The cost of pandemics, and how to reduce it

SARS, bird flu, swine flu, Ebola, Zika. It is hard to believe that not too long ago, there was an idea that infectious diseases had been largely conquered, at least in principle. Then along came AIDS, and now with more people on the planet and more travelling, new infections are actually becoming more common.

Ebola has infected almost 30,000 people, killing 11,000, and inflicted an economic cost of more than $2 billion on some of the poorest countries in the world. SARS infected far fewer – 8,000, and killed 800, but because it hit richer places, it cost more than $40 billion. A recent report on global health risks put potential global losses from pandemics at around $60bn a year.

America’s National Academy of Medicine suggests that $4.5bn a year, about 3% of what the rich world spends on development aid, invested in medical research, public health services and better emergency co-ordination could significantly strengthen our defences against disease.

More effective health systems would help fight illnesses such as tuberculosis that costs perhaps $12bn a year, and malaria which probably costs several times that. Better research could help find vaccines to treat diseases that at the moment are mercifully rare, but which could become pandemics, such as Lassa fever and Crimean-Congo haemorrhagic fever.

Mosquitoes strike again - this time it's zika

First there was malaria, then yellow fever, then dengue (see my post of 31 July 2013), then it was chikungunya (see my post of 21 May 2014), now it is zika – all of them spread by mosquitoes. In the case of zika, now moving through Latin America and the Caribbean, it is the same mosquito (see picture) that spreads dengue and yellow fever.

If a pregnant woman is infected with zika, it is believed the virus can cause her baby to have an abnormally small head – a condition known as microcephaly, which is often caused by the failure of the brain to develop at its usual speed. Nearly 4,000 such babies have been born in Brazil since October, and 49 have died.

A number of countries including Colombia, Ecuador, El Salvador and Jamaica, have advised women to delay becoming pregnant until more is known about the disease, which was first identified in Africa in the 1940s. Some believe it was introduced to Brazil during the World Cup in 2014.

There is no known cure for zika, and the only way to prevent it is to avoid being bitten by the mosquitoes that carry it. In Brazil, they are working to clear stagnant water where the insects breed.

Accidental anti-malaria drug

A Nobel prize-winning drug that kills parasitic worms may also work against malaria. Trials of ivermectin in villages in Burkina Faso are estimated to have prevented nearly 100 cases of the disease.

In communities where people took the drug, 25% of children avoided catching malaria during the rainy season, compared with just 16% in the untreated villages. The drug appears to work by weakening or killing the mosquitoes that spread the illness.

The trial does not end until next week, and these are preliminary results, but one of the investigators said they were ‘pretty excited’. Deaths from malaria have been reduced dramatically over the last 15 years, but it still kills about 430,000 people a year, most of them in Africa.

Fighting parasitic worms is also crucial. They can cause illnesses such as river blindness and elephantiasis, and by some estimates, they affect a third of the world’s population.

Malaria - progress in the fight

Malaria is projected to kill more than 430,000 people this year. That's bad enough, but it represents a cut of around 60 per cent since 2000, the year the disease was targeted by the UN's Millennium Development Goals programme.

The WHO says 6 million lives have been saved. Its director general, Dr Margaret Chan, describes this as 'one of the great public health success stories of the past 15 years. It's a sign that our strategies are on target, and that we can beat this ancient killer.' 

Nearly 70 per cent of the reduction is put down to the distribution of a billion insecticide-treated bed nets. But there are some worrying signs. The mosquitoes that carry the disease are becoming more resistant to some insecticides, and the rate at which cases are being reduced is falling. 

Africa still accounts for about 80 per cent of all cases. (See also my posts of 11 June 2009, 23 May 2012, 23 Sept 2011, 29 April 2013.) 

Malaria - a pugnacious parasite

New drug-resistant strains of the parasite that causes malaria have been identified in western Cambodia.    There have been reports of drug resistance in the region since 2008, and the problem has now spread to other parts of South-east Asia.

Scientists investigating the new organism say that all the most effective drugs developed in the last few decades ‘have been one by one rendered useless by the remarkable ability of this parasite to mutate and develop resistance.’   They do not know why this part of Cambodia should be such a hotbed of resistance.

