The inconvenient truth about malaria

Al Gore’s film, An Inconvenient Truth, was a masterpiece. Like an elder brother to all humanity, he patiently explained the familiar litany of disasters — droughts, floods, hurricanes, sea-level rise and the rest — spiced with heartrending personal stories: his baby son’s near-fatal accident, the agony of losing a sister to lung cancer. It was a science lecture crafted by Hollywood.

In his book — the version for adults, not the one for schoolchildren — he even included a colour photograph of a corpse, a young man, floating face downward, drowned by Hurricane Katrina. I wonder whether the dead boy’s family were consulted.

I am a scientist, not a climatologist, so I don’t dabble in climatology. My speciality is the epidemiology of mosquito-borne diseases. As the film began, I knew Mr Gore would get to mosquitoes: they’re a favourite with climate-change activists. When he got to them, it was all I feared.

In his serious voice, Mr Gore presented a nifty animation, a band of little mosquitoes fluttering their way up the slopes of a snow-capped mountain, and he repeated the old line: Nairobi used to be ‘above the mosquito line, the limit at which mosquitoes can survive, but now…’ Those little mosquitoes kept climbing.

The truth? Nairobi means ‘the place of cool waters’ in the Masai language. The town grew up around a camp, set up in 1899 during the construction of a railway, the famous ‘Lunatic Express’. There certainly was water there — and mosquitoes. From the start, the place was plagued with malaria, so much so that a few years later doctors tried to have the whole town moved to a healthier place. By 1927, the disease had become such a plague in the ‘White Highlands’ that £40,000 (equivalent to about £350,000 today) was earmarked for malaria control.