — rabhas, meaning “to do violence” — dates back even further, to 3000 BC.
In principle, no human in this day and age should die from rabies, and yet, according to a study last year, the virus kills 59,000 people annually. That is 160 people every day and the actual number might be far higher if we could count unreported or untreated cases. Most of these deaths occur in Asia and Africa, with India alone accounting for one-third of the world’s total mortality from rabies.
That total is not as high as the death toll from tuberculosis, HIV/AIDS and malaria; but, unlike those diseases, every mammal appears to be susceptible to rabies. Dogs, the predominant host in most regions, can become infected from any rabid wild animal and then infect humans. Dogs showing symptoms might bite a human, but they can also transmit the virus simply by licking if their saliva comes into contact with a scratch, damaged skin or mucosa.
The rabies virus hijacks the nervous system and actually manipulates neural processes to make its host move faster. Infected humans will eventually hallucinate, become aggressive and even fear water in the advanced stages of the disease.
Once these symptoms appear, rabies has no known cure and death is almost certain. Fortunately, unlike most vaccine-preventable diseases, rabies allows for post-exposure inoculation, because the time of infection is generally known by the victim — especially if they were bitten — and the disease’s incubation period is relatively long, ranging from days to years, but averaging three to eight weeks. Whether administered before or after exposure, the vaccine is the same, but the immunization schedule and the dosage differ between the two scenarios.
French scientist Louis Pasteur formulated the first rabies vaccine in 1885, by injecting the virus into rabbits, waiting for it to kill them and then drying the infected nerve tissues to weaken the virus to the point that it could be safely administered. Then he successfully tested it on a nine-year-old boy who had been bitten by a rabid dog.
In today’s world, Pasteur would be thrown in jail for practicing as an unlicensed physician and not following proper clinical-practice standards, but we can all be thankful for his discovery.
Today, rabies vaccines are grown in a lab using cell cultures. The virus is then rendered inactive, purified and administered by injection into the arm. The WHO recommends pre-exposure vaccinations for anyone whose occupation or residence implies continual, frequent or increased risk of encountering rabies. This applies to everyone in rabies-endemic countries; unfortunately, not everyone in these countries gets vaccinated.
The rabies vaccine is on the WHO List of Essential Medicines and has an average wholesale price of US$11 per dose in the developing world, and as much as US$250 per dose in the US. Of course, because the alternative to post-exposure vaccination is death, the treatment is extremely cost-effective however one looks at it.
Smallpox, which is believed to have emerged even before rabies, has now been eradicated, and programs are currently under way to put an end to polio, Guinea worm disease and other infectious ailments. So why is rabies still prevalent?
One reason is that the virus is almost always transmitted by animals, rather than by other humans. To address this, we should be investing in pet vaccinations, reducing wild and stray-animal populations, and enforcing strict quarantines on animals crossing national borders.
In developed countries, preventing rabies largely requires controlling and immunizing wildlife populations, which has proved effective in Switzerland and Germany. In Latin American countries, where bat rabies is a threat, bovine vaccines have been used, as have anticoagulants, to kill bats that feed off the blood of the treated cattle.
Ultimately, the world’s poorest regions still bear most of the rabies burden. Dogs are not widely vaccinated, as they are in developed countries; and even when they are, their populations turn over very rapidly. Within a year of a large-scale vaccination effort, a new population of unvaccinated dogs will be roaming the streets and increasing the chances of an outbreak.
Meanwhile, developing countries’ healthcare systems are already grappling with tuberculosis, HIV/AIDS and malaria; and post-exposure prophylaxis supplies are limited.
Barring real progress on these challenges, one of the world’s oldest known viruses will continue to afflict humans and animals alike.
Melvin Sanicas, a public health physician and vaccinologist, is regional medical expert at Sanofi Pasteur, Asia, Japan and the Pacific.
Copyright: Project Syndicate
Chinese strongman Xi Jinping (習近平) hasn’t had a very good spring, either economically or politically. Not that long ago, he seemed to be riding high. The PRC economy had been on a long winning streak of more than six percent annual growth, catapulting the world’s most populous nation into the second-largest power, behind only the United States. Hundreds of millions had been brought out of poverty. Beijing’s military too had emerged as the most powerful in Asia, lagging only behind the US, the long-time leader on the global stage. One can attribute much of the recent downturn to the international economic
Asked whether he declined to impose sanctions against China, US President Donald Trump said: “Well, we were in the middle of a major trade deal... [W]hen you’re in the middle of a negotiation and then all of a sudden you start throwing additional sanctions on — we’ve done a lot.” It was not a proud moment for Trump or the US. Yet, just three days later, John Bolton’s replacement as director of the National Security Council, Robert O’Brien, delivered a powerful indictment of the Chinese communist government and criticized prior administrations’ “passivity” in the face of Beijing’s contraventions of international law
In an opinion piece, Chang Jui-chuan (張睿銓) suggested that Taiwan focus its efforts not on making citizens “bilingual,” but on building a robust translation industry, as Japan has done (“The social cost of English education,” June 29, page 6). Although Chang makes some good points — Taiwan could certainly improve its translation capabilities — the nation needs a different sort of pivot: from bilingualism to multilingualism. There are reasons why Japan might not be the most suitable role model for the nation’s language policy. Bluntly put, Japan’s status in the world is unquestioned. The same cannot be said of Taiwan. Many confuse