In 2010, there were more than 200 million cases of malaria and 600,000 deaths – 90 per cent of them in Africa.   The World Health Organisation has made preventing the spread of resistant strains a major objective.  

See also my blogs of 11 April, 30 May, and 24 Sept, 2009; 21 Oct, 2010; 23 Sept, 2011 and 23 May, 2012.

*I’ve just started to post a series of videos on Britain’s 20 Worst Military Disasters.   This is the first -  https://www.youtube.com/watch?v=D0Bgf-xHHGE

Fakes undermine fight against malaria

Recent successes in the fight against malaria are being undermined by the way counterfeit drugs have penetrated the supply chain in sub-Saharan Africa and south-east Asia.   American researchers examined 4,000 anti-malaria drug samples from 28 countries and found that a third were fake.

The problem is that not only do they fail to protect the people who take them, but they can also lead to resistant strains appearing, and the researchers think the problem may be even worse than their findings suggest.

Death rates from malaria have fallen by more than a quarter since 2000, but more than 3 billion people in 106 countries are still at risk, and up to 1.2 million die every year.

There has been concern in recent years over the emergence of resistance to the most effective drugs in western Cambodia.    (See also my blogs April 11, May 30, Sept 24, 2009 and Oct 21, 2010 and Sept 23, 2011.)

Malaria - a glimmer of hope?

Some hopeful signs from a new anti-malaria vaccine.    Preliminary trials had begun in Burkina Faso to test its safety, but it soon became clear that children who had been given the injection were getting a high degree of protection.

The results are described as ‘most encouraging’, and a bigger trial is about to start in Mali.  About 100 different vaccines have been tried against the disease, and this one, developed by the Pasteur Institute in Paris, is only the second to have shown promise.

The Burkina Faso study involved only 45 children, but the incidence of malaria was three or four time lower among those who were given the vaccine.    Eight hundred children will be enrolled in the new trial in Mali.

Malaria still kills around 1 million people a year, 90 per cent of them in Africa, and most of these are young children.  (See also my blogs of 11 April, 30 May, 24 Sept and 21 Oct, 2009.)

Malaria - is it even worse than we thought?

A new report, produced by the US National Institutes of Health among others, claims there are perhaps 13 times more deaths from malaria in India than official figures suggest. In rural India, well over 1 million people a year die from infectious diseases, where acute fever is the main symptom, but beyond that the condition often goes undiagnosed.

By interviewing a sample of bereaved families, the researchers came to the conclusion that there are up to 205,000 malaria deaths a year in India, compared to the World Health Organisation’s figure of 10-21,000. The WHO does not accept this conclusion, but agrees there might be limitations in its own calculations.

Across the world, malaria is thought to kill more than 1 million people a year, though, if the researchers are right about India, this may be a serious underestimate. The number of cases has risen over the last 30 years, partly through mosquitoes becoming resistant to drugs and insecticides. (See also my blogs of 11 April, 30 May, 24 Sept, 2009.)

*Out next month in paperback! A Disastrous History of the World. http://www.littlebrown.co.uk/Title/9780749909796

Battling malaria

Fourteen African countries have joined forces to fight malaria, which still kills nearly 900,000 people a year – most of them young children in sub-Saharan Afirca – that’s more than AIDS and tuberculosis combined in those areas. No less than 86% of all the world’s malaria cases, and 91% of the deaths happen in the Dark Continent.

The African Leaders Malaria Alliance has raised nearly £2 billion to buy 240 million mosquito nets treated with insecticide. The aim, which cannot be faulted for ambition, is to stop nearly all malaria-related deaths within six years.

The announcement came just as the World Health Organisation was reiterating the concern that the malaria parasite was growing increasingly resistant to artemisinin, regarded as the most effective drug for combatting the disease.

Malaria is one of the oldest illnesses known to man, and has been infecting human beings for at least 50,000 years. (See also my blogs of April 11th and May 30th)

AIDS - some (kind of) good news

On April 11, I wrote about a new drug that may offer us hope against malaria, now there are grounds for some optimism in the global battle with AIDS. Researchers have discovered two powerful new antibodies against the virus.

They are found in only a minority of those infected and are the first of their type to be identified in more than a decade. It is hoped that the discovery may speed up the search for an effective vaccine, though Keith Alcorn, of the HIV information service NAM, warned that that prospect was still a long way off.

He said this was an extremely complex project and that “we certainly shouldn't expect these findings to lead to a vaccine in a few years.”

Across the world last year, the World Health Organisation said that there were 33 million people living with the AIDS virus, and that 2 million had died from the disease during 2007. About 1.6 million of those deaths were in sub-Saharan Africa - the region that is worst affected with two thirds of the world’s cases. Countries such as Botswana, Swaziland, South Africa and Zimbabwe all have infection rates of over 15 per cent. (see my blog of Feb 18th)

Unpronounceable killer

Twenty-nine people have now died from swine flu in the UK. Bilharzia kills 280,000 every year in sub-Saharan Africa. The disease, which also has the less pronounceable name schistosomiasis, infects 200 million people every year, and across the world 20 million have to live with the anaemia, chronic diarrhoea, internal bleeding and organ damage it brings.

The illness is caused by tiny flatworms that live in water, and use forked tails to burrow into the skin of humans. For more than 20 years, we have had a cheap drug that can combat bliharzia, but the problem is that it does not prevent people from being infected again.

Now scientists have decoded the worm’s genetic blueprint. That’s the good news. The bad news is that it is complex - made up of nearly 12,000 genes, about ten times as many as the genome of the malaria parasite.

However, the researchers are confident that it reveals new ways in which the worm can be fought, and they also say it has helped them to identify more than 60 drugs that we already have that could disrupt its deadly activities.

Malaria worry + 1381 and all that

Last month there was some good news on malaria (see my blog of April 11). Now there’s some bad, with worrying signs that the parasite is becoming resistant to what is at present the most effective drug for treating the disease. The trend has appeared in Cambodia, where use of the drug is often poorly controlled and where fakes are sold widely.

Scientists say there is no cause for immediate alarm, but earlier anti-malarial drugs have been undermined by resistance starting in this part of the world. A million people a year die from malaria, and it’s estimated that no less than half of the world’s population is exposed to the disease.

On this day….628 years ago, a group of government officials rode into Brentwood in Essex, and summoned people from the villages around to come and pay the hated poll tax – raised to pay for the Hundred Years’ War. A hundred turned up, and stoned them out of town. It was the start of the Peasants’ Revolt.

The rebels would plunder Rochester and Canterbury, and take control of London, burning down the Savoy Palace and many other buildings. They killed tax collectors and foreigners, then they executed the Chancellor and the King’s Treasurer. Eventually, the authorities managed to murder the rebel leader Wat Tyler, and make enough concessions to con his followers into going home. The government quickly disowned the promises it had made, and pursued the rebels mercilessly, carrying out so many mass executions that there was a shortage of gibbets. For the full story, see A Disastrous History of Britain.

Malaria - new hope against old enemy?

A new anti-malaria drug is being developed by researchers in the United States. When mosquitoes feed on human blood, they produce a substance called haem that can poison them. The new medicine prevents them getting rid of the haem, and it can also enhance the effectiveness of traditional anti-malaria drugs like chloroquine and quinine, to which mosquitoes have been developing resistance. It could be a decade, though, before the treatment comes into general use.

Malaria has probably been around much longer than human beings. The parasite that causes it goes back perhaps 30 million years. The disease was described by Hippocrates in ancient Greece 400 years before Christ, and it may have killed Alexander the Great.

Its name comes from the Medieval Italian for “bad air”, and some historians believe that recurrent epidemics reduced the birth rate in Italy at the time of the Roman Empire, making it more dependent on “barbarian” auxiliaries to defend its frontiers, and eventually leading to its decline and fall. On the other hand, fear of the disease may have halted Attila the Hun in 452 when he seemed on the point of sacking Rome.

It was only at the beginning of the twentieth century that a British army medical officer, Major Ronald Ross, proved the disease was spread by mosquitoes, and today malaria still kills nearly 900,000 people every year – mostly young children in sub-Saharan Africa.