Rory Carroll in Buhig Thursday December 18, 2003 The Guardian
The farmers of Karuzi province were among Africa's poorest, but they had won at least one of nature's lotteries: for as long as anyone could remember their corner of Burundi had been free of malaria.
Geography and climate deterred malarial mosquitoes from the cool highlands, sparing the province a deadly disease which affects millions of Africans every year.
Looking back, it is easy to see how delicate was that blessing, how malaria's absence meant the population built up no immunity and were as vulnerable as the 19th century European explorers it felled.
Two events ended Karuzi's luck. Some farmers cleared papyrus from the lower wetlands to cultivate rice, not realising that by releasing an oil on the water's surface the papyrus had acted as a barrier against certain mosquitoes. Then a civil war in 1994 brought an influx of lowlanders with malaria to Karuzi.
The mosquitoes feasted on the newcomers' blood, thus becoming malaria carriers. Each subsequent rainy season left a slowly growing number of locals stricken with the classic symptoms of fever and nausea.
Then, in the course of several terrible weeks in October and November 2000, the trickle turned into a torrent. About half a million cases of malaria were recorded in a population of 350,000 as almost every man, woman and child was infected, many more than once.
"It was an explosion. In just one or two months it spread extremely fast," said Natacha Protopopoff, the coordinator of Médecins sans Frontières' anti-malaria campaign in Burundi, one of central Africa's smaller countries.
Nobody knows how many thousands died - Karuzi was too poor and remote for proper records - but the epidemic was devastating. With entire families incapacitated the fields were untilled, so there was less food, worsening the chronic malnutrition which left people even more vulnerable to disease, said Ms Protopopoff.
Shuttling between the Institute of Trop ical Medicine in Anvers, outside Brussels, and a one-room laboratory with a rickety wooden chair in Buhiga, Karuzi's main town, her mission is to prevent another disastrous epidemic.
The battle against malaria is ancient but the stakes have never been higher.
Once transmitted to humans the parasite infects the liver and red blood cells, impairing the blood flow to vital organs. Your head and body aches, you sweat, shiver and feel as if you are dying.
In Africa, you often are. Of the 900m cases reported last year by the US Agency for International Development, more than 1 million were fatal, the vast majority in Africa, making malaria a killer to rival Aids.
Mubona Niyukuri will be in the next batch of statistics. The four-month-old boy lay alone, wrapped in his mother's shawl, in the concrete outhouse that serves as Buhiga hospital's mortuary, dead three days after being admitted unconscious with cerebral malaria.
In a nearby ward the same affliction had reduced Madeleine Gakobwa, 49, to a mumbling, delirious wreck, but the doctors were confident she would survive, thanks to combination therapy of artesunate and amodiaquine.
Once-effective drugs such as chloroquine and sulphadoxine-pyrimethamine (Fansidar) have become almost useless in the Great Lakes region of Africa, because the parasite has become resistant.
Last month Burundi adopted combination therapy as a new protocol, the culmination of three years of hard lobbying by MSF, among others, to ease the government's concern about the cost and to break bureaucratic inertia.
After treatment, prevention is the other battle. Once a year MSF sprays 18,000 homes - covering a quarter of Karuzi's population - which have been identified as malaria hotspots. It has also distributed 36,000 malaria nets, which are vulnerable to another pest: rats. MSF prescribes cats as a lo-tech solution.
· On Saturday Jonathan Steele reports on the work of Médecins sans Frontières in Chechnya