91色情片

Marburg and Ebola viruses, the villains of thrillers like The Hot Zone, are among the scariest pathogens on the planet. But somebody has to study them, and for most of his career Bob Swanepoel has been pursuing them in the wild like a big game hunter. Most recently, he helped track down the probable source of the Marburg virus. He tells Debora MacKenzie what it鈥檚 like to track these killers.

You鈥檝e spent years searching for the source of the Marburg virus. Why?

It鈥檚 important to find out where these viruses live so we can get people to avoid them. We and colleagues tested thousands of ground-dwelling animals, insects and birds, and didn鈥檛 find it, but the evidence suggested it had to be in bats. We netted bats in the Democratic Republic of the Congo (DRC) and Gabon and scoured the forest canopy in Ivory Coast, but it鈥檚 hard to find the few bats that are infected. We eventually in a mine in the DRC where there was a long history of miners suffering a Marburg-like disease.

How did you end up working with some of the world鈥檚 scariest viruses?

In 1975 I was running the Veterinary Research Laboratory in what is now Harare in Zimbabwe. Marburg virus had recently been discovered in lab monkeys in Marburg, Germany, and in Yugoslavia, but never anywhere else. A couple of young Australians were hitch-hiking in Zimbabwe and South Africa and stopped at a little place called Marburg, by a weird coincidence. The guy got sick and was taken back to Johannesburg, where he died. Then his girlfriend got sick, then a nurse. It turned out to be Marburg virus. Then the next year in Zaire (now the DRC) they discovered Ebola virus. South Africa decided to build a high-security lab so we could handle these infections safely. When it opened in 1980 I went to run it.

Like many virus experts, you qualified as a vet.

I always knew I wanted to be a scientist. I just had this vision of white coats and labs. At first I didn鈥檛 have the money to go to medical school, so I worked as a miner. One day my hard hat got stuck. I realised this wasn鈥檛 the place to be, living 1800 metres above sea level and working 600 metres under it. Later I applied to medical and veterinary college at the same time, and I got the vet reply first.

You鈥檝e worked at many haemorrhagic fever outbreaks. Isn鈥檛 it dangerous?

The viruses aren鈥檛 the only problem. These are places with very limited resources, and there are doctors, nurses, admin people, epidemiologists, and only so many vehicles, security guards, satellite phones and so on to go around. Then we start running around the jungle, catching strange animals and donning weird outfits to perform weird dissecting rituals, and the local people become convinced that we are perpetuating the outbreak. Sometimes the other international staff don鈥檛 even want to share accommodation with us. Studies are put on the back burner until the situation stabilises, and by then it can be too late to find the original source of the virus.

Now gorillas are endangered by Ebola, and there鈥檚 talk of vaccinating them.

Yes, several candidate vaccines are giving very good results. Gorilla vaccination will be a challenge. But with people there are also huge problems. There tend to be long intervals between Ebola outbreaks, and then the next one鈥檚 a different strain. One of worst things you can do is go in with a vaccine that doesn鈥檛 match the current strain and won鈥檛 give immunity. If you vaccinate someone today and he gets the disease tomorrow, then local people will start killing you.

It must get frustrating battling Africa鈥檚 disease problems.

We have increasingly sophisticated technology. The problem is maintaining these things. In the 1995 Ebola outbreak in Zaire, when we got to Kikwit there was just one old paraffin fridge we couldn鈥檛 get to go below 10 掳C. Even a dipstick test has to be kept cool in that climate, or soon there鈥檚 fungus growing all over it.

One problem is that the whole health structure can be blind to certain problems. It鈥檚 not just HIV denialists: there are denialists of every kind. I鈥檝e dealt with rabies in the backwoods, and village people say: 鈥淥ur forefathers knew how to deal with it. You just kill the dogs.鈥� Then there鈥檚 one country 鈥� I won鈥檛 say which 鈥� that utterly refuses to let us survey it for the ticks that carry Crimean-Congo haemorrhagic fever. It鈥檚 surrounded by countries that have them, but it doesn鈥檛 want to know because then it would have to do something about it.

How does disease control in Africa compare with that in the west?

It鈥檚 not that people aren鈥檛 trying. In a hospital in one of the most godforsaken places in Sierra Leone they have 600 suspected cases of Lassa fever each year, and they all need stringent infection control. But they cope. If the fanciest hospital in the US had just six in a row they would be on their knees.

The tragedy is that rich countries are siphoning off medical people. In the DRC there was a scheme that gave epidemiology and public health bursaries in the US to 15 people. Not one came back. When 70 medical people died at Kikwit, many others left. Then these places that are backward become worse 鈥� it鈥檚 a spiral. The solution all comes back to the standard of living and, like Nelson Mandela says, education.

At your own personal level you do what you can do, what鈥檚 obvious for you to do, what feels good. I鈥檓 amazed at how many people are so shallow, only interested in their Mercedes and nothing else. I鈥檓 not Mother Theresa but I think I鈥檝e made some efforts.

鈥淚鈥檓 not Mother Theresa but I think I鈥檝e made some efforts鈥�

Are there more new diseases out there?

If you walk into the forest in Africa, no matter how far in you go, you鈥檒l find spent shotgun cartridges. Man has penetrated everywhere. Yet by one estimate we鈥檝e only picked up 3 per cent of the nasty viruses. There is a catalogue of 500 insect-borne viruses: 36 cause serious disease, the rest we know about only because someone caught a million mosquitoes to see what was in them. Who knows what they might do